JP5969859B2 - Method for producing metal particle aggregate - Google Patents
Method for producing metal particle aggregate Download PDFInfo
- Publication number
- JP5969859B2 JP5969859B2 JP2012183321A JP2012183321A JP5969859B2 JP 5969859 B2 JP5969859 B2 JP 5969859B2 JP 2012183321 A JP2012183321 A JP 2012183321A JP 2012183321 A JP2012183321 A JP 2012183321A JP 5969859 B2 JP5969859 B2 JP 5969859B2
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- JP
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- Prior art keywords
- metal
- particles
- average
- based particle
- particle
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- 239000002923 metal particle Substances 0.000 title claims description 101
- 238000004519 manufacturing process Methods 0.000 title claims description 49
- 239000002245 particle Substances 0.000 claims description 579
- 229910052751 metal Inorganic materials 0.000 claims description 413
- 239000002184 metal Substances 0.000 claims description 413
- 239000000758 substrate Substances 0.000 claims description 126
- 229910052709 silver Inorganic materials 0.000 claims description 64
- 239000004332 silver Substances 0.000 claims description 64
- 238000000862 absorption spectrum Methods 0.000 claims description 55
- 239000000463 material Substances 0.000 claims description 51
- 238000002835 absorbance Methods 0.000 claims description 31
- 238000004544 sputter deposition Methods 0.000 claims description 19
- XKRFYHLGVUSROY-UHFFFAOYSA-N argon Substances [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 6
- 229910052786 argon Inorganic materials 0.000 claims description 5
- 229910000510 noble metal Inorganic materials 0.000 claims description 5
- 229910004298 SiO 2 Inorganic materials 0.000 claims description 3
- 229920003023 plastic Polymers 0.000 claims description 2
- 239000004033 plastic Substances 0.000 claims description 2
- 239000010409 thin film Substances 0.000 description 142
- 230000000052 comparative effect Effects 0.000 description 96
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 63
- 230000000694 effects Effects 0.000 description 41
- 238000000034 method Methods 0.000 description 38
- WZFUQSJFWNHZHM-UHFFFAOYSA-N 2-[4-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]piperazin-1-yl]-1-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)ethanone Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)N1CCN(CC1)CC(=O)N1CC2=C(CC1)NN=N2 WZFUQSJFWNHZHM-UHFFFAOYSA-N 0.000 description 35
- 239000011521 glass Substances 0.000 description 34
- 230000003287 optical effect Effects 0.000 description 32
- 238000006243 chemical reaction Methods 0.000 description 29
- 239000000243 solution Substances 0.000 description 28
- ZYGHJZDHTFUPRJ-UHFFFAOYSA-N coumarin Chemical compound C1=CC=C2OC(=O)C=CC2=C1 ZYGHJZDHTFUPRJ-UHFFFAOYSA-N 0.000 description 24
- 239000010408 film Substances 0.000 description 23
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 20
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 18
- OHVLMTFVQDZYHP-UHFFFAOYSA-N 1-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)-2-[4-[2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidin-5-yl]piperazin-1-yl]ethanone Chemical compound N1N=NC=2CN(CCC=21)C(CN1CCN(CC1)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)=O OHVLMTFVQDZYHP-UHFFFAOYSA-N 0.000 description 15
- 230000005284 excitation Effects 0.000 description 15
- 238000005259 measurement Methods 0.000 description 15
- 239000002082 metal nanoparticle Substances 0.000 description 15
- 238000001878 scanning electron micrograph Methods 0.000 description 15
- 238000000089 atomic force micrograph Methods 0.000 description 14
- 230000009471 action Effects 0.000 description 13
- 238000000295 emission spectrum Methods 0.000 description 13
- 230000003993 interaction Effects 0.000 description 13
- 229960000956 coumarin Drugs 0.000 description 12
- 235000001671 coumarin Nutrition 0.000 description 12
- WWSJZGAPAVMETJ-UHFFFAOYSA-N 2-[4-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]-3-ethoxypyrazol-1-yl]-1-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)ethanone Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)C=1C(=NN(C=1)CC(=O)N1CC2=C(CC1)NN=N2)OCC WWSJZGAPAVMETJ-UHFFFAOYSA-N 0.000 description 11
- 239000002105 nanoparticle Substances 0.000 description 11
- 238000002347 injection Methods 0.000 description 10
- 239000007924 injection Substances 0.000 description 10
- 239000007769 metal material Substances 0.000 description 10
- 230000002708 enhancing effect Effects 0.000 description 9
- 238000004020 luminiscence type Methods 0.000 description 9
- CONKBQPVFMXDOV-QHCPKHFHSA-N 6-[(5S)-5-[[4-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]piperazin-1-yl]methyl]-2-oxo-1,3-oxazolidin-3-yl]-3H-1,3-benzoxazol-2-one Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)N1CCN(CC1)C[C@H]1CN(C(O1)=O)C1=CC2=C(NC(O2)=O)C=C1 CONKBQPVFMXDOV-QHCPKHFHSA-N 0.000 description 7
- 239000000975 dye Substances 0.000 description 7
- KZEVSDGEBAJOTK-UHFFFAOYSA-N 1-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)-2-[5-[2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidin-5-yl]-1,3,4-oxadiazol-2-yl]ethanone Chemical compound N1N=NC=2CN(CCC=21)C(CC=1OC(=NN=1)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)=O KZEVSDGEBAJOTK-UHFFFAOYSA-N 0.000 description 6
- YJLUBHOZZTYQIP-UHFFFAOYSA-N 2-[5-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]-1,3,4-oxadiazol-2-yl]-1-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)ethanone Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)C1=NN=C(O1)CC(=O)N1CC2=C(CC1)NN=N2 YJLUBHOZZTYQIP-UHFFFAOYSA-N 0.000 description 6
- 239000003574 free electron Substances 0.000 description 6
- 230000007246 mechanism Effects 0.000 description 6
- 229920000642 polymer Polymers 0.000 description 5
- 238000004528 spin coating Methods 0.000 description 5
- 238000012546 transfer Methods 0.000 description 5
- 238000001771 vacuum deposition Methods 0.000 description 5
- VWVRASTUFJRTHW-UHFFFAOYSA-N 2-[3-(azetidin-3-yloxy)-4-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]pyrazol-1-yl]-1-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)ethanone Chemical compound O=C(CN1C=C(C(OC2CNC2)=N1)C1=CN=C(NC2CC3=C(C2)C=CC=C3)N=C1)N1CCC2=C(C1)N=NN2 VWVRASTUFJRTHW-UHFFFAOYSA-N 0.000 description 4
- JQMFQLVAJGZSQS-UHFFFAOYSA-N 2-[4-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]piperazin-1-yl]-N-(2-oxo-3H-1,3-benzoxazol-6-yl)acetamide Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)N1CCN(CC1)CC(=O)NC1=CC2=C(NC(O2)=O)C=C1 JQMFQLVAJGZSQS-UHFFFAOYSA-N 0.000 description 4
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 4
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 4
- -1 argon ion Chemical class 0.000 description 4
- 238000000151 deposition Methods 0.000 description 4
- 230000008021 deposition Effects 0.000 description 4
- 238000000605 extraction Methods 0.000 description 4
- 230000001443 photoexcitation Effects 0.000 description 4
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 4
- 230000027756 respiratory electron transport chain Effects 0.000 description 4
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 3
- 230000009849 deactivation Effects 0.000 description 3
- 239000006185 dispersion Substances 0.000 description 3
- 150000002500 ions Chemical class 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 239000011159 matrix material Substances 0.000 description 3
- 238000000691 measurement method Methods 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- TVIVIEFSHFOWTE-UHFFFAOYSA-K tri(quinolin-8-yloxy)alumane Chemical compound [Al+3].C1=CN=C2C([O-])=CC=CC2=C1.C1=CN=C2C([O-])=CC=CC2=C1.C1=CN=C2C([O-])=CC=CC2=C1 TVIVIEFSHFOWTE-UHFFFAOYSA-K 0.000 description 3
- IHCCLXNEEPMSIO-UHFFFAOYSA-N 2-[4-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]piperidin-1-yl]-1-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)ethanone Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)C1CCN(CC1)CC(=O)N1CC2=C(CC1)NN=N2 IHCCLXNEEPMSIO-UHFFFAOYSA-N 0.000 description 2
- JVKRKMWZYMKVTQ-UHFFFAOYSA-N 2-[4-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]pyrazol-1-yl]-N-(2-oxo-3H-1,3-benzoxazol-6-yl)acetamide Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)C=1C=NN(C=1)CC(=O)NC1=CC2=C(NC(O2)=O)C=C1 JVKRKMWZYMKVTQ-UHFFFAOYSA-N 0.000 description 2
- NRZJOTSUPLCYDJ-UHFFFAOYSA-N 7-(ethylamino)-6-methyl-4-(trifluoromethyl)chromen-2-one Chemical compound O1C(=O)C=C(C(F)(F)F)C2=C1C=C(NCC)C(C)=C2 NRZJOTSUPLCYDJ-UHFFFAOYSA-N 0.000 description 2
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- MVPPADPHJFYWMZ-UHFFFAOYSA-N chlorobenzene Chemical compound ClC1=CC=CC=C1 MVPPADPHJFYWMZ-UHFFFAOYSA-N 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 239000000470 constituent Substances 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 230000005684 electric field Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 2
- 229910052737 gold Inorganic materials 0.000 description 2
- 239000010931 gold Substances 0.000 description 2
- 239000010445 mica Substances 0.000 description 2
- 229910052618 mica group Inorganic materials 0.000 description 2
- 239000003960 organic solvent Substances 0.000 description 2
- 229910052763 palladium Inorganic materials 0.000 description 2
- 229910052697 platinum Inorganic materials 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- MUSLHCJRTRQOSP-UHFFFAOYSA-N rhodamine 101 Chemical compound [O-]C(=O)C1=CC=CC=C1C(C1=CC=2CCCN3CCCC(C=23)=C1O1)=C2C1=C(CCC1)C3=[N+]1CCCC3=C2 MUSLHCJRTRQOSP-UHFFFAOYSA-N 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- JNGRENQDBKMCCR-UHFFFAOYSA-N 2-(3-amino-6-iminoxanthen-9-yl)benzoic acid;hydrochloride Chemical compound [Cl-].C=12C=CC(=[NH2+])C=C2OC2=CC(N)=CC=C2C=1C1=CC=CC=C1C(O)=O JNGRENQDBKMCCR-UHFFFAOYSA-N 0.000 description 1
- HVTQDSGGHBWVTR-UHFFFAOYSA-N 2-[4-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]-3-phenylmethoxypyrazol-1-yl]-1-morpholin-4-ylethanone Chemical compound C(C1=CC=CC=C1)OC1=NN(C=C1C=1C=NC(=NC=1)NC1CC2=CC=CC=C2C1)CC(=O)N1CCOCC1 HVTQDSGGHBWVTR-UHFFFAOYSA-N 0.000 description 1
- ZRPAUEVGEGEPFQ-UHFFFAOYSA-N 2-[4-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]pyrazol-1-yl]-1-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)ethanone Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)C=1C=NN(C=1)CC(=O)N1CC2=C(CC1)NN=N2 ZRPAUEVGEGEPFQ-UHFFFAOYSA-N 0.000 description 1
- MGGVALXERJRIRO-UHFFFAOYSA-N 4-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]-2-[2-oxo-2-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)ethyl]-1H-pyrazol-5-one Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)C=1C(=NN(C=1)CC(=O)N1CC2=C(CC1)NN=N2)O MGGVALXERJRIRO-UHFFFAOYSA-N 0.000 description 1
- WTFUTSCZYYCBAY-SXBRIOAWSA-N 6-[(E)-C-[[4-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]piperazin-1-yl]methyl]-N-hydroxycarbonimidoyl]-3H-1,3-benzoxazol-2-one Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)N1CCN(CC1)C/C(=N/O)/C1=CC2=C(NC(O2)=O)C=C1 WTFUTSCZYYCBAY-SXBRIOAWSA-N 0.000 description 1
- DFGKGUXTPFWHIX-UHFFFAOYSA-N 6-[2-[4-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]piperazin-1-yl]acetyl]-3H-1,3-benzoxazol-2-one Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)N1CCN(CC1)CC(=O)C1=CC2=C(NC(O2)=O)C=C1 DFGKGUXTPFWHIX-UHFFFAOYSA-N 0.000 description 1
- 239000005964 Acibenzolar-S-methyl Substances 0.000 description 1
- 238000012935 Averaging Methods 0.000 description 1
- 239000004372 Polyvinyl alcohol Substances 0.000 description 1
- FOIXSVOLVBLSDH-UHFFFAOYSA-N Silver ion Chemical compound [Ag+] FOIXSVOLVBLSDH-UHFFFAOYSA-N 0.000 description 1
- UPZKDDJKJWYWHQ-UHFFFAOYSA-O [6-amino-9-(2-carboxyphenyl)xanthen-3-ylidene]azanium Chemical compound C=12C=CC(=[NH2+])C=C2OC2=CC(N)=CC=C2C=1C1=CC=CC=C1C(O)=O UPZKDDJKJWYWHQ-UHFFFAOYSA-O 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 229910052790 beryllium Inorganic materials 0.000 description 1
- ATBAMAFKBVZNFJ-UHFFFAOYSA-N beryllium atom Chemical compound [Be] ATBAMAFKBVZNFJ-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- VYXSBFYARXAAKO-WTKGSRSZSA-N chembl402140 Chemical compound Cl.C1=2C=C(C)C(NCC)=CC=2OC2=C\C(=N/CC)C(C)=CC2=C1C1=CC=CC=C1C(=O)OCC VYXSBFYARXAAKO-WTKGSRSZSA-N 0.000 description 1
- 229920000547 conjugated polymer Polymers 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- KPUWHANPEXNPJT-UHFFFAOYSA-N disiloxane Chemical class [SiH3]O[SiH3] KPUWHANPEXNPJT-UHFFFAOYSA-N 0.000 description 1
- 238000010292 electrical insulation Methods 0.000 description 1
- 238000005401 electroluminescence Methods 0.000 description 1
- 238000000609 electron-beam lithography Methods 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- 230000031700 light absorption Effects 0.000 description 1
- 238000001755 magnetron sputter deposition Methods 0.000 description 1
- 150000002736 metal compounds Chemical class 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 239000013528 metallic particle Substances 0.000 description 1
- 239000002086 nanomaterial Substances 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 229920003229 poly(methyl methacrylate) Polymers 0.000 description 1
- 229920000553 poly(phenylenevinylene) Polymers 0.000 description 1
- 239000004926 polymethyl methacrylate Substances 0.000 description 1
- 229920002451 polyvinyl alcohol Polymers 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000002096 quantum dot Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- HTNRBNPBWAFIKA-UHFFFAOYSA-M rhodamine 700 perchlorate Chemical compound [O-]Cl(=O)(=O)=O.C1CCN2CCCC3=C2C1=C1OC2=C(CCC4)C5=[N+]4CCCC5=CC2=C(C(F)(F)F)C1=C3 HTNRBNPBWAFIKA-UHFFFAOYSA-M 0.000 description 1
- PYWVYCXTNDRMGF-UHFFFAOYSA-N rhodamine B Chemical compound [Cl-].C=12C=CC(=[N+](CC)CC)C=C2OC2=CC(N(CC)CC)=CC=C2C=1C1=CC=CC=C1C(O)=O PYWVYCXTNDRMGF-UHFFFAOYSA-N 0.000 description 1
- 229940043267 rhodamine b Drugs 0.000 description 1
- 239000001022 rhodamine dye Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 150000003384 small molecules Chemical class 0.000 description 1
- 239000004094 surface-active agent Substances 0.000 description 1
- 229910052715 tantalum Inorganic materials 0.000 description 1
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 1
- 238000000870 ultraviolet spectroscopy Methods 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y20/00—Nanooptics, e.g. quantum optics or photonic crystals
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
- C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material
- C23C14/14—Metallic material, boron or silicon
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
- C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
- C23C14/223—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating specially adapted for coating particles
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
- C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
- C23C14/34—Sputtering
- C23C14/35—Sputtering by application of a magnetic field, e.g. magnetron sputtering
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K50/00—Organic light-emitting devices
- H10K50/80—Constructional details
- H10K50/85—Arrangements for extracting light from the devices
- H10K50/856—Arrangements for extracting light from the devices comprising reflective means
Description
本発明は、発光素子〔有機ＥＬ（エレクトロルミネッセンス）素子、無機ＥＬ素子、無機ＬＥＤ（ライトエミッティングダイオード）素子、量子ドット発光素子など〕の発光効率向上や光電変換素子（太陽電池素子など）の変換効率向上などに有用なプラズモン材料（プラズモニックマテリアル）である金属系粒子集合体の製造方法に関する。 The present invention improves the luminous efficiency of light-emitting elements [organic EL (electroluminescence) elements, inorganic EL elements, inorganic LED (light-emitting diode) elements, quantum dot light-emitting elements, etc.] and photoelectric conversion elements (solar cell elements, etc.). The present invention relates to a method for producing a metal-based particle aggregate which is a plasmon material (plasmonic material) useful for improving conversion efficiency.
金属粒子をナノサイズにまで微細化すると、バルク状態では見られなかった機能を発現するようになることが従来知られており、なかでも応用が期待されているのが「局在プラズモン共鳴」である。プラズモンとは、金属ナノ構造体中の自由電子の集団的な振動によって生起する自由電子の粗密波のことである。 It has been known that when metal particles are miniaturized to nano-size, functions that were not seen in the bulk state will be developed. Among them, the application is expected to be “localized plasmon resonance”. is there. Plasmon is a free-electron rough wave generated by collective oscillation of free electrons in a metal nanostructure.
近年、上記プラズモンを扱う技術分野は、「プラズモニクス」と呼ばれ大きな注目を集めているとともに活発な研究が行なわれており、かかる研究は金属ナノ粒子の局在プラズモン共鳴現象を利用した発光素子の発光効率向上や、光電変換素子（太陽電池素子など）の変換効率向上を目的とするものを含む。 In recent years, the above-mentioned technical field dealing with plasmons is called “plasmonics” and has attracted a great deal of attention and has been actively researched. Such research has been conducted on light-emitting elements using localized plasmon resonance phenomenon of metal nanoparticles. Including those intended to improve luminous efficiency and conversion efficiency of photoelectric conversion elements (solar cell elements, etc.).
たとえば特許文献１〜３には、局在プラズモン共鳴現象を利用して蛍光を増強させる技術が開示されている。また非特許文献１には、銀ナノ粒子による局在プラズモン共鳴に関する研究が示されている。 For example, Patent Documents 1 to 3 disclose techniques for enhancing fluorescence using a localized plasmon resonance phenomenon. Non-Patent Document 1 shows a study on localized plasmon resonance by silver nanoparticles.
金属ナノ粒子の局在プラズモン共鳴現象を利用した従来の発光増強には次のような課題があった。すなわち、金属ナノ粒子による発光増強作用の要因には、１）金属ナノ粒子中に局在プラズモンが生起されることによって粒子近傍の電場が増強される（第１の因子）、および、２）励起された分子からのエネルギー移動により金属ナノ粒子中の自由電子の振動モードが励起されることによって、励起された分子の発光性双極子よりも大きい発光性の誘起双極子が金属ナノ粒子中に生起し、これにより発光量子効率自体が増加する（第２の因子）、という２つの因子があるところ、より大きな要因である第２の因子における発光性誘起双極子を金属ナノ粒子に有効に生じさせるためには、金属ナノ粒子と励起される分子（蛍光物質など）との距離を、電子の直接移動であるデクスター機構によるエネルギー移動が起こらない範囲であって、フェルスター機構のエネルギー移動が発現する範囲内（１ｎｍ〜１０ｎｍ）にすることが求められる。これは、発光性誘起双極子の生起がフェルスターのエネルギー移動の理論に基づくためである（上記非特許文献１参照）。 Conventional enhancement of light emission using the localized plasmon resonance phenomenon of metal nanoparticles has the following problems. That is, the factors of the light emission enhancing action by the metal nanoparticles are 1) the electric field in the vicinity of the particles is enhanced by the occurrence of localized plasmons in the metal nanoparticles (first factor), and 2) the excitation As the energy transfer from the excited molecule excites the vibrational mode of free electrons in the metal nanoparticle, a luminescent induced dipole is generated in the metal nanoparticle that is larger than the luminescent dipole of the excited molecule. However, there are two factors that increase the luminescence quantum efficiency itself (second factor), so that the luminescence-induced dipole in the second factor, which is a larger factor, is effectively generated in the metal nanoparticles. For this purpose, the distance between the metal nanoparticle and the molecule to be excited (such as a fluorescent substance) is within a range where energy transfer by the Dexter mechanism, which is direct electron transfer, does not occur. It is required that energy transfer Rusuta mechanism is within the range expressed (1 nm to 10 nm). This is because the occurrence of the luminescence-induced dipole is based on Förster energy transfer theory (see Non-Patent Document 1 above).
一般に、上記１ｎｍ〜１０ｎｍの範囲内において、金属ナノ粒子と励起される分子との距離を近づけるほど、発光性誘起双極子が生起しやすくなり、発光増強効果が高まる一方、上記距離を大きくしていくと、局在プラズモン共鳴が有効に影響しなくなることによって発光増強効果は徐々に弱まり、フェルスター機構のエネルギー移動が発現する範囲を超えると（一般に１０ｎｍ程度以上の距離になると）、発光増強効果をほとんど得ることはできなかった。上記特許文献１〜３に記載の発光増強方法においても、効果的な発光増強効果を得るために有効な金属ナノ粒子と励起される分子との間の距離は１０ｎｍ以下とされている。 In general, within the range of 1 nm to 10 nm, the closer the distance between the metal nanoparticle and the molecule to be excited, the easier it is to generate luminescence-induced dipoles, and the luminescence enhancement effect is enhanced, while the distance is increased. As a result, the luminescence enhancement effect gradually weakens due to the fact that the localized plasmon resonance does not effectively affect. When the energy transfer of the Förster mechanism is exceeded (generally, when the distance is about 10 nm or more), the luminescence enhancement effect. Could hardly get. Also in the light emission enhancement methods described in Patent Documents 1 to 3, the distance between the metal nanoparticles effective for obtaining an effective light emission enhancement effect and the excited molecule is 10 nm or less.
このように従来の金属ナノ粒子を用いた局在プラズモン共鳴においては、その作用範囲が金属ナノ粒子表面から１０ｎｍ以下と極めて狭い範囲内に限定されるという本質的な課題があった。この課題は必然的に、金属ナノ粒子による局在プラズモン共鳴を発光素子や光電変換素子などに利用して発光効率や変換効率向上を図る試みにおいて、ほとんど向上効果が認められないという課題を招来する。すなわち、発光素子や光電変換素子は通常、厚みが数十ｎｍまたはそれ以上の活性層（たとえば発光素子の発光層や光電変換素子の光吸収層）を有しているが、仮に金属ナノ粒子を活性層に近接、あるいは内在させて配置することができたとしても、局在プラズモン共鳴による直接的な増強効果は、活性層のごく一部でしか得ることができない。 As described above, in the localized plasmon resonance using the conventional metal nanoparticles, there is an essential problem that the range of action is limited to an extremely narrow range of 10 nm or less from the surface of the metal nanoparticles. This problem inevitably leads to a problem that almost no improvement effect is observed in an attempt to improve luminous efficiency and conversion efficiency by utilizing localized plasmon resonance by metal nanoparticles for a light emitting device or a photoelectric conversion device. . That is, a light-emitting element or a photoelectric conversion element usually has an active layer (for example, a light-emitting layer of a light-emitting element or a light absorption layer of a photoelectric conversion element) having a thickness of several tens of nm or more. Even if it can be arranged close to or in the active layer, the direct enhancement effect by localized plasmon resonance can be obtained only in a small part of the active layer.
本発明は、上記課題に鑑みなされたものであり、その目的は、発光素子、光電変換素子（太陽電池素子など）等を含む各種光学素子の増強要素として有用なプラズモン材料（プラズモニックマテリアル）を製造するための方法を提供することにある。 The present invention has been made in view of the above problems, and its purpose is to provide a plasmon material (plasmonic material) useful as an enhancement element for various optical elements including a light emitting element, a photoelectric conversion element (such as a solar cell element) and the like. It is to provide a method for manufacturing.
上記特許文献１（段落００１０〜００１１）では、局在プラズモン共鳴による発光増強と金属ナノ粒子の粒径との関係についての理論的な説明がなされており、これによれば、粒径が約５００ｎｍの真球状の銀粒子を用いる場合、理論上、発光効率φはおよそ１となるものの、実際にはこのような銀粒子は発光増強作用をほとんど示さない。このような大型銀粒子が発光増強作用をほとんど示さないのは、銀粒子中の表面自由電子があまりにも多いために、一般的なナノ粒子（比較的小粒径のナノ粒子）で見られる双極子型の局在プラズモンが生起し難いためであると推測される。しかしながら、大型ナノ粒子が内包する極めて多数の表面自由電子を有効にプラズモンとして励起することができれば、プラズモンによる増強効果を飛躍的に向上できると考えられる。 In the above-mentioned Patent Document 1 (paragraphs 0010 to 0011), there is a theoretical explanation about the relationship between emission enhancement by localized plasmon resonance and the particle size of metal nanoparticles, and according to this, the particle size is about 500 nm. In this case, although the luminous efficiency φ is theoretically about 1, such a silver particle does not exhibit a light emission enhancing action in practice. The reason why such large silver particles show almost no light emission enhancement is because the surface free electrons in the silver particles are so large that the bipolars seen in general nanoparticles (relatively small nanoparticles) This is presumably because child-type localized plasmons hardly occur. However, if an extremely large number of surface free electrons contained in the large nanoparticles can be effectively excited as plasmons, the enhancement effect by plasmons can be dramatically improved.
本発明者は、鋭意研究した結果、所定条件下で特定数以上の金属系粒子を基板上に成長させて得られる金属系粒子集合体は、これを構成する金属系粒子が、上記のように一般に発光増強効果が小さくなると考えられている比較的大粒径であるにもかかわらず、特定の形状を有すること等に起因して、極めて強いプラズモン共鳴を示すとともに、著しく伸長されたプラズモン共鳴の作用範囲（プラズモンによる増強効果の及ぶ範囲）を示すことを見出した。 As a result of earnest research, the inventor of the present invention has obtained a metal-based particle aggregate obtained by growing a specific number or more of metal-based particles on a substrate under a predetermined condition. Although it has a relatively large particle size that is generally considered to have a small emission enhancement effect, it exhibits extremely strong plasmon resonance due to having a specific shape, etc. It has been found that the range of action (the range in which the plasmon enhances) is exhibited.
すなわち本発明は以下のものを含む。
［１］ ３０個以上の金属系粒子が互いに離間して二次元的に配置されてなる金属系粒子集合体を製造する方法であって、
１００〜４５０℃の範囲内に温度調整された基板上に、１ｎｍ／分未満の平均高さ成長速度で金属系粒子を成長させる工程を含む金属系粒子集合体の製造方法。
That is, the present invention includes the following.
[1] A method of producing a metal-based particle assembly in which 30 or more metal-based particles are two-dimensionally arranged apart from each other,
A method for producing a metal-based particle assembly, comprising a step of growing metal-based particles at an average height growth rate of less than 1 nm / min on a substrate whose temperature is adjusted within a range of 100 to 450 ° C.
［２］ 金属系粒子を成長させる工程において、金属系粒子は、１００〜４５０℃の範囲内に温度調整された基板上に、１ｎｍ／分未満の平均高さ成長速度、かつ、５ｎｍ／分未満の平均粒径成長速度で成長される［１］に記載の金属系粒子集合体の製造方法。 [2] In the step of growing metal-based particles, the metal-based particles have an average height growth rate of less than 1 nm / min and less than 5 nm / min on a substrate whose temperature is adjusted within a range of 100 to 450 ° C. The method for producing a metal-based particle assembly according to [1], wherein the metal particle aggregate is grown at an average particle size growth rate of [1].
［３］ 前記金属系粒子集合体を構成する金属系粒子は、その平均粒径が２００〜１６００ｎｍの範囲内、平均高さが５５〜５００ｎｍの範囲内、前記平均高さに対する前記平均粒径の比で定義されるアスペクト比が１〜８の範囲内にあり、かつ、その隣り合う金属系粒子との平均距離（以下、平均粒子間距離ともいう。）が１〜１５０ｎｍの範囲内となるように配置されている［１］または［２］に記載の金属系粒子集合体の製造方法。 [3] The metal-based particles constituting the metal-based particle aggregate have an average particle diameter within a range of 200 to 1600 nm, an average height within a range of 55 to 500 nm, and the average particle diameter with respect to the average height. The aspect ratio defined by the ratio is in the range of 1 to 8, and the average distance between the adjacent metal particles (hereinafter also referred to as the average interparticle distance) is in the range of 1 to 150 nm. The method for producing a metal-based particle assembly according to [1] or [2], which is disposed in [1].
［４］ 前記金属系粒子集合体を構成する金属系粒子は、その平均粒径が２００〜１６００ｎｍの範囲内、平均高さが５５〜５００ｎｍの範囲内、前記平均高さに対する前記平均粒径の比で定義されるアスペクト比が１〜８の範囲内にあり、
前記金属系粒子集合体は、可視光領域における吸光スペクトルにおいて、前記平均粒径と同じ粒径、前記平均高さと同じ高さおよび同じ材質からなる金属系粒子を、金属系粒子間の距離がすべて１〜２μｍの範囲内となるように配置した参照金属系粒子集合体（Ｘ）と比べて、最も長波長側にあるピークの極大波長が３０〜５００ｎｍの範囲で短波長側にシフトしている［１］または［２］に記載の金属系粒子集合体の製造方法。
[4] The metal-based particles constituting the metal-based particle aggregate have an average particle diameter in the range of 200 to 1600 nm, an average height in the range of 55 to 500 nm, and the average particle diameter with respect to the average height. The aspect ratio defined by the ratio is in the range of 1-8,
In the absorption spectrum in the visible light region, the metal-based particle aggregate is a metal particle composed of the same particle size, the same height as the average height, and the same material as the average particle diameter. Compared to the reference metal-based particle aggregate (X) arranged to be in the range of 1 to 2 μm, the maximum wavelength of the peak on the longest wavelength side is shifted to the short wavelength side in the range of 30 to 500 nm. The method for producing a metal-based particle assembly according to [1] or [2].
［５］ 前記金属系粒子集合体を構成する金属系粒子は、その平均粒径が２００〜１６００ｎｍの範囲内、平均高さが５５〜５００ｎｍの範囲内、前記平均高さに対する前記平均粒径の比で定義されるアスペクト比が１〜８の範囲内にあり、
前記金属系粒子集合体は、可視光領域における吸光スペクトルにおいて、前記平均粒径と同じ粒径、前記平均高さと同じ高さおよび同じ材質からなる金属系粒子を、金属系粒子間の距離がすべて１〜２μｍの範囲内となるように配置した参照金属系粒子集合体（Ｙ）よりも、同じ金属系粒子数での比較において、最も長波長側にあるピークの極大波長における吸光度が高い［１］または［２］に記載の金属系粒子集合体の製造方法。
[5] The metal-based particles constituting the metal-based particle aggregate have an average particle diameter within a range of 200 to 1600 nm, an average height within a range of 55 to 500 nm, and the average particle diameter with respect to the average height. The aspect ratio defined by the ratio is in the range of 1-8,
In the absorption spectrum in the visible light region, the metal-based particle aggregate is a metal particle composed of the same particle size, the same height as the average height, and the same material as the average particle diameter. Compared with the same number of metal particles, the absorbance at the maximum wavelength of the peak on the longest wavelength side is higher than that of the reference metal particle aggregate (Y) arranged to be in the range of 1 to 2 μm [1. ] Or the manufacturing method of the metal type particle aggregate as described in [2].
［６］ 金属系粒子を成長させる工程における基板の温度が２５０〜３５０℃の範囲内である［１］〜［５］のいずれかに記載の金属系粒子集合体の製造方法。 [6] The method for producing a metal-based particle assembly according to any one of [1] to [5], wherein the temperature of the substrate in the step of growing metal-based particles is in the range of 250 to 350 ° C.
［７］ 金属系粒子を成長させる工程が６Ｐａ以上の圧力下で行なわれる［１］〜［６］のいずれかに記載の金属系粒子集合体の製造方法。 [7] The method for producing a metal-based particle assembly according to any one of [1] to [6], wherein the step of growing the metal-based particles is performed under a pressure of 6 Pa or more.
［８］ 金属系粒子を成長させる工程が１０Ｐａ以上の圧力下で行なわれる［７］に記載の金属系粒子集合体の製造方法。 [8] The method for producing a metal particle aggregate according to [7], wherein the step of growing metal particles is performed under a pressure of 10 Pa or more.
［９］ 金属系粒子を成長させる工程がスパッタリング法により行なわれる［１］〜［８］のいずれかに記載の金属系粒子集合体の製造方法。 [9] The method for producing a metal-based particle assembly according to any one of [1] to [8], wherein the step of growing metal-based particles is performed by a sputtering method.
［１０］ 金属系粒子を成長させる工程が直流スパッタリング法により行なわれる［９］に記載の金属系粒子集合体の製造方法。 [10] The method for producing a metal particle aggregate according to [9], wherein the step of growing metal particles is performed by a direct current sputtering method.
［１１］ 金属系粒子を成長させる工程が直流アルゴンイオンスパッタリング法により行なわれる［１０］に記載の金属系粒子集合体の製造方法。 [11] The method for producing a metal particle aggregate according to [10], wherein the step of growing metal particles is performed by a direct current argon ion sputtering method.
［１２］ 前記金属系粒子集合体を構成する金属系粒子が貴金属からなる［１］〜［１１］のいずれかに記載の金属系粒子集合体の製造方法。 [12] The method for producing a metal-based particle assembly according to any one of [1] to [11], wherein the metal-based particles constituting the metal-based particle assembly are made of a noble metal.
［１３］ 前記金属系粒子集合体を構成する金属系粒子が銀からなる［１２］に記載の金属系粒子集合体の製造方法。 [13] The method for producing a metal-based particle assembly according to [12], wherein the metal-based particles constituting the metal-based particle assembly are made of silver.
本発明の製造方法によれば、所定の形状（平均粒径、平均高さおよびアスペクト比）、さらには所定の平均粒子間距離を有する金属系粒子からなる金属系粒子集合体の薄膜を制御良く得ることができる。本発明の製造方法によって得られる金属系粒子集合体は、発光素子、光電変換素子（太陽電池素子など）等を含む光学素子の増強要素として極めて有用であり、適用した光学素子の発光効率や変換効率を顕著に向上させることができる。 According to the production method of the present invention, a thin film of a metal-based particle assembly composed of metal-based particles having a predetermined shape (average particle diameter, average height, and aspect ratio) and a predetermined average interparticle distance can be controlled with good control. Can be obtained. The metal-based particle aggregate obtained by the production method of the present invention is extremely useful as an enhancement element for optical elements including light-emitting elements, photoelectric conversion elements (solar cell elements, etc.), and the luminous efficiency and conversion of the applied optical elements. Efficiency can be significantly improved.
＜金属系粒子集合体の製造方法＞
本発明の金属系粒子集合体の製造方法は、所定温度に調整された基板上に、極めて低速で金属系粒子を成長させる工程（以下、粒子成長工程ともいう。）を含むものである。かかる粒子成長工程を含む製造方法によれば、３０個以上の金属系粒子が互いに離間して二次元的に配置されており、該金属系粒子が、所定範囲内の形状（平均粒径２００〜１６００ｎｍ、平均高さ５５〜５００ｎｍおよびアスペクト比１〜８）、さらに好ましくは所定範囲内の平均粒子間距離（１〜１５０ｎｍ）を有する金属系粒子集合体の薄膜を制御良く得ることができる。
<Method for producing metal-based particle assembly>
The method for producing a metal-based particle assembly of the present invention includes a step of growing metal-based particles (hereinafter also referred to as a particle growth step) on a substrate adjusted to a predetermined temperature at an extremely low speed. According to the production method including such a particle growth step, 30 or more metal-based particles are two-dimensionally arranged apart from each other, and the metal-based particles have a shape within a predetermined range (average particle diameter of 200 to 200). 1600 nm, average height of 55 to 500 nm, and aspect ratio of 1 to 8), more preferably, a thin film of metal-based particle aggregate having an average interparticle distance (1 to 150 nm) within a predetermined range can be obtained with good control.
粒子成長工程において、基板上に金属系粒子を成長させる速度は、平均高さ成長速度で１ｎｍ／分未満、好ましくは０．５ｎｍ／分以下とされる。ここでいう平均高さ成長速度とは、平均堆積速度または金属系粒子の平均厚み成長速度とも呼ぶことができ、下記式：
金属系粒子の平均高さ／金属系粒子成長時間（金属系材料の供給時間）
で定義される。「金属系粒子の平均高さ」の定義は後述するとおりである。
In the particle growth step, the growth rate of the metal-based particles on the substrate is less than 1 nm / min, preferably 0.5 nm / min or less in terms of average height growth rate. The average height growth rate here can also be referred to as an average deposition rate or an average thickness growth rate of metal-based particles.
Average height of metal particles / Metal particle growth time (metal material supply time)
Defined by The definition of “average height of metal particles” is as described later.
粒子成長工程における基板の温度は、１００〜４５０℃の範囲内とされ、好ましくは２００〜４５０℃、より好ましくは２５０〜３５０℃、さらに好ましくは３００℃またはその近傍（３００℃±１０℃程度）である。 The temperature of the substrate in the particle growth step is in the range of 100 to 450 ° C., preferably 200 to 450 ° C., more preferably 250 to 350 ° C., still more preferably 300 ° C. or its vicinity (about 300 ° C. ± 10 ° C.). It is.
１００〜４５０℃の範囲内に温度調整された基板上に、１ｎｍ／分未満の平均高さ成長速度で金属系粒子を成長させる粒子成長工程を含む本発明の製造方法では、粒子成長初期において、供給された金属系材料からなる島状構造物が複数形成され、この島状構造物が、さらなる金属系材料の供給を受けて大きく成長しながら、周囲の島状構造物と合体していき、その結果、個々の金属系粒子が互いに完全に分離されていながらも、比較的平均粒径の大きい粒子が密に配置された金属系粒子集合体が形成される。したがって、所定範囲内の形状（平均粒径、平均高さおよびアスペクト比）、さらに好ましくは所定範囲内の平均粒子間距離を有するように制御された金属系粒子からなる金属系粒子集合体を製造することが可能となる。 In the production method of the present invention including a particle growth step in which metal-based particles are grown at an average height growth rate of less than 1 nm / min on a substrate temperature-controlled within a range of 100 to 450 ° C., in the initial stage of particle growth, A plurality of island-like structures made of the supplied metal-based material are formed, and while this island-like structure grows greatly upon receiving further supply of metal-based material, it merges with the surrounding island-like structures, As a result, a metal particle aggregate in which particles having a relatively large average particle diameter are densely arranged is formed while the individual metal particles are completely separated from each other. Accordingly, a metal-based particle assembly is produced which comprises metal-based particles controlled to have a shape (average particle size, average height and aspect ratio) within a predetermined range, and more preferably with an average interparticle distance within a predetermined range. It becomes possible to do.
また、平均高さ成長速度、基板温度および／または金属系粒子の成長時間（金属系材料の供給時間）の調整によって、基板上に成長される金属系粒子の平均粒径、平均高さ、アスペクト比および／または平均粒子間距離を所定の範囲内で制御することも可能である。 Also, by adjusting the average height growth rate, substrate temperature, and / or metal-based particle growth time (metal-based material supply time), the average particle diameter, average height, and aspect of the metal-based particles grown on the substrate It is also possible to control the ratio and / or the average interparticle distance within a predetermined range.
さらに、本発明の製造方法によれば、粒子成長工程における基板温度および平均高さ成長速度以外の諸条件を比較的自由に選択できることから、所望のサイズの基板上に所望のサイズの金属系粒子集合体薄膜を効率的に形成できるという利点もある。 Furthermore, according to the manufacturing method of the present invention, since various conditions other than the substrate temperature and the average height growth rate in the particle growth step can be selected relatively freely, a metal-based particle having a desired size on a substrate having a desired size. There is also an advantage that an aggregate thin film can be formed efficiently.
平均高さ成長速度が１ｎｍ／分以上である場合や、基板温度が１００℃未満または４５０℃を超える場合には、島状構造物が大きく成長する前に周囲の島状構造物と連続体を形成し、互いに完全に分離された大粒径の金属系粒子からなる金属系集合体を得ることができないか、または、所望の形状を有する金属系粒子からなる金属系集合体を得ることができない（たとえば平均高さや平均粒子間距離、アスペクト比が所望の範囲から外れてしまう）。 When the average height growth rate is 1 nm / min or more, or when the substrate temperature is less than 100 ° C. or more than 450 ° C., the surrounding island-like structure and the continuum are formed before the island-like structure grows large It is not possible to obtain a metal-based aggregate composed of large-sized metal particles that are formed and completely separated from each other, or a metal-based aggregate composed of metal-based particles having a desired shape cannot be obtained. (For example, the average height, average interparticle distance, and aspect ratio deviate from the desired ranges).
金属系粒子を成長させる際の圧力（装置チャンバ内の圧力）は、粒子成長可能な圧力である限り特に制限されないが、通常、大気圧未満である。圧力の下限は特に制限されないが、平均高さ成長速度を上記範囲内に調整し易いことから、好ましくは６Ｐａ以上、より好ましくは１０Ｐａ以上、さらに好ましくは３０Ｐａ以上である。 The pressure for growing metal-based particles (pressure in the apparatus chamber) is not particularly limited as long as it is a pressure at which particles can be grown, but is usually less than atmospheric pressure. The lower limit of the pressure is not particularly limited, but is preferably 6 Pa or more, more preferably 10 Pa or more, and further preferably 30 Pa or more because the average height growth rate can be easily adjusted within the above range.
基板上に金属系粒子を成長させる具体的方法は、１ｎｍ／分未満の平均高さ成長速度で粒子成長できる方法である限り特に制限されないが、スパッタリング法、真空蒸着等の蒸着法を挙げることができる。スパッタリング法のなかでも、比較的簡便に金属系粒子集合体を成長させることができ、かつ、１ｎｍ／分未満の平均高さ成長速度を維持しやすいことから、直流（ＤＣ）スパッタリング法を用いることが好ましい。スパッタンリング方式は特に制限されず、イオンガンやプラズマ放電で発生したアルゴンイオンを電界で加速してターゲットに照射する直流アルゴンイオンスパッタリング法などを用いることができる。スパッタリング法における電流値、電圧値、基板・ターゲット間距離等の他の諸条件は、１ｎｍ／分未満の平均高さ成長速度で粒子成長がなされるよう適宜調整される。 A specific method for growing metal-based particles on the substrate is not particularly limited as long as the particles can be grown at an average height growth rate of less than 1 nm / min. it can. Among sputtering methods, it is possible to grow a metal-based particle aggregate relatively easily, and it is easy to maintain an average height growth rate of less than 1 nm / min, so a direct current (DC) sputtering method should be used. Is preferred. The sputtering method is not particularly limited, and a direct current argon ion sputtering method in which argon ions generated by an ion gun or plasma discharge are accelerated by an electric field and irradiated onto a target can be used. Other conditions such as a current value, a voltage value, and a substrate-target distance in the sputtering method are appropriately adjusted so that particle growth is performed at an average height growth rate of less than 1 nm / min.
なお、所定範囲内の形状（平均粒径、平均高さおよびアスペクト比）、さらに好ましくは所定範囲内の平均粒子間距離を有する金属系粒子からなる金属系粒子集合体の薄膜を制御良く得るためには、粒子成長工程において平均高さ成長速度を１ｎｍ／分未満とすることに加えて、平均粒径成長速度を５ｎｍ未満とすることが好ましいが、平均高さ成長速度が１ｎｍ／分未満である場合、通常、平均粒径成長速度は５ｎｍ未満となる。平均粒径成長速度は、より好ましくは１ｎｍ／分以下である。平均粒径成長速度とは、下記式：
金属系粒子の平均粒径／金属系粒子成長時間（金属系材料の供給時間）
で定義される。「金属系粒子の平均粒径」の定義は後述するとおりである。
In addition, in order to obtain a thin film of metal-based particle aggregates composed of metal-based particles having a shape (average particle diameter, average height and aspect ratio) within a predetermined range, more preferably metal particles having an average inter-particle distance within a predetermined range. In addition to setting the average height growth rate to less than 1 nm / min in the particle growth step, it is preferable to set the average particle size growth rate to less than 5 nm, but the average height growth rate is less than 1 nm / min. In some cases, the average particle size growth rate is usually less than 5 nm. The average particle size growth rate is more preferably 1 nm / min or less. The average grain size growth rate is the following formula:
Average particle size of metal particles / Metal particle growth time (metal material supply time)
Defined by The definition of “average particle diameter of metal particles” is as described later.
粒子成長工程における金属系粒子の成長時間（金属系材料の供給時間）は、少なくとも、基板上に担持された金属系粒子が所定範囲内の形状、さらに好ましくは所定範囲内の平均粒子間距離に達する時間であり、かつ、当該所定範囲内の形状、平均粒子間距離から逸脱し始める時間未満である。たとえば、上記所定範囲内の平均高さ成長速度および基板温度で粒子成長を行なっても、成長時間が極端に長すぎる場合には、金属系材料の担持量が多くなり過ぎて、互いに離間して配置された金属系粒子の集合体とはならずに連続膜となったり、金属系粒子の平均粒径や平均高さが大きくなり過ぎたりする。 The growth time of metal-based particles in the particle growth step (supply time of the metal-based material) is at least a shape in which the metal-based particles supported on the substrate are in a predetermined range, and more preferably an average interparticle distance within the predetermined range. It is the time to reach and less than the time within which the shape within the predetermined range and the average interparticle distance start to deviate. For example, even if particle growth is performed at an average height growth rate and a substrate temperature within the above predetermined range, if the growth time is extremely long, the amount of the metal-based material loaded becomes too large and separated from each other. It does not become an aggregate of arranged metal-based particles, but becomes a continuous film, or the average particle diameter and average height of the metal-based particles become too large.
したがって、金属系粒子の成長時間を適切な時間に設定する（粒子成長工程を適切な時間で停止する）必要があるが、このような時間の設定は、たとえば、あらかじめ予備実験を行なうことにより得られる、平均高さ成長速度および基板温度と、得られる金属系粒子集合体における金属系粒子の形状および平均粒子間距離との関係に基づいて行なうことができる。あるいは、基板上に成長された金属系材料からなる薄膜が導電性を示すまでの時間（すなわち、薄膜が金属系粒子集合体膜ではなく、連続膜となってしまう時間）をあらかじめ予備実験により求めておき、この時間に達するまでに粒子成長工程を停止するようにしてもよい。 Therefore, it is necessary to set the growth time of the metal-based particles to an appropriate time (the particle growth process is stopped at an appropriate time). Such a time setting can be obtained, for example, by conducting a preliminary experiment in advance. The average height growth rate and the substrate temperature, and the relationship between the shape of the metal-based particles and the average distance between the particles in the obtained metal-based particle aggregate can be performed. Alternatively, the time until the thin film made of the metal-based material grown on the substrate exhibits conductivity (that is, the time for the thin film to become a continuous film instead of the metal-based particle assembly film) is obtained in advance by a preliminary experiment. In addition, the particle growth process may be stopped until this time is reached.
金属系粒子集合体を構成する金属系粒子（基板上に供給される金属系材料）は、ナノ粒子またはその集合体としたときに、吸光光度法による吸光スペクトル測定において紫外〜可視領域に現れるプラズモン共鳴ピーク（以下、プラズモンピークともいう。）を示す材料からなる限り特に限定されず、たとえば、金、銀、銅、白金、パラジウム等の貴金属や、アルミニウム、タンタル等の金属；該貴金属または金属を含有する合金；該貴金属または金属を含む金属化合物（金属酸化物や金属塩など）を挙げることができる。これらのなかでも、金、銀、銅、白金、パラジウム等の貴金属が好ましく、安価で吸収が小さい（可視光波長において誘電関数の虚部が小さい）という観点からは銀であることがより好ましい。ただし、金属系材料の種類は、金属系粒子集合体を増強要素として適用する光学素子の種類に応じて適切に選択されることが好ましい。 The metal-based particles (metal-based material supplied on the substrate) constituting the metal-based particle aggregate are plasmons that appear in the ultraviolet to visible region in the absorption spectrum measurement by absorptiometry when they are nanoparticles or aggregates thereof. The material is not particularly limited as long as it is made of a material exhibiting a resonance peak (hereinafter also referred to as a plasmon peak). For example, a noble metal such as gold, silver, copper, platinum, palladium, or a metal such as aluminum or tantalum; An alloy to be contained; the noble metal or a metal compound containing a metal (metal oxide, metal salt, etc.). Among these, noble metals such as gold, silver, copper, platinum, and palladium are preferable, and silver is more preferable from the viewpoint of low cost and low absorption (small imaginary part of dielectric function at visible light wavelength). However, the type of the metal-based material is preferably selected appropriately according to the type of optical element to which the metal-based particle aggregate is applied as an enhancement element.
ここで、本発明の製造方法によって得られる基板上に形成される金属系粒子集合体の薄膜において、金属系粒子間は互いに絶縁されている、換言すれば、隣り合う金属系粒子との間に関して非導電性（金属系粒子集合体薄膜として非導電性）であることが好ましい。一部もしくは全ての金属系粒子間で電子の授受が可能であると、プラズモンピークは先鋭さを失い、バルク金属の吸光スペクトルに近づき、また高いプラズモン共鳴が得られない。したがって、金属系粒子間は確実に離間されており、金属系粒子間には導電性物質が介在されないことが好ましい。 Here, in the thin film of the metal-based particle aggregate formed on the substrate obtained by the manufacturing method of the present invention, the metal-based particles are insulated from each other, in other words, between adjacent metal-based particles. It is preferably nonconductive (nonconductive as a metal particle aggregate thin film). When electrons can be exchanged between some or all of the metal-based particles, the plasmon peak loses sharpness, approaches the absorption spectrum of the bulk metal, and high plasmon resonance cannot be obtained. Therefore, it is preferable that the metal-based particles are reliably separated from each other and no conductive substance is interposed between the metal-based particles.
金属系粒子集合体薄膜の非導電性を確保する観点から、基板としては非導電性基板を用いることが好ましい。非導電性基板としては、ガラス、各種無機絶縁材料（ＳｉＯ2、ＺｒＯ2、マイカ等）、各種プラスチック材料を用いることができる。なかでも、たとえば発光素子に適用したときに、基板表面（金属系粒子集合体薄膜とは反対側の面）からの光取り出しが可能になることから、透光性を有する基板を用いることが好ましく、光学的に透明な基板を用いることがより好ましい。 From the viewpoint of ensuring non-conductivity of the metal-based particle assembly thin film, it is preferable to use a non-conductive substrate as the substrate. As the non-conductive substrate, glass, various inorganic insulating materials (SiO 2 , ZrO 2 , mica, etc.) and various plastic materials can be used. In particular, for example, when applied to a light-emitting element, it is possible to extract light from the substrate surface (the surface opposite to the metal-based particle assembly thin film). Therefore, it is preferable to use a light-transmitting substrate. It is more preferable to use an optically transparent substrate.
金属系粒子を成長させる基板表面は、できるだけ平滑であることが好ましく、とりわけ、たとえばマイカの剥離面のように原子レベルで平滑であることがより好ましい。基板表面が平滑であるほど、基板から受け取った熱エネルギーにより、成長中の金属系粒子が別の周囲の隣接金属系粒子と合体成長しやすくなるため、より大きなサイズの金属系粒子からなる膜が得られやすい傾向にある。 The surface of the substrate on which the metal-based particles are grown is preferably as smooth as possible, and more preferably smooth at the atomic level, such as a mica peeling surface. The smoother the substrate surface, the easier it is for the growing metal-based particles to coalesce with other neighboring metal-based particles due to the thermal energy received from the substrate, so a film made of larger-sized metal-based particles is formed. It tends to be easily obtained.
なお、本発明の製造方法は、後で詳述するように、金属系粒子集合体の薄膜表面に絶縁層を形成する工程を含んでいてもよい。 In addition, the manufacturing method of this invention may include the process of forming an insulating layer in the thin film surface of a metal type particle aggregate so that it may explain in full detail later.
＜金属系粒子集合体＞
上述のように、本発明に係る製造方法によれば、３０個以上の金属系粒子が互いに離間して二次元的に配置されており、該金属系粒子の平均粒径が２００〜１６００ｎｍの範囲内、平均高さが５５〜５００ｎｍの範囲内、平均高さに対する平均粒径の比で定義されるアスペクト比が１〜８の範囲内である金属系粒子集合体の薄膜を制御良く得ることができる。
<Metal-based particle assembly>
As described above, according to the production method of the present invention, 30 or more metal-based particles are two-dimensionally arranged apart from each other, and the average particle diameter of the metal-based particles is in the range of 200 to 1600 nm. Among them, a thin film of a metal-based particle aggregate having an average height in the range of 55 to 500 nm and an aspect ratio defined by the ratio of the average particle diameter to the average height in the range of 1 to 8 can be obtained with good control. it can.
本発明に係る製造方法によって得られる金属系粒子集合体は、さらに下記のいずれかの特徴を有する。 The metal-based particle aggregate obtained by the production method according to the present invention further has any of the following characteristics.
〔ｉ〕金属系粒子集合体を構成する金属系粒子が、その隣り合う金属系粒子との平均距離（平均粒子間距離）が１〜１５０ｎｍの範囲内となるように配置されている、
〔ｉｉ〕金属系粒子集合体は、可視光領域における吸光スペクトルにおいて、上記平均粒径と同じ粒径、上記平均高さと同じ高さおよび同じ材質からなる金属系粒子を、金属系粒子間の距離がすべて１〜２μｍの範囲内となるように配置した参照金属系粒子集合体（Ｘ）と比べて、最も長波長側にあるピークの極大波長が３０〜５００ｎｍの範囲で短波長側にシフトしている、
〔ｉｉｉ〕金属系粒子集合体は、可視光領域における吸光スペクトルにおいて、上記平均粒径と同じ粒径、上記平均高さと同じ高さおよび同じ材質からなる金属系粒子を、金属系粒子間の距離がすべて１〜２μｍの範囲内となるように配置した参照金属系粒子集合体（Ｙ）よりも、同じ金属系粒子数での比較において、最も長波長側にあるピークの極大波長における吸光度が高い。
[I] The metal-based particles constituting the metal-based particle aggregate are arranged so that the average distance (average interparticle distance) between the adjacent metal-based particles is in the range of 1 to 150 nm.
[Ii] The metal-based particle aggregate is a distance between the metal-based particles in the absorption spectrum in the visible light region, wherein the metal-based particles having the same particle size, the same height as the average height, and the same material are used. Compared to the reference metal particle aggregate (X) arranged so that all are in the range of 1 to 2 μm, the peak maximum wavelength on the longest wavelength side shifts to the short wavelength side in the range of 30 to 500 nm. ing,
[Iii] The metal-based particle aggregate has a distance between the metal-based particles that is the same as the average particle diameter, the same height as the average height, and the same material in the absorption spectrum in the visible light region. In comparison with the same number of metal particles, the absorbance at the maximum wavelength of the peak on the longest wavelength side is higher than that of the reference metal particle aggregate (Y) arranged so that all are in the range of 1 to 2 μm .
本明細書において、金属系粒子集合体の平均粒径および平均高さが参照金属系粒子集合体（Ｘ）または（Ｙ）と「同じ」であるとは、平均粒径の差が±５ｎｍの範囲内であり、平均高さの差が±１０ｎｍの範囲内であることをいう。 In the present specification, the average particle diameter and average height of the metal-based particle aggregate are “same” as that of the reference metal-based particle aggregate (X) or (Y). The difference in average particle diameter is ± 5 nm. It means that the difference in average height is within a range of ± 10 nm.
（金属系粒子集合体〔ｉ〕）
上記〔ｉ〕の特徴を有する金属系粒子集合体（金属系粒子集合体〔ｉ〕）は、次の点において極めて有利である。
(Metal-based particle aggregate [i])
The metal particle aggregate (metal particle aggregate [i]) having the above feature [i] is extremely advantageous in the following points.
（１）極めて強いプラズモン共鳴を示すため、発光素子に適用した場合には、従来のプラズモン材料を用いる場合と比較して、より強い発光増強効果を得ることができ、これにより発光効率を飛躍的に高めることができる。また、光電変換素子に適用した場合には、その変換効率を飛躍的に高めることができる。金属系粒子集合体〔ｉ〕が示すプラズモン共鳴の強さは、特定波長における個々の金属系粒子が示す局在プラズモン共鳴の単なる総和ではなく、それ以上の強さである。すなわち、３０個以上の所定形状の金属系粒子が上記の所定間隔で密に配置されることにより、個々の金属系粒子が相互作用して、極めて強いプラズモン共鳴が発現する。これは、金属系粒子の局在プラズモン間の相互作用により発現したものと考えられる。 (1) Since it exhibits extremely strong plasmon resonance, when applied to a light-emitting element, a stronger light emission enhancement effect can be obtained compared to the case of using a conventional plasmon material, thereby dramatically improving the light emission efficiency. Can be increased. Moreover, when it applies to a photoelectric conversion element, the conversion efficiency can be improved greatly. The intensity of the plasmon resonance indicated by the metal-based particle aggregate [i] is not a mere sum of the localized plasmon resonances exhibited by individual metal-based particles at a specific wavelength, but is higher than that. That is, when 30 or more metal particles having a predetermined shape are densely arranged at the predetermined interval, individual metal particles interact with each other, and extremely strong plasmon resonance is expressed. This is considered to be expressed by the interaction between the localized plasmons of the metal-based particles.
一般にプラズモン材料は、吸光光度法で吸光スペクトルを測定したとき、紫外〜可視領域におけるピークとしてプラズモンピークが観測され、このプラズモンピークの極大波長における吸光度値の大小から、そのプラズモン材料のプラズモン共鳴の強さを略式に評価することができるが、ガラス基板上に形成された金属系粒子集合体〔ｉ〕は、吸光スペクトルを測定したとき、可視光領域において最も長波長側にあるプラズモンピークの極大波長における吸光度が１以上、さらには１．５以上、なおさらには２程度となり得る。 In general, when an absorption spectrum of a plasmon material is measured by absorptiometry, a plasmon peak is observed as a peak in the ultraviolet to visible region. From the magnitude of the absorbance value at the maximum wavelength of the plasmon peak, the intensity of plasmon resonance of the plasmon material is observed. The metal-based particle aggregate [i] formed on the glass substrate has a maximum wavelength of the plasmon peak on the longest wavelength side in the visible light region when the absorption spectrum is measured. Can be about 1 or more, more preferably 1.5 or more, and even more preferably about 2.
金属系粒子集合体の吸光スペクトルは、ガラス基板上に形成したものを測定サンプルとして、吸光光度法によって測定される。具体的には、吸光スペクトルは、金属系粒子集合体薄膜が積層されたガラス基板の裏面側（金属系粒子集合体薄膜とは反対側）であって、基板面に垂直な方向から紫外〜可視光領域の入射光を照射し、金属系粒子集合体薄膜側に透過した全方向における透過光の強度Ｉと、該測定サンプルの基板と同じ厚み、材質の基板であって、金属系粒子集合体薄膜が積層されていない基板の面に垂直な方向から先と同じ入射光を照射し、入射面の反対側から透過した全方向における透過光の強度Ｉ0を、それぞれ積分球分光光度計を用いて測定することにより得られる。このとき、吸光スペクトルの縦軸である吸光度は、下記式：
吸光度＝−ｌｏｇ10（Ｉ／Ｉ0）
で表される。
The absorption spectrum of the metal-based particle aggregate is measured by absorptiometry using a sample formed on a glass substrate as a measurement sample. Specifically, the absorption spectrum is on the back side of the glass substrate on which the metal-based particle assembly thin film is laminated (the side opposite to the metal-based particle assembly thin film), and is ultraviolet to visible from the direction perpendicular to the substrate surface. A substrate having the same thickness and material as the substrate of the measurement sample, the intensity I of transmitted light in all directions irradiated with incident light in the optical region and transmitted to the metal-based particle assembly thin film side. Using an integrating sphere spectrophotometer, the intensity I 0 of the transmitted light in all directions is irradiated from the direction perpendicular to the surface of the substrate on which the thin film is not laminated and transmitted from the opposite side of the incident surface. It is obtained by measuring. At this time, the absorbance, which is the vertical axis of the absorption spectrum, has the following formula:
Absorbance = −log 10 (I / I 0 )
It is represented by
（２）プラズモン共鳴の作用範囲（プラズモンによる増強効果の及ぶ範囲）が著しく伸長されている。このような伸長作用もまた、３０個以上の所定形状の金属系粒子を所定間隔で密に配置したことによって生じた金属系粒子の局在プラズモン間の相互作用により発現したものと考えられる。金属系粒子集合体〔ｉ〕によれば、従来では概ねフェルスター距離の範囲内（約１０ｎｍ以下）に限定されていたプラズモン共鳴の作用範囲を、たとえば数百ｎｍ程度まで伸長することができる。 (2) The action range of plasmon resonance (the range in which the enhancement effect by plasmons reaches) is significantly extended. Such an elongation action is also considered to be manifested by the interaction between localized plasmons of metal-based particles generated by densely arranging 30 or more predetermined-shaped metal particles at a predetermined interval. According to the metal-based particle aggregate [i], it is possible to extend the plasmon resonance action range, which is conventionally limited to the range of about the Forster distance (about 10 nm or less), to about several hundred nm, for example.
上記のようなプラズモン共鳴の作用範囲の伸長は、発光素子や光電変換素子（太陽電子素子など）等の光学素子の増強に極めて有利である。すなわち、この作用範囲の大幅な伸長によって、通常数十ｎｍまたはそれ以上の厚みを有する活性層（発光素子における発光層や光電変換素子における光吸収層など）の全体を増強させることが可能になり、これにより光学素子の増強効果（発光効率や変換効率など）を著しく向上させることができる。 The extension of the plasmon resonance operating range as described above is extremely advantageous for enhancing optical elements such as light-emitting elements and photoelectric conversion elements (solar electronic elements). That is, it is possible to reinforce the entire active layer (such as a light emitting layer in a light emitting element or a light absorbing layer in a photoelectric conversion element) having a thickness of usually several tens of nanometers or more by greatly extending the working range. Thereby, the enhancement effect (emission efficiency, conversion efficiency, etc.) of the optical element can be remarkably improved.
また、従来のプラズモン材料においては、プラズモン材料を活性層との距離がフェルスター距離の範囲内となるように配置する必要があったが、金属系粒子集合体〔ｉ〕によれば、活性層から、たとえば１０ｎｍ、さらには数十ｎｍ（たとえば２０ｎｍ）、なおさらには数百ｎｍ離れた位置に配置してもプラズモン共鳴による増強効果を得ることができる。このことは、たとえば発光素子であれば、発光層からかなり離れた光取り出し面近傍にプラズモン材料（金属系粒子集合体）を配置することが可能になることを意味しており、これにより光取り出し効率を大幅に向上させることができる。従来のプラズモン材料を利用した発光素子では、プラズモン材料を発光層の極めて近傍に配置せざるを得ず、プラズモン材料と光取り出し面との距離が大きく離れていたため、生じた光が光取り出し面に到達するまでの間に、その多くが、通過する各種発光素子構成層の界面で全反射されてしまい、光取り出し効率が極めて小さくなることがあった。 In the conventional plasmon material, the plasmon material has to be arranged so that the distance from the active layer is within the range of the Förster distance. According to the metal-based particle aggregate [i], the active layer Therefore, for example, the enhancement effect by plasmon resonance can be obtained even if they are arranged at a position 10 nm, further several tens of nm (for example, 20 nm), or even several hundred nm apart. This means that, for example, in the case of a light emitting device, it becomes possible to place a plasmon material (metal particle aggregate) in the vicinity of a light extraction surface that is considerably away from the light emitting layer. Efficiency can be greatly improved. In a conventional light emitting device using a plasmon material, the plasmon material has to be disposed very close to the light emitting layer, and the distance between the plasmon material and the light extraction surface is greatly separated, so that the generated light is incident on the light extraction surface. In the meantime, most of the light is totally reflected at the interfaces of the various light-emitting element constituent layers that pass therethrough, and the light extraction efficiency may become extremely small.
このように金属系粒子集合体〔ｉ〕は、それ単独では双極子型の局在プラズモンが可視光領域で生起し難い比較的大型の金属系粒子を用いるにもかかわらず、このような大型の金属系粒子（所定の形状を有していることが必要であるが）の特定数以上を、特定の間隔を置いて密に配置することにより、当該大型の金属系粒子が内包する極めて多数の表面自由電子を有効にプラズモンとして励起することができ、著しく強いプラズモン共鳴およびプラズモン共鳴の作用範囲の著しい伸長の実現を可能にしたものである。 In this way, the metal particle aggregate [i] alone uses such a large-sized metal particle in which a dipole-type localized plasmon alone is difficult to occur in the visible light region. By arranging a specific number or more of metal-based particles (although it is necessary to have a predetermined shape) closely spaced with a specific interval, an extremely large number of the metal-based particles included in the large-sized metal particles The surface free electrons can be effectively excited as plasmons, and it is possible to realize remarkably strong plasmon resonance and a significant extension of the range of action of plasmon resonance.
また、金属系粒子集合体〔ｉ〕は、特定の形状を有する比較的大型な金属系粒子の特定数以上を二次元的に特定の間隔で離間して配置した構造を有していることに起因して、次のような有利な効果を奏し得る。 In addition, the metal particle aggregate [i] has a structure in which a specific number or more of relatively large metal particles having a specific shape are two-dimensionally spaced apart at a specific interval. As a result, the following advantageous effects can be obtained.
（３）可視光領域における吸光スペクトルにおいて、金属系粒子の平均粒径および平均粒子間距離に依存して、プラズモンピークの極大波長が特異なシフトを示し得る。具体的には、平均粒子間距離を一定にして金属系粒子の平均粒径を大きくするに従い、可視光領域において最も長波長側にあるプラズモンピークの極大波長が短波長側にシフト（ブルーシフト）する。同様に、大型の金属系粒子の平均粒径を一定にして平均粒子間距離を小さくするに従い（金属系粒子をより密に配置すると）、可視光領域において最も長波長側にあるプラズモンピークの極大波長が短波長側にシフトする。この特異な現象は、プラズモン材料に関して一般的に認められているミー散乱理論〔この理論に従えば、粒径が大きくなるとプラズモンピークの極大波長は長波長側にシフト（レッドシフト）する。〕に反するものである。 (3) In the absorption spectrum in the visible light region, the maximum wavelength of the plasmon peak can show a specific shift depending on the average particle diameter of metal-based particles and the average interparticle distance. Specifically, the maximum wavelength of the plasmon peak on the longest wavelength side in the visible light region shifts to the short wavelength side (blue shift) as the average particle size of the metal-based particles increases with a constant average interparticle distance. To do. Similarly, as the average particle size of large metal particles is kept constant and the distance between the average particles is decreased (when metal particles are arranged more densely), the maximum of the plasmon peak on the longest wavelength side in the visible light region The wavelength shifts to the short wavelength side. This peculiar phenomenon is the Mie scattering theory generally accepted for plasmon materials [in accordance with this theory, the maximum wavelength of the plasmon peak shifts to the longer wavelength side (red shift) as the particle size increases. ] Is against this.
上記のような特異なブルーシフトもまた、金属系粒子集合体〔ｉ〕が大型の金属系粒子を特定の間隔を置いて密に配置した構造を有しており、これに伴い、金属系粒子の局在プラズモン間の相互作用が生じていることによるものと考えられる。金属系粒子集合体〔ｉ〕（ガラス基板上に積層した状態）は、金属系粒子の形状や平均粒子間距離に応じて、吸光光度法によって測定される可視光領域における吸光スペクトルにおいて、最も長波長側にあるプラズモンピークが、たとえば３５０〜５５０ｎｍの波長領域に極大波長を示し得る。また、金属系粒子集合体〔ｉ〕は、金属系粒子が十分に長い粒子間距離（たとえば１μｍ）を置いて配置される場合と比較して、典型的には３０〜５００ｎｍ程度（たとえば３０〜２５０ｎｍ）のブルーシフトを生じ得る。 The unique blue shift as described above also has a structure in which the metal-based particle aggregate [i] has a structure in which large-sized metal particles are densely arranged at specific intervals. This is thought to be due to the interaction between the localized plasmons of. The metal-based particle aggregate [i] (in a state of being laminated on the glass substrate) has the longest absorption spectrum in the visible light region measured by the absorptiometry according to the shape of the metal-based particles and the average interparticle distance. The plasmon peak on the wavelength side can exhibit a maximum wavelength in a wavelength region of 350 to 550 nm, for example. Further, the metal-based particle aggregate [i] typically has a thickness of about 30 to 500 nm (for example 30 to 30 nm) as compared with the case where the metal-based particles are arranged with a sufficiently long inter-particle distance (for example, 1 μm). 250 nm) blue shift can occur.
このような、従来のものと比べてプラズモンピークの極大波長がブルーシフトしている金属系粒子集合体は、たとえば次の点で極めて有利である。すなわち、高い発光効率を示す青色（もしくはその近傍波長領域、以下同様）発光材料（特に青色燐光材料）の実現が強く求められている一方で、十分実用に耐えるこのような材料の開発が現状では困難であるところ、たとえば青色の波長領域にプラズモンピークを有する金属系粒子集合体〔ｉ〕を増強要素として発光素子に適用することにより、比較的発光効率の低い青色発光材料を用いる場合であっても、その発光効率を十分な程度にまで増強させることができる。また、光電変換素子（太陽電池素子など）に適用した場合には、たとえば共鳴波長をブルーシフトさせることによって活性層自体では利用できなかった波長領域を有効利用できるようになり、変換効率を向上させ得る。 Such a metal-based particle aggregate in which the maximum wavelength of the plasmon peak is blue-shifted compared to the conventional one is extremely advantageous, for example, in the following points. In other words, while there is a strong demand for the realization of a blue (or near-wavelength region, hereinafter the same) luminescent material (especially a blue phosphorescent material) that exhibits high luminous efficiency, development of such a material that can withstand practical use is currently underway. It is difficult to use a blue light-emitting material with relatively low luminous efficiency by applying, for example, a metal-based particle aggregate [i] having a plasmon peak in the blue wavelength region as an enhancement element to a light-emitting element. The luminous efficiency can be increased to a sufficient level. In addition, when applied to photoelectric conversion elements (solar cell elements, etc.), for example, the wavelength region that could not be used in the active layer itself can be effectively utilized by blue shifting the resonance wavelength, thereby improving the conversion efficiency. obtain.
次に、金属系粒子集合体〔ｉ〕の具体的構成についてより詳細に説明する。
金属系粒子の平均粒径は２００〜１６００ｎｍの範囲内であり、上記（１）〜（３）の効果を効果的に得るために、好ましくは２００〜１２００ｎｍ、より好ましくは２５０〜５００ｎｍ、さらに好ましくは３００〜５００ｎｍの範囲内である。金属系粒子の平均粒径は、金属系粒子集合体を増強要素として適用する光学素子の種類や金属系粒子を構成する材料の種類に応じて適切に選択されることが好ましい。
Next, the specific configuration of the metal-based particle aggregate [i] will be described in more detail.
The average particle size of the metal-based particles is in the range of 200 to 1600 nm, and in order to effectively obtain the effects (1) to (3) above, preferably 200 to 1200 nm, more preferably 250 to 500 nm, still more preferably Is in the range of 300-500 nm. The average particle diameter of the metal-based particles is preferably selected appropriately depending on the type of optical element to which the metal-based particle aggregate is applied as an enhancement element and the type of material constituting the metal-based particles.
ここで特筆すべき点は、たとえば平均粒径５００ｎｍという大型の金属系粒子は、上述のように、それ単独では局在プラズモンによる増強効果がほとんど認められないということである。これに対し金属系粒子集合体〔ｉ〕は、このような大型の金属系粒子の所定数（３０個）以上を所定の間隔で密に配置することにより、著しく強いプラズモン共鳴およびプラズモン共鳴の作用範囲の著しい伸長、さらには上記（３）の効果を実現するものである。 What should be noted here is that, for example, large metal particles having an average particle diameter of 500 nm, as described above, hardly show an enhancement effect by localized plasmons alone. On the other hand, the metal particle aggregate [i] has an extremely strong plasmon resonance and plasmon resonance action by densely arranging a predetermined number (30) or more of such large metal particles at a predetermined interval. The remarkable extension of the range and further the effect (3) are realized.
金属系粒子の平均粒径とは、二次元的に金属系粒子が配置された金属系粒子集合体薄膜の直上からのＳＥＭ観察画像において、無作為に粒子を１０個選択し、各粒子像内に無作為に接線径を５本引き（ただし、接線径となる直線はいずれも粒子像内部のみを通ることができ、このうち１本は粒子内部のみ通り、最も長く引ける直線であるものとする）、その平均値を各粒子の粒径としたときの、選択した１０個の粒径の平均値である。接線径とは、粒子の輪郭（投影像）をこれに接する２本の平行線で挟んだときの間隔（日刊工業新聞社 「粒子計測技術」，１９９４，第５頁）を結ぶ垂線と定義する。 The average particle size of the metal-based particles refers to 10 particles randomly selected from the SEM observation image from directly above the metal-based particle assembly thin film in which the metal-based particles are two-dimensionally arranged. Randomly draw 5 tangential diameters (however, any straight line with a tangential diameter can only pass through the interior of the particle image, and one of them is only the interior of the particle and is the longest drawn straight line) ), The average value of the 10 selected particle sizes when the average value is the particle size of each particle. The tangent diameter is defined as a perpendicular line connecting the interval (projection image) of a particle between two parallel lines in contact with it (Nikkan Kogyo Shimbun “Particle Measurement Technology”, 1994, page 5). .
金属系粒子の平均高さは５５〜５００ｎｍの範囲内であり、上記（１）〜（３）の効果を効果的に得るために、好ましくは５５〜３００ｎｍ、より好ましくは７０〜１５０ｎｍの範囲内である。金属系粒子の平均高さとは、金属系粒子集合体薄膜のＡＦＭ観察画像において、無作為に粒子を１０個選択し、これら１０個の粒子の高さを測定したときの、１０個の測定値の平均値である。 The average height of the metal-based particles is in the range of 55 to 500 nm, and in order to effectively obtain the effects (1) to (3), preferably in the range of 55 to 300 nm, more preferably 70 to 150 nm. It is. The average height of the metal-based particles is 10 measured values when 10 particles are randomly selected in the AFM observation image of the metal-based particle assembly thin film and the heights of these 10 particles are measured. Is the average value.
金属系粒子のアスペクト比は１〜８の範囲内であり、この範囲内で金属系粒子集合体を増強要素として適用する光学素子の種類に応じて適切に選択することが好ましい。たとえば発光素子の増強要素として用いる場合には、金属系粒子は扁平形状を有することが好ましい傾向にあり、この場合、より高い増強効果を得るために、アスペクト比は２〜８であることが好ましく、２．５〜８であることがより好ましい。一方、光電変換素子の増強要素として用いる場合、より高い増強効果を得るためには、金属系粒子は真球状に近いほど好ましい傾向にある。金属系粒子のアスペクト比は、上記平均高さに対する上記平均粒径の比（平均粒径／平均高さ）で定義される。 The aspect ratio of the metal-based particles is in the range of 1 to 8, and it is preferable that the metal-based particle aggregate is appropriately selected depending on the type of the optical element to which the metal-based particle aggregate is applied as the enhancement element. For example, when used as an enhancement element of a light emitting device, the metal-based particles tend to have a flat shape. In this case, in order to obtain a higher enhancement effect, the aspect ratio is preferably 2 to 8. 2.5 to 8 is more preferable. On the other hand, when used as an enhancement element of a photoelectric conversion element, in order to obtain a higher enhancement effect, the metal particles tend to be more preferable as they are closer to a true sphere. The aspect ratio of the metal-based particles is defined by the ratio of the average particle diameter to the average height (average particle diameter / average height).
金属系粒子は、効果の高いプラズモンを励起する観点から、その表面が滑らかな曲面からなることが好ましいが、表面に微小な凹凸（粗さ）を幾分含んでいてもよく、このような意味において金属系粒子は不定形であってもよい。 From the viewpoint of exciting highly effective plasmons, the surface of the metal-based particles is preferably a smooth curved surface, but the surface may contain some minute irregularities (roughness). The metal particles may be indefinite.
金属系粒子集合体の面内におけるプラズモン共鳴の強さの均一性に鑑み、金属系粒子間のサイズのバラツキはできるだけ小さいことが好ましい。ただし、粒径に多少バラツキが生じたとしても、大型粒子間の距離が大きくなることは好ましくなく、その間を小型の粒子が埋めることで大型粒子間の相互作用を発現しやすくすることが好ましい。 In view of the uniformity of the intensity of plasmon resonance in the plane of the metal-based particle aggregate, it is preferable that the size variation between the metal-based particles is as small as possible. However, even if there is some variation in the particle size, it is not preferable that the distance between the large particles is increased, and it is preferable that the interaction between the large particles is facilitated by filling the space between the small particles.
金属系粒子集合体〔ｉ〕において金属系粒子は、その隣り合う金属系粒子との平均距離（平均粒子間距離）が１〜１５０ｎｍの範囲内となるように配置される。このように金属系粒子を密に配置することにより、著しく強いプラズモン共鳴およびプラズモン共鳴の作用範囲の著しい伸長、さらには上記（３）の効果を実現することができる。平均粒子間距離は、上記（１）〜（３）の効果を効果的に得るために、好ましくは１〜１００ｎｍ、より好ましくは１〜５０ｎｍ、さらに好ましくは１〜２０ｎｍの範囲内である。平均粒子間距離が１ｎｍ未満であると、粒子間でデクスター機構に基づく電子移動が生じ、局在プラズモンの失活の点で不利となる。 In the metal particle aggregate [i], the metal particles are arranged such that the average distance (average interparticle distance) between the adjacent metal particles is in the range of 1 to 150 nm. By arranging the metal-based particles densely in this way, it is possible to achieve extremely strong plasmon resonance, a significant extension of the plasmon resonance action range, and further the effect (3) above. In order to effectively obtain the effects (1) to (3) above, the average interparticle distance is preferably in the range of 1 to 100 nm, more preferably 1 to 50 nm, and even more preferably 1 to 20 nm. When the average interparticle distance is less than 1 nm, electron transfer based on the Dexter mechanism occurs between particles, which is disadvantageous in terms of deactivation of localized plasmons.
平均粒子間距離とは、二次元的に金属系粒子が配置された金属系粒子集合体薄膜の直上からのＳＥＭ観察画像において、無作為に粒子を３０個選択し、選択したそれぞれの粒子について、隣り合う粒子との粒子間距離を求めたときの、これら３０個の粒子の粒子間距離の平均値である。隣り合う粒子との粒子間距離とは、すべての隣り合う粒子との距離（表面同士間の距離である）をそれぞれ測定し、これらを平均した値である。 In the SEM observation image from directly above the metal-based particle assembly thin film in which the metal-based particles are two-dimensionally arranged, the average interparticle distance is 30 particles selected at random, and for each selected particle, It is the average value of the interparticle distances of these 30 particles when the interparticle distance between adjacent particles is obtained. The inter-particle distance between adjacent particles is a value obtained by measuring the distances between all adjacent particles (the distance between the surfaces) and averaging them.
金属系粒子集合体〔ｉ〕に含まれる金属系粒子の数は３０個以上であり、好ましくは５０個以上である。金属系粒子を３０個以上含む集合体を形成することにより、金属系粒子の局在プラズモン間の相互作用によって極めて強いプラズモン共鳴およびプラズモン共鳴の作用範囲の伸長が発現する。 The number of metal particles contained in the metal particle aggregate [i] is 30 or more, preferably 50 or more. By forming an aggregate containing 30 or more metal-based particles, extremely strong plasmon resonance and extension of the plasmon resonance action range are expressed by the interaction between localized plasmons of the metal-based particles.
金属系粒子集合体〔ｉ〕を増強素子として光学素子に適用する場合、光学素子の一般的な素子面積に照らせば、金属系粒子集合体〔ｉ〕に含まれる金属系粒子の数は、たとえば３００個以上、さらには１７５００個以上となり得る。 When the metal-based particle aggregate [i] is applied to an optical element as an enhancement element, the number of metal-based particles contained in the metal-based particle aggregate [i] is, for example, in light of the general element area of the optical element, It can be 300 or more, and further 17500 or more.
金属系粒子集合体〔ｉ〕における金属系粒子の数密度は、７個／μｍ2以上であることが好ましく、１５個／μｍ2以上であることがより好ましい。 The number density of metal particles in the metal particle aggregate [i] is preferably 7 particles / μm 2 or more, and more preferably 15 particles / μm 2 or more.
（金属系粒子集合体〔ｉｉ〕）
上記〔ｉｉ〕の特徴を有する金属系粒子集合体（金属系粒子集合体〔ｉｉ〕）は、次の点において極めて有利である。
(Metal-based particle aggregate [ii])
The metal particle aggregate (metal particle aggregate [ii]) having the above feature [ii] is extremely advantageous in the following points.
（Ｉ）可視光領域における吸光スペクトルにおいて、最も長波長側にあるプラズモンピークの極大波長が特異的な波長領域に存在する。具体的には、金属系粒子集合体〔ｉｉ〕は、吸光スペクトルを測定したとき、上記プラズモンピークの極大波長が、後述する参照金属系粒子集合体（Ｘ）の極大波長に比べて、３０〜５００ｎｍの範囲（たとえば３０〜２５０ｎｍの範囲）で短波長側にシフト（ブルーシフト）しており、典型的には、上記プラズモンピークの極大波長は３５０〜５５０ｎｍの範囲内にある。 (I) In the absorption spectrum in the visible light region, the maximum wavelength of the plasmon peak on the longest wavelength side exists in a specific wavelength region. Specifically, when the metal-based particle aggregate [ii] has an absorption spectrum, the maximum wavelength of the plasmon peak is 30 to more than the maximum wavelength of the reference metal-based particle aggregate (X) described later. It shifts to the short wavelength side (blue shift) in the range of 500 nm (for example, in the range of 30 to 250 nm), and typically the maximum wavelength of the plasmon peak is in the range of 350 to 550 nm.
このような青色またはその近傍波長領域にプラズモンピークを有し得る金属系粒子集合体〔ｉｉ〕は、青色またはその近傍波長領域の発光材料を用いた発光素子の発光増強などに極めて有用であり、かかる金属系粒子集合体〔ｉｉ〕を備える発光素子では、比較的発光効率の低い青色発光材料を用いる場合であっても、その発光効率を十分な程度にまで増強させることができる。また、光電変換素子（太陽電池素子など）に適用した場合には、たとえば共鳴波長をブルーシフトさせることによって活性層自体では利用できなかった波長領域を有効利用できるようになり、変換効率を向上させ得る。 Such a metal-based particle aggregate [ii] that can have a plasmon peak in blue or in the vicinity wavelength region thereof is extremely useful for enhancing light emission of a light-emitting element using a light-emitting material in blue or in the vicinity wavelength region, In a light-emitting device including such a metal-based particle aggregate [ii], even when a blue light-emitting material having a relatively low light emission efficiency is used, the light emission efficiency can be enhanced to a sufficient level. In addition, when applied to photoelectric conversion elements (solar cell elements, etc.), for example, the wavelength region that could not be used in the active layer itself can be effectively utilized by blue shifting the resonance wavelength, thereby improving the conversion efficiency. obtain.
上記ブルーシフトは、金属系粒子集合体〔ｉｉ〕が特定の形状を有する大型な金属系粒子の特定数以上を二次元的に離間して配置した構造を有しており、これに伴い、金属系粒子の局在プラズモン間の相互作用が生じていることによるものと考えられる。 The blue shift has a structure in which the metal-based particle aggregate [ii] has a structure in which a specific number or more of large-sized metal-based particles having a specific shape are two-dimensionally spaced. This is thought to be due to the interaction between the local plasmons of the system particles.
ここで、ある金属系粒子集合体と参照金属系粒子集合体（Ｘ）との間で最も長波長側にあるピークの極大波長や該極大波長における吸光度を比較する場合には、両者について、顕微鏡（Ｎｉｋｏｎ社製「ＯＰＴＩＰＨＯＴ−８８」と分光光度計（大塚電子社製「ＭＣＰＤ−３０００」）とを用い、測定視野を絞って吸光スペクトル測定を行なう。 Here, when comparing the maximum wavelength of the peak on the longest wavelength side and the absorbance at the maximum wavelength between a certain metal-based particle assembly and the reference metal-based particle assembly (X), Using an “OPTIPHOT-88” manufactured by Nikon and a spectrophotometer (“MCPD-3000” manufactured by Otsuka Electronics Co., Ltd.), the absorption spectrum is measured with the measurement field of view narrowed.
参照金属系粒子集合体（Ｘ）は、吸光スペクトル測定の対象となる金属系粒子集合体が有する平均粒径、平均高さと同じ粒径、高さおよび同じ材質を有する金属系粒子Ａを、金属系粒子間の距離がすべて１〜２μｍの範囲内となるように配置した金属系粒子集合体であって、ガラス基板に積層した状態で、上記の顕微鏡を利用した吸光スペクトル測定を行ない得る程度の大きさを有するものである。 The reference metal-based particle aggregate (X) is obtained by replacing the metal-based particles A having the same average particle diameter, the same particle size, the same height as the average height, and the same material with the metal particle aggregates to be subjected to absorption spectrum measurement. An assembly of metal particles arranged such that the distances between the system particles are all within the range of 1 to 2 μm, and the absorption spectrum measurement using the above microscope can be performed in a state of being laminated on the glass substrate. It has a size.
参照金属系粒子集合体（Ｘ）の吸光スペクトル波形は、金属系粒子Ａの粒径および高さ、金属系粒子Ａの材質の誘電関数、金属系粒子Ａ周辺の媒体（たとえば空気）の誘電関数、基板（たとえばガラス基板）の誘電関数を用いて、３Ｄ−ＦＤＴＤ法によって理論上計算することも可能である。 The absorption spectrum waveform of the reference metal-based particle aggregate (X) includes the particle size and height of the metal-based particle A, the dielectric function of the material of the metal-based particle A, and the dielectric function of the medium (for example, air) around the metal-based particle A. It is also possible to theoretically calculate by the 3D-FDTD method using the dielectric function of the substrate (for example, a glass substrate).
また、金属系粒子集合体〔ｉｉ〕は、特定の形状を有する比較的大型な金属系粒子の特定数以上を二次元的に離間して配置した構造を有していることに起因して、（ＩＩ）極めて強いプラズモン共鳴を示し得る（上記金属系粒子集合体〔ｉ〕の効果（１）と同様）、および（ＩＩＩ）プラズモン共鳴の作用範囲（プラズモンによる増強効果の及ぶ範囲）が著しく伸長され得る（上記金属系粒子集合体〔ｉ〕の効果（２）と同様）、などの効果を奏し得る。金属系粒子集合体〔ｉｉ〕は、これをガラス基板上に積層した状態で吸光スペクトルを測定したとき、可視光領域において最も長波長側にあるプラズモンピークの極大波長における吸光度が１以上、さらには１．５以上、なおさらには２程度となり得る。 Further, the metal-based particle aggregate [ii] has a structure in which a specific number or more of relatively large metal-based particles having a specific shape are arranged two-dimensionally apart from each other, (II) Extremely strong plasmon resonance can be exhibited (similar to the effect (1) of the metal-based particle aggregate [i]), and (III) the range of action of plasmon resonance (the range over which the plasmon enhances) is significantly extended. (Similar to the effect (2) of the metal-based particle aggregate [i]). The metal-based particle aggregate [ii] has an absorbance at the maximum wavelength of the plasmon peak on the longest wavelength side in the visible light region when the absorption spectrum is measured in a state where it is laminated on a glass substrate, It can be 1.5 or more, or even about 2.
金属系粒子集合体〔ｉｉ〕の具体的構成は、金属系粒子集合体〔ｉ〕の具体的構成（金属系粒子の材質、平均粒径、平均高さ、アスペクト比、平均粒子間距離、金属系粒子の数、金属系粒子集合体の非導電性など）と基本的には同様であることができる。平均粒径、平均高さ、アスペクト比、平均粒子間距離などの用語の定義も金属系粒子集合体〔ｉ〕と同じである。 The specific configuration of the metal-based particle aggregate [ii] is the specific configuration of the metal-based particle aggregate [i] (the material of the metal-based particles, the average particle diameter, the average height, the aspect ratio, the average interparticle distance, the metal The number of the system particles, the non-conductivity of the metal-based particle aggregate, etc.) can be basically the same. Definitions of terms such as average particle diameter, average height, aspect ratio, and average interparticle distance are the same as those for the metal-based particle aggregate [i].
金属系粒子の平均粒径は２００〜１６００ｎｍの範囲内であり、上記（Ｉ）〜（ＩＩＩ）の効果を効果的に得るために、好ましくは２００〜１２００ｎｍ、より好ましくは２５０〜５００ｎｍ、さらに好ましくは３００〜５００ｎｍの範囲内である。このような大型の金属系粒子の所定数（３０個）以上を二次元的に配置した集合体とすることにより、著しく強いプラズモン共鳴およびプラズモン共鳴の作用範囲の著しい伸長の実現が可能となる。また、上記〔ｉｉ〕の特徴（短波長側へのプラズモンピークのシフト）を発現させるうえでも、金属系粒子は、平均粒径が２００ｎｍ以上であることが必須であり、好ましくは２５０ｎｍ以上である。金属系粒子の平均粒径は、金属系粒子集合体を増強要素として適用する光学素子の種類や金属系粒子を構成する材料の種類に応じて適切に選択されることが好ましい。 The average particle diameter of the metal-based particles is in the range of 200 to 1600 nm, and in order to effectively obtain the effects (I) to (III), preferably 200 to 1200 nm, more preferably 250 to 500 nm, still more preferably Is in the range of 300-500 nm. By forming an aggregate in which a predetermined number (30) or more of such large metal particles are two-dimensionally arranged, it is possible to realize extremely strong plasmon resonance and a significant extension of the plasmon resonance operating range. Further, in order to develop the above feature [ii] (plasmon peak shift to the short wavelength side), the metal particles must have an average particle size of 200 nm or more, preferably 250 nm or more. . The average particle diameter of the metal-based particles is preferably selected appropriately depending on the type of optical element to which the metal-based particle aggregate is applied as an enhancement element and the type of material constituting the metal-based particles.
金属系粒子集合体〔ｉｉ〕では、可視光領域において最も長波長側にあるプラズモンピークの極大波長は、金属系粒子の平均粒径に依存する。すなわち、金属系粒子の平均粒径が一定の値を超えると、当該プラズモンピークの極大波長は短波長側にシフト（ブルーシフト）する。 In the metal-based particle aggregate [ii], the maximum wavelength of the plasmon peak on the longest wavelength side in the visible light region depends on the average particle diameter of the metal-based particles. That is, when the average particle diameter of the metal-based particles exceeds a certain value, the maximum wavelength of the plasmon peak shifts (blue shift) to the short wavelength side.
金属系粒子の平均高さは５５〜５００ｎｍの範囲内であり、上記（Ｉ）〜（ＩＩＩ）の効果を効果的に得るために、好ましくは５５〜３００ｎｍ、より好ましくは７０〜１５０ｎｍの範囲内である。金属系粒子のアスペクト比は１〜８の範囲内であり、金属系粒子集合体〔ｉ〕と同様、この範囲内で金属系粒子集合体を増強要素として適用する光学素子の種類に応じて適切に選択することが好ましい。 The average height of the metal-based particles is in the range of 55 to 500 nm, and in order to effectively obtain the effects (I) to (III), preferably in the range of 55 to 300 nm, more preferably 70 to 150 nm. It is. The aspect ratio of the metal-based particles is in the range of 1 to 8, and, as in the case of the metal-based particle aggregate [i], it is appropriate depending on the type of optical element to which the metal-based particle aggregate is applied as an enhancement element. It is preferable to select.
金属系粒子集合体〔ｉｉ〕において金属系粒子は、平均粒子間距離が１〜１５０ｎｍの範囲内となるように配置されることが好ましい。より好ましくは１〜１００ｎｍ、さらに好ましくは１〜５０ｎｍ、特に好ましくは１〜２０ｎｍの範囲内である。このように金属系粒子を密に配置することにより、金属系粒子の局在プラズモン間の相互作用が効果的に生じ、上記（Ｉ）〜（ＩＩＩ）の効果が発現されやすくなる。プラズモンピークの極大波長は、金属系粒子の平均粒子間距離に依存するので、平均粒子間距離の調整により、最も長波長側にあるプラズモンピークのブルーシフトの程度や当該プラズモンピークの極大波長を制御することが可能である。平均粒子間距離が１ｎｍ未満であると、粒子間でデクスター機構に基づく電子移動が生じ、局在プラズモンの失活の点で不利となる。 In the metal particle aggregate [ii], the metal particles are preferably arranged so that the average interparticle distance is in the range of 1 to 150 nm. More preferably, it is 1-100 nm, More preferably, it is 1-50 nm, Most preferably, it exists in the range of 1-20 nm. By arranging the metal-based particles densely as described above, the interaction between the local plasmons of the metal-based particles is effectively generated, and the effects (I) to (III) are easily expressed. Since the maximum wavelength of the plasmon peak depends on the average interparticle distance of the metal particles, the degree of blue shift of the plasmon peak on the longest wavelength side and the maximum wavelength of the plasmon peak are controlled by adjusting the average interparticle distance. Is possible. When the average interparticle distance is less than 1 nm, electron transfer based on the Dexter mechanism occurs between particles, which is disadvantageous in terms of deactivation of localized plasmons.
金属系粒子集合体〔ｉｉ〕に含まれる金属系粒子の数は３０個以上であり、好ましくは５０個以上である。金属系粒子を３０個以上含む集合体を形成することにより、金属系粒子の局在プラズモン間の相互作用が効果的に生じ、上記〔ｉｉ〕の特徴および上記（Ｉ）〜（ＩＩＩ）の効果の発現が可能となる。 The number of metal particles contained in the metal particle aggregate [ii] is 30 or more, and preferably 50 or more. By forming an aggregate including 30 or more metal-based particles, an interaction between localized plasmons of the metal-based particles is effectively generated, and the characteristics of [ii] and the effects of (I) to (III) are achieved. Expression is possible.
金属系粒子集合体〔ｉｉ〕を増強素子として光学素子に適用する場合、光学素子の一般的な素子面積に照らせば、金属系粒子集合体〔ｉｉ〕に含まれる金属系粒子の数は、たとえば３００個以上、さらには１７５００個以上となり得る。 When the metal-based particle aggregate [ii] is applied to an optical element as an enhancement element, the number of metal-based particles contained in the metal-based particle aggregate [ii] is, for example, in light of the general element area of the optical element, It can be 300 or more, and further 17500 or more.
金属系粒子集合体〔ｉｉ〕における金属系粒子の数密度は、７個／μｍ2以上であることが好ましく、１５個／μｍ2以上であることがより好ましい。 The number density of metal particles in the metal particle aggregate [ii] is preferably 7 particles / μm 2 or more, and more preferably 15 particles / μm 2 or more.
（金属系粒子集合体〔ｉｉｉ〕）
上記〔ｉｉｉ〕の特徴を有する金属系粒子集合体（金属系粒子集合体〔ｉｉｉ〕）は、次の点において極めて有利である。
(Metal-based particle aggregate [iii])
The metal particle aggregate (metal particle aggregate [iii]) having the above feature [iii] is extremely advantageous in the following points.
（Ａ）プラズモンピークである可視光領域において最も長波長側にあるピークの極大波長における吸光度が、金属系粒子が何らの粒子間相互作用もなく単に集合した集合体とみなすことができる後述の参照金属系粒子集合体（Ｙ）よりも大きく、したがって、極めて強いプラズモン共鳴を示すため、発光素子に適用した場合には、従来のプラズモン材料を用いる場合と比較して、より強い発光増強効果を得ることができ、これにより発光効率を飛躍的に高めることができる。また、光電変換素子に適用した場合には、この変換効率を飛躍的に高めることができる。このような強いプラズモン共鳴は、金属系粒子の局在プラズモン間の相互作用により発現したものと考えられる。 (A) References to be described later that the absorbance at the maximum wavelength of the peak on the longest wavelength side in the visible light region, which is a plasmon peak, can be regarded as an aggregate in which metal-based particles are simply assembled without any interparticle interaction. Since it is larger than the metal-based particle aggregate (Y) and thus exhibits extremely strong plasmon resonance, when applied to a light-emitting element, a stronger emission enhancement effect is obtained compared to the case of using a conventional plasmon material. As a result, the luminous efficiency can be dramatically increased. Further, when applied to a photoelectric conversion element, this conversion efficiency can be dramatically increased. Such strong plasmon resonance is considered to be expressed by the interaction between localized plasmons of metal-based particles.
上記のように、プラズモンピークの極大波長における吸光度値の大小から、そのプラズモン材料のプラズモン共鳴の強さを略式に評価することが可能であるが、金属系粒子集合体〔ｉｉｉ〕は、これをガラス基板上に積層した状態で吸光スペクトルを測定したとき、可視光領域において最も長波長側にあるプラズモンピークの極大波長における吸光度が１以上、さらには１．５以上、なおさらには２程度となり得る。 As described above, from the magnitude of the absorbance value at the maximum wavelength of the plasmon peak, it is possible to roughly evaluate the intensity of the plasmon resonance of the plasmon material, but the metal-based particle aggregate [iii] When an absorption spectrum is measured in a state of being laminated on a glass substrate, the absorbance at the maximum wavelength of the plasmon peak on the longest wavelength side in the visible light region can be 1 or more, further 1.5 or more, and even about 2 .
上述のように、ある金属系粒子集合体と参照金属系粒子集合体（Ｙ）との間で最も長波長側にあるピークの極大波長や該極大波長における吸光度を比較する場合には、両者について、顕微鏡（Ｎｉｋｏｎ社製「ＯＰＴＩＰＨＯＴ−８８」と分光光度計（大塚電子社製「ＭＣＰＤ−３０００」）とを用い、測定視野を絞って吸光スペクトル測定を行なう。 As described above, when comparing the maximum wavelength of the peak on the longest wavelength side and the absorbance at the maximum wavelength between a certain metal-based particle assembly and the reference metal-based particle assembly (Y), Using a microscope ("OPTIPHOT-88" manufactured by Nikon Corporation) and a spectrophotometer ("MCPD-3000" manufactured by Otsuka Electronics Co., Ltd.), the absorption spectrum is measured by narrowing the measurement field of view.
参照金属系粒子集合体（Ｙ）は、吸光スペクトル測定の対象となる金属系粒子集合体が有する平均粒径、平均高さと同じ粒径、高さおよび同じ材質を有する金属系粒子Ｂを、金属系粒子間の距離がすべて１〜２μｍの範囲内となるように配置した金属系粒子集合体であって、ガラス基板に積層した状態で、上記の顕微鏡を利用した吸光スペクトル測定を行ない得る程度の大きさを有するものである。 The reference metal-based particle aggregate (Y) is obtained by replacing the metal-based particles B having the same average particle size, average particle size, height and same material as the average particle diameter of the metal-based particle aggregate that is the target of absorption spectrum measurement. An assembly of metal particles arranged such that the distances between the system particles are all within the range of 1 to 2 μm, and the absorption spectrum measurement using the above microscope can be performed in a state of being laminated on the glass substrate. It has a size.
吸光スペクトル測定の対象となる金属系粒子集合体と参照金属系粒子集合体（Ｙ）との間で、最も長波長側にあるピークの極大波長における吸光度を比較する際には、以下に述べるように、同じ金属系粒子数になるように換算した参照金属系粒子集合体（Ｙ）の吸光スペクトルを求め、当該吸光スペクトルにおける最も長波長側にあるピークの極大波長における吸光度を比較の対象とする。具体的には、金属系粒子集合体と参照金属系粒子集合体（Ｙ）の吸光スペクトルをそれぞれ求め、それぞれの吸光スペクトルにおける最も長波長側にあるピークの極大波長における吸光度を、それぞれの被覆率（金属系粒子による基板表面の被覆率）で除した値を算出し、これらを比較する。 When comparing the absorbance at the maximum wavelength of the peak on the longest wavelength side between the metal-based particle aggregate to be subjected to the absorption spectrum measurement and the reference metal-based particle aggregate (Y), the following is described. Next, an absorption spectrum of the reference metal-based particle aggregate (Y) converted so as to have the same number of metal-based particles is obtained, and the absorbance at the maximum wavelength of the peak on the longest wavelength side in the absorption spectrum is used for comparison. . Specifically, the absorption spectrum of each of the metal-based particle assembly and the reference metal-based particle assembly (Y) is obtained, and the absorbance at the maximum wavelength of the peak on the longest wavelength side in each of the absorption spectra is expressed as the coverage ratio. The value divided by (the coverage of the substrate surface with the metal particles) is calculated and compared.
また、金属系粒子集合体〔ｉｉｉ〕は、特定の形状を有する比較的大型な金属系粒子の特定数以上を二次元的に離間して配置した構造を有していることに起因して、（Ｂ）プラズモン共鳴の作用範囲（プラズモンによる増強効果の及ぶ範囲）が著しく伸長され得る（上記金属系粒子集合体〔ｉ〕の効果（２）と同様）、および（Ｃ）プラズモンピークの極大波長が特異なシフトを示し得る（上記金属系粒子集合体〔ｉ〕の効果（３）と同様）、などの効果を奏し得る。 Further, the metal particle aggregate [iii] has a structure in which a specific number or more of relatively large metal particles having a specific shape are arranged two-dimensionally apart from each other, (B) The action range of plasmon resonance (the range in which the enhancement effect by plasmon reaches) can be significantly extended (similar to the effect (2) of the metal-based particle aggregate [i] above), and (C) the maximum wavelength of the plasmon peak Can exhibit a peculiar shift (similar to the effect (3) of the metal-based particle aggregate [i]).
金属系粒子集合体〔ｉｉｉ〕（ガラス基板上に積層した状態）は、金属系粒子の形状や平均粒子間距離に応じて、吸光光度法によって測定される可視光領域における吸光スペクトルにおいて、最も長波長側にあるプラズモンピークが、たとえば３５０〜５５０ｎｍの波長領域に極大波長を示し得る。また、金属系粒子集合体〔ｉｉｉ〕は、金属系粒子が十分に長い粒子間距離（たとえば１μｍ）を置いて配置される場合と比較して、典型的には３０〜５００ｎｍ程度（たとえば３０〜２５０ｎｍ）のブルーシフトを生じ得る。 The metal-based particle aggregate [iii] (in the state of being laminated on the glass substrate) has the longest absorption spectrum in the visible light region measured by the absorptiometry according to the shape of the metal-based particles and the average interparticle distance. The plasmon peak on the wavelength side can exhibit a maximum wavelength in a wavelength region of 350 to 550 nm, for example. The metal-based particle aggregate [iii] is typically about 30 to 500 nm (for example 30 to 30 nm) as compared with the case where the metal-based particles are arranged with a sufficiently long inter-particle distance (for example, 1 μm). 250 nm) blue shift can occur.
金属系粒子集合体〔ｉｉｉ〕の具体的構成は、金属系粒子集合体〔ｉ〕の具体的構成（金属系粒子の材質、平均粒径、平均高さ、アスペクト比、平均粒子間距離、金属系粒子の数、金属系粒子集合体の非導電性など）と基本的には同様であることができる。平均粒径、平均高さ、アスペクト比、平均粒子間距離などの用語の定義も金属系粒子集合体〔ｉ〕と同じである。 The specific configuration of the metal-based particle aggregate [iii] is the specific configuration of the metal-based particle aggregate [i] (the material of the metal-based particles, the average particle diameter, the average height, the aspect ratio, the average interparticle distance, the metal The number of the system particles, the non-conductivity of the metal-based particle aggregate, etc.) can be basically the same. Definitions of terms such as average particle diameter, average height, aspect ratio, and average interparticle distance are the same as those for the metal-based particle aggregate [i].
金属系粒子の平均粒径は２００〜１６００ｎｍの範囲内であり、上記〔ｉｉｉ〕の特徴（最も長波長側にあるプラズモンピークの極大波長における吸光度が参照金属系粒子集合体（Ｙ）のそれよりも高いという特徴）、さらには上記（Ａ）〜（Ｃ）の効果を効果的に得るために、好ましくは２００〜１２００ｎｍ、より好ましくは２５０〜５００ｎｍ、さらに好ましくは３００〜５００ｎｍの範囲内である。このように、比較的大型の金属系粒子を形成することが肝要であり、大型の金属系粒子の所定数（３０個）以上を二次元的に配置した集合体とすることにより、著しく強いプラズモン共鳴、さらにはプラズモン共鳴の作用範囲の著しい伸長、短波長側へのプラズモンピークのシフトの実現が可能となる。金属系粒子の平均粒径は、金属系粒子集合体を増強要素として適用する光学素子の種類や金属系粒子を構成する材料の種類に応じて適切に選択されることが好ましい。 The average particle diameter of the metal-based particles is in the range of 200 to 1600 nm, and the above-mentioned feature [iii] (the absorbance at the maximum wavelength of the plasmon peak on the longest wavelength side is that of the reference metal-based particle aggregate (Y)). In order to effectively obtain the effects (A) to (C) above, it is preferably in the range of 200 to 1200 nm, more preferably 250 to 500 nm, and still more preferably 300 to 500 nm. . Thus, it is important to form relatively large metal particles, and by forming an aggregate in which a predetermined number (30) or more of large metal particles are two-dimensionally arranged, extremely strong plasmons are obtained. It is possible to realize a significant extension of the action range of resonance and further plasmon resonance and shift of the plasmon peak to the short wavelength side. The average particle diameter of the metal-based particles is preferably selected appropriately depending on the type of optical element to which the metal-based particle aggregate is applied as an enhancement element and the type of material constituting the metal-based particles.
金属系粒子の平均高さは５５〜５００ｎｍの範囲内であり、上記〔ｉｉｉ〕の特徴、さらには上記（Ａ）〜（Ｃ）の効果を効果的に得るために、好ましくは５５〜３００ｎｍ、より好ましくは７０〜１５０ｎｍの範囲内である。金属系粒子のアスペクト比は１〜８の範囲内であり、金属系粒子集合体〔ｉ〕と同様、この範囲内で金属系粒子集合体を増強要素として適用する光学素子の種類に応じて適切に選択することが好ましい。 The average height of the metal-based particles is in the range of 55 to 500 nm, and in order to effectively obtain the characteristics of [iii] and further the effects (A) to (C), preferably 55 to 300 nm, More preferably, it exists in the range of 70-150 nm. The aspect ratio of the metal-based particles is in the range of 1 to 8, and, as in the case of the metal-based particle aggregate [i], it is appropriate depending on the type of optical element to which the metal-based particle aggregate is applied as an enhancement element. It is preferable to select.
上記〔ｉｉｉ〕の特徴が効果的に得られることから、金属系粒子集合体〔ｉｉｉ〕を構成する金属系粒子は、それらのサイズおよび形状（平均粒径、平均高さ、アスペクト比）ができるだけ均一であることが好ましい。すなわち、金属系粒子のサイズおよび形状を均一にすることにより、プラズモンピークが先鋭化し、これに伴い、最も長波長側にあるプラズモンピークの吸光度が参照金属系粒子集合体（Ｙ）のそれよりも高くなりやすくなる。金属系粒子間のサイズおよび形状のバラツキの低減は、金属系粒子集合体面内におけるプラズモン共鳴の強さの均一性の観点からも有利である。ただし上述のように、粒径に多少バラツキが生じたとしても、大型粒子間の距離が大きくなることは好ましくなく、その間を小型の粒子が埋めることで大型粒子間の相互作用を発現しやすくすることが好ましい。 Since the characteristics of [iii] can be effectively obtained, the size and shape (average particle diameter, average height, aspect ratio) of the metal particles constituting the metal particle aggregate [iii] can be as much as possible. It is preferable that it is uniform. That is, by making the size and shape of the metal-based particles uniform, the plasmon peak is sharpened. Accordingly, the absorbance of the plasmon peak on the longest wavelength side is higher than that of the reference metal-based particle aggregate (Y). It tends to be higher. Reduction of the size and shape variation between the metal-based particles is advantageous from the viewpoint of the uniformity of the intensity of plasmon resonance in the plane of the metal-based particle aggregate. However, as described above, even if there is some variation in the particle size, it is not preferable that the distance between the large particles increases, and the interaction between the large particles is facilitated by filling the space between the small particles. It is preferable.
金属系粒子集合体〔ｉｉｉ〕において金属系粒子は、平均粒子間距離が１〜１５０ｎｍの範囲内となるように配置されることが好ましい。より好ましくは１〜１００ｎｍ、さらに好ましくは１〜５０ｎｍ、特に好ましくは１〜２０ｎｍの範囲内である。このように金属系粒子を密に配置することにより、金属系粒子の局在プラズモン間の相互作用が効果的に生じ、上記〔ｉｉｉ〕の特徴、さらには上記（Ａ）〜（Ｃ）の効果を効果的に発現させることができる。平均粒子間距離が１ｎｍ未満であると、粒子間でデクスター機構に基づく電子移動が生じ、局在プラズモンの失活の点で不利となる。 In the metal particle aggregate [iii], the metal particles are preferably arranged so that the average interparticle distance is in the range of 1 to 150 nm. More preferably, it is 1-100 nm, More preferably, it is 1-50 nm, Most preferably, it exists in the range of 1-20 nm. By arranging the metal-based particles densely as described above, the interaction between the localized plasmons of the metal-based particles is effectively generated, and the characteristics of [iii] and the effects (A) to (C) described above are achieved. Can be effectively expressed. When the average interparticle distance is less than 1 nm, electron transfer based on the Dexter mechanism occurs between particles, which is disadvantageous in terms of deactivation of localized plasmons.
金属系粒子集合体〔ｉｉｉ〕に含まれる金属系粒子の数は３０個以上であり、好ましくは５０個以上である。金属系粒子を３０個以上含む集合体を形成することにより、金属系粒子の局在プラズモン間の相互作用が効果的に生じ、上記〔ｉｉｉ〕の特徴、さらには上記（Ａ）〜（Ｃ）の効果を効果的に発現させることができる。 The number of metal particles contained in the metal particle aggregate [iii] is 30 or more, and preferably 50 or more. By forming an aggregate containing 30 or more metal-based particles, an interaction between localized plasmons of the metal-based particles is effectively generated, and the characteristics of [iii] above, and further the above (A) to (C) The effect of can be expressed effectively.
金属系粒子集合体〔ｉｉｉ〕を増強素子として光学素子に適用する場合、光学素子の一般的な素子面積に照らせば、金属系粒子集合体〔ｉｉｉ〕に含まれる金属系粒子の数は、たとえば３００個以上、さらには１７５００個以上となり得る。 When the metal-based particle aggregate [iii] is applied to an optical element as an enhancement element, the number of metal-based particles contained in the metal-based particle aggregate [iii] is, for example, in light of the general element area of the optical element, It can be 300 or more, and further 17500 or more.
金属系粒子集合体〔ｉｉｉ〕における金属系粒子の数密度は、７個／μｍ2以上であることが好ましく、１５個／μｍ2以上であることがより好ましい。 The number density of the metal particles in the metal particle aggregate [iii] is preferably 7 particles / μm 2 or more, and more preferably 15 particles / μm 2 or more.
以上のように、金属系粒子集合体〔ｉｉｉ〕は、これを構成する金属系粒子の金属種、サイズ、形状、金属系粒子間の平均距離などの制御により得ることができる。 As described above, the metal-based particle aggregate [iii] can be obtained by controlling the metal species, size, shape, average distance between the metal-based particles, and the like of the metal-based particles constituting the metal-based particle aggregate [iii].
本発明の製造方法によって得られる金属系粒子集合体は、上記〔ｉ〕〜〔ｉｉｉ〕の少なくともいずれか１つの特徴を有するものであり、より典型的には、〔ｉ〕〜〔ｉｉｉ〕のいずれか２つ以上の特徴を有し、さらに典型的には、〔ｉ〕〜〔ｉｉｉ〕のすべての特徴を有する。 The metal-based particle aggregate obtained by the production method of the present invention has at least one of the above-mentioned [i] to [iii] characteristics, and more typically, [i] to [iii]. It has any two or more features, and more typically has all the features [i] to [iii].
本発明においては、上述の粒子成長工程の後に絶縁層形成工程を設けて、金属系粒子集合体の薄膜上に、各金属系粒子の表面を覆う絶縁層を形成してもよい。このような絶縁層は、上述した金属系粒子集合体薄膜の非導電性（金属系粒子間の非導電性）を担保するうえで好ましいだけでなく、金属系粒子集合体を光学素子に適用する場合にも好ましい。すなわち、電気エネルギー駆動の発光素子や光電変換素子等の光学素子では、これを構成する各層に電流が流れるが、金属系粒子集合体薄膜に電流が流れてしまうと、プラズモン共鳴による増強効果が十分に得られないおそれがある。金属系粒子集合体薄膜をキャップする絶縁層を設けることにより、光学素子に適用した場合においても金属系粒子集合体薄膜と、これに隣接する光学素子の構成層との間の電気的絶縁を図ることができるため、金属系粒子集合体薄膜を構成する金属系粒子に電流が注入されることを防止することができる。 In the present invention, an insulating layer forming step may be provided after the above-described particle growth step to form an insulating layer covering the surface of each metal particle on the thin film of the metal particle aggregate. Such an insulating layer is not only preferable for ensuring the non-conductivity (non-conductivity between metal-based particles) of the metal-based particle assembly thin film described above, but also applies the metal-based particle assembly to an optical element. Also preferred in some cases. That is, in an optical element such as an electric energy-driven light emitting element or photoelectric conversion element, a current flows in each layer constituting the element, but if the current flows in the metal-based particle assembly thin film, the enhancement effect by plasmon resonance is sufficient. May not be obtained. By providing an insulating layer that caps the metal-based particle assembly thin film, electrical insulation is achieved between the metal-based particle assembly thin film and the constituent layers of the optical element adjacent thereto even when applied to an optical element. Therefore, current can be prevented from being injected into the metal-based particles constituting the metal-based particle assembly thin film.
絶縁層を構成する材料としては、良好な絶縁性を有するものであれば特に制限されず、たとえば、スピンオングラス（ＳＯＧ；たとえば有機シロキサン材料を含有するもの）のほか、ＳｉＯ2やＳｉ3Ｎ4などを用いることができる。絶縁層の厚みは、所望の絶縁性が確保される限り特に制限はないが、後述するように光学素子に適用したときの活性層（たとえば発光素子の発光層や光電変換素子の光吸収層）と金属系粒子集合体薄膜との距離は近いほど好ましいことから、所望の絶縁性が確保される範囲で薄いほどよい。 The material constituting the insulating layer is not particularly limited as long as it has good insulating properties. For example, in addition to spin-on glass (SOG; for example, containing an organic siloxane material), SiO 2 or Si 3 N 4 Etc. can be used. The thickness of the insulating layer is not particularly limited as long as desired insulating properties are ensured, but an active layer when applied to an optical element as described later (for example, a light emitting layer of a light emitting element or a light absorbing layer of a photoelectric conversion element). And the metal-based particle assembly thin film is preferably as short as possible.
本発明の製造方法によって得られる金属系粒子集合体は、発光素子、光電変換素子（太陽電池素子など）等の光学素子のための増強要素として極めて有用である。本発明に係る金属系粒子集合体を光学素子に適用することにより、光学素子の発光効率や変換効率を顕著に向上させることができる。金属系粒子集合体は、これを製造する際に用いる基板と一体化した状態で、各種光学素子に組み込むことができる。 The metal-based particle aggregate obtained by the production method of the present invention is extremely useful as an enhancement element for optical elements such as light-emitting elements and photoelectric conversion elements (solar cell elements). By applying the metal-based particle aggregate according to the present invention to an optical element, the light emission efficiency and conversion efficiency of the optical element can be significantly improved. The metal-based particle aggregate can be incorporated into various optical elements in a state of being integrated with a substrate used for manufacturing the metal-based particle aggregate.
上述のように、本発明の製造方法によって得られる金属系粒子集合体は、極めて強いプラズモン共鳴を示し、さらにはプラズモン共鳴の作用範囲（プラズモンによる増強効果の及ぶ範囲）が著しく伸長されているため、たとえば、１０ｎｍ以上、さらには２０ｎｍ以上、なおさらにはそれ以上の厚みを有する活性層（発光素子における発光層や光電変換素子における光吸収層など）の全体を増強させることが可能である。また、たとえば１０ｎｍ、さらには数十ｎｍ（たとえば２０ｎｍ）、なおさらには数百ｎｍ以上離れた位置に配置された活性層をも、極めて効果的に増強することができる。 As described above, the metal-based particle aggregate obtained by the production method of the present invention exhibits extremely strong plasmon resonance, and further, the action range of plasmon resonance (the range in which the plasmon enhances the effect) is significantly extended. For example, the entire active layer (such as a light-emitting layer in a light-emitting element or a light-absorbing layer in a photoelectric conversion element) having a thickness of 10 nm or more, further 20 nm or more, and even more can be enhanced. In addition, the active layer disposed at a position separated by, for example, 10 nm, further several tens of nm (for example, 20 nm), or even several hundred nm or more can be enhanced extremely effectively.
なお、プラズモンによる増強効果は、その性質上、活性層と金属系粒子集合体との距離が大きくなるほど小さくなる傾向にあることから、当該距離は小さいほど好ましい。活性層と金属系粒子集合体との距離は、好ましくは１００ｎｍ以下であり、より好ましくは２０ｎｍ以下であり、さらに好ましくは１０ｎｍ以下である。 In addition, since the enhancement effect by plasmon tends to become smaller as the distance between the active layer and the metal-based particle aggregate increases, the smaller the distance, the better. The distance between the active layer and the metal-based particle aggregate is preferably 100 nm or less, more preferably 20 nm or less, and further preferably 10 nm or less.
活性層が示す発光波長（たとえば発光素子の場合）または吸収波長（たとえば光電変換素子の場合）の極大波長は、金属系粒子集合体のプラズモンピークの極大波長と一致するかまたは近いことが好ましい。これにより、プラズモン共鳴による増強効果をより効果的に高めることができる。金属系粒子集合体のプラズモンピークの極大波長は、これを構成する金属系粒子の金属種、平均粒径、平均高さ、アスペクト比および／または平均粒子間距離の調整により制御可能である。 The maximum wavelength of the emission wavelength (for example, in the case of a light emitting device) or the absorption wavelength (for example in the case of a photoelectric conversion device) exhibited by the active layer is preferably equal to or close to the maximum wavelength of the plasmon peak of the metal-based particle aggregate. Thereby, the enhancement effect by plasmon resonance can be enhanced more effectively. The maximum wavelength of the plasmon peak of the metal particle aggregate can be controlled by adjusting the metal species, average particle diameter, average height, aspect ratio and / or average particle distance of the metal particles constituting the metal particle aggregate.
上記発光層は、たとえば、１）色素分子を平面状に配置した単分子膜からなるもの、２）マトリックス中に色素分子をドープしてなるもの、３）発光性低分子からなるもの、４）発光性高分子からなるもの、などであることができる。 The light emitting layer is, for example, 1) composed of a monomolecular film in which dye molecules are arranged in a plane, 2) composed of a matrix doped with dye molecules, 3) composed of a light emitting low molecule, 4) It can be made of a light-emitting polymer.
１）の発光層は、色素分子含有液をスピンコートした後、溶媒を除去する方法により得ることができる。色素分子の具体例は、Ｅｘｃｉｔｏｎ社から販売されているローダミン１０１、ローダミン１１０、ローダミン５６０、ローダミン６Ｇ、ローダミンＢ、ローダミン６４０、ローダミン７００等のローダミン系色素、Ｅｘｃｉｔｏｎ社から販売されているクマリン５０３等のクマリン系色素などを含む。 The light emitting layer of 1) can be obtained by a method of removing the solvent after spin-coating the dye molecule-containing liquid. Specific examples of the dye molecule include rhodamine 101, rhodamine 110, rhodamine 560, rhodamine 6G, rhodamine B, rhodamine 640, rhodamine 700 and other rhodamine dyes sold by Exciton, coumarin 503 sold by Exciton, etc. Including coumarin pigments.
２）の発光層は、色素分子およびマトリックス材料を含有する液をスピンコートした後、溶媒を除去する方法により得ることができる。マトリックス材料としては、ポリビニルアルコール、ポリメタクリル酸メチルのような透明高分子を用いることができる。色素分子の具体例は１）の発光層と同様であることができる。 The light emitting layer of 2) can be obtained by a method of spin-coating a liquid containing dye molecules and a matrix material and then removing the solvent. As the matrix material, a transparent polymer such as polyvinyl alcohol or polymethyl methacrylate can be used. Specific examples of the dye molecule can be the same as those in the light emitting layer of 1).
３）の発光層は、スピンコート法、蒸着法をはじめとするドライまたはウェット成膜法によって得ることができる。発光性低分子の具体例は、トリス（８−キノリノラト）アルミニウム錯体〔トリス（８−ヒドロキシキノリン）アルミニウム錯体；Ａｌｑ3〕、ビス（ベンゾキノリノラト）ベリリウム錯体〔ＢｅＢｑ〕などを含む。 The light emitting layer 3) can be obtained by a dry or wet film forming method including a spin coating method and a vapor deposition method. Specific examples of the light-emitting small molecule include tris (8-quinolinolato) aluminum complex [tris (8-hydroxyquinoline) aluminum complex; Alq 3 ], bis (benzoquinolinolato) beryllium complex [BeBq] and the like.
４）の発光層は、スピンコート法など、発光性高分子含有液を用いたウェット成膜法によって得ることができる。発光性高分子の具体例は、Ｆ８ＢＴ〔ポリ(９，９−ジオクチルフルオレン−ａｌｔ−ベンゾチアジアゾール）〕、ポリ（ｐ−フェニレンビニレン）、ポリアルキルチオフェンのようなπ共役系高分子などを含む。 The light emitting layer of 4) can be obtained by a wet film forming method using a light emitting polymer-containing liquid such as a spin coat method. Specific examples of the light-emitting polymer include π-conjugated polymers such as F8BT [poly (9,9-dioctylfluorene-alt-benzothiadiazole)], poly (p-phenylenevinylene), and polyalkylthiophene.
以下、実施例を挙げて本発明をより詳細に説明するが、本発明はこれら実施例に限定されるものではない。 EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these Examples.
〔金属系粒子集合体の作製〕
＜実施例１＞
直流マグネトロンスパッタリング装置を用いて、下記の条件で、ソーダガラス基板上に、銀粒子を極めてゆっくりと成長させ、基板表面の全面に金属系粒子集合体の薄膜を形成して、金属系粒子集合体薄膜積層基板を得た。
[Production of metal particle aggregates]
<Example 1>
Using a DC magnetron sputtering apparatus, silver particles are grown very slowly on a soda glass substrate under the following conditions, and a thin film of metal particle aggregates is formed on the entire surface of the substrate. A thin film laminated substrate was obtained.
使用ガス：アルゴン、
チャンバ内圧力（スパッタガス圧）：１０Ｐａ、
基板・ターゲット間距離：１００ｍｍ、
スパッタ電力：４Ｗ、
平均粒径成長速度（平均粒径／スパッタ時間）：０．９ｎｍ／分、
平均高さ成長速度（＝平均堆積速度＝平均高さ／スパッタ時間）：０．２５ｎｍ／分、
基板温度：３００℃、
基板サイズおよび形状：一辺が５ｃｍの正方形。
Gas used: Argon,
In-chamber pressure (sputtering gas pressure): 10 Pa,
Distance between substrate and target: 100 mm,
Sputtering power: 4W
Average particle size growth rate (average particle size / sputtering time): 0.9 nm / min,
Average height growth rate (= average deposition rate = average height / sputtering time): 0.25 nm / min,
Substrate temperature: 300 ° C.
Substrate size and shape: A square with a side of 5 cm.
図１は、得られた金属系粒子集合体薄膜を直上から見たときのＳＥＭ画像である。図１（ａ）は１００００倍スケールの拡大像であり、図１（ｂ）は５００００倍スケールの拡大像である。また図２は、得られた金属系粒子集合体薄膜を示すＡＦＭ画像である。ＡＦＭ像撮影にはキーエンス社製「ＶＮ−８０１０」を用いた（以下同様）。図２に示される画像のサイズは５μｍ×５μｍである。 FIG. 1 is an SEM image when the obtained metal-based particle assembly thin film is viewed from directly above. FIG. 1A is an enlarged image on a 10000 times scale, and FIG. 1B is an enlarged image on a 50000 times scale. FIG. 2 is an AFM image showing the obtained metal-based particle assembly thin film. For the AFM image shooting, “VN-8010” manufactured by Keyence Corporation was used (the same applies hereinafter). The size of the image shown in FIG. 2 is 5 μm × 5 μm.
図１に示されるＳＥＭ画像より、本実施例の金属系粒子集合体を構成する銀粒子の上記定義に基づく平均粒径は３３５ｎｍ、平均粒子間距離は１６．７ｎｍと求められた。また図２に示されるＡＦＭ画像より、平均高さは９６．２ｎｍと求められた。これらより銀粒子のアスペクト比（平均粒径／平均高さ）は３．４８と算出され、また、取得した画像からも銀粒子は扁平形状を有していることがわかる。さらにＳＥＭ画像より、本実施例の金属系粒子集合体は、約６．２５×１０10個（約２５個／μｍ2）の銀粒子を有することがわかる。 From the SEM image shown in FIG. 1, the average particle diameter based on the above definition of the silver particles constituting the metal-based particle assembly of this example was determined to be 335 nm, and the average interparticle distance was 16.7 nm. From the AFM image shown in FIG. 2, the average height was determined to be 96.2 nm. From these, the aspect ratio (average particle diameter / average height) of the silver particles is calculated to be 3.48, and it can be seen from the acquired image that the silver particles have a flat shape. Furthermore, it can be seen from the SEM image that the metal-based particle aggregate of this example has about 6.25 × 10 10 (about 25 particles / μm 2 ) silver particles.
また、金属系粒子集合体薄膜の表面にテスター〔マルチメーター（ヒューレット・パッカード社製「Ｅ２３７８Ａ」〕を接続して導電性を確認したところ、導電性を有しないことが確認された。 Further, when a tester [Multimeter (“E2378A” manufactured by Hewlett-Packard Co., Ltd.)] was connected to the surface of the metal-based particle assembly thin film to confirm the conductivity, it was confirmed that the metal particle aggregate thin film did not have conductivity.
＜比較例１＞
平均高さ成長速度（堆積速度）を６０．６ｎｍ／分、処理時間（堆積時間）を２分としたこと以外は実施例１と同様にしてスパッタリングを行ない、銀からなる薄膜を形成した。図３は、得られた銀薄膜を示すＡＦＭ画像である。図３に示される画像のサイズは５μｍ×５μｍである。
<Comparative Example 1>
Sputtering was performed in the same manner as in Example 1 except that the average height growth rate (deposition rate) was 60.6 nm / min and the processing time (deposition time) was 2 minutes, to form a thin film made of silver. FIG. 3 is an AFM image showing the obtained silver thin film. The size of the image shown in FIG. 3 is 5 μm × 5 μm.
なお、本比較例における平均高さ成長速度とは、基板上に形成された銀層の平均高さをスパッタ時間で除した値である。銀層の平均高さは、ピンセットの先で銀層に剥離線を設け、該剥離線における銀層の外側表面と基板の銀層側表面との高さの差を無作為に５点選択したときの当該５点の平均値として求めた。 In addition, the average height growth rate in this comparative example is a value obtained by dividing the average height of the silver layer formed on the substrate by the sputtering time. For the average height of the silver layer, a peeling line was provided on the silver layer at the tip of the tweezers, and the height difference between the outer surface of the silver layer and the silver layer side surface of the substrate at the peeling line was randomly selected at five points. It was calculated as an average value of the 5 points.
図３に示されるＡＦＭ画像より、平均高さは１２１．３ｎｍと求められた。上記と同じテスターを用いて銀薄膜の導電性を確認したところ、導電性を有することが確認された。すなわち、本比較例における基板への銀の担持量は、上記実施例１とおよそ同じであるが、個々の銀粒子が互いに分離しておらず、連続膜となっていることが確認された。 From the AFM image shown in FIG. 3, the average height was determined to be 121.3 nm. When the conductivity of the silver thin film was confirmed using the same tester as described above, it was confirmed to have conductivity. That is, the amount of silver supported on the substrate in this comparative example was approximately the same as in Example 1, but it was confirmed that the individual silver particles were not separated from each other and were a continuous film.
〔銀薄膜の吸光スペクトル測定〕
図４は、実施例１で得られた金属系粒子集合体薄膜および比較例１で得られた銀薄膜（ともに基板に積層された状態）の吸光光度法により測定された吸光スペクトルである。非特許文献（K. Lance Kelly, et al., "The Optical Properties of Metal Nanoparticles: The Influence of Size, Shape, and Dielectric Environment", The Journal of Physical Chemistry B, 2003, 107, 668）に示されているように、実施例１のような扁平形状の銀粒子は、平均粒径が２００ｎｍのとき約５５０ｎｍ付近に、平均粒径が３００ｎｍのときは６５０ｎｍ付近にプラズモンピークを持つことが一般的である（いずれも銀粒子単独の場合である）。
[Absorption spectrum measurement of silver thin film]
FIG. 4 is an absorption spectrum measured by absorptiometry of the metal-based particle assembly thin film obtained in Example 1 and the silver thin film obtained in Comparative Example 1 (both laminated on a substrate). Non-patent literature (K. Lance Kelly, et al., "The Optical Properties of Metal Nanoparticles: The Influence of Size, Shape, and Dielectric Environment", The Journal of Physical Chemistry B, 2003, 107, 668) As shown, the flat silver particles as in Example 1 generally have a plasmon peak around 550 nm when the average particle size is 200 nm, and around 650 nm when the average particle size is 300 nm. (All are silver particles alone).
一方、実施例１の金属系粒子集合体薄膜は、これを構成する銀粒子の平均粒径が約３００ｎｍ（３３５ｎｍ）であるにもかかわらず、図４に示されるように、可視光領域において最も長波長側にあるプラズモンピークの極大波長は約４５０ｎｍ付近と、短波長側にシフトしていることがわかる。この現象は、実施例１のように、銀粒子が、上記所定の形状を有する大型の粒子であり、かつ上記好ましい平均粒子間距離で極めて密に配置されている場合に発現し得る。 On the other hand, the metal-based particle assembly thin film of Example 1 is the most visible in the visible light region as shown in FIG. 4, despite the average particle size of the silver particles constituting the thin film being approximately 300 nm (335 nm). It can be seen that the maximum wavelength of the plasmon peak on the long wavelength side is shifted to the short wavelength side, around 450 nm. This phenomenon can occur when the silver particles are large particles having the predetermined shape and are arranged very densely at the preferable average interparticle distance as in Example 1.
また、可視光領域において最も長波長側にあるプラズモンピークの極大波長における吸光度が約１．９と、極めて強いプラズモン共鳴を示すことがわかる。これに対し、比較例１の銀薄膜は、連続膜となっているために、プラズモン共鳴に基づくプラズモンピークを示さなかった。 It can also be seen that the absorbance at the maximum wavelength of the plasmon peak on the longest wavelength side in the visible light region is about 1.9, indicating extremely strong plasmon resonance. On the other hand, since the silver thin film of Comparative Example 1 was a continuous film, it did not show a plasmon peak based on plasmon resonance.
なお、図４に示される吸光スペクトルは、銀薄膜が積層されたガラス基板の裏面側（銀薄膜とは反対側）であって、基板面に垂直な方向から紫外〜可視光領域の入射光を照射し、銀薄膜側に透過した全方向における透過光の強度Ｉと、上記基板と同じ厚み、材質の基板であって、銀薄膜が積層されていない基板の面に垂直な方向から先と同じ入射光を照射し、入射面の反対側から透過した全方向における透過光の強度Ｉ0を、それぞれ積分球分光光度計を用いて測定することによって得られたものである。縦軸の吸光度は、下記式：
吸光度＝−ｌｏｇ10（Ｉ／Ｉ0）
で表される。
In addition, the absorption spectrum shown in FIG. 4 is the back side (the side opposite to the silver thin film) of the glass substrate on which the silver thin film is laminated, and the incident light in the ultraviolet to visible light region from the direction perpendicular to the substrate surface. Irradiated and transmitted light intensity I in all directions transmitted to the silver thin film side, and the same thickness and material as the above substrate, and the same as before from the direction perpendicular to the surface of the substrate on which the silver thin film is not laminated It was obtained by measuring the intensity I 0 of transmitted light in all directions irradiated with incident light and transmitted from the opposite side of the incident surface using an integrating sphere spectrophotometer. The absorbance on the vertical axis is the following formula:
Absorbance = −log 10 (I / I 0 )
It is represented by
〔参照金属系粒子集合体の作製および吸光スペクトル測定〕
図５に示される方法に従って、参照金属系粒子集合体が積層された基板を作製した。まず、縦５ｃｍ、横５ｃｍのソーダガラス基板１００のおよそ全面にレジスト（日本ゼオン株式会社製 ＺＥＰ５２０Ａ）をスピンコートした（図５（ａ））。レジスト４００の厚みは約１２０ｎｍとした。次に、電子ビームリソグラフィーによってレジスト４００に円形開口４０１を形成した（図５（ｂ））。円形開口４０１の直径は約３５０ｎｍとした。また、隣り合う円形開口４０１の中心間距離は約１５００ｎｍとした。
[Preparation of reference metal particle aggregate and measurement of absorption spectrum]
According to the method shown in FIG. 5, a substrate on which a reference metal-based particle assembly was laminated was produced. First, a resist (ZEP520A, manufactured by Nippon Zeon Co., Ltd.) was spin-coated on approximately the entire surface of a soda glass substrate 100 having a length of 5 cm and a width of 5 cm (FIG. 5A). The thickness of the resist 400 was about 120 nm. Next, a circular opening 401 was formed in the resist 400 by electron beam lithography (FIG. 5B). The diameter of the circular opening 401 was about 350 nm. The distance between the centers of the adjacent circular openings 401 was set to about 1500 nm.
ついで、円形開口４０１を有するレジスト４００に、真空蒸着法により銀膜２０１を蒸着した（図５（ｃ））。銀膜２０１の膜厚は約１００ｎｍとした。最後に、銀膜２０１を有する基板をＮＭＰ（東京化成工業製 Ｎ−メチル−２−ピロリドン）に浸漬し、超音波装置内で１分間常温静置することによりレジスト４００およびレジスト４００上に成膜された銀膜２０１を剥離して、円形開口４０１内の銀膜２０１（銀粒子）のみがソーダガラス基板１００上に残存、積層された参照金属系粒子集合体薄膜積層基板を得た（図５（ｄ））。 Next, a silver film 201 was deposited on the resist 400 having the circular opening 401 by a vacuum deposition method (FIG. 5C). The film thickness of the silver film 201 was about 100 nm. Finally, the substrate having the silver film 201 is dipped in NMP (N-methyl-2-pyrrolidone manufactured by Tokyo Chemical Industry Co., Ltd.) and left at room temperature in an ultrasonic device for 1 minute to form a film on the resist 400 and the resist 400. The resulting silver film 201 was peeled off, and only the silver film 201 (silver particles) in the circular opening 401 remained on the soda glass substrate 100 to obtain a reference metal-based particle assembly thin film laminated substrate (FIG. 5). (D)).
図６は、得られた参照金属系粒子集合体薄膜積層基板における参照金属系粒子集合体薄膜を直上から見たときのＳＥＭ画像である。図６（ａ）は２００００倍スケールの拡大像であり、図６（ｂ）は５００００倍スケールの拡大像である。図６に示されるＳＥＭ画像より、参照金属系粒子集合体薄膜を構成する銀粒子の上記定義に基づく平均粒径は３３３ｎｍ、平均粒子間距離は１２６４ｎｍと求められた。また別途取得したＡＦＭ画像より、平均高さは１０５．９ｎｍと求められた。またＳＥＭ画像より、参照金属系粒子集合体は、約６２５００個の銀粒子を有することがわかった。 FIG. 6 is an SEM image when the reference metal-based particle assembly thin film in the obtained reference metal-based particle assembly thin film laminated substrate is viewed from directly above. 6A is an enlarged image of 20000 times scale, and FIG. 6B is an enlarged image of 50000 times scale. From the SEM image shown in FIG. 6, the average particle diameter based on the above definition of the silver particles constituting the reference metal-based particle assembly thin film was determined to be 333 nm and the average interparticle distance was 1264 nm. The average height was determined to be 105.9 nm from the separately acquired AFM image. Further, from the SEM image, it was found that the reference metal-based particle aggregate had about 62500 silver particles.
上述した顕微鏡の対物レンズ（１００倍）を用いた測定法により、実施例１の金属系粒子集合体薄膜積層基板の吸光スペクトル測定を行なった。具体的には、図７を参照して、金属系粒子集合体薄膜積層基板５００の基板５０１側（金属系粒子集合体薄膜５０２とは反対側）であって、基板面に垂直な方向から可視光領域の入射光を照射した。そして、金属系粒子集合体薄膜５０２側に透過し、かつ１００倍の対物レンズ６００に到達した透過光を対物レンズ６００で集光し、この集光光を分光光度計７００によって検出して吸光スペクトルを得た。 The absorption spectrum of the metal-based particle assembly thin film multilayer substrate of Example 1 was measured by the measurement method using the objective lens (100 times) of the microscope described above. Specifically, referring to FIG. 7, it is visible from the direction perpendicular to the substrate surface on the substrate 501 side of metal-based particle assembly thin film multilayer substrate 500 (the side opposite to metal-based particle assembly thin film 502). Incident light in the light region was irradiated. Then, the transmitted light that has passed through the metal-based particle assembly thin film 502 side and has reached 100 times the objective lens 600 is condensed by the objective lens 600, and this condensed light is detected by the spectrophotometer 700 and absorbed. Got.
分光光度計７００には大塚電子社製の紫外可視分光光度計「ＭＣＰＤ−３０００」を、対物レンズ６００にはＮｉｋｏｎ社製の「ＢＤ Ｐｌａｎ １００／０．８０ ＥＬＷＤ」を用いた。結果を図８に示す。可視光領域において最も長波長側にあるプラズモンピークの極大波長は、図４の吸光スペクトルと同様、約４５０ｎｍであった。一方、同じく顕微鏡の対物レンズを用いた測定法により参照金属系粒子集合体薄膜積層基板の吸光スペクトル測定を行なったところ、可視光領域において最も長波長側にあるピークの極大波長は、６５４ｎｍであった。実施例１の金属系粒子集合体薄膜積層基板は、参照金属系粒子集合体薄膜積層基板と比べて、可視光領域において最も長波長側にあるピークの極大波長が約２００ｎｍブルーシフトしている。 The spectrophotometer 700 was an ultraviolet-visible spectrophotometer “MCPD-3000” manufactured by Otsuka Electronics Co., Ltd., and the objective lens 600 was a “BD Plan 100 / 0.80 ELWD” manufactured by Nikon. The results are shown in FIG. The maximum wavelength of the plasmon peak on the longest wavelength side in the visible light region was about 450 nm, similar to the absorption spectrum of FIG. On the other hand, when the absorption spectrum of the reference metal-based particle assembly thin film laminated substrate was similarly measured using a microscope objective lens, the maximum wavelength of the peak on the longest wavelength side in the visible light region was 654 nm. It was. In the metal-based particle assembly thin film multilayer substrate of Example 1, the peak maximum wavelength on the longest wavelength side in the visible light region is blue-shifted by about 200 nm compared to the reference metal-based particle assembly thin film multilayer substrate.
実施例１の金属系粒子集合体薄膜積層基板は、可視光領域において最も長波長側にあるピークの極大波長における吸光度が１．７４４であり（図８）、参照金属系粒子集合体薄膜積層基板は０．０３３であった。実施例１の金属系粒子集合体薄膜積層基板と参照金属系粒子集合体薄膜積層基板との間で最も長波長側にあるピークの極大波長における吸光度を比較するにあたって同じ金属系粒子数での比較となるようにするために、吸光スペクトルから得られる吸光度を、金属系粒子数に相当するパラメータである、金属系粒子による基板表面の被覆率で除して、吸光度／被覆率を算出した。実施例１の金属系粒子集合体薄膜積層基板の吸光度／被覆率は２．０４であり（被覆率８５．３％）、参照金属系粒子集合体薄膜積層基板の吸光度／被覆率は０．８４であった（被覆率３．９％）。 The metal-based particle assembly thin film multilayer substrate of Example 1 has an absorbance at the maximum wavelength of the peak on the longest wavelength side in the visible light region of 1.744 (FIG. 8), and the reference metal-based particle assembly thin film multilayer substrate. Was 0.033. When comparing the absorbance at the maximum wavelength of the peak on the longest wavelength side between the metal-based particle assembly thin film laminated substrate of Example 1 and the reference metal-based particle assembly thin film laminated substrate, comparison was made with the same number of metal-based particles. Therefore, the absorbance / coverage was calculated by dividing the absorbance obtained from the absorption spectrum by the coverage of the substrate surface with metal particles, which is a parameter corresponding to the number of metal particles. The absorbance / coverage of the metal-based particle assembly thin film multilayer substrate of Example 1 is 2.04 (coverage 85.3%), and the absorbance / coverage of the reference metal-based particle assembly thin film multilayer substrate is 0.84. (Coverage 3.9%).
〔有機ＥＬ素子の作製および発光強度の評価〕
＜実施例２＞
実施例１と同条件で銀粒子を成長させることにより、０．５ｍｍ厚のソーダガラス基板上に実施例１に記載の金属系粒子集合体薄膜を形成した。その後直ちに、スピンオングラス（ＳＯＧ）溶液を金属系粒子集合体薄膜上にスピンコートして、平均厚み８０ｎｍの絶縁層を積層した。ＳＯＧ溶液には、有機系ＳＯＧ材料である東京応化工業株式会社製「ＯＣＤ Ｔ−７ ５５００Ｔ」をエタノールで希釈したものを用いた。
[Production of organic EL element and evaluation of emission intensity]
<Example 2>
By growing silver particles under the same conditions as in Example 1, the metal-based particle assembly thin film described in Example 1 was formed on a 0.5 mm thick soda glass substrate. Immediately thereafter, a spin-on-glass (SOG) solution was spin-coated on the metal-based particle assembly thin film, and an insulating layer having an average thickness of 80 nm was laminated. As the SOG solution, an organic SOG material “OCD T-7 5500T” manufactured by Tokyo Ohka Kogyo Co., Ltd. diluted with ethanol was used.
次に、イオンスパッタリング法により、アノード極としてのＩＺＯ層（厚み２２ｎｍ）を絶縁層上に積層した後、正孔注入層形成用溶液をアノード極上にスピンコートして、平均厚み２０ｎｍの正孔注入層を積層した。正孔注入層形成用溶液には、ＰＬＥＸＴＲＯＮＩＣＳ社製、商品名「Ｐｌｅｘｃｏｒｅ ＡＱ １２００」を、エタノールを用いて所定濃度に希釈したものを用いた。絶縁層、アノード極および正孔注入層の合計平均厚み（すなわち、金属系粒子集合体薄膜表面から発光層までの平均距離）は１２２ｎｍである。 Next, after an IZO layer (thickness 22 nm) as an anode electrode is stacked on the insulating layer by ion sputtering, a hole injection layer forming solution is spin-coated on the anode electrode to inject holes with an average thickness of 20 nm. Layers were laminated. As the hole injection layer forming solution, a product manufactured by Plextronics, trade name “Plexcore AQ 1200” diluted to a predetermined concentration using ethanol was used. The total average thickness of the insulating layer, anode electrode, and hole injection layer (that is, the average distance from the surface of the metal-based particle assembly thin film to the light emitting layer) is 122 nm.
ついで、有機溶媒に溶解可能な高分子発光体を、所定濃度で有機溶媒に溶解し、これを正孔注入層上にスピンコートして、１００ｎｍ厚の発光層を形成した。その後、真空蒸着法により、電子注入層としてのＮａＦ層（２ｎｍ厚）、カソード極としてのＭｇ層（２ｎｍ厚）およびＡｇ層（１０ｎｍ厚）をこの順で発光層上に積層した。得られた素子を表面側から封止剤（ナガセケムテックス社製 紫外線硬化性樹脂「ＸＮＲ５５１６ＺＬＶ」）を用いて封止し、有機ＥＬ素子を得た。 Next, a polymer light-emitting body that can be dissolved in an organic solvent was dissolved in an organic solvent at a predetermined concentration, and this was spin-coated on the hole injection layer to form a light-emitting layer having a thickness of 100 nm. Thereafter, an NaF layer (2 nm thickness) as an electron injection layer, an Mg layer (2 nm thickness) and an Ag layer (10 nm thickness) as a cathode electrode were laminated on the light emitting layer in this order by vacuum deposition. The obtained element was sealed from the surface side using a sealing agent (UV curable resin “XNR5516ZLV” manufactured by Nagase ChemteX Corporation) to obtain an organic EL element.
＜比較例２＞
金属系粒子集合体薄膜を形成しないこと以外は実施例２と同様にして有機ＥＬ素子を作製した。
<Comparative example 2>
An organic EL device was produced in the same manner as in Example 2 except that the metal-based particle assembly thin film was not formed.
実施例２の有機ＥＬ素子に、ソースメーター（ケースレーインスツルメンツ株式会社製 ソースメーター ２６０２Ａ 型）により１５Ｖの一定電圧を印加し、電極間に流れる電流値を２．３ｍＡとして素子を発光させた。発光スペクトルをコニカミノルタ社製 分光測定装置「ＣＳ−２０００」を用いて測定し、得られた発光スペクトルを可視光波長域で積分して、発光強度を求めた。電極間に流れる電流値を２．７ｍＡとしたこと以外は実施例２の有機ＥＬ素子と同様にして（印加電圧は、実施例２の有機ＥＬ素子と同じく１５Ｖである）、比較例２の有機ＥＬ素子についても発光強度を求めた。その結果、実施例２の有機ＥＬ素子は、比較例２の有機ＥＬ素子と比較して約３．８倍の発光強度を示すことが確認された。 A constant voltage of 15 V was applied to the organic EL element of Example 2 with a source meter (source meter 2602A type, manufactured by Keithley Instruments Co., Ltd.), and the element was caused to emit light with a current value flowing between the electrodes being 2.3 mA. The emission spectrum was measured using a spectrophotometer “CS-2000” manufactured by Konica Minolta, and the obtained emission spectrum was integrated in the visible light wavelength range to obtain the emission intensity. The organic current of Comparative Example 2 was the same as that of the organic EL device of Example 2 except that the value of the current flowing between the electrodes was 2.7 mA (applied voltage was 15 V as in the organic EL device of Example 2). The emission intensity was also determined for the EL element. As a result, it was confirmed that the organic EL device of Example 2 showed a light emission intensity of about 3.8 times that of the organic EL device of Comparative Example 2.
＜実施例３＞
実施例１と同条件で銀粒子を成長させることにより、０．５ｍｍ厚のソーダガラス基板上に実施例１に記載の金属系粒子集合体薄膜を形成した。その後直ちに、スピンオングラス（ＳＯＧ）溶液を金属系粒子集合体薄膜上にスピンコートして、平均厚み３０ｎｍの絶縁層を積層した。ＳＯＧ溶液には、有機系ＳＯＧ材料である東京応化工業株式会社製「ＯＣＤ Ｔ−７ ５５００Ｔ」をエタノールで希釈したものを用いた。
<Example 3>
By growing silver particles under the same conditions as in Example 1, the metal-based particle assembly thin film described in Example 1 was formed on a 0.5 mm thick soda glass substrate. Immediately thereafter, a spin-on-glass (SOG) solution was spin-coated on the metal-based particle assembly thin film, and an insulating layer having an average thickness of 30 nm was laminated. As the SOG solution, an organic SOG material “OCD T-7 5500T” manufactured by Tokyo Ohka Kogyo Co., Ltd. diluted with ethanol was used.
次に、イオンスパッタリング法により、アノード極としてのＩＺＯ層（厚み２２ｎｍ）を絶縁層上に積層した後、正孔注入層形成用溶液をアノード極上にスピンコートして、平均厚み２０ｎｍの正孔注入層を積層した。正孔注入層形成用溶液には、ＰＬＥＸＴＲＯＮＩＣＳ社製、商品名「Ｐｌｅｘｃｏｒｅ ＡＱ １２００」を、エタノールを用いて所定濃度に希釈したものを用いた。絶縁層、アノード極および正孔注入層の合計平均厚み（すなわち、金属系粒子集合体薄膜表面から発光層までの平均距離）は７２ｎｍである。 Next, after an IZO layer (thickness 22 nm) as an anode electrode is stacked on the insulating layer by ion sputtering, a hole injection layer forming solution is spin-coated on the anode electrode to inject holes with an average thickness of 20 nm. Layers were laminated. As the hole injection layer forming solution, a product manufactured by Plextronics, trade name “Plexcore AQ 1200” diluted to a predetermined concentration using ethanol was used. The total average thickness of the insulating layer, anode electrode, and hole injection layer (that is, the average distance from the surface of the metal-based particle assembly thin film to the light emitting layer) is 72 nm.
ついで、真空蒸着法によって正孔注入層上に発光層としてＡｌｑ3を８０ｎｍ成膜した。その後、真空蒸着法により、電子注入層としてのＮａＦ層（２ｎｍ厚）、カソード極としてのＭｇ層（２ｎｍ厚）およびＡｇ層（１０ｎｍ厚）をこの順で発光層上に積層した。得られた素子を表面側から封止剤（ナガセケムテックス社製 紫外線硬化性樹脂「ＸＮＲ５５１６ＺＬＶ」）を用いて封止し、有機ＥＬ素子を得た。 Next, an Alq 3 film having a thickness of 80 nm was formed as a light emitting layer on the hole injection layer by vacuum deposition. Thereafter, an NaF layer (2 nm thickness) as an electron injection layer, an Mg layer (2 nm thickness) and an Ag layer (10 nm thickness) as a cathode electrode were laminated on the light emitting layer in this order by vacuum deposition. The obtained element was sealed from the surface side using a sealing agent (UV curable resin “XNR5516ZLV” manufactured by Nagase ChemteX Corporation) to obtain an organic EL element.
＜比較例３＞
金属系粒子集合体薄膜を形成しないこと以外は実施例３と同様にして有機ＥＬ素子を作製した。
<Comparative Example 3>
An organic EL device was produced in the same manner as in Example 3 except that the metal-based particle assembly thin film was not formed.
実施例３の有機ＥＬ素子に、ソースメーター（ケースレーインスツルメンツ株式会社製 ソースメーター ２６０２Ａ 型）により１１Ｖの一定電圧を印加し、電極間に流れる電流値を０．７ｍＡとして素子を発光させた。発光スペクトルをコニカミノルタ社製 分光測定装置「ＣＳ−２０００」を用いて測定し、得られた発光スペクトルを可視光波長域で積分して、発光強度を求めた。電極間に流れる電流値を１．１ｍＡに調節したこと以外は実施例３の有機ＥＬ素子と同様にして（印加電圧は、実施例３の有機ＥＬ素子と同じく１１Ｖである）、比較例３の有機ＥＬ素子についても発光強度を求めた。その結果、実施例３の有機ＥＬ素子は、比較例３の有機ＥＬ素子と比較して約２．６倍の発光強度を示すことが確認された。 A constant voltage of 11 V was applied to the organic EL element of Example 3 with a source meter (source meter 2602A type, manufactured by Keithley Instruments Co., Ltd.), and the element was caused to emit light with a current value flowing between the electrodes being 0.7 mA. The emission spectrum was measured using a spectrophotometer “CS-2000” manufactured by Konica Minolta, and the obtained emission spectrum was integrated in the visible light wavelength range to obtain the emission intensity. In the same manner as in the organic EL element of Example 3 except that the value of the current flowing between the electrodes was adjusted to 1.1 mA (applied voltage is 11 V as in the organic EL element of Example 3), The emission intensity was also determined for the organic EL element. As a result, it was confirmed that the organic EL device of Example 3 showed a light emission intensity about 2.6 times that of the organic EL device of Comparative Example 3.
〔光励起発光素子の作製および発光増強の評価〕
＜実施例４−１＞
実施例１とほぼ同じ条件で銀粒子を成長させることにより、０．５ｍｍ厚のソーダガラス基板上に実施例１と同様の金属系粒子集合体薄膜を形成した。この金属系粒子集合体薄膜は、金属系粒子の平均高さが６６．１ｎｍであること以外は実施例１と同じ粒子形状および平均粒子間距離を有するものであった。
[Production of light-excited light-emitting elements and evaluation of light emission enhancement]
<Example 4-1>
By growing silver particles under substantially the same conditions as in Example 1, a metal-based particle assembly thin film similar to that in Example 1 was formed on a 0.5 mm thick soda glass substrate. This metal-based particle assembly thin film had the same particle shape and average interparticle distance as in Example 1 except that the average height of the metal-based particles was 66.1 nm.
次に、金属系粒子集合体薄膜上にクマリン系発光層用溶液を３０００ｒｐｍでスピンコートし、極薄い（単分子膜スケールの）クマリン系発光層を形成して、発光素子を得た。クマリン系発光層用溶液は次のように調製した。まずクマリン色素（Ｅｘｃｉｔｏｎ社 Ｃｏｕｍａｒｉｎ５０３）をエタノールに溶解し５ｍＭクマリン溶液とした。また別途、有機系スピンオングラス（ＳＯＧ）材料（東京応化工業株式会社製「ＯＣＤ Ｔ−７ ５５００Ｔ」）をエタノールで３３体積％に希釈した。この３３体積％有機系ＳＯＧ材料希釈液、５ｍＭクマリン溶液、エタノールを、体積比が１：５：５となるように混合し、クマリン系発光層用溶液を得た。 Next, a coumarin light emitting layer solution was spin-coated at 3000 rpm on the metal particle aggregate thin film to form a very thin (monomolecular film scale) coumarin light emitting layer to obtain a light emitting device. A solution for a coumarin-based light emitting layer was prepared as follows. First, a coumarin dye (Exciton Coumarin 503) was dissolved in ethanol to obtain a 5 mM coumarin solution. Separately, an organic spin-on-glass (SOG) material (“OCD T-7 5500T” manufactured by Tokyo Ohka Kogyo Co., Ltd.) was diluted to 33% by volume with ethanol. The 33 volume% organic SOG material diluted solution, 5 mM coumarin solution, and ethanol were mixed so that the volume ratio was 1: 5: 5 to obtain a coumarin light emitting layer solution.
＜実施例４−２＞
実施例４−１と同条件で銀粒子を成長させることにより、０．５ｍｍ厚のソーダガラス基板上に実施例４−１に記載の金属系粒子集合体薄膜を形成した。その後直ちに、ＳＯＧ溶液を金属系粒子集合体薄膜上にスピンコートして、平均厚み１０ｎｍの絶縁層を積層した。ＳＯＧ溶液には、有機系ＳＯＧ材料である東京応化工業株式会社製「ＯＣＤ Ｔ−７ ５５００Ｔ」をエタノールで希釈したものを用いた。「平均厚み」とは、表面凹凸を有する金属系粒子集合体薄膜上に形成されたときの平均厚みを意味しており、ＳＯＧ溶液をソーダガラス基板上に直接スピンコートしたときの厚みとして測定した（以下の実施例、比較例についても同様）。平均厚みが比較的小さい値のときは金属系粒子集合体薄膜の谷部分にのみ絶縁層が形成され、金属系粒子集合体薄膜の最表面全体を被覆できないことがある。
<Example 4-2>
By growing silver particles under the same conditions as in Example 4-1, the metal-based particle assembly thin film described in Example 4-1 was formed on a 0.5 mm thick soda glass substrate. Immediately thereafter, the SOG solution was spin-coated on the metal-based particle assembly thin film, and an insulating layer having an average thickness of 10 nm was laminated. As the SOG solution, an organic SOG material “OCD T-7 5500T” manufactured by Tokyo Ohka Kogyo Co., Ltd. diluted with ethanol was used. “Average thickness” means the average thickness when formed on a metal-based particle aggregate thin film having surface irregularities, and was measured as the thickness when the SOG solution was directly spin-coated on a soda glass substrate. (The same applies to the following Examples and Comparative Examples). When the average thickness is a relatively small value, an insulating layer is formed only in the valley portion of the metal-based particle assembly thin film, and the entire outermost surface of the metal-based particle assembly thin film may not be covered.
次に、上記の絶縁層を有する金属系粒子集合体薄膜の最表面に、実施例４−１で用いたものと同じクマリン系発光層用溶液を３０００ｒｐｍでスピンコートし、極薄い（単分子膜スケールの）クマリン系発光層を形成して、発光素子を得た。 Next, on the outermost surface of the metal-based particle assembly thin film having the above insulating layer, the same coumarin-based light emitting layer solution as used in Example 4-1 was spin-coated at 3000 rpm to obtain an extremely thin (monomolecular film) A coumarin-based light emitting layer was formed to obtain a light emitting device.
＜実施例４−３＞
絶縁層の平均厚みを３０ｎｍとしたこと以外は実施例４−２と同様にして、発光素子を得た。
<Example 4-3>
A light emitting device was obtained in the same manner as in Example 4-2, except that the average thickness of the insulating layer was 30 nm.
＜実施例４−４＞
絶縁層の平均厚みを８０ｎｍとしたこと以外は実施例４−２と同様にして、発光素子を得た。
<Example 4-4>
A light emitting device was obtained in the same manner as in Example 4-2, except that the average thickness of the insulating layer was 80 nm.
＜実施例４−５＞
絶縁層の平均厚みを１５０ｎｍとしたこと以外は実施例４−２と同様にして、発光素子を得た。
<Example 4-5>
A light emitting device was obtained in the same manner as in Example 4-2, except that the average thickness of the insulating layer was 150 nm.
＜実施例４−６＞
絶縁層の平均厚みを３５０ｎｍとしたこと以外は実施例４−２と同様にして、発光素子を得た。
<Example 4-6>
A light emitting device was obtained in the same manner as in Example 4-2 except that the average thickness of the insulating layer was 350 nm.
＜比較例４−１＞
銀ナノ粒子水分散物（三菱製紙社製、銀ナノ粒子濃度：２５重量％）を純水で、銀ナノ粒子濃度が６重量％となるように希釈した。次いで、この銀ナノ粒子水分散物に対して１体積％の界面活性剤を添加して良く攪拌した後、得られた銀ナノ粒子水分散物に対して８０体積％のアセトンを添加して常温で十分振り混ぜ、銀ナノ粒子塗工液を調製した。
<Comparative Example 4-1>
A silver nanoparticle aqueous dispersion (manufactured by Mitsubishi Paper Industries, Ltd., silver nanoparticle concentration: 25 wt%) was diluted with pure water so that the silver nanoparticle concentration was 6 wt%. Next, 1% by volume of a surfactant was added to the silver nanoparticle aqueous dispersion and stirred well, and then 80% by volume of acetone was added to the obtained silver nanoparticle aqueous dispersion at room temperature. And sufficiently mixed to prepare a silver nanoparticle coating solution.
次に、表面をアセトン拭きした１ｍｍ厚のソーダガラス基板上に上記銀ナノ粒子塗工液を１５００ｒｐｍでスピンコートした後、そのまま大気中で１分間放置し、その後５５０℃の電気炉内で５分間焼成して、金属系粒子集合体薄膜積層基板を得た。 Next, after spin-coating the above silver nanoparticle coating solution on a 1 mm thick soda glass substrate whose surface has been wiped with acetone at 1500 rpm, it is allowed to stand in the air for 1 minute, and then in an electric furnace at 550 ° C. for 5 minutes. Firing was performed to obtain a metal-based particle assembly thin film multilayer substrate.
図９は、本比較例４−１で得られた金属系粒子集合体薄膜積層基板における金属系粒子集合体薄膜を直上から見たときのＳＥＭ画像であり、１００００倍スケールの拡大像である。また図１０は、本比較例４−１で得られた金属系粒子集合体薄膜積層基板における金属系粒子集合体薄膜を示すＡＦＭ画像である。図１０に示される画像のサイズは５μｍ×５μｍである。 FIG. 9 is an SEM image when the metal-based particle assembly thin film in the metal-based particle assembly thin film laminated substrate obtained in Comparative Example 4-1 is viewed from directly above, and is an enlarged image of 10000 times scale. FIG. 10 is an AFM image showing the metal-based particle assembly thin film in the metal-based particle assembly thin film laminated substrate obtained in Comparative Example 4-1. The size of the image shown in FIG. 10 is 5 μm × 5 μm.
図９に示されるＳＥＭ画像より、本比較例４−１の金属系粒子集合体薄膜を構成する銀粒子の上記定義に基づく平均粒径は２７８ｎｍ、平均粒子間距離は１９５．５ｎｍと求められた。また図１０に示されるＡＦＭ画像より、平均高さは９９．５ｎｍと求められた。これらより銀粒子のアスペクト比（平均粒径／平均高さ）は２．７９と算出され、また、取得した画像からも銀粒子は扁平形状を有していることがわかる。さらにＳＥＭ画像より、本比較例４−１の金属系粒子集合体は、約２．１８×１０10個（約８．７２個／μｍ2）の銀粒子を有することがわかる。 From the SEM image shown in FIG. 9, the average particle diameter based on the above definition of the silver particles constituting the metal-based particle assembly thin film of Comparative Example 4-1 was determined to be 278 nm, and the average interparticle distance was 195.5 nm. . From the AFM image shown in FIG. 10, the average height was determined to be 99.5 nm. From these, the aspect ratio (average particle diameter / average height) of the silver particles is calculated to be 2.79, and it can be seen from the acquired image that the silver particles have a flat shape. Furthermore, it can be seen from the SEM image that the metal-based particle assembly of Comparative Example 4-1 has about 2.18 × 10 10 (about 8.72 particles / μm 2 ) silver particles.
上記実施例４−１および本比較例４−１で得られた金属系粒子集合体薄膜積層基板の、上述した積分球分光光度計を用いた測定法による吸光スペクトルを図１１に示す。また、本比較例４−１で得られた金属系粒子集合体薄膜積層基板の、顕微鏡の対物レンズ（１００倍）を用いた測定法による吸光スペクトルを図１２に示す。いずれの測定法においても本比較例４−１で得られた金属系粒子集合体薄膜積層基板は、可視光領域において最も長波長側にあるピークの極大波長が６１１ｎｍであった。この極大波長は、本比較例４−１の金属系粒子集合体薄膜積層基板に対応する参照金属系粒子集合体薄膜積層基板の極大波長とほぼ同じであり、本比較例４−１の金属系粒子集合体薄膜はほとんどブルーシフトを示さない。また図１１から、実施例４−１の吸光スペクトルのピーク波長（最も長波長側にあるプラズモンピークの極大波長）は、比較例４−１の吸光スペクトルのピーク波長に比べブルーシフトの程度が大きく、かつ、最も長波長側にあるプラズモンピークが先鋭化し、その極大波長における吸光度が高くなっていることがわかる。 FIG. 11 shows the absorption spectrum of the metal-based particle assembly thin film laminated substrate obtained in Example 4-1 and Comparative Example 4-1 by the measurement method using the integrating sphere spectrophotometer described above. Moreover, the absorption spectrum by the measuring method using the objective lens (100 times) of a microscope of the metal type particle assembly thin film laminated substrate obtained in this Comparative Example 4-1 is shown in FIG. In any measurement method, the maximum wavelength of the peak on the longest wavelength side in the visible light region of the metal-based particle assembly thin film laminated substrate obtained in Comparative Example 4-1 was 611 nm. This maximum wavelength is substantially the same as the maximum wavelength of the reference metal-based particle assembly thin film multilayer substrate corresponding to the metal-based particle assembly thin-film multilayer substrate of Comparative Example 4-1, and the metal system of Comparative Example 4-1 The particle aggregate thin film shows almost no blue shift. Also, from FIG. 11, the peak wavelength of the absorption spectrum of Example 4-1 (the maximum wavelength of the plasmon peak on the longest wavelength side) has a greater blue shift than the peak wavelength of the absorption spectrum of Comparative Example 4-1. It can also be seen that the plasmon peak on the longest wavelength side is sharpened, and the absorbance at the maximum wavelength is high.
図１２の吸光スペクトルから得られる可視光領域において最も長波長側にあるピークの極大波長における吸光度は０．４４４であり、金属系粒子による基板表面の被覆率が５３．２％であることから、吸光度／被覆率は０．８３と算出される。この吸光度／被覆率は、参照金属系粒子集合体薄膜積層基板より小さい。 The absorbance at the maximum wavelength of the peak on the longest wavelength side in the visible light region obtained from the absorption spectrum of FIG. 12 is 0.444, and the coverage of the substrate surface with metal-based particles is 53.2%. Absorbance / coverage is calculated as 0.83. This absorbance / coverage is smaller than that of the reference metal-based particle assembly thin film laminated substrate.
次に、実施例４−１と同様にして、金属系粒子集合体薄膜上にクマリン系発光層を形成して、発光素子を得た。 Next, in the same manner as in Example 4-1, a coumarin light emitting layer was formed on the metal particle aggregate thin film to obtain a light emitting device.
＜比較例４−２＞
比較例４−１と同じ方法で、１ｍｍ厚のソーダガラス基板上に比較例４−１に記載の金属系粒子集合体薄膜を形成した。その後直ちに、ＳＯＧ溶液を金属系粒子集合体薄膜上にスピンコートして、平均厚み１０ｎｍの絶縁層を積層した。ＳＯＧ溶液には、有機系ＳＯＧ材料である東京応化工業株式会社製「ＯＣＤ Ｔ−７ ５５００Ｔ」をエタノールで希釈したものを用いた。
<Comparative Example 4-2>
By the same method as Comparative Example 4-1, the metal-based particle assembly thin film described in Comparative Example 4-1 was formed on a 1 mm thick soda glass substrate. Immediately thereafter, the SOG solution was spin-coated on the metal-based particle assembly thin film, and an insulating layer having an average thickness of 10 nm was laminated. As the SOG solution, an organic SOG material “OCD T-7 5500T” manufactured by Tokyo Ohka Kogyo Co., Ltd. diluted with ethanol was used.
次に、実施例４−２と同様にして、上記の絶縁層を有する金属系粒子集合体薄膜の最表面にクマリン系発光層を形成して、発光素子を得た。 Next, in the same manner as in Example 4-2, a coumarin light emitting layer was formed on the outermost surface of the metal particle aggregate thin film having the above insulating layer to obtain a light emitting device.
＜比較例４−３＞
絶縁層の平均厚みを３０ｎｍとしたこと以外は比較例４−２と同様にして、発光素子を得た。
<Comparative Example 4-3>
A light emitting device was obtained in the same manner as in Comparative Example 4-2, except that the average thickness of the insulating layer was 30 nm.
＜比較例４−４＞
絶縁層の平均厚みを８０ｎｍとしたこと以外は比較例４−２と同様にして、発光素子を得た。
<Comparative Example 4-4>
A light emitting device was obtained in the same manner as in Comparative Example 4-2, except that the average thickness of the insulating layer was 80 nm.
＜比較例４−５＞
絶縁層の平均厚みを１５０ｎｍとしたこと以外は比較例４−２と同様にして、発光素子を得た。
<Comparative Example 4-5>
A light emitting device was obtained in the same manner as in Comparative Example 4-2, except that the average thickness of the insulating layer was 150 nm.
＜比較例４−６＞
絶縁層の平均厚みを３５０ｎｍとしたこと以外は比較例４−２と同様にして、発光素子を得た。
<Comparative Example 4-6>
A light emitting device was obtained in the same manner as in Comparative Example 4-2, except that the average thickness of the insulating layer was 350 nm.
＜比較例５＞
金属系粒子集合体薄膜を形成しないこと以外は実施例４−１と同様にして発光素子を得た。
<Comparative Example 5>
A light emitting device was obtained in the same manner as in Example 4-1, except that the metal-based particle assembly thin film was not formed.
＜実施例５−１＞
実施例４−１と同じ方法で、０．５ｍｍ厚のソーダガラス基板上に実施例４−１に記載の金属系粒子集合体薄膜を形成した。
<Example 5-1>
In the same manner as in Example 4-1, the metal-based particle assembly thin film described in Example 4-1 was formed on a 0.5 mm thick soda glass substrate.
次に、金属系粒子集合体薄膜上にＡｌｑ3発光層用溶液をスピンコートして、平均厚み３０ｎｍのＡｌｑ3発光層を形成した。Ａｌｑ3発光層用溶液は、Ａｌｑ3（シグマアルドリッチ社 Ｔｒｉｓ−（８−ｈｙｄｒｏｘｙｑｕｉｎｏｌｉｎｅ）ａｌｕｍｉｎｕｍ）を、濃度が０．５重量％となるようにクロロホルムに溶解して調製した。 Next, an Alq 3 light emitting layer solution was spin-coated on the metal-based particle assembly thin film to form an Alq 3 light emitting layer having an average thickness of 30 nm. The solution for the Alq 3 light-emitting layer was prepared by dissolving Alq 3 (Sigma-Aldrich Tris- (8-hydroxyquinoline) aluminum) in chloroform so that the concentration was 0.5 wt%.
＜実施例５−２＞
実施例４−２と同じ方法で、平均厚み１０ｎｍの絶縁層を有する金属系粒子集合体薄膜を形成した後、実施例５−１と同じ方法で平均厚み３０ｎｍのＡｌｑ3発光層を形成して、発光素子を得た。
<Example 5-2>
After forming a metal-based particle assembly thin film having an insulating layer with an average thickness of 10 nm by the same method as in Example 4-2, an Alq 3 light emitting layer with an average thickness of 30 nm was formed by the same method as in Example 5-1. A light emitting device was obtained.
＜実施例５−３＞
絶縁層の平均厚みを３０ｎｍとしたこと以外は実施例５−２と同様にして、発光素子を得た。
<Example 5-3>
A light emitting device was obtained in the same manner as in Example 5-2 except that the average thickness of the insulating layer was 30 nm.
＜実施例５−４＞
絶縁層の平均厚みを８０ｎｍとしたこと以外は実施例５−２と同様にして、発光素子を得た。
<Example 5-4>
A light emitting device was obtained in the same manner as in Example 5-2 except that the average thickness of the insulating layer was 80 nm.
＜実施例５−５＞
絶縁層の平均厚みを１５０ｎｍとしたこと以外は実施例５−２と同様にして、発光素子を得た。
<Example 5-5>
A light emitting device was obtained in the same manner as in Example 5-2 except that the average thickness of the insulating layer was 150 nm.
＜比較例６−１＞
比較例４−１と同じ方法で、１ｍｍ厚のソーダガラス基板上に比較例４−１に記載の金属系粒子集合体薄膜を形成した後、実施例５−１と同じ方法で平均厚み３０ｎｍのＡｌｑ3発光層を形成して、発光素子を得た。
<Comparative Example 6-1>
After forming the metal-based particle assembly thin film described in Comparative Example 4-1 on a 1 mm-thick soda glass substrate by the same method as Comparative Example 4-1, the average thickness of 30 nm was determined by the same method as Example 5-1. An Alq 3 light emitting layer was formed to obtain a light emitting device.
＜比較例６−２＞
比較例４−２と同じ方法で、平均厚み１０ｎｍの絶縁層を有する金属系粒子集合体薄膜を形成した後、実施例５−１と同じ方法で平均厚み３０ｎｍのＡｌｑ3発光層を形成して、発光素子を得た。
<Comparative Example 6-2>
After forming a metal-based particle assembly thin film having an insulating layer having an average thickness of 10 nm by the same method as in Comparative Example 4-2, an Alq 3 light emitting layer having an average thickness of 30 nm was formed by the same method as in Example 5-1. A light emitting device was obtained.
＜比較例６−３＞
絶縁層の平均厚みを３０ｎｍとしたこと以外は比較例６−２と同様にして、発光素子を得た。
<Comparative Example 6-3>
A light emitting device was obtained in the same manner as in Comparative Example 6-2 except that the average thickness of the insulating layer was 30 nm.
＜比較例６−４＞
絶縁層の平均厚みを８０ｎｍとしたこと以外は比較例６−２と同様にして、発光素子を得た。
<Comparative Example 6-4>
A light emitting device was obtained in the same manner as in Comparative Example 6-2 except that the average thickness of the insulating layer was 80 nm.
＜比較例６−５＞
絶縁層の平均厚みを１５０ｎｍとしたこと以外は比較例６−２と同様にして、発光素子を得た。
<Comparative Example 6-5>
A light emitting device was obtained in the same manner as in Comparative Example 6-2, except that the average thickness of the insulating layer was 150 nm.
＜比較例７＞
金属系粒子集合体薄膜を形成しないこと以外は実施例５−１と同様にして発光素子を得た。
<Comparative Example 7>
A light emitting device was obtained in the same manner as in Example 5-1, except that the metal-based particle assembly thin film was not formed.
＜実施例６−１＞
実施例４−１と同じ方法で、０．５ｍｍ厚のソーダガラス基板上に実施例４−１に記載の金属系粒子集合体薄膜を形成した。
<Example 6-1>
In the same manner as in Example 4-1, the metal-based particle assembly thin film described in Example 4-1 was formed on a 0.5 mm thick soda glass substrate.
次に、金属系粒子集合体薄膜上にＦ８ＢＴ発光層用溶液をスピンコートした後、ホットプレートで１７０℃、３０分間焼成して、平均厚み３０ｎｍのＦ８ＢＴ発光層を形成した。Ｆ８ＢＴ発光層用溶液は、Ｆ８ＢＴ（Ｌｕｍｉｎｅｓｃｅｎｃｅ Ｔｅｃｈｎｏｌｏｇｙ社）を、濃度が１重量％となるようにクロロベンゼンに溶解して調製した。 Next, after spin-coating the F8BT light emitting layer solution on the metal-based particle aggregate thin film, the F8BT light emitting layer having an average thickness of 30 nm was formed by baking on a hot plate at 170 ° C. for 30 minutes. The solution for the F8BT light emitting layer was prepared by dissolving F8BT (Luminescence Technology) in chlorobenzene so that the concentration would be 1% by weight.
＜実施例６−２＞
実施例４−２と同じ方法で、平均厚み１０ｎｍの絶縁層を有する金属系粒子集合体薄膜を形成した後、実施例６−１と同じ方法で平均厚み３０ｎｍのＦ８ＢＴ発光層を形成して、発光素子を得た。
<Example 6-2>
After forming a metal-based particle assembly thin film having an insulating layer with an average thickness of 10 nm by the same method as in Example 4-2, an F8BT light-emitting layer with an average thickness of 30 nm is formed by the same method as in Example 6-1, A light emitting device was obtained.
＜実施例６−３＞
絶縁層の平均厚みを３０ｎｍとしたこと以外は実施例６−２と同様にして、発光素子を得た。
<Example 6-3>
A light emitting device was obtained in the same manner as in Example 6-2 except that the average thickness of the insulating layer was 30 nm.
＜比較例８−１＞
比較例４−１と同じ方法で、１ｍｍ厚のソーダガラス基板上に比較例４−１に記載の金属系粒子集合体薄膜を形成した後、実施例６−１と同じ方法で平均厚み３０ｎｍのＦ８ＢＴ発光層を形成して、発光素子を得た。
<Comparative Example 8-1>
After forming the metal-based particle assembly thin film described in Comparative Example 4-1 on a 1 mm-thick soda glass substrate by the same method as Comparative Example 4-1, an average thickness of 30 nm was formed by the same method as Example 6-1. A light emitting element was obtained by forming an F8BT light emitting layer.
＜比較例８−２＞
比較例４−２と同じ方法で、平均厚み１０ｎｍの絶縁層を有する金属系粒子集合体薄膜積層基板を形成した後、実施例６−１と同じ方法で平均厚み３０ｎｍのＦ８ＢＴ発光層を形成して、発光素子を得た。
<Comparative Example 8-2>
After forming a metal-based particle assembly thin film multilayer substrate having an insulating layer with an average thickness of 10 nm by the same method as Comparative Example 4-2, an F8BT light-emitting layer with an average thickness of 30 nm is formed by the same method as in Example 6-1. Thus, a light emitting element was obtained.
＜比較例８−３＞
絶縁層の平均厚みを３０ｎｍとしたこと以外は比較例８−２と同様にして、発光素子を得た。
<Comparative Example 8-3>
A light emitting device was obtained in the same manner as Comparative Example 8-2 except that the average thickness of the insulating layer was 30 nm.
＜比較例９＞
金属系粒子集合体薄膜を形成しないこと以外は実施例６−１と同様にして発光素子を得た。
<Comparative Example 9>
A light emitting device was obtained in the same manner as in Example 6-1 except that the metal-based particle assembly thin film was not formed.
＜比較例１０−１＞
１ｍｍ厚のソーダガラス基板上に、真空蒸着法によって膜厚１３ｎｍの導電性銀薄膜を成膜した。成膜の際のチャンバ内圧力は３×１０-3Ｐａとした。次に、導電性銀薄膜が成膜された基板を４００℃の電気炉内で１０分間焼成し、金属系粒子集合体薄膜積層基板を得た。
<Comparative Example 10-1>
A conductive silver thin film having a film thickness of 13 nm was formed on a 1 mm thick soda glass substrate by vacuum deposition. The pressure in the chamber at the time of film formation was 3 × 10 −3 Pa. Next, the substrate on which the conductive silver thin film was formed was baked for 10 minutes in an electric furnace at 400 ° C. to obtain a metal-based particle assembly thin film laminated substrate.
図１３は、得られた金属系粒子集合体薄膜積層基板における金属系粒子集合体薄膜を直上から見たときのＳＥＭ画像である。図１３（ａ）は１００００倍スケールの拡大像であり、図１３（ｂ）は５００００倍スケールの拡大像である。また図１４は、本比較例１０−１で得られた金属系粒子集合体薄膜積層基板における金属系粒子集合体薄膜を示すＡＦＭ画像である。図１４に示される画像のサイズは５μｍ×５μｍである。 FIG. 13 is an SEM image when the metal-based particle assembly thin film in the obtained metal-based particle assembly thin film laminated substrate is viewed from directly above. FIG. 13A is an enlarged image on a 10000 times scale, and FIG. 13B is an enlarged image on a 50000 times scale. FIG. 14 is an AFM image showing the metal-based particle assembly thin film in the metal-based particle assembly thin film laminated substrate obtained in Comparative Example 10-1. The size of the image shown in FIG. 14 is 5 μm × 5 μm.
図１３に示されるＳＥＭ画像より、本比較例１０−１の金属系粒子集合体を構成する銀粒子の上記定義に基づく平均粒径は９５ｎｍ、平均粒子間距離は３５．２ｎｍと求められた。また図１４に示されるＡＦＭ画像より、平均高さは２９．６ｎｍと求められた。これらより銀粒子のアスペクト比（平均粒径／平均高さ）は３．２０と算出される。 From the SEM image shown in FIG. 13, the average particle size based on the above definition of the silver particles constituting the metal-based particle assembly of Comparative Example 10-1 was determined to be 95 nm, and the average interparticle distance was determined to be 35.2 nm. The average height was determined to be 29.6 nm from the AFM image shown in FIG. From these, the aspect ratio (average particle diameter / average height) of the silver particles is calculated to be 3.20.
本比較例１０−１で得られた金属系粒子集合体薄膜積層基板の吸光スペクトルを図１５に示す（吸光スペクトルの測定方法は上記のとおりである）。比較例１０−１の吸光スペクトルのピーク波長（最も長波長側にあるプラズモンピークの極大波長）は、図１１に示される実施例４−１の吸光スペクトルのピーク波長に比べてより長波長側にあり、また、そのピーク波長における吸光度も低い。 FIG. 15 shows an absorption spectrum of the metal-based particle assembly thin film multilayer substrate obtained in Comparative Example 10-1 (the method for measuring the absorption spectrum is as described above). The peak wavelength of the absorption spectrum of Comparative Example 10-1 (the maximum wavelength of the plasmon peak on the longest wavelength side) is longer than the peak wavelength of the absorption spectrum of Example 4-1 shown in FIG. In addition, the absorbance at the peak wavelength is low.
次に、実施例５−１と同じ方法で平均厚み３０ｎｍのＡｌｑ3発光層を形成して、発光素子を得た。 Next, an Alq 3 light emitting layer having an average thickness of 30 nm was formed in the same manner as in Example 5-1, to obtain a light emitting element.
＜比較例１０−２＞
比較例１０−１と同じ方法で、１ｍｍ厚のソーダガラス基板上に比較例１０−１に記載の金属系粒子集合体薄膜を形成した。その後直ちに、ＳＯＧ溶液を金属系粒子集合体薄膜上にスピンコートして、平均厚み１０ｎｍの絶縁層を積層した。ＳＯＧ溶液には、有機系ＳＯＧ材料である東京応化工業株式会社製「ＯＣＤ Ｔ−７ ５５００Ｔ」をエタノールで希釈したものを用いた。その後、実施例５−１と同じ方法で平均厚み３０ｎｍのＡｌｑ3発光層を形成して、発光素子を得た。
<Comparative Example 10-2>
The metal-based particle assembly thin film described in Comparative Example 10-1 was formed on a 1 mm thick soda glass substrate by the same method as Comparative Example 10-1. Immediately thereafter, the SOG solution was spin-coated on the metal-based particle assembly thin film, and an insulating layer having an average thickness of 10 nm was laminated. As the SOG solution, an organic SOG material “OCD T-7 5500T” manufactured by Tokyo Ohka Kogyo Co., Ltd. diluted with ethanol was used. Then, to form an Alq 3 light emitting layer having an average thickness of 30nm in the same manner as in Example 5-1 to obtain a light-emitting element.
＜比較例１０−３＞
絶縁層の平均厚みを３０ｎｍとしたこと以外は比較例１０−２と同様にして、発光素子を得た。
<Comparative Example 10-3>
A light emitting device was obtained in the same manner as in Comparative Example 10-2 except that the average thickness of the insulating layer was 30 nm.
＜比較例１０−４＞
絶縁層の平均厚みを８０ｎｍとしたこと以外は比較例１０−２と同様にして、発光素子を得た。
<Comparative Example 10-4>
A light emitting device was obtained in the same manner as Comparative Example 10-2 except that the average thickness of the insulating layer was 80 nm.
＜比較例１０−５＞
絶縁層の平均厚みを１５０ｎｍとしたこと以外は比較例１０−２と同様にして、発光素子を得た。
<Comparative Example 10-5>
A light emitting device was obtained in the same manner as Comparative Example 10-2 except that the average thickness of the insulating layer was 150 nm.
実施例４−１、４−２、４−３、４−４、４−５、４−６、実施例５−１、５−２、５−３、５−４、５−５、実施例６−１、６−２、６−３、比較例４−１、４−２、４−３、４−４、４−５、４−６、比較例５、比較例６−１、６−２、６−３、６−４、６−５、比較例７、比較例８−１、８−２、８−３、比較例９、比較例１０−１、１０−２、１０−３、１０−４、１０−５のそれぞれの光励起発光素子について、次のようにして発光増強の程度を評価した。光励起発光素子の発光スペクトルの測定系を示す図１６（ａ）および光励起発光素子の断面模式図である図１６（ｂ）を参照して、光励起発光素子１の発光層２側に、発光層２の表面に対して垂直な方向から励起光３を照射することにより光励起発光素子１を発光させた。励起光源４にはＵＶ−ＬＥＤ（サウスウォーカー社製 ＵＶ−ＬＥＤ３７５−ｎａｎｏ、励起光波長３７５ｎｍ）を用い、励起光源４からの発光をレンズ５で集光して励起光３とし、これを照射した。励起光３の光軸に対して４０°の方向に放射される光励起発光素子１からの発光６をレンズ７で集光し、励起光の波長の光をカットする波長カットフィルタ８（シグマ光機社製 ＳＣＦ−５０Ｓ−４４Ｙ）を通して、分光測定器９（大塚電子社製 ＭＣＰＤ−３０００）により検出した。図１６（ｂ）は実施例および比較例で作製したソーダガラス基板１００上に、金属系粒子集合体薄膜２００、絶縁層３００、発光層２をこの順に備える光励起発光素子１を示す断面模式図である。 Examples 4-1, 4-2, 4-3, 4-4, 4-5, 4-6, Examples 5-1, 5-2, 5-3, 5-4, 5-5, Examples 6-1, 6-2, 6-3, Comparative Examples 4-1, 4-2, 4-3, 4-4, 4-5, 4-6, Comparative Example 5, Comparative Examples 6-1, 6-6 2, 6-3, 6-4, 6-5, Comparative Example 7, Comparative Examples 8-1, 8-2, 8-3, Comparative Example 9, Comparative Examples 10-1, 10-2, 10-3, For each of the photoexcited light emitting devices 10-4 and 10-5, the degree of light emission enhancement was evaluated as follows. Referring to FIG. 16A showing the measurement system of the emission spectrum of the photo-excited light-emitting element and FIG. 16B which is a schematic sectional view of the photo-excited light-emitting element, the light-emitting layer 2 The photoexcited light-emitting element 1 was caused to emit light by irradiating the excitation light 3 from a direction perpendicular to the surface of the substrate. As the excitation light source 4, a UV-LED (South Walker UV-LED 375-nano, excitation light wavelength: 375 nm) was used, and the light emitted from the excitation light source 4 was condensed by the lens 5 to be excitation light 3, which was irradiated. . A wavelength cut filter 8 (sigma optical machine) that collects the light emission 6 from the optical excitation light emitting element 1 emitted in the direction of 40 ° with respect to the optical axis of the excitation light 3 by the lens 7 and cuts the light having the wavelength of the excitation light. Through SCF-50S-44Y (manufactured by Co., Ltd.), the spectrophotometer 9 (MCPD-3000 manufactured by Otsuka Electronics Co., Ltd.) was used for detection. FIG. 16B is a schematic cross-sectional view showing the photoexcited light-emitting element 1 including the metal-based particle assembly thin film 200, the insulating layer 300, and the light-emitting layer 2 in this order on the soda glass substrate 100 manufactured in the examples and comparative examples. is there.
検出された発光のスペクトルについて発光波長領域における積分値を求めた。実施例４−１、４−２、４−３、４−４、４−５、４−６、および、比較例４−１、４−２、４−３、４−４、４−５、４−６の光励起発光素子について測定した発光スペクトルから求めた積分値を、比較例５の光励起発光素子について測定した発光スペクトルから求めた積分値で除した値を「発光増強倍率」とし、これを縦軸としたグラフを図１７に示した。 The integrated value in the emission wavelength region was determined for the detected emission spectrum. Examples 4-1, 4-2, 4-3, 4-4, 4-5, 4-6, and Comparative Examples 4-1, 4-2, 4-3, 4-4, 4-5, A value obtained by dividing the integrated value obtained from the emission spectrum measured for the photoexcited light emitting device of 4-6 by the integrated value obtained from the emission spectrum measured for the photoexcited light emitting device of Comparative Example 5 is referred to as “emission enhancement magnification”. A graph with the vertical axis is shown in FIG.
実施例５−１、５−２、５−３、５−４、５−５、比較例６−１、６−２、６−３、６−４、６−５および比較例１０−１、１０−２、１０−３、１０−４、１０−５の光励起発光素子について測定した発光スペクトルから求めた積分値を、比較例７の光励起発光素子について測定した発光スペクトルから求めた積分値で除した値を「発光増強倍率」とし、これを縦軸としたグラフを図１８に示した。 Examples 5-1, 5-2, 5-3, 5-4, 5-5, Comparative Examples 6-1, 6-2, 6-3, 6-4, 6-5 and Comparative Example 10-1. The integrated value obtained from the emission spectrum measured for the photoexcited light emitting elements 10-2, 10-3, 10-4, and 10-5 is divided by the integrated value obtained from the emission spectrum measured for the photoexcited light emitting element of Comparative Example 7. FIG. 18 shows a graph in which the obtained value is “luminescence enhancement magnification” and this is taken as the vertical axis.
実施例６−１、６−２、６−３、および、比較例８−１、８−２、８−３の光励起発光素子について測定した発光スペクトルから求めた積分値を、比較例９の光励起発光素子について測定した発光スペクトルから求めた積分値で除した値を「発光増強倍率」とし、これを縦軸としたグラフを図１９に示した。 The integrated value obtained from the emission spectra measured for the photoexcitation light-emitting elements of Examples 6-1, 6-2, 6-3 and Comparative Examples 8-1, 8-2, and 8-3 was used as the photoexcitation of Comparative Example 9. FIG. 19 shows a graph in which the value obtained by dividing the integrated value obtained from the emission spectrum measured for the light emitting element is “emission enhancement magnification”, and this is taken as the vertical axis.
１ 光励起発光素子、２ 発光層、３ 励起光、４ 励起光源、５，７ レンズ、６ 光励起発光素子からの発光、８ 波長カットフィルタ、９ 分光測定器、１００ ソーダガラス基板、２００ 金属系粒子集合体薄膜、２０１ 銀膜、３００ 絶縁層、４００ レジスト、４０１ 円形開口、５００ 金属系粒子集合体薄膜積層基板、５０１ 基板、５０２ 金属系粒子集合体薄膜、６００ 対物レンズ、７００ 分光光度計。 DESCRIPTION OF SYMBOLS 1 Photoexcitation light emitting element, 2 Light emitting layer, 3 Excitation light, 4 Excitation light source, 5,7 Lens, 6 Light emission from photoexcitation light emitting element, 8 Wavelength cut filter, 9 Spectrometer, 100 Soda glass substrate, 200 Metal particle assembly Body thin film, 201 silver film, 300 insulating layer, 400 resist, 401 circular opening, 500 metal-based particle assembly thin film laminated substrate, 501 substrate, 502 metal-based particle assembly thin film, 600 objective lens, 700 spectrophotometer.
Claims (13)
１００〜４５０℃の範囲内に温度調整された、ＳｉＯ 2 、ＺｒＯ 2 、及びプラスチック材料からなる群より選択される少なくとも１種で構成される基板上に、０．５ｎｍ／分以下の平均高さ成長速度で金属系粒子を成長させる工程を含む金属系粒子集合体の製造方法。 A method for producing a metal-based particle aggregate in which 30 or more metal-based particles are two-dimensionally arranged apart from each other,
On the substrate composed of at least one selected from the group consisting of SiO 2 , ZrO 2 , and plastic material , the temperature of which is adjusted within the range of 100 to 450 ° C., the average height of 0.5 nm / min or less A method for producing a metal-based particle assembly, comprising a step of growing metal-based particles at a growth rate.
前記金属系粒子集合体は、可視光領域における吸光スペクトルにおいて、前記平均粒径と同じ粒径、前記平均高さと同じ高さおよび同じ材質からなる金属系粒子を、金属系粒子間の距離がすべて１〜２μｍの範囲内となるように配置した参照金属系粒子集合体と比べて、最も長波長側にあるピークの極大波長が３０〜５００ｎｍの範囲で短波長側にシフトしている請求項１または２に記載の金属系粒子集合体の製造方法。 The metal-based particles constituting the metal-based particle aggregate are defined by a ratio of the average particle diameter to the average height within an average particle diameter of 200 to 1600 nm and an average height of 55 to 500 nm. The aspect ratio is in the range of 1-8,
In the absorption spectrum in the visible light region, the metal-based particle aggregate is a metal particle composed of the same particle size, the same height as the average height, and the same material as the average particle diameter. 2. The peak maximum wavelength on the longest wavelength side is shifted to the short wavelength side in the range of 30 to 500 nm as compared with the reference metal-based particle aggregate arranged to be in the range of 1 to 2 μm. Or the manufacturing method of the metal type particle aggregate of 2.
前記金属系粒子集合体は、可視光領域における吸光スペクトルにおいて、前記平均粒径と同じ粒径、前記平均高さと同じ高さおよび同じ材質からなる金属系粒子を、金属系粒子間の距離がすべて１〜２μｍの範囲内となるように配置した参照金属系粒子集合体よりも、同じ金属系粒子数での比較において、最も長波長側にあるピークの極大波長における吸光度が高い請求項１または２に記載の金属系粒子集合体の製造方法。 The metal-based particles constituting the metal-based particle aggregate are defined by a ratio of the average particle diameter to the average height within an average particle diameter of 200 to 1600 nm and an average height of 55 to 500 nm. The aspect ratio is in the range of 1-8,
In the absorption spectrum in the visible light region, the metal-based particle aggregate is a metal particle composed of the same particle size, the same height as the average height, and the same material as the average particle diameter. The absorbance at the maximum wavelength of the peak on the longest wavelength side is higher in comparison with the same number of metal-based particles than the reference metal-based particle aggregate disposed so as to be in the range of 1 to 2 µm. A method for producing a metal-based particle assembly as described in 1.
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| WO2010047177A1 (en) * | 2008-10-21 | 2010-04-29 | 独立行政法人産業技術総合研究所 | Method for producing metal oxide thin film |
| JP2010241638A (en) * | 2009-04-06 | 2010-10-28 | Riichi Murakami | Thin film laminate with metal nanoparticle layer interposed |
| KR20110045256A (en) * | 2009-10-26 | 2011-05-04 | 삼성전자주식회사 | Nanophosphor, light emitting device including nanophosphor and method for preparing nanophosphor |
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2012
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- 2012-07-24 WO PCT/JP2012/068661 patent/WO2013042449A1/en active Application Filing
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| TW201317562A (en) | 2013-05-01 |
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| WO2013042449A1 (en) | 2013-03-28 |
| JP2013079442A (en) | 2013-05-02 |
| KR102002190B1 (en) | 2019-07-19 |
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