CN101816073B - Method for the formation of a non-rectifying back-contact in a CDTE /CDS thin film solar cell - Google Patents
Method for the formation of a non-rectifying back-contact in a CDTE /CDS thin film solar cell Download PDFInfo
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- 229910004613 CdTe Inorganic materials 0.000 claims abstract description 63
- 238000000151 deposition Methods 0.000 claims abstract description 35
- 239000004065 semiconductor Substances 0.000 claims abstract description 9
- 239000000758 substrate Substances 0.000 claims abstract description 8
- 239000010408 film Substances 0.000 claims description 50
- 230000008021 deposition Effects 0.000 claims description 28
- 230000008569 process Effects 0.000 claims description 9
- 238000004544 sputter deposition Methods 0.000 claims description 7
- 238000003486 chemical etching Methods 0.000 claims description 6
- 238000004062 sedimentation Methods 0.000 claims description 5
- 238000001704 evaporation Methods 0.000 claims description 4
- 238000010276 construction Methods 0.000 claims description 3
- 230000008020 evaporation Effects 0.000 claims description 3
- 238000002207 thermal evaporation Methods 0.000 claims description 3
- 238000004070 electrodeposition Methods 0.000 claims description 2
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- 239000010949 copper Substances 0.000 description 74
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- 238000005286 illumination Methods 0.000 description 6
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- 229910052751 metal Inorganic materials 0.000 description 5
- 238000002441 X-ray diffraction Methods 0.000 description 4
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- 238000005530 etching Methods 0.000 description 4
- 238000000859 sublimation Methods 0.000 description 4
- 230000008022 sublimation Effects 0.000 description 4
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 3
- 230000004888 barrier function Effects 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 229910052731 fluorine Inorganic materials 0.000 description 3
- 239000011737 fluorine Substances 0.000 description 3
- 238000011031 large-scale manufacturing process Methods 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 229910052786 argon Inorganic materials 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
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- 238000012360 testing method Methods 0.000 description 2
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- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 229910006404 SnO 2 Inorganic materials 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
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- 229910052785 arsenic Inorganic materials 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
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- AMGQUBHHOARCQH-UHFFFAOYSA-N indium;oxotin Chemical compound [In].[Sn]=O AMGQUBHHOARCQH-UHFFFAOYSA-N 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/02—Details
- H01L31/0224—Electrodes
- H01L31/022408—Electrodes for devices characterised by at least one potential jump barrier or surface barrier
- H01L31/022425—Electrodes for devices characterised by at least one potential jump barrier or surface barrier for solar cells
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/0248—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies
- H01L31/0256—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by the material
- H01L31/0264—Inorganic materials
- H01L31/0296—Inorganic materials including, apart from doping material or other impurities, only AIIBVI compounds, e.g. CdS, ZnS, HgCdTe
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
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Abstract
The invention relates to a method for the formation of a non-rectifying, ohmic contact on a p-type semiconductor CdTe thin film comprising the steps of depositing a layer of As2Te3 on the CdTe layer at a substrate temperature comprised between ambient temperature and 200 DEG C; depositing a layer of Cu on the As2Te3 layer; bringing at least the deposited Cu layer to a temperature comprised between 150 DEG and 250 DEG C.The method is used to form a stable back-contact on CdTe/CdS thin film solar cells.
Description
Technical field
The present invention relates to technical field of solar batteries, relate more specifically to the large scale production method of CdTe/CdS thin-film solar cells.Especially, the present invention relates to this about forming the improvement of the method that contacts after the non-rectification.Although be called " CdTe/CdS film " solar cell in this manual for the sake of simplicity, it being understood that this term comprises formula Zn
xCd
1-xS/CdTe
yS
1-yIn all contained salt mixtures, wherein 0≤x≤0.2 and 0.95≤y≤1.
Background technology
As known; The typical construction of CdTe/CdS solar cell has the film sequence that multilayer is arranged, and comprising: carrying transparent conductive oxide (TCO) film transparent glass substrate, show as the semi-conductive CdS film of n-, contact after showing as the semi-conductive CdTe film of p-and metal.Solar cell with such layer arrangement and structure is for example disclosed among the US 5304499.
Commercial float glass can be used as transparent substrates, although its cost is low, usually preferred special glass is diffused in the TCO film to avoid the shortcoming of float glass, particularly Na.
Modal TCO is the In that contains 10%Sn
2O
3(ITO).This material has about 3 * 10
-4The utmost point low-resistivity of Ω cm and the high grade of transparency in the solar spectrum visible region (＞85%).But this material is through the sputter manufacturing, and the ITO target forms some tubercles that contain excessive In in the back several times in operation, in sputter procedure, the discharge between the tubercle can take place, and this possibly damage this film.Another kind of common used material is the SnO of doped with fluorine
2, but it shows near 10
-3The higher electric resistivity of Ω cm, therefore for realize about 10 Ω/square sheet resistance, need the layer of 1 micron thick.So high TCO thickness reduces the transparency of solar cell and reduces photoelectric current.NREL group has also proposed to use Cd
2SnO
4(people such as X.Wu, Thin Solid Films, 286 (1996) 274-276).This material also has some shortcomings, because target is by CdO and SnO
2Mixture constitute, and CdO height moisture absorption, thus the stability of this target maybe be unsatisfactory.
At same Applicant WO03/032406 under one's name the method that is used for large-scale production of CdTe/CdS thin-film solar cells is disclosed, wherein with the film that can deposit utmost point low-resistivity and on target, do not form any metal tubercle and allow to use the mode of inexpensive substrate to carry out the deposition of TCO film.For this reason, through at hydrogen or argon gas-hydrogen mixture and gaseous fluorine alkyls CHF for example
3Inert atmosphere in sputter, form tco layer.By this way, this TCO is mixed by fluorine.
Deposit CdS film or layer by the CdS bulk material through sputter or close-spaced sublimation (CSS).This back one technology allows the much higher underlayer temperature of temperature used in than simple vacuum evaporation or sputter to prepare film down because substrate and evaporation source each other very near, apart from the 2-6 millimeter, and at inert gas such as Ar, He or N
2Exist down 10
-1Deposit under-100 millibars of pressure.Higher underlayer temperature allows growth crystalline quality better material.The key character of close-spaced sublimation is the high growth rate up to 10 microns/minute, and this is suitable for large-scale production.
On the CdS film, depositing CdTe film or layer through close-spaced sublimation (CSS) under 480-520 ℃ the underlayer temperature.Usually use the CdTe particle as the CdTe source of from open crucible, evaporating.
Usually through deposition CdTe is electrically contacted for the rear portion that the film of height p-dopant metal (like copper, in the contact of graphite for example) obtains on the CdTe film, this metal can spread in the CdTe film when annealing.Identical inventor discloses in the CdTe/CdS solar cell and has used Sb
2Te
3Film as back contact (people such as N.Romeo, A highly efficient andstable CdTe/CdS thin film solar cell, Solar Energy Materials&Solar Cells, 58 (1999), 209-218).
Back contact in the CdTe/Cd thin-film solar cells is realizing playing important effect aspect the said battery efficiency.Rectification contact (rectifying contact); Promptly do not follow the metal-semiconductor contact (this means and between voltage and current, do not have linear relationship) of Ohm's law; In the J-V characteristic curve; Promptly in the figure of the functional relation that shows current density behavior and voltage, cause " upset (roll over) " (intersection in dark condition/characteristic first quartile of illumination condition J-V), this significantly reduces " fill factor "; Therefore and reduce battery efficiency (D.Bonnet and P.V.Meyers, J.Mater.Res.13 (1998) 2740-2753)).Because CdTe has high electron affinity (x) and high forbidden band (1.5eV), therefore most of metal forms Schottky barrier, limits the hole transport among this p type CdTe.When using Cu on CdTe, to form contact, before the Cu deposition, it is surperficial to produce rich Te in phosphoric acid/nitric acid bath, on CdTe, to carry out chemical etching (so-called N-P etching), thereby forms Cu with Cu
xTe (1≤X≤2) compound.
This compound closely contacts through diffuseing to form each other with the low resistance of CdTe, but its stability is subject to Cu
xTe phase (1≤X≤1.4), and Cu
2Te is not a stable compound mutually, therefore discharges Cu, and Cu is a rapid diffusion property element, and via crystal grain edge penetration CdTe, this possibly cause deterioration of battery especially.Because Cu is a cation, the internal electric field of this knot is depended in its diffusion in CdTe, and this depends on that again battery stands the situation of external bias or illumination.When this device be heated above 60 ℃ temperature or stand intense light irradiation (＞1sun) time, the deterioration of this device is obviously faster.
For fear of or limit this shortcoming at least; Adopt the solar cell that contacts behind this type; The solar cell produced of First Solar Inc. (USA) for example; The 2 nanometer Cu thickness that use deposits after CdTe is carried out chemical etching (people such as C.R.Corwine, Sites, Sol.Energy Mat.&Solar Cells 82 (2004) 481-489).
For fear of any deterioration of this device, in same Applicant WO03/032406 patent application under one's name, disclosing novel back contact material (is Sb
2Te
3And As
2Te
3) as the substitution material of Cu.Especially, Sb
2Te
3Be material with low band gaps (0.3eV), be the p-type and have and approach 10
-4The resistivity of Ω cm.When the underlayer temperature deposit 300 ℃ of ≈, it forms with tight the contact also of CdTe can reach the efficient near 16%.Even such contact verified at 10-20sun the device illumination and be higher than under 100 ℃ the temperature also highly stable.Yet, although form the ohmic contact of better quality by this way, under specific CdTe film growth conditions, still to observe and in the J-V characteristic curve, have " upset ", this is illustrated in the contact of back and has certain rectification, even be not very obvious.
Therefore, general purpose of the present invention provides and a kind ofly forms complete non-rectification and guarantee the method for the ohmic contact of membrane stability for the CdTe film.
A specific purpose of the present invention provides a kind of method of ohm back contact of the CdS/CdTe of formation thin-film solar cells, even it also can be guaranteed the stability of battery and therefore compared with prior art improve battery efficiency or battery efficiency is remained unchanged under high illumination and temperature conditions.
Another object of the present invention provides the method that contacts after the thin-film solar cells that forms the above-mentioned type; Wherein, Even in the formation of said back contact, use Cu, the THICKNESS CONTROL of the Cu film of deposition seriously influences stability test also can be in the method for prior art.
Another object of the present invention provides the method that contacts after the thin-film solar cells that forms the above-mentioned type, wherein before forming the contact of said back, needn't carry out chemical etching to the CdTe film and handle.
A purpose more of the present invention provides a kind of thin-film solar cells; Wherein the back contact is complete non-rectification; Even make and under high illumination and temperature conditions, also guarantee high stability, and compare the efficient of improving battery thus with known similar solar cell or it is remained unchanged.
Summary of the invention
Be adopted as the CdTe/CdS thin-film solar cells and form the method that contacts after the non-rectification and realized these purposes, in claim 1 and 14, set forth their essential characteristic according to the solar cell of this method.
According to an aspect of the present invention; A kind of method that forms ohmic contact is provided; Disclosed method is compared among this method and the WO 03/032406; Under the situation of the processing mode that does not change the CdTe film, make photovoltaic device keep stable in time, and therefore need not the etching of any kind of is carried out on CdTe film surface.
The new mode that this p-of making type CdTe obtains contacting is: deposit As at first in succession through sputter
2Te
3Film and Cu film then, but truly contact neither by As
2Te
3Provide and be not to provide by Cu, but via Cu
xTe (1≤x≤1.4) compound provides.Thereby ohm behavior and time stability that this just compound is guaranteed this contact and guaranteed solar cell.
In other words, method of the present invention provides the mode that contacts behind non-rectification ohm of a kind of CdTe of formation film, comprises forming Cu above that
xTe (1≤x≤1.4) is because the reactive script between Cu and the Te can not form this Cu
xTe.In fact, if adopt any method to deposit the film that contains Cu and Te, under any circumstance final result will be the separation of some phases, comprise not producing ohmic contact and because of discharging the unsettled Cu of Cu atom
2The Te phase.Stable phase between Cu and the Te is that Cu content is 1 to 1.4 phase, promptly under the energy advantageous conditions, passes through at As
2Te
3Sputtering sedimentation Cu film on the film and the phase that forms, said As
2Te
3Film is deposited on the surface of the CdTe film of handling in due form.
Be suitable for being deposited on As
2Te
3Maximum Cu amount on the layer must be guaranteed good nonrectifying contact and stable system simultaneously, and therefore must allow do not staying free Cu or avoiding forming Cu
2Form Cu under the situation of Te (it can cause atom Cu to diffuse through the CdTe film and therefore cause p-n function deterioration)
xTe (1≤x≤1.4).
Especially, can form Cu by natural way
xTe (1≤x≤1.4) compound: or pass through under 150 ℃ to 250 ℃ temperature at As
2Te
3On carry out Cu film deposition and come directly to form, or through at low temperature (＜100 ℃) deposit As
2Te
3The combination of this layer of heating forms under 150 ℃ to 250 ℃ temperature then.Preferred especially temperature all is at least 180 ℃ in these two kinds of situations.Even needn't reach Cu
xIt is last that Te (1≤x≤1.4) compound forms, and is useful but make the back contact of formation like this under this temperature, keep at least 1 minute.
In the formation of back according to the present invention contact, at As
2Te
3Utilize the specific interaction between these materials in the process of last sputtering sedimentation Cu film.In this sputtering technology, the atom that arrives substrate can have tens electron-volts energy (when using thermal evaporation, it can be several electron-volts of zero points at the most).Under 200 ℃, As
2Te
3The film surface thermally labile (it begins to evaporate under 250 ℃ again) that begins to become.On the other hand, it is excessive that the Cu atom has big energy, and the excessive part of this energy is lost through surface impacts and part is used to separate As
2Te
3Thereby molecule and alternative As form more stable compound (promptly having higher formation ability), i.e. Cu under this temperature
xTe (1≤x≤1.4).This stoichiometric proportion is variable (X is variable between 1 and 1.4), because the hydridization of chemical bond possibly take place, this possibly cause the formation ability that increases progressively from x=1.4 to x=1.
Shown in x-ray diffraction pattern, As
2Te
3Stop Cu, if because itself and Cu reaction and Cu film remain on the value that is not more than 20 nanometers, then form stabilizing material, promptly x is 1 to 1.4 Cu
xTe, it forms the nonrectifying contact (seeing Fig. 3 and 4) with CdTe.
Observe, if use Sb
2Te
3Replace As
2Te
3, can't realize identical result, because Sb
2Te
3Highly stable and not with Cu reaction, therefore Cu can diffuse through Sb in the CdTe layer
2Te
3Film destroys this device thus.
Description of drawings
Now with reference to accompanying drawing the present invention is described in more detail, wherein:
Fig. 1 schematically illustrates the structure of the CdTe/CdS thin-film solar cells with back of the present invention contact;
Fig. 2 has shown according to the method for the invention but the J-V characteristic curve of two solar cells after two kinds of different deposition temperatures deposit, contacting (that is: ambient temperature, curve a; 200 ℃, curve b);
Fig. 3 is at As on glass 200 ℃ of underlayer temperature deposit
2Te
3The x-ray analysis of film, this As
2Te
3Film has (curve b) and does not have that (curve is a) at uniform temp deposit 20 nanometer Cu layers above that;
Fig. 4 is at As on glass 200 ℃ of underlayer temperature deposit
2Te
3The x-ray analysis of film, this As
2Te
3Film has (curve b) and does not have that (curve is a) at uniform temp deposit 50 nanometer Cu layers above that.
Embodiment
Has this new A s according to the inventive method
2Te
3The peculiar key step of production of the CdTe/CdS thin-film solar cells that contacts behind+the Cu is:
A. cleaning glass is with the organic residue (grease, solvent etc.) of removing any trace and particulate (size greater than 1 micron dust).
B. through sputtering at the transparent preceding contact of deposition on glass; Said contact comprises two-layer: ground floor is the ITO (indium tin oxide) that guarantees conductivity; The second layer is ZnO, and this ZnO serves as resilient coating or serves as the barrier layer that possibly spread of impurity in the layer that prevents will deposit in the subsequent step.This is two-layer must guarantee in visible wavelength range, to be not less than 85% transparency on the whole.
C. pass through reactive sputtering (RF-magnetron) at Ar+%5CHF3 environment deposit CdS film, this CdS provides the n-N-type semiconductor N of the first of this knot.
D. through CSS (close-spaced sublimation) deposition CdTe film.This CdTe is the p-N-type semiconductor N, the absorption fully that it provides the second portion of this knot and guarantees visible light.
E. the combining structure of whole previous preparation is being heat-treated under 400 ℃: make CdTe film surface in the atmosphere of Ar+ freon, expose no more than 5 minutes; Temperature was kept other 5 minutes at 400 ℃; Set up vacuum condition, the volatile compound that forms during the first is evaporated from this CdTe film surface again.
F. deposit the back contact through sputter, back according to the present invention contact comprises two-layer: ground floor As
2Te
3, and second layer Cu: subsequently on back contact that so forms deposition Mo film to guarantee suitable sheet resistance.
The schematic structure of the solar cell of so processing is presented among Fig. 1.
On the CdTe surface, directly deposit As
2Te
3Layer does not carry out any chemical etching to this CdTe surface, and at about 200 ℃, preferred 180 ℃ underlayer temperature deposit Cu layer.As
2Te
3Be that the forbidden band is that 0.6eV and resistivity are about 10
-3The p-N-type semiconductor N of Ω cm.As
2Te
3Thickness can not wait for 100 to 300 nanometers, and Cu thickness can not wait for 2 to 20 nanometers.In experimental test, As
2Te
3All pass through sputtering sedimentation with Cu, the former with 10 to
Deposition rate deposition, the latter with
Deposition rate deposition.
If As
2Te
3All having no under the heat treated situation deposition at ambient temperature with Cu, the result produces as from the visible rectification contact of the curve a of Fig. 2, wherein can see " upset " (bending of J-V curve) in this J-V characteristic curve first quartile.If at about 200 ℃ underlayer temperature deposit Cu, then should upset disappear (the curve b of Fig. 2), and the fill factor of this device high in this case (0.7, but not 0.57 in first kind of situation).
In order to understand this As
2Te
3The behavior that+Cu is double-deck is through directly at deposition on glass As
2Te
3+ Cu prepares some samples and at about 200 ℃ underlayer temperature deposit Cu.In addition, through at As
2Te
3The Cu thickness of maximum 20 nanometers of last deposition prepares some samples, and prepares other samples through the Cu layer that deposits about 50 nanometers.To these samples carry out the x-ray analysis and with only contain As
2Te
3Sample compare.According to observations, contain the sample that layer thickness is not more than the Cu of 20 nanometers and show several Cu of 1≤X≤1.4
xTe phase (Fig. 3, curve a and b), and contain layer thickness be 50 nanometers Cu sample in addition show Cu
2Te phase (Fig. 4, curve a and b).The result of above-mentioned test is, thereby the Cu layer that can deposit maximum 20 nanometer thickness forms Cu
xTe phase (1≤X≤1.4), it forms the stable nonrectifying contact with CdTe.CdTe/CdS battery J-V characteristic curve-curve b shown in Fig. 2 has also confirmed this point, in this battery, through under about 200 ℃ underlayer temperature, depositing the As of 200 nanometers in succession
2Te
3With contact after the Cu of 20 nanometers makes, and any etching is not carried out on this CdTe surface.The fill factor of this battery is～0.7.
Can reach a conclusion As by these data
2Te
3The barrier layer of serving as Cu, and when depositing Cu at a lower temperature and after deposition, making it reach about 200 ℃, at As
2Te
3And solid-state reaction takes place between the Cu, thereby wherein Cu displacement As forms Cu
xThe Te phase.
The mode that on p-type CdTe, forms nonrectifying contact seems to be similar to mode commonly used, wherein at first produces the surface of rich Te through the chemical etching of CdTe, deposits Cu then to form Cu
xTe.Yet marked difference is, does not carry out any CdTe etching in the method for the invention, and is to use the Cu amount up to 10 times.This makes the risk that forms the rectification contact more inessential, thereby allows this contact to have bigger stability.
For assess performance and photovoltaic parameter, according to the As of method of the present invention through different-thickness listed in the sputtering sedimentation following table in succession
2Te
3Prepare several solar cell samples with Cu:
Under the situation of sample 3, make the system that forms by all sedimentary deposits in Ar atmosphere, be issued to 180 ℃ to 250 ℃ underlayer temperature at 100 millibars of pressure to 1atm.In all samples, through at this As
2Te
3The Mo layer of deposition 150nm on the+Cu film surface, accomplishing should contact.
When speed be several
to
and underlayer temperature when being 150 ℃ to 250 ℃, do not observe the physics relevant difference of the touching act that depends on deposition rate.
Under all these situation, this back contact is verified to be excellent contact for the CdTe/Cds thin-film solar cells, shown in J-V characteristic curve (Fig. 2, curve b).In fact, in this characteristic positive part (first quartile), show crookedly, this confirms that this contact is non-rectification, and can be derived by the slope of curve and fill factor and not have any series resistance effect.Therefore, this contact be non-rectification and have a low resistance.Through under open-circuit condition, making this device stand " light is saturated ", promptly, carry out stability test exposing 8 hours up to the strong illumination of 10sun with under up to 100 ℃ temperature, do not notice the remarkable variation of the photovoltaic parameter of this device.
Although As
2Te
3With this two-layer preferred deposition technique of Cu be through sputter, yet they also can be through thermal evaporation, through electron gun evaporation or electrodeposition process deposition.
Can be under not deviating from make and change and/or revise to the formation method of the non-rectification ohmic contact that is used for the CdTe/CdS film with to thin-film solar cells of the present invention like the situation of the described scope of the invention of following claim.
Claims (14)
1. on p-N-type semiconductor N CdTe film, form the method for non-rectification ohmic contact, it is characterized in that this method comprises the following step:
A) under the underlayer temperature of ambient temperature to 200 ℃, on said CdTe layer, deposit As
2Te
3Layer,
B) at said As
2Te
3Deposition Cu layer on the layer, wherein the thickness of the Cu layer of this deposition is the 2-20 nanometer,
C) making at least, the Cu layer of this deposition reaches 150 ℃ to 250 ℃ temperature.
2. according to the process of claim 1 wherein that the thickness of Cu layer of this deposition is not more than 20 nanometers.
3. according to the method for claim 1 or 2, wherein under 150 to 250 ℃ temperature, carry out the deposition of this Cu layer.
4. according to the method for claim 1 or 2, wherein, make this Cu layer and said As then being lower than the deposition of carrying out the Cu layer under 100 ℃ the temperature
2Te
3The combination of layer reaches 150 ℃ to 250 ℃ temperature.
5. according to the method for claim 4, wherein to 1 atmospheric pressure, carry out the heating under 150 ℃ to 250 ℃ temperature Ar atmosphere and 100 millibars.
6. according to the method for claim 4 or 5, wherein with this Cu layer and said As
2Te
3Being combined under 150 ℃ to 250 ℃ the temperature of layer kept 1 minute at least.
7. according to the process of claim 1 wherein the As of this deposition
2Te
3The thickness of layer is 100 to 300 nanometers.
8. according to the process of claim 1 wherein that said contact is the back contact of CdTe/CdS thin-film solar cells.
9. on the CdTe layer that does not stand any chemical etching processing, deposit As according to the process of claim 1 wherein
2Te
3Layer.
10. according to the process of claim 1 wherein deposition Mo layer on this Cu layer.
11. according to the method for claim 10, wherein through sputtering sedimentation As2Te
3Layer, Cu layer and Mo layer.
12. according to the method for claim 10, wherein through thermal evaporation, electron gun evaporation or electrodeposition process deposition As
2Te
3Layer, Cu layer and Mo layer.
13. according to the process of claim 1 wherein the Cu of said ohmic contact by 1≤X≤1.4
xTe forms.
14. the CdTe/CdS thin-film solar cells that forms by sandwich construction; This sandwich construction comprises transparent substrates, be deposited on conductive oxide layer on the said substrate, n-type CdS semiconductor layer, p-type CdTe semiconductor layer, at least one contains the back contact of Cu, it is characterized in that the back contact of the said Cu of containing comprises the As that is deposited on the said CdTe semiconductor layer
2Te
3The layer and at said As
2Te
3The Cu of middle 1≤X≤1.4 that form
xThe Te layer.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/IT2007/000469 WO2009001389A1 (en) | 2007-06-28 | 2007-06-28 | Method for the formation of a non-rectifying back-contact in a cdte /cds thin film solar cell |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101816073A CN101816073A (en) | 2010-08-25 |
| CN101816073B true CN101816073B (en) | 2012-02-01 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2007801000524A Expired - Fee Related CN101816073B (en) | 2007-06-28 | 2007-06-28 | Method for the formation of a non-rectifying back-contact in a CDTE /CDS thin film solar cell |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP2171760A1 (en) |
| JP (1) | JP5042363B2 (en) |
| CN (1) | CN101816073B (en) |
| AU (1) | AU2007355717A1 (en) |
| CA (1) | CA2691506A1 (en) |
| WO (1) | WO2009001389A1 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IT1396166B1 (en) * | 2009-10-13 | 2012-11-16 | Arendi S P A | METHOD OF ACTIVATION OF THIN CDTE FILMS FOR APPLICATIONS IN SOLAR FILMS WITH THIN FILMS OF THE CDTE / CDS TYPE. |
| DE102010004996B4 (en) * | 2010-01-19 | 2014-03-06 | Institut Für Photonische Technologien E.V. | Process for producing a cadmium telluride solar cell |
| US20110265874A1 (en) * | 2010-04-29 | 2011-11-03 | Primestar Solar, Inc. | Cadmium sulfide layers for use in cadmium telluride based thin film photovoltaic devices and methods of their manufacture |
| JP5918218B2 (en) * | 2010-04-30 | 2016-05-18 | ダウ グローバル テクノロジーズ エルエルシー | Method for producing chalcogenide photovoltaic cell |
| JP5508966B2 (en) * | 2010-07-07 | 2014-06-04 | 株式会社豊田中央研究所 | Photoelectric conversion element |
| US9461186B2 (en) * | 2010-07-15 | 2016-10-04 | First Solar, Inc. | Back contact for a photovoltaic module |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4650921A (en) * | 1985-10-24 | 1987-03-17 | Atlantic Richfield Company | Thin film cadmium telluride solar cell |
| CN1120246A (en) * | 1995-07-20 | 1996-04-10 | 四川联合大学 | Cadmium telluride solar cell with transition layer |
| US5557146A (en) * | 1993-07-14 | 1996-09-17 | University Of South Florida | Ohmic contact using binder paste with semiconductor material dispersed therein |
| CN1252169A (en) * | 1997-01-31 | 2000-05-03 | 西门子公司 | Optoelectronic semiconductor component |
| CN1440572A (en) * | 2000-04-06 | 2003-09-03 | 阿克佐诺贝尔股份有限公司 | Method of manufacturing photovoltaic foil |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ATE440385T1 (en) | 2001-10-05 | 2009-09-15 | Solar Systems & Equioments S R | METHOD FOR THE LARGE-SCALE PRODUCTION OF CDTE/CDS THIN FILM SOLAR CELLS |
| ITLU20050002A1 (en) * | 2005-02-08 | 2006-08-09 | Solar Systems & Equipments Srl | A NEW PROCESS FOR THE TREATMENT IN CHLORINE ENVIRONMENT OF SOLID FILM CELLS OF CdTe / CdS without the use of CdC12. |
-
2007
- 2007-06-28 WO PCT/IT2007/000469 patent/WO2009001389A1/en active Application Filing
- 2007-06-28 AU AU2007355717A patent/AU2007355717A1/en not_active Abandoned
- 2007-06-28 CA CA2691506A patent/CA2691506A1/en not_active Abandoned
- 2007-06-28 JP JP2010514259A patent/JP5042363B2/en not_active Expired - Fee Related
- 2007-06-28 EP EP07805681A patent/EP2171760A1/en not_active Withdrawn
- 2007-06-28 CN CN2007801000524A patent/CN101816073B/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4650921A (en) * | 1985-10-24 | 1987-03-17 | Atlantic Richfield Company | Thin film cadmium telluride solar cell |
| US5557146A (en) * | 1993-07-14 | 1996-09-17 | University Of South Florida | Ohmic contact using binder paste with semiconductor material dispersed therein |
| CN1120246A (en) * | 1995-07-20 | 1996-04-10 | 四川联合大学 | Cadmium telluride solar cell with transition layer |
| CN1252169A (en) * | 1997-01-31 | 2000-05-03 | 西门子公司 | Optoelectronic semiconductor component |
| CN1440572A (en) * | 2000-04-06 | 2003-09-03 | 阿克佐诺贝尔股份有限公司 | Method of manufacturing photovoltaic foil |
Also Published As
| Publication number | Publication date |
|---|---|
| AU2007355717A1 (en) | 2008-12-31 |
| CN101816073A (en) | 2010-08-25 |
| WO2009001389A1 (en) | 2008-12-31 |
| JP2010531547A (en) | 2010-09-24 |
| EP2171760A1 (en) | 2010-04-07 |
| CA2691506A1 (en) | 2008-12-31 |
| JP5042363B2 (en) | 2012-10-03 |
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