JP2015088365A - Evaluation method of carrier block performance in organic electroluminescent element - Google Patents

Evaluation method of carrier block performance in organic electroluminescent element Download PDF

Info

Publication number
JP2015088365A
JP2015088365A JP2013226642A JP2013226642A JP2015088365A JP 2015088365 A JP2015088365 A JP 2015088365A JP 2013226642 A JP2013226642 A JP 2013226642A JP 2013226642 A JP2013226642 A JP 2013226642A JP 2015088365 A JP2015088365 A JP 2015088365A
Authority
JP
Japan
Prior art keywords
voltage
organic
evaluation method
carrier block
frequency
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.)
Pending
Application number
JP2013226642A
Other languages
Japanese (ja)
Inventor
歳幸 遠藤
Toshiyuki Endo
歳幸 遠藤
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nissan Chemical Corp
Original Assignee
Nissan Chemical Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Nissan Chemical Corp filed Critical Nissan Chemical Corp
Priority to JP2013226642A priority Critical patent/JP2015088365A/en
Priority to TW103136297A priority patent/TW201531719A/en
Priority to KR1020140148213A priority patent/KR20150050452A/en
Priority to CN201410601766.5A priority patent/CN104597385A/en
Publication of JP2015088365A publication Critical patent/JP2015088365A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/26—Testing of individual semiconductor devices
    • G01R31/2601—Apparatus or methods therefor
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/26—Testing of individual semiconductor devices
    • G01R31/2607—Circuits therefor
    • G01R31/2632—Circuits therefor for testing diodes
    • G01R31/2635—Testing light-emitting diodes, laser diodes or photodiodes

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Electroluminescent Light Sources (AREA)

Abstract

PROBLEM TO BE SOLVED: To provide an evaluation method capable of evaluating the carrier block performance, by using an organic EL element of real element structure.SOLUTION: In an evaluation method of the carrier block performance in an organic electroluminescent element using an impedance spectroscopy, a DC voltage equal to or higher than an emission threshold voltage is applied to the organic electroluminescent element and then an AC voltage is applied while superposing thereon. Frequency of the AC voltage is changed, and the frequency when the capacitance becomes 0 is measured.

Description

本発明は、有機エレクトロルミネッセンス素子（以下、有機ＥＬ素子という）におけるキャリアブロック性の評価方法に関する。   The present invention relates to a method for evaluating carrier block property in an organic electroluminescence element (hereinafter referred to as an organic EL element).

有機ＥＬ素子とは、陽極から注入された正孔キャリアと、陰極から注入された電子キャリアとが、発光層または発光層とそれに接する層との界面で再結合することで、電界発光を生じる素子であり、その発光効率は正孔キャリアおよび電子キャリアの再結合の確率に依存する。
この発光効率の低下要因の一つとして、正孔キャリアまたは電子キャリアが、発光層内で再結合せずに発光層を通過し、陰極または陽極側へ抜け出すことが挙げられ、これを改善することで効果的に素子特性向上を図ることができる。 An organic EL element is an element that generates electroluminescence by recombination of a hole carrier injected from an anode and an electron carrier injected from a cathode at an interface between a light emitting layer or a light emitting layer and a layer in contact with the light emitting layer. The luminous efficiency depends on the probability of recombination of hole carriers and electron carriers.
One of the causes of this decrease in luminous efficiency is that hole carriers or electron carriers pass through the light emitting layer without recombining in the light emitting layer and escape to the cathode or anode side, and this can be improved. Thus, the device characteristics can be effectively improved.

正孔キャリアまたは電子キャリアの抜け出し易さに関しては、用いる材料間のＨＯＭＯ準位やＬＵＭＯ準位で議論されることが多い。
すなわち、発光層より陰極側に、発光層のＨＯＭＯ準位より浅いＨＯＭＯ準位を有する材料を積層すると、正孔キャリアが発光層から陰極側へ抜け出し易く、また、発光層より陽極側に、発光層のＬＵＭＯ準位より深いＬＵＭＯ準位を有する材料を積層すると、電子キャリアが発光層から陽極側へ抜け出し易い。
したがって、発光層より陰極側に、発光層のＨＯＭＯ準位よりも深いＨＯＭＯ準位を有する材料を正孔ブロック層として設け、また、発光層より陽極側に、発光層のＬＵＭＯ準位よりも浅いＬＵＭＯ準位を有する材料を電子ブロック層として設けることで、発光効率が改善できると考えられている。 The ease of escape of hole carriers or electron carriers is often discussed in terms of HOMO levels and LUMO levels between materials used.
That is, when a material having a HOMO level shallower than the HOMO level of the light emitting layer is laminated on the cathode side from the light emitting layer, hole carriers easily escape from the light emitting layer to the cathode side, and light is emitted from the light emitting layer to the anode side. When a material having a LUMO level deeper than the LUMO level of the layer is stacked, electron carriers are likely to escape from the light emitting layer to the anode side.
Therefore, a material having a HOMO level deeper than the HOMO level of the light emitting layer is provided as a hole blocking layer on the cathode side of the light emitting layer, and is shallower than the LUMO level of the light emitting layer on the anode side of the light emitting layer. It is considered that luminous efficiency can be improved by providing a material having an LUMO level as an electron blocking layer.

しかし、このようなＨＯＭＯ準位およびＬＵＭＯ準位の値に基づいたキャリアブロック性の評価は、材料物性のみに着目した評価方法であり、ヘテロ界面（電極／有機膜、有機膜／有機膜）で形成される真空準位シフトによるエネルギー障壁（非特許文献１）といった、デバイス構造起因の影響を除外した考え方である。そのため、エネルギー準位から算出されたキャリアブロック性が十分に発揮されず、予想されるような素子性能（例えば駆動電圧低下や発光効率向上など）が得られない場合がある。   However, the carrier block property evaluation based on the values of the HOMO level and the LUMO level is an evaluation method paying attention only to the material physical properties, and at the heterointerface (electrode / organic film, organic film / organic film). This is an idea that excludes the influence caused by the device structure, such as an energy barrier (Non-Patent Document 1) due to the formed vacuum level shift. For this reason, the carrier blockability calculated from the energy level is not sufficiently exhibited, and the expected device performance (for example, reduction in driving voltage or improvement in luminous efficiency) may not be obtained.

また、キャリアバランスの評価方法としては、積層素子の一方の電極面積を変化させ、そのキャリア注入量のみを変化させることにより、注入キャリア量の変化と輝度の変化から多数キャリアを判別し、キャリアバランスを調整する方法が知られている（特許文献１）。
しかし、この評価方法では、少なくとも一方の電極面積が実素子とは異なる大きさとなるため、電極面積変化によるキャリア注入量の変化は、実素子構造でのキャリア注入量の変化にそのまま対応するものではないという欠点がある。 In addition, as a carrier balance evaluation method, by changing one electrode area of the laminated element and changing only the carrier injection amount, majority carriers are discriminated from changes in the injected carrier amount and changes in luminance, and carrier balance is determined. There is known a method of adjusting the above (Patent Document 1).
However, in this evaluation method, at least one of the electrode areas has a size different from that of the actual element. Therefore, the change in the carrier injection amount due to the change in the electrode area does not directly correspond to the change in the carrier injection amount in the actual element structure. There is a disadvantage of not.

ところで、有機ＥＬ素子におけるキャリア移動度などの材料物性や、材料の組合せによるデバイス物性を、実素子構造かつ非破壊により解析する手法として、近年、インピーダンス分光法が着目されている。インピーダンス分光法とは、微小正弦波交流電圧を素子に印加した際の、応答電流信号の電流振幅と入力信号との位相差から、素子のインピーダンスを算出する方法である。
このインピーダンス分光法を用いた材料評価として、静電容量の周波数応答を用いたキャリア移動度の評価法が広く知られている（非特許文献２）。 By the way, in recent years, impedance spectroscopy has attracted attention as a technique for analyzing material properties such as carrier mobility in organic EL elements and device properties based on a combination of materials by an actual element structure and nondestructive. Impedance spectroscopy is a method of calculating the impedance of an element from the phase difference between the current amplitude of the response current signal and the input signal when a minute sine wave AC voltage is applied to the element.
As a material evaluation using this impedance spectroscopy, a carrier mobility evaluation method using a frequency response of capacitance is widely known (Non-Patent Document 2).

また、インピーダンス分光法を用いたデバイス解析としては、積層素子内の構成材料の誘電緩和時間の差により各層を分離した等価回路解析により、素子の効率や安定性の良し悪しを判定する（特許文献２）、駆動劣化前後の素子の劣化部位の推定する（非特許文献３）、および発光閾値電圧以下での静電容量−電圧曲線から、素子寿命の優劣を比較する（特許文献３）といったものが提案されている。   In addition, as device analysis using impedance spectroscopy, the efficiency and stability of the element are judged based on equivalent circuit analysis in which each layer is separated by the difference in dielectric relaxation time of the constituent materials in the laminated element (Patent Document) 2) Estimating the deterioration part of the element before and after driving deterioration (Non-Patent Document 3), and comparing the superiority and inferiority of the element life from the capacitance-voltage curve below the light emission threshold voltage (Patent Document 3) Has been proposed.

しかし、インピーダンス分光法を、有機ＥＬ素子のキャリアバランスやキャリアブロック性の評価手法として応用するといった具体的な提案はなされていない。
キャリアバランスやキャリアブロック性は、有機ＥＬ素子設計上の重要なファクターであるにも関わらず、実素子構造にてこれらの因子を評価する方法は、上記のようにこれまで知られていない。 However, no specific proposal has been made for applying impedance spectroscopy as a method for evaluating the carrier balance or carrier block property of an organic EL element.
Although carrier balance and carrier blockability are important factors in designing an organic EL element, a method for evaluating these factors in an actual element structure has not been known as described above.

特開２００８−１４６９５６号公報JP 2008-14695 A 特開２０１１−３４８０５号公報JP 2011-34805 A 特開２００９−１６６６５号公報JP 2009-16665 A

Ｊｏｕｒｎａｌ ｏｆ ｔｈｅ Ｖａｃｕｕｍ Ｓｏｃｉｅｔｙ ｏｆ Ｊａｐａｎ、２００７年、５０（１２）、ｐ．ｐ．７１６Journal of the Vacuum Society of Japan, 2007, 50 (12), p. p. 716 Ｊｏｕｒｎａｌ ｏｆ Ａｐｐｌｉｄ Ｐｈｙｓｉｃｓ、２００６年、９９、ｐ．ｐ．０１３７０６Journal of Applied Physics, 2006, 99, p. p. 013706 有機ＥＬ討論会第５回例会予稿集、２００７年、ｐ．ｐ．４７Proceedings of the 5th Annual Meeting of the Organic EL Discussion Group, 2007, p. p. 47

本発明は、上記事情に鑑みてなされたものであり、実素子構造の有機ＥＬ素子を用いてキャリアブロック性を評価できる評価方法を提供することを目的とする。   This invention is made | formed in view of the said situation, and it aims at providing the evaluation method which can evaluate carrier block property using the organic EL element of a real element structure.

本発明者は、上記目的を達成するために鋭意検討を重ねた結果、所定の直流電圧を印加した実素子構造の有機ＥＬ素子に対してインピーダンス分光を行い、静電容量が０となる周波数を測定することで素子のキャリアブロック性を評価できることを見出すとともに、複数の有機ＥＬ素子を用い、注入キャリア数一定の条件下でインピーダンス分光を行い、各素子における静電容量が０となる周波数を比較することでキャリアブロック性の優劣を評価できることを見出し、本発明を完成した。   As a result of intensive studies in order to achieve the above object, the present inventor conducted impedance spectroscopy on an organic EL element having an actual element structure to which a predetermined DC voltage was applied, and determined a frequency at which the capacitance became zero. It is found that the carrier block property of the element can be evaluated by measuring, and using a plurality of organic EL elements, impedance spectroscopy is performed under the condition that the number of injected carriers is constant, and the frequency at which the capacitance in each element becomes zero is determined. It was found that the superiority or inferiority of the carrier block property can be evaluated by comparison, and the present invention was completed.

すなわち、本発明は、
１． インピーダンス分光法を用いた有機エレクトロルミネッセンス素子におけるキャリアブロック性の評価方法であって、前記有機エレクトロルミネッセンス素子に発光閾値電圧以上の直流電圧を印加するとともに交流電圧を重畳して印加し、この交流電圧の周波数を変化させて静電容量が０となる周波数を測定することを特徴とするキャリアブロック性の評価方法、
２． 前記有機エレクトロルミネッセンス素子が複数個あり、それら各素子のそれぞれに、注入キャリア数が一定となる条件下で前記直流電圧および交流電圧を印加し、この交流電圧の周波数を変化させて静電容量が０となる周波数を測定し、それらを比較する１のキャリアブロック性の評価方法、
３． 前記周波数測定時の前記各素子の発光輝度を一定とすることで、前記注入キャリア数を一定とする２のキャリアブロック性の評価方法、
４． 前記周波数測定時の前記各素子の電流密度を一定とすることで、前記注入キャリア数を一定とする２のキャリアブロック性の評価方法、
５． 前記交流電圧が、直流電圧の１／５以下である１〜４のいずれかのキャリアブロック性の評価方法、
６． 前記有機エレクトロルミネッセンス素子が、陽極および陰極と、これら各極間に介在する、発光層を含む２層以上の有機膜とから構成される１〜５のいずれかのキャリアブロック性の評価方法
を提供する。 That is, the present invention
1. An evaluation method of carrier block property in an organic electroluminescence device using impedance spectroscopy, wherein a direct current voltage equal to or higher than a light emission threshold voltage is applied to the organic electroluminescence device and an alternating current voltage is superimposed and applied. A carrier block property evaluation method, wherein the frequency at which the capacitance becomes 0 is measured by changing the frequency of
2. There are a plurality of the organic electroluminescence elements, and the DC voltage and the AC voltage are applied to each of the elements under the condition that the number of injected carriers is constant, and the frequency of the AC voltage is changed to change the capacitance. A method for evaluating carrier blockiness of 1 for measuring frequencies that become 0 and comparing them;
3. The carrier block property evaluation method of 2 that makes the number of injected carriers constant by making the light emission luminance of each element at the time of frequency measurement constant,
4). The carrier block property evaluation method of 2, wherein the number of injected carriers is made constant by making the current density of each element at the time of frequency measurement constant,
5. The evaluation method of the carrier block property according to any one of 1 to 4, wherein the AC voltage is 1/5 or less of the DC voltage,
6). The organic electroluminescence device is provided with an evaluation method for carrier blockability according to any one of 1 to 5, wherein the organic electroluminescence device comprises an anode and a cathode, and two or more organic films including a light emitting layer interposed between the anode and the cathode. To do.

本発明のキャリアブロック性の評価方法を用いることで、実素子構造の多層型有機ＥＬ素子にて、各層の材料を変更させた場合や層膜厚を変更した場合の、キャリア閉じ込め効果の優劣を時間スケールといったパラメータで評価することが可能となる。
この評価方法は、駆動電圧の低下や発光効率の向上などを目的とする素子構造の最適化に寄与する有用なものである。 By using the carrier block property evaluation method of the present invention, in the multilayer organic EL element having a real element structure, the superiority or inferiority of the carrier confinement effect when the material of each layer is changed or the layer thickness is changed. It is possible to evaluate with parameters such as a time scale.
This evaluation method is useful for contributing to optimization of the element structure for the purpose of lowering the driving voltage and improving the light emission efficiency.

作製例１および作製例２で作製した有機ＥＬ素子の電圧−電流密度特性を示す図である。It is a figure which shows the voltage-current density characteristic of the organic EL element produced by the manufacture examples 1 and 2. 作製例１および作製例２で作製した有機ＥＬ素子の電圧−輝度特性を示す図である。It is a figure which shows the voltage-luminance characteristic of the organic EL element produced by the manufacture example 1 and the manufacture example 2. FIG. 作製例１および作製例２で作製した有機ＥＬ素子の電流密度−電流効率特性を示す図である。It is a figure which shows the current density-current efficiency characteristic of the organic EL element produced by the manufacture example 1 and the manufacture example 2. FIG. 作製例１および作製例２で作製した有機ＥＬ素子の輝度：５００ｃｄ／ｍ2での周波数−静電容量特性を示す図である。It is a figure which shows the frequency-capacitance characteristic in the brightness | luminance: 500cd / m < 2 > of the organic EL element produced by the manufacture example 1 and the manufacture example 2. FIG. 作製例１および作製例２で作製した有機ＥＬ素子の電流密度：５０ｍＡ／ｃｍ2での周波数−静電容量特性を示す図である。It is a figure which shows the frequency-capacitance characteristic in the current density: 50mA / cm < 2 > of the organic EL element produced by the manufacture example 1 and the manufacture example 2. FIG.

以下、本発明についてさらに詳しく説明する。
一般に「半導体」と呼ばれる材料は、電気化学における等価回路として記述すると、抵抗成分Ｒと静電容量Ｃの並列回路（以下、ＲＣ並列回路と記述する）として表現できる。ここで、静電容量ＣはＣ＝ε0・εr・Ｓ／ｄで表され、ε0は真空の誘電率、εrは材料の比誘電率、Ｓは素子面積、ｄは素子膜厚である。抵抗成分Ｒは直流回路により算出されるが、静電容量Ｃは交流回路により算出される。このため、静電容量は印加交流電圧の周波数に応じて変化する。
外部電極からのキャリア注入や、光照射によるキャリア生成が起きていない場合、半導体のキャリア密度は非常に低く絶縁性を示し、高抵抗かつ幾何容量（材料および構造由来の静電容量）を示す。
一方、外部電極からのキャリア注入または光照射によるキャリア生成が起きると、半導体のキャリア密度が増加して絶縁性から導電性へと変化し、それにともない、抵抗値が減少して静電容量にも変化が生じる。 Hereinafter, the present invention will be described in more detail.
In general, a material called “semiconductor” can be expressed as a parallel circuit of a resistance component R and a capacitance C (hereinafter referred to as an RC parallel circuit) when described as an equivalent circuit in electrochemistry. Here, the capacitance C is expressed by C = ε 0 · ε r · S / d, where ε 0 is the dielectric constant of vacuum, ε r is the relative dielectric constant of the material, S is the element area, and d is the element thickness. It is. The resistance component R is calculated by a DC circuit, while the capacitance C is calculated by an AC circuit. For this reason, the capacitance changes according to the frequency of the applied AC voltage.
In the case where carrier injection from an external electrode or generation of carriers due to light irradiation does not occur, the carrier density of the semiconductor is very low and exhibits insulating properties, and exhibits high resistance and geometric capacitance (capacitance derived from materials and structures).
On the other hand, when carrier generation from external electrode injection or light irradiation occurs, the carrier density of the semiconductor increases and changes from insulating to conductive, and accordingly, the resistance value decreases and the capacitance also increases. Change occurs.

外部電極から注入されるキャリア種が１種である場合は（単電荷注入）、静電容量は正の値の範囲内で変化するが、外部電極から正孔キャリアおよび電子キャリアが注入される複注入状態では、静電容量が正の値から負の値へと変化する。
有機ＥＬ素子において、この負の静電容量が観測されるのは、発光層内に注入された正孔キャリアおよび電子キャリアのうち、再結合し得なかった両キャリアが対向電極に到達することに起因している（Ｐｈｙｓｉｃｓ Ｒｅｖｉｅｗ Ｂ、２００５年、７２、ｐ．ｐ．２３５２０４）。つまり、有機ＥＬ素子に対して外部電極から単キャリアのみを注入した場合、または注入された両キャリアが素子内で全て消費された場合には、負の静電容量は観測されない（Ｊｏｕｒｎａｌ ｏｆ Ａｐｐｌｉｅｄ Ｐｈｙｓｉｃｓ、２００６年、１００、ｐ．ｐ．０８４５０２）。
しかし、現実の発光素子では、全ての注入キャリアが再結合されることはなく、発光閾値電圧以上の駆動電圧にて、負の静電容量が必ず観測される。なお、ここで言う「発光閾値電圧」とは、有機ＥＬ素子が０．１ｃｄ／ｍ2の輝度で発光するのに必要な電圧のことを示す。 When the number of carrier types injected from the external electrode is one (single charge injection), the capacitance changes within the range of positive values, but a plurality of hole carriers and electron carriers are injected from the external electrode. In the injection state, the capacitance changes from a positive value to a negative value.
In the organic EL element, this negative capacitance is observed when both of the hole carriers and electron carriers injected into the light emitting layer, which have not been recombined, reach the counter electrode. (Physics Review B, 2005, 72, pp. 235204). That is, when only a single carrier is injected into the organic EL element from the external electrode, or when both injected carriers are consumed in the element, no negative capacitance is observed (Journal of Applied Physics). 2006, 100, pp. 084502).
However, in an actual light emitting device, all injected carriers are not recombined, and a negative electrostatic capacity is always observed at a driving voltage equal to or higher than the light emission threshold voltage. The “emission threshold voltage” mentioned here indicates a voltage necessary for the organic EL element to emit light with a luminance of 0.1 cd / m 2 .

上記のように、有機ＥＬ素子において負の静電容量が観察されるということは、両キャリアが対向電極に到達することを示している。
実際の素子ではキャリア注入量やキャリア移動度といった点で正孔キャリアと電子キャリアに差が生じるため、どちらか一方が少数キャリアとなる。したがって、両キャリアが対向電極に到達するということは、少数キャリアが対向電極に到達することと同義であり、したがって、負の静電容量が観測される周波数とは、少数キャリアが対向電極に到達する周波数と言い換えることができる。 As described above, the fact that a negative capacitance is observed in the organic EL element indicates that both carriers reach the counter electrode.
In an actual device, there is a difference between hole carriers and electron carriers in terms of carrier injection amount and carrier mobility, and either one becomes a minority carrier. Therefore, the fact that both carriers reach the counter electrode is synonymous with the fact that minority carriers reach the counter electrode. Therefore, the frequency at which a negative capacitance is observed is the minority carrier reaches the counter electrode. In other words, the frequency of

以上のような技術背景のもと、本発明に係るキャリアブロック性の評価方法は、インピーダンス分光法を用い、有機ＥＬ素子に発光閾値電圧以上の直流電圧を印加するとともに交流電圧を重畳して印加し、この交流電圧の周波数を変化させて静電容量が０となる周波数を測定するものである。
すなわち、周波数は時間の逆数の物理量であるため、負の静電容量の観測周波数（ゼロ点周波数）が低い素子とは、少数キャリアが対向電極に到達するまでに時間を要する素子のことであり、少数キャリアを素子内に閉じ込める効果の高い素子であると言い換えることができる。
したがって、静電容量が０となる周波数を知ることで、その素子のキャリアブロック性を評価することができる。 Based on the above technical background, the carrier block property evaluation method according to the present invention uses impedance spectroscopy, and applies a DC voltage equal to or higher than the light emission threshold voltage to the organic EL element and applies an AC voltage superimposed thereon. The frequency at which the capacitance becomes zero is measured by changing the frequency of the AC voltage.
In other words, since the frequency is a physical quantity that is the reciprocal of time, an element having a low negative capacitance observation frequency (zero point frequency) is an element that requires time until minority carriers reach the counter electrode. In other words, the device is highly effective in confining minority carriers in the device.
Therefore, by knowing the frequency at which the capacitance becomes 0, the carrier block property of the element can be evaluated.

より具体的には、本発明における有機ＥＬ素子の静電容量は、周波数応答アナライザ等の市販のインピーダンス測定装置を用いて測定できる。この場合、測定装置の要求性能には特に制限はないが、広い周波数域（０．１ｍＨｚ〜１０ＭＨｚ）で高いＳ／Ｎ比が得られる測定装置を使用することが好ましい。このような装置としては、例えば、ソーラトロン社製の１２６０型周波数応答アナライザ等が挙げられるが、もちろんこれに限定されるものではない。
素子回路に大電流が流れる条件下では、インピーダンス測定装置単独で目的とする静電容量を測定できる。
一方、素子回路に流れる電流が少ない条件下では、インピーダンス測定装置に誘電率測定インターフェイスを組み合わせることで、より精度の高い測定が可能となる。この誘電率測定インターフェイスとしては、例えば、ソーラトロン社製１２９６型誘電率測定インターフェイス等が挙げられるが、これに限定されるものではない。 More specifically, the capacitance of the organic EL element in the present invention can be measured using a commercially available impedance measuring device such as a frequency response analyzer. In this case, the required performance of the measuring device is not particularly limited, but it is preferable to use a measuring device that can obtain a high S / N ratio in a wide frequency range (0.1 mHz to 10 MHz). Examples of such an apparatus include, but are not limited to, a 1260 type frequency response analyzer manufactured by Solartron.
Under the condition that a large current flows through the element circuit, the target capacitance can be measured by the impedance measuring device alone.
On the other hand, under a condition where the current flowing through the element circuit is small, it is possible to perform measurement with higher accuracy by combining the impedance measurement device with the dielectric constant measurement interface. Examples of the dielectric constant measurement interface include a 1296 type dielectric constant measurement interface manufactured by Solartron, but are not limited thereto.

静電容量の周波数依存性（Ｃ−ｆ特性）は、評価対象の有機ＥＬ素子をインピーダンス測定装置に接続し、ある一定の直流電圧に微小交流電圧を重畳して印加し、交流電圧の周波数を、例えば、高周波から低周波へと変化させ、その電流応答を計測することで、素子の複素インピーダンスの周波数変化を測定すればよい。
上記直流電圧は発光閾値電圧（有機ＥＬ素子が０．１ｃｄ／ｍ2の輝度で発光するのに必要な電圧）以上の所望の電圧である。
一方、交流電圧は微小信号条件を満たす範囲内でより大きな電圧であることが好ましく、このような条件とすることで、高いＳ／Ｎ比が得られる。具体的な振幅電圧は、直流電圧に対して１／５以下であることが好ましく、電圧値としては５ｍＶ〜２００ｍＶ程度が好ましい。
測定周波数範囲については、その範囲内に静電容量が正から負へ反転する周波数が含まれていればよく、通常、０．１ｍＨｚ〜１０ＭＨｚ程度、好ましくは１Ｈｚ〜１ＭＨｚである。 The frequency dependence of the capacitance (Cf characteristic) is determined by connecting the organic EL element to be evaluated to an impedance measuring device, applying a small AC voltage superimposed on a certain DC voltage, and changing the frequency of the AC voltage. For example, the frequency change of the complex impedance of the element may be measured by changing from a high frequency to a low frequency and measuring the current response.
The DC voltage is a desired voltage equal to or higher than a light emission threshold voltage (a voltage necessary for the organic EL element to emit light with a luminance of 0.1 cd / m 2 ).
On the other hand, the AC voltage is preferably a larger voltage within the range satisfying the minute signal condition, and a high S / N ratio can be obtained under such a condition. The specific amplitude voltage is preferably 1/5 or less of the DC voltage, and the voltage value is preferably about 5 mV to 200 mV.
About the measurement frequency range, the frequency which a capacitance reverses from positive to negative should just be included in the range, and it is about 0.1mHz-10MHz normally, Preferably it is 1Hz-1MHz.

本発明の評価方法を用いて実際に有機ＥＬ素子のキャリア閉じ込め効果の優劣を比較する際には、各層を形成する材料や、各層の膜厚が異なる素子同士で比較することが考えられる。このため、素子毎にキャリア注入障壁等が異なり、印加直流電圧を一定としても、発光層内に注入されるキャリア数は一定とはならない。
評価対象となる各有機ＥＬ素子のキャリアの閉じ込め効果の優劣を正確に比較するには、前提条件として、発光層内に注入されるキャリア数を一定とする必要がある。
すなわち、比較対象となる各素子のそれぞれに、注入キャリア数が一定となる条件下で先に説明した直流電圧および交流電圧を印加し、この交流電圧の周波数を変化させて各素子の静電容量が０となる周波数を測定し、それらを比較することで、キャリア閉じ込め効果の優劣が判定できることになる。
この場合、印加直流電圧に依存せずに注入キャリア数を一定とするには、発光に寄与するキャリア数を同数とする、つまり負の静電容量の観測周波数を比較する際の輝度を一定とする、または、外部回路へ流れ出るキャリア数を同数とする、つまり負の静電容量の観測周波数を比較する際の電流密度を一定とする、という二通りの手法が考えられ、測定にあたっていずれかの条件を任意に選択すればよい。 When actually comparing the superiority or inferiority of the carrier confinement effect of the organic EL element using the evaluation method of the present invention, it is conceivable to compare the elements forming the layers and the elements having different film thicknesses. For this reason, the carrier injection barrier and the like are different for each element, and the number of carriers injected into the light emitting layer is not constant even when the applied DC voltage is constant.
In order to accurately compare the superiority or inferiority of the carrier confinement effect of each organic EL element to be evaluated, it is necessary to make the number of carriers injected into the light emitting layer constant as a precondition.
That is, the DC voltage and the AC voltage described above are applied to each element to be compared under the condition that the number of injected carriers is constant, and the capacitance of each element is changed by changing the frequency of the AC voltage. It is possible to determine the superiority or inferiority of the carrier confinement effect by measuring the frequency at which becomes zero and comparing them.
In this case, in order to make the number of injected carriers constant without depending on the applied DC voltage, the number of carriers contributing to light emission is made the same, that is, the luminance when comparing the observation frequency of the negative capacitance is made constant. Or the same number of carriers flowing out to the external circuit, that is, the current density when comparing the observation frequency of the negative capacitance is constant. What is necessary is just to select conditions arbitrarily.

本発明の評価対象である有機ＥＬ素子としては、陽極および陰極と、これら各極間に介在する、発光層を含む２層以上の有機層とから構成されるものであれば特に限定されるものではない。
発光層以外の有機層としては、正孔注入層、正孔輸送層、電子ブロック層、正孔ブロック層、電子輸送層、電子注入層等が挙げられ、これらのうち少なくとも一層が必要に応じて上記発光層とともに用いられる。
有機ＥＬ素子の素子構造の一例としては、陽極／正孔注入層／正孔輸送層／電子ブロック層／発光層／正孔ブロック層／電子輸送層／電子注入層／陰極が挙げられるが、これに限定されるものではない。 The organic EL element which is an evaluation object of the present invention is particularly limited as long as it is composed of an anode and a cathode and two or more organic layers including a light emitting layer interposed between these electrodes. is not.
Examples of the organic layer other than the light emitting layer include a hole injection layer, a hole transport layer, an electron block layer, a hole block layer, an electron transport layer, an electron injection layer, and the like. Used together with the light emitting layer.
Examples of the element structure of the organic EL element include anode / hole injection layer / hole transport layer / electron block layer / light emitting layer / hole block layer / electron transport layer / electron injection layer / cathode. It is not limited to.

上述した有機ＥＬ素子のキャリア閉じ込め効果の優劣を比較する際に用いられる素子の例を挙げると、少数キャリアが電子の素子としては、正孔注入層または正孔輸送層が電子ブロック性を有する素子、または正孔注入層／正孔輸送層／発光層のいずれかに電子ブロック性を有する素子などが例示でき、この場合、これらの各素子と電子ブロック性を有する層を備えない素子とを比較すればよい。
一方、少数キャリアが正孔である素子としては、電子注入層または電子輸送層が正孔ブロック性を有する素子、または電子注入層／電子輸送層／発光層のいずれかに正孔ブロック性を有する素子などが例示でき、この場合、これらの各素子と正孔ブロック性を有する層を備えない素子とを比較すればよい。 As an example of an element used when comparing the superiority or inferiority of the carrier confinement effect of the organic EL element described above, an element in which a minority carrier is an electron is an element in which a hole injection layer or a hole transport layer has an electron blocking property. Or a device having an electron blocking property in any of a hole injection layer / a hole transporting layer / a light emitting layer. In this case, each of these devices is compared with a device not provided with a layer having an electron blocking property. do it.
On the other hand, as an element in which minority carriers are holes, the electron injection layer or the electron transport layer has a hole blocking property, or the electron injection layer / electron transport layer / light-emitting layer has a hole blocking property. An element etc. can be illustrated, In this case, what is necessary is just to compare each of these elements with the element which is not provided with the layer which has hole blocking property.

有機ＥＬ素子を構成する電極や各有機層を構成する材料としては特に限定されるものではなく、従来公知の各種材料から適宜選択して用いることができる。
また、有機ＥＬ素子の製法についても特に制限はない。 It does not specifically limit as an electrode which comprises an organic EL element, or the material which comprises each organic layer, It can select suitably from conventionally well-known various materials and can use.
Moreover, there is no restriction | limiting in particular also about the manufacturing method of an organic EL element.

以下、製造例および実施例を挙げて、本発明をより具体的に説明するが、本発明は下記の実施例に限定されるものではない。なお、実施例で使用した装置は以下のとおりである。
（１）基板洗浄：長州産業（株）製 基板洗浄装置（減圧プラズマ方式）
（２）インク塗布：ミカサ（株）製 スピンコーターＭＳ−Ａ１００
（３）グローブボックス：山八物産（株）製 ＶＡＣグローブボックスシステム
（４）素子作製：長州産業（株）製 多機能蒸着装置システムＣ−Ｅ２Ｌ１Ｇ１−Ｎ
（５）電流・輝度・電圧測定：（有）テック・ワールド製 Ｉ−Ｖ−Ｌ測定システム
（６）インピーダンス測定：ソーラトロン社製 １２６０型周波数応答アナライザ、および１２９６型誘電率測定インターフェイス EXAMPLES Hereinafter, although a manufacture example and an Example are given and this invention is demonstrated more concretely, this invention is not limited to the following Example. In addition, the apparatus used in the Example is as follows.
(1) Substrate cleaning: Choshu Sangyo Co., Ltd. substrate cleaning equipment (decompressed plasma method)
(2) Ink application: Mikasa Co., Ltd. spin coater MS-A100
(3) Glove box: VAC glove box system manufactured by Yamahachi Bussan Co., Ltd. (4) Device fabrication: Multifunctional vapor deposition system C-E2L1G1-N manufactured by Choshu Sangyo Co., Ltd.
(5) Current / luminance / voltage measurement: IV World measurement system manufactured by Tech World (6) Impedance measurement: Solartron 1260 type frequency response analyzer and 1296 type dielectric constant measurement interface

［１］正孔注入層溶液の作製
［調製例１］
国際公開第２０１３／０８４６６４号記載の方法に従って合成した式（１）で表されるアニリン誘導体０．１３７ｇと、国際公開第２００６／０２５３４２号記載の方法に従って合成した式（２）で表されるアリールスルホン酸０．２７１ｇとを、窒素雰囲気下で１，３−ジメチル−２−イミダゾリジノン６．７ｇに溶解させた。得られた溶液に、シクロヘキサノール１０ｇ、プロピレングリコール３．３ｇを順次加えて撹拌し、正孔注入層溶液を調製した。 [1] Preparation of hole injection layer solution [Preparation Example 1]
0.137 g of the aniline derivative represented by the formula (1) synthesized according to the method described in International Publication No. 2013/084664 and the aryl represented by Formula (2) synthesized according to the method described in International Publication No. 2006/025342 0.271 g of sulfonic acid was dissolved in 6.7 g of 1,3-dimethyl-2-imidazolidinone under a nitrogen atmosphere. To the obtained solution, 10 g of cyclohexanol and 3.3 g of propylene glycol were sequentially added and stirred to prepare a hole injection layer solution.

Figure 2015088365
Figure 2015088365

［２］有機ＥＬ素子の作製と評価
［作製例１］
ＩＴＯ基板として、インジウム錫酸化物（ＩＴＯ）が表面上に膜厚１５０ｎｍでパターニングされた２５ｍｍ×２５ｍｍ×０．７ｔのガラス基板を用い、使用前にＯ2プラズマ洗浄装置（１５０Ｗ、３０秒間）によって表面上の不純物を除去した。続いて、調製例１で作製した正孔注入層溶液をスピンコートにより塗布成膜し、大気中、ホットプレート上で５０℃に加熱して５分間乾燥後、さらに２３０℃で１５分間の加熱焼成を行い、正孔注入層（膜厚：３０ｎｍ）を形成した。
次に、窒素雰囲気のグローブボックス内で、正孔輸送材料（アメリカンダイソース社製、商品名：ＡＤＳ２５９ＢＥ）の０．４質量％トルエン溶液を正孔注入層上にスピンコートにより塗布成膜し、１８０℃で１０分間の加熱焼成を行い、正孔輸送層Ａ（膜厚：１０ｎｍ）を形成した。 [2] Production and evaluation of organic EL element [Production Example 1]
As the ITO substrate, a glass substrate of 25 mm × 25 mm × 0.7 t in which indium tin oxide (ITO) was patterned on the surface with a film thickness of 150 nm was used by an O 2 plasma cleaning apparatus (150 W, 30 seconds) before use. Impurities on the surface were removed. Subsequently, the hole injection layer solution prepared in Preparation Example 1 was applied and formed by spin coating, heated to 50 ° C. on a hot plate in the air, dried for 5 minutes, and then heated and fired at 230 ° C. for 15 minutes. Then, a hole injection layer (film thickness: 30 nm) was formed.
Next, in a glove box in a nitrogen atmosphere, a 0.4% by mass toluene solution of a hole transport material (manufactured by American Dice Source, trade name: ADS259BE) was applied onto the hole injection layer by spin coating, and formed into a film. Heat-firing was performed at 180 ° C. for 10 minutes to form a hole transport layer A (film thickness: 10 nm).

次に蒸着装置（真空度１．０×１０-5Ｐａ）を用いてトリス（８−キノリノラート）アルミニウム（ＩＩＩ）（Ａｌｑ3）、フッ化リチウム、およびアルミニウムの薄膜を順次積層し、有機ＥＬ素子を得た。この際、蒸着レートは、Ａｌｑ3およびアルミニウムについては０．２ｎｍ／秒、フッ化リチウムについては０．０２ｎｍ／秒の条件でそれぞれ行い、膜厚は、それぞれ４０ｎｍ、０．５ｎｍおよび１００ｎｍとした。
なお、空気中の酸素、水等の影響による特性劣化を防止するため、有機ＥＬ素子は封止基板により封止した後、その特性を評価した。封止は、以下の手順で行った。
酸素濃度４０ｐｐｍ以下、露点−８５℃以下の窒素雰囲気中で、有機ＥＬ素子を封止基板の間に収め、封止基板を接着材（ナガセケムテックス（株）製，ＸＮＲ５５１６Ｚ−Ｂ１）により貼り合わせた。この際、補水剤（ダイニック（株）製，ＨＤ−０７１０１０Ｗ−４０）を有機ＥＬ素子と共に封止基板内に収めた。
貼り合わせた封止基板に対し、ＵＶ光を照射（波長：３６５ｎｍ、照射量：６０００ｍＪ／ｃｍ2）した後、８０℃で１時間、アニーリング処理して接着材を硬化させた。 Next, tris (8-quinolinolato) aluminum (III) (Alq 3 ), lithium fluoride, and an aluminum thin film are sequentially laminated using a vapor deposition apparatus (degree of vacuum: 1.0 × 10 −5 Pa), and an organic EL element Got. At this time, the deposition rate was 0.2 nm / second for Alq 3 and aluminum, and 0.02 nm / second for lithium fluoride, and the film thicknesses were 40 nm, 0.5 nm, and 100 nm, respectively.
In addition, in order to prevent the characteristic deterioration by the influence of oxygen in the air, water, etc., after sealing the organic EL element with the sealing substrate, the characteristic was evaluated. Sealing was performed according to the following procedure.
In a nitrogen atmosphere with an oxygen concentration of 40 ppm or less and a dew point of −85 ° C. or less, the organic EL element is placed between the sealing substrates, and the sealing substrate is bonded with an adhesive (XNR5516Z-B1 manufactured by Nagase ChemteX Corporation). It was. At this time, a water replenisher (manufactured by Dynic Co., Ltd., HD-071010W-40) was placed in the sealing substrate together with the organic EL element.
The bonded sealing substrate was irradiated with UV light (wavelength: 365 nm, irradiation amount: 6000 mJ / cm 2 ), and then annealed at 80 ° C. for 1 hour to cure the adhesive.

［作製例２］
正孔輸送層Ａに換えて、正孔輸送材料（アメリカンダイソース社製、商品名：ＡＤＳ２５２ＢＥ）の０．７質量％キシレン溶液を正孔注入層上にスピンコートにより塗布成膜し、１８０℃で１０分間の加熱焼成を行って正孔輸送層Ｂ（膜厚１０ｎｍ）を形成した以外は、作製例１と同様の方法で有機ＥＬ素子を作製した。 [Production Example 2]
In place of the hole transport layer A, a 0.7% by mass xylene solution of a hole transport material (manufactured by American Dice Source, trade name: ADS252BE) was applied onto the hole injection layer by spin coating, and the film was formed at 180 ° C. An organic EL device was produced in the same manner as in Production Example 1 except that the hole transport layer B (film thickness 10 nm) was formed by heating and baking for 10 minutes.

上記各作製例で得られた有機ＥＬ素子について、電圧−電流密度特性、電圧−輝度特性および電流密度−電流効率特性を測定した。結果を図１〜３にそれぞれ示す。
図２，３に示されるように、作製例１の素子の方が、作製例２の素子よりも輝度および電流効率に優れていることがわかる。 About the organic EL element obtained by each said manufacture example, the voltage-current density characteristic, the voltage-luminance characteristic, and the current density-current efficiency characteristic were measured. The results are shown in FIGS.
As shown in FIGS. 2 and 3, it can be seen that the device of Production Example 1 is superior in luminance and current efficiency to the device of Production Example 2.

［２］インピーダンス分光法による有機ＥＬ素子の静電容量の周波数特性の評価
［実施例１］
作製例１，２で作製した有機ＥＬ素子において、再結合に寄与するキャリア数一定（＝発光輝度：５００ｃｄ／ｍ2の一定）の条件下で、静電容量の周波数特性を測定した。その結果を図４に示す。
図４に示されるように、静電容量が０となる周波数は、それぞれ作製例１の素子：７４１Ｈｚ、作製例２の素子：２７５４Ｈｚであった。この結果より、同輝度で比較した際、作製例２の素子よりも作製例１の素子の方が、より電子ブロック性の高い素子であると判定できる。 [2] Evaluation of frequency characteristics of capacitance of organic EL element by impedance spectroscopy [Example 1]
In the organic EL elements produced in Production Examples 1 and 2, the frequency characteristics of the capacitance were measured under the condition that the number of carriers contributing to recombination was constant (= emission luminance: constant 500 cd / m 2 ). The result is shown in FIG.
As shown in FIG. 4, the frequency at which the capacitance becomes 0 was 741 Hz for the manufacturing example 1 and 2754 Hz for the 2nd manufacturing example. From this result, when compared at the same luminance, it can be determined that the element of Preparation Example 1 is an element having a higher electron blocking property than the element of Preparation Example 2.

［実施例２］
作製例１，２で作製した有機ＥＬ素子において、素子を通過するキャリア数一定（＝電流密度：５０ｍＡ／ｃｍ2の一定）の条件下で、静電容量の周波数特性を測定した。その結果を図５に示す。
図５に示されるように、静電容量が０となる周波数は、それぞれ作製例１の素子：１６９８Ｈｚ、作製例２の素子：２０４２Ｈｚであった。この結果より、同電流密度で比較した際、作製例２の素子よりも作製例１の素子が、より電子ブロック性の高い素子であると判定できる。 [Example 2]
In the organic EL devices manufactured in Preparation Examples 1 and 2, the frequency characteristics of capacitance were measured under the condition that the number of carriers passing through the device was constant (= current density: constant 50 mA / cm 2 ). The result is shown in FIG.
As shown in FIG. 5, the frequencies at which the capacitance becomes 0 were, respectively, the element of Production Example 1: 1698 Hz and the element of Production Example 2: 2042 Hz. From this result, when compared at the same current density, it can be determined that the element of Production Example 1 is an element having a higher electron blocking property than the element of Production Example 2.

Claims (6)

インピーダンス分光法を用いた有機エレクトロルミネッセンス素子におけるキャリアブロック性の評価方法であって、
前記有機エレクトロルミネッセンス素子に発光閾値電圧以上の直流電圧を印加するとともに交流電圧を重畳して印加し、この交流電圧の周波数を変化させて静電容量が０となる周波数を測定することを特徴とするキャリアブロック性の評価方法。 An evaluation method of carrier block property in an organic electroluminescence device using impedance spectroscopy,
A DC voltage equal to or higher than a light emission threshold voltage is applied to the organic electroluminescence element and an AC voltage is superimposed and applied, and the frequency at which the capacitance becomes 0 is measured by changing the frequency of the AC voltage. To evaluate carrier block performance. 前記有機エレクトロルミネッセンス素子が複数個あり、それら各素子のそれぞれに、注入キャリア数が一定となる条件下で前記直流電圧および交流電圧を印加し、この交流電圧の周波数を変化させて静電容量が０となる周波数を測定し、それらを比較する請求項１記載のキャリアブロック性の評価方法。   There are a plurality of the organic electroluminescence elements, and the DC voltage and the AC voltage are applied to each of the elements under the condition that the number of injected carriers is constant, and the frequency of the AC voltage is changed to change the capacitance. The carrier block property evaluation method according to claim 1, wherein frequencies that become 0 are measured and compared. 前記周波数測定時の前記各素子の発光輝度を一定とすることで、前記注入キャリア数を一定とする請求項２記載のキャリアブロック性の評価方法。   3. The carrier block property evaluation method according to claim 2, wherein the number of injected carriers is made constant by making light emission luminance of each element constant during the frequency measurement. 前記周波数測定時の前記各素子の電流密度を一定とすることで、前記注入キャリア数を一定とする請求項２記載のキャリアブロック性の評価方法。   3. The carrier block property evaluation method according to claim 2, wherein the number of injected carriers is made constant by making the current density of each element at the time of frequency measurement constant. 前記交流電圧が、直流電圧の１／５以下である請求項１〜４のいずれか１項記載のキャリアブロック性の評価方法。   The carrier block property evaluation method according to any one of claims 1 to 4, wherein the AC voltage is 1/5 or less of a DC voltage. 前記有機エレクトロルミネッセンス素子が、陽極および陰極と、これら各極間に介在する、発光層を含む２層以上の有機膜とから構成される請求項１〜５のいずれか１項記載のキャリアブロック性の評価方法。   The carrier block property according to any one of claims 1 to 5, wherein the organic electroluminescent element is composed of an anode and a cathode, and two or more organic films including a light emitting layer interposed between the anode and the cathode. Evaluation method.
JP2013226642A 2013-10-31 2013-10-31 Evaluation method of carrier block performance in organic electroluminescent element Pending JP2015088365A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
JP2013226642A JP2015088365A (en) 2013-10-31 2013-10-31 Evaluation method of carrier block performance in organic electroluminescent element
TW103136297A TW201531719A (en) 2013-10-31 2014-10-21 Evaluation method of carrier blocking performance of organic electroluminescent element
KR1020140148213A KR20150050452A (en) 2013-10-31 2014-10-29 Mathod for evaluating carrier blocking property in organic electroluminescent device
CN201410601766.5A CN104597385A (en) 2013-10-31 2014-10-31 Assessment method for current carrier barrier performance in organic electroluminescent element

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2013226642A JP2015088365A (en) 2013-10-31 2013-10-31 Evaluation method of carrier block performance in organic electroluminescent element

Publications (1)

Publication Number Publication Date
JP2015088365A true JP2015088365A (en) 2015-05-07

Family

ID=53050934

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2013226642A Pending JP2015088365A (en) 2013-10-31 2013-10-31 Evaluation method of carrier block performance in organic electroluminescent element

Country Status (4)

Country Link
JP (1) JP2015088365A (en)
KR (1) KR20150050452A (en)
CN (1) CN104597385A (en)
TW (1) TW201531719A (en)

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008146956A (en) * 2006-12-08 2008-06-26 Seiko Epson Corp Light-emitting device, electronic apparatus, and detecting method of carrier balancing
JP2010217848A (en) * 2009-03-19 2010-09-30 Hitachi Displays Ltd Image display device
JP2010272286A (en) * 2009-05-20 2010-12-02 Konica Minolta Holdings Inc Method of manufacturing white light emitting organic electroluminescent element
JP2011090889A (en) * 2009-10-22 2011-05-06 Panasonic Corp Manufacturing method of organic el display device, its inspection device, and inspection method
WO2013073169A1 (en) * 2011-11-15 2013-05-23 出光興産株式会社 White organic electroluminescent element
WO2013111459A1 (en) * 2012-01-25 2013-08-01 コニカミノルタ株式会社 Evaluation method, evaluation device, evaluation program, recording medium, and manufacturing method for organic electroluminescent element
WO2013118507A1 (en) * 2012-02-10 2013-08-15 出光興産株式会社 Material for organic electroluminescent element, and organic electroluminescent element using same

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4554721B1 (en) * 2009-07-31 2010-09-29 富士フイルム株式会社 Organic electroluminescence device and evaluation method thereof

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008146956A (en) * 2006-12-08 2008-06-26 Seiko Epson Corp Light-emitting device, electronic apparatus, and detecting method of carrier balancing
JP2010217848A (en) * 2009-03-19 2010-09-30 Hitachi Displays Ltd Image display device
JP2010272286A (en) * 2009-05-20 2010-12-02 Konica Minolta Holdings Inc Method of manufacturing white light emitting organic electroluminescent element
JP2011090889A (en) * 2009-10-22 2011-05-06 Panasonic Corp Manufacturing method of organic el display device, its inspection device, and inspection method
WO2013073169A1 (en) * 2011-11-15 2013-05-23 出光興産株式会社 White organic electroluminescent element
WO2013111459A1 (en) * 2012-01-25 2013-08-01 コニカミノルタ株式会社 Evaluation method, evaluation device, evaluation program, recording medium, and manufacturing method for organic electroluminescent element
WO2013118507A1 (en) * 2012-02-10 2013-08-15 出光興産株式会社 Material for organic electroluminescent element, and organic electroluminescent element using same

Also Published As

Publication number Publication date
CN104597385A (en) 2015-05-06
KR20150050452A (en) 2015-05-08
TW201531719A (en) 2015-08-16

Similar Documents

Publication Publication Date Title
CN107710439B (en) Organic charge transfer layer, organic el device, organic semiconductor equipment and organic optoelectronic equipment
Deng et al. The doping effect of cesium-based compounds on carrier transport and operational stability in organic light-emitting diodes
Lee et al. Analysis of interrelationship between efficiency and charge transport properties of green TADF organic light-emitting diodes with mixed host by impedance spectroscopy
Yang et al. Hybrid intermediate connector for tandem OLEDs with the combination of MoO3-based interlayer and p-type doping
WO2013103093A1 (en) Organic electroluminescent device and manufacturing method thereof
Jin et al. Intense green-light emission from 9, 10-bis (4-(1, 2, 2-triphenylvinyl) styryl) anthracene emitting electroluminescent devices
Kim et al. Understanding the charge dynamics in organic light-emitting diodes using convolutional neural network
Kim et al. A study of the characteristics of indium tin oxide after chlorine electro-chemical treatment
Zhang et al. Hole injection engineering with MoO3 interlayer in organic light-emitting diode revealed by impedance spectroscopy
JP2015088365A (en) Evaluation method of carrier block performance in organic electroluminescent element
Tsai et al. Characterization studies of NiO: K anode buffer layer in Alq3 and TADF-based organic light-emitting diodes by secondary ion mass spectrometry and admittance spectroscopy
JP6405579B2 (en) Organic EL device
Sarjidan et al. Determination of energy band diagram and charge carrier mobility of white emitting polymer from optical, electrical and impedance spectroscopy
KR100977152B1 (en) Method for manufacturing a transparent conducting oxides for organic semiconductor device having increased work function
Park et al. Optimization of organic light-emitting diode containing hydrochlorosilole electron transport layer through impedance spectroscopy analysis
Jou et al. Back Migration Based Long Lifetime Approach for Organic Light‐Emitting Diode
Park et al. Hole-Injection Properties Characteristics of Fluorinated Self-Assembled Monolayer on Polymeric and Organic Light-Emitting Diodes
JP6663142B2 (en) Organic electroluminescent device
Pinato et al. Impact of Trapped Charge and Interface Defects on the Degradation of the Optical and Electrical Characteristics in $\hbox {NPD/Alq} _ {3} $ OLEDs
Chen et al. Investigation and optimization of the charge generation layer (CGL) in tandem OLEDs using Taguchi’s orthogonal arrays and nondestructive capacitance-voltage (CV) measurements
KR20160065264A (en) Manufacturing method of organic light emitting device
JP5785871B2 (en) Organic EL device manufacturing method, organic EL device inspection method, and organic EL device determination method
KR20220108632A (en) Analysis of interrelationship between efficiency and charge transport properties of green TADF organic light-emitting diodes with mixed host by impedance spectroscopy
Khan et al. Estimation of electron mobility of n-doped 4, 7-diphenyl-1, 10-phenanthroline using space-charge-limited currents
Lee et al. Analysis of thermal stress effect on blue phosphorescent organic light-emitting diodes for device stability

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20160815

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20170317

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20170328

A601 Written request for extension of time

Free format text: JAPANESE INTERMEDIATE CODE: A601

Effective date: 20170526

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20170725

A02 Decision of refusal

Free format text: JAPANESE INTERMEDIATE CODE: A02

Effective date: 20170912