JPH06283267A - Electroluminescent element - Google Patents
Electroluminescent elementInfo
- Publication number
- JPH06283267A JPH06283267A JP5067002A JP6700293A JPH06283267A JP H06283267 A JPH06283267 A JP H06283267A JP 5067002 A JP5067002 A JP 5067002A JP 6700293 A JP6700293 A JP 6700293A JP H06283267 A JPH06283267 A JP H06283267A
- Authority
- JP
- Japan
- Prior art keywords
- light emitting
- organic
- complex
- complex salt
- emitting layer
- 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.)
- Granted
Links
- 239000003446 ligand Substances 0.000 claims abstract description 36
- 150000003839 salts Chemical class 0.000 claims abstract description 33
- 239000010409 thin film Substances 0.000 claims description 6
- 239000000463 material Substances 0.000 abstract description 48
- 229910052751 metal Inorganic materials 0.000 abstract description 12
- 239000002184 metal Substances 0.000 abstract description 12
- 238000002347 injection Methods 0.000 abstract description 11
- 239000007924 injection Substances 0.000 abstract description 11
- 239000011701 zinc Substances 0.000 abstract description 11
- 150000004697 chelate complex Chemical class 0.000 abstract description 8
- 239000007787 solid Substances 0.000 abstract description 8
- 229910052725 zinc Inorganic materials 0.000 abstract description 8
- BSKHPKMHTQYZBB-UHFFFAOYSA-N 2-methylpyridine Chemical compound CC1=CC=CC=N1 BSKHPKMHTQYZBB-UHFFFAOYSA-N 0.000 abstract description 4
- 239000011521 glass Substances 0.000 abstract description 3
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 abstract description 2
- YZEUHQHUFTYLPH-UHFFFAOYSA-N 2-nitroimidazole Chemical compound [O-][N+](=O)C1=NC=CN1 YZEUHQHUFTYLPH-UHFFFAOYSA-N 0.000 abstract 1
- 239000010410 layer Substances 0.000 description 36
- 230000007935 neutral effect Effects 0.000 description 13
- 239000000126 substance Substances 0.000 description 12
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 9
- 150000001875 compounds Chemical class 0.000 description 9
- 229920006395 saturated elastomer Polymers 0.000 description 9
- 229910021645 metal ion Chemical group 0.000 description 7
- 238000000859 sublimation Methods 0.000 description 7
- 230000008022 sublimation Effects 0.000 description 7
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 6
- 150000001450 anions Chemical class 0.000 description 6
- 150000001768 cations Chemical class 0.000 description 6
- 239000013522 chelant Substances 0.000 description 5
- 239000010408 film Substances 0.000 description 5
- 230000005525 hole transport Effects 0.000 description 5
- 238000003860 storage Methods 0.000 description 5
- 239000000758 substrate Substances 0.000 description 5
- DGEZNRSVGBDHLK-UHFFFAOYSA-N [1,10]phenanthroline Chemical compound C1=CN=C2C3=NC=CC=C3C=CC2=C1 DGEZNRSVGBDHLK-UHFFFAOYSA-N 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 150000004696 coordination complex Chemical class 0.000 description 4
- 150000002894 organic compounds Chemical class 0.000 description 4
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 229940052810 complex b Drugs 0.000 description 3
- 239000013078 crystal Substances 0.000 description 3
- 239000000975 dye Substances 0.000 description 3
- 238000005401 electroluminescence Methods 0.000 description 3
- 229920000642 polymer Polymers 0.000 description 3
- 238000001556 precipitation Methods 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- 229910017911 MgIn Inorganic materials 0.000 description 2
- YNPNZTXNASCQKK-UHFFFAOYSA-N Phenanthrene Natural products C1=CC=C2C3=CC=CC=C3C=CC2=C1 YNPNZTXNASCQKK-UHFFFAOYSA-N 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 239000011365 complex material Substances 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- AMGQUBHHOARCQH-UHFFFAOYSA-N indium;oxotin Chemical compound [In].[Sn]=O AMGQUBHHOARCQH-UHFFFAOYSA-N 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000000746 purification Methods 0.000 description 2
- SMQUZDBALVYZAC-UHFFFAOYSA-N salicylaldehyde Chemical compound OC1=CC=CC=C1C=O SMQUZDBALVYZAC-UHFFFAOYSA-N 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 238000001308 synthesis method Methods 0.000 description 2
- TXBBUSUXYMIVOS-UHFFFAOYSA-N thenoyltrifluoroacetone Chemical compound FC(F)(F)C(=O)CC(=O)C1=CC=CS1 TXBBUSUXYMIVOS-UHFFFAOYSA-N 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- FQJQNLKWTRGIEB-UHFFFAOYSA-N 2-(4-tert-butylphenyl)-5-[3-[5-(4-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]phenyl]-1,3,4-oxadiazole Chemical compound C1=CC(C(C)(C)C)=CC=C1C1=NN=C(C=2C=C(C=CC=2)C=2OC(=NN=2)C=2C=CC(=CC=2)C(C)(C)C)O1 FQJQNLKWTRGIEB-UHFFFAOYSA-N 0.000 description 1
- 229910052693 Europium Inorganic materials 0.000 description 1
- ROHFNLRQFUQHCH-UHFFFAOYSA-N Leucine Natural products CC(C)CC(N)C(O)=O ROHFNLRQFUQHCH-UHFFFAOYSA-N 0.000 description 1
- ZOIORXHNWRGPMV-UHFFFAOYSA-N acetic acid;zinc Chemical compound [Zn].CC(O)=O.CC(O)=O ZOIORXHNWRGPMV-UHFFFAOYSA-N 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 239000003599 detergent Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 150000004985 diamines Chemical class 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- OGPBJKLSAFTDLK-UHFFFAOYSA-N europium atom Chemical compound [Eu] OGPBJKLSAFTDLK-UHFFFAOYSA-N 0.000 description 1
- 150000002500 ions Chemical group 0.000 description 1
- 239000004973 liquid crystal related substance Substances 0.000 description 1
- 239000012044 organic layer Substances 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 150000003384 small molecules Chemical group 0.000 description 1
- 238000004506 ultrasonic cleaning Methods 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
- 239000004246 zinc acetate Substances 0.000 description 1
Classifications
-
- 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
- H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
- H10K50/11—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers
Landscapes
- Electroluminescent Light Sources (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は電界発光素子に関し、詳
しくはその発光材料の改良に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electroluminescent device, and more particularly to improvement of its light emitting material.
【０００２】[0002]
【従来の技術】近年、情報機器の多様化に伴って、ＣＲ
Ｔより低消費電力で空間占有容積が少ない平面表示素子
のニーズが高まっている。このような平面表示素子とし
ては、液晶、プラズマディスプレイ等があるが、特に最
近は、自己発光型で表示が鮮明な電界発光素子〔エレク
トロルミネッセンス（ＥＬ）素子〕が注目されている。2. Description of the Related Art In recent years, with the diversification of information equipment, CR
There is an increasing need for a flat panel display device that consumes less power and occupies less space than T. Liquid crystal, plasma display, and the like are available as such a flat display element, and in recent years, an electroluminescent element (electroluminescence (EL) element) which is self-luminous and has a clear display has recently attracted attention.
【０００３】ここで、上記電界発光素子は構成する材料
により、無機電界発光素子と有機電界発光素子とに大別
することができる。この中でも、低電圧で駆動すること
ができ、しかも、理論的には、有機化合物の分子構造を
変更することによって任意の発光色を容易に得ることが
できるといった利点を有している有機電界発光素子は、
これからの表示素子として、非常に有望である。Here, the above electroluminescent device can be roughly classified into an inorganic electroluminescent device and an organic electroluminescent device depending on the constituent materials. Among these, organic electroluminescence, which has an advantage that it can be driven at a low voltage, and that theoretically, any luminescent color can be easily obtained by changing the molecular structure of the organic compound The element is
It is very promising as a display device in the future.
【０００４】有機電界発光素子の発光材料として用いら
れる材料は、以下に示す３種類に大別できる。 （有機色素系材料） 有機色素系材料は低分子で、しかも金属元素を含まな
い、全て有機化合物で構成されている材料である。Materials used as a light emitting material of an organic electroluminescent device can be roughly classified into the following three types. (Organic dye-based material) The organic dye-based material is a material that is a low molecular weight compound and does not contain a metal element, and that is composed of all organic compounds.
【０００５】（キレート金属錯体系材料） キレート錯体系材料は有機化合物で構成されている配位
子と金属イオンが錯体を形成している材料である。 （高分子化合物系材料） 高分子化合物系材料は、分子量の高い有機化合物で構成
されている材料である。(Chelate Metal Complex Material) A chelate complex material is a material in which a ligand composed of an organic compound and a metal ion form a complex. (Polymer compound material) The polymer compound material is a material composed of an organic compound having a high molecular weight.
【０００６】上記した材料の中で最も優れた特性を示す
のが、８−Hydroxyquinoline-alnminum 錯体（Ａｌ
ｑ3 ）で代表されるようなキレート金属錯体である。キ
レート金属錯体は、製膜安定性が高いこと（製膜後、結
晶の析出が起こり難い）、電子輸送性が高いこと、螢光
収率が高いこと、など優れた物性を持っており、有機電
界発光素子の発光層に用いた場合、非常に安定で高輝度
を示す。さらに、合成が容易であるという利点も有して
いる。The most excellent property among the above-mentioned materials is the 8-Hydroxyquinoline-alnminum complex (Al
It is a chelate metal complex represented by q 3 ). The chelate metal complex has excellent physical properties such as high film formation stability (precipitation of crystals does not easily occur after film formation), high electron transport property, and high fluorescence yield. When used in the light emitting layer of an electroluminescent device, it is very stable and exhibits high brightness. Further, it has an advantage that it can be easily synthesized.
【０００７】[0007]
【発明が解決しようとする課題】上記したように、キレ
ート錯体は発光材料として様々な優れた特性を持ってい
る。しかしながら、キレート錯体の多くは、溶液に溶解
した状態では発光しても固体では発光しなかったり、或
いは、固体で螢光を発光しても極性が高いため昇華性が
大変低いという問題点を有している。このような問題点
を有する化合物は発光材料として素子に用いることはで
きない。実際、現在までキレート錯体金属を発光材料と
した素子の発表されたものは、Ａｌｑ3 系（C.W. Tang
and S.A. VanSlyke: Appl. Phys. Lett. 57 (1987) 91
3)や希土類元素系（J. Kido, K. Nagai, Y. Okamoto an
d T. Skotheim; Chem. Lett. (1991) 1267) など、他の
有機色素、高分子化合物に比べて極めて少ない。従っ
て、キレート錯体を発光材料に用いる場合、材料選択の
幅が大変に狭いという問題があった。As described above, the chelate complex has various excellent properties as a light emitting material. However, many chelate complexes have a problem that they do not emit light in a solid state even if they emit light in a state of being dissolved in a solution, or they have a very low sublimation property because they have high polarity even if they emit fluorescent light in a solid state. is doing. A compound having such a problem cannot be used for a device as a light emitting material. In fact, up to now, the announced devices using chelate complex metal as a light emitting material are Alq 3 (CW Tang)
and SA VanSlyke: Appl. Phys. Lett. 57 (1987) 91
3) and rare earth elements (J. Kido, K. Nagai, Y. Okamoto an
d T. Skotheim; Chem. Lett. (1991) 1267) and other organic dyes and polymer compounds are extremely small. Therefore, when the chelate complex is used as the light emitting material, there is a problem that the range of material selection is very narrow.
【０００８】本発明は、上記現状に鑑みなされたもので
あり、有機電界発光素子の有機発光層の材料選択の幅を
広げることを目的とする。The present invention has been made in view of the above situation, and it is an object of the present invention to broaden the selection range of materials for an organic light emitting layer of an organic electroluminescent device.
【０００９】[0009]
【課題を解決するための手段】上記目的を達成するため
に、請求項１の発明は、ホール注入電極と、電子注入電
極との間に少なくとも有機発光層を含む有機薄膜層を有
する電界発光素子において、上記有機薄膜層の材料とし
て、２種類以上の配位子を含む分子内錯塩が用いられて
いることを特徴とする。In order to achieve the above object, the invention of claim 1 is an electroluminescent device having an organic thin film layer including at least an organic light emitting layer between a hole injecting electrode and an electron injecting electrode. In the above, as the material of the organic thin film layer, an intramolecular complex salt containing two or more kinds of ligands is used.
【００１０】請求項２の発明は、請求項１記載の電界発
光素子において、上記分子内錯塩が、有機発光層に用い
られていることを特徴とする。請求項３の発明は、請求
項２記載の電界発光素子において、上記有機薄膜層が更
に有機電子輸送層を有しており、当該有機電子輸送層に
分子内錯塩を用いたことを特徴とする。The invention according to claim 2 is the electroluminescent element according to claim 1, wherein the intramolecular complex salt is used in an organic light emitting layer. According to a third aspect of the invention, in the electroluminescent device according to the second aspect, the organic thin film layer further has an organic electron transport layer, and an intramolecular complex salt is used for the organic electron transport layer. .
【００１１】[0011]
【作用】一般的にキレート錯体は、図２に示すように、
０世代〜３世代の４つの世代に分類することができる。
先ず、第０世代の錯体とは電荷を帯び、配位数が不飽和
なものをである。具体的な化合物の例は、図中の錯体ａ
である。錯体ａの中心金属はＡｌであり、配位数が６で
３価の陽イオンである。一方、配位子はアゾメチンであ
り、ドナー基の数が３で２価の陰イオンである。錯体ａ
は上記のような金属イオンと配位子との１対１の錯体で
あるため、プラスの電荷を帯び、しかも配位数も不飽和
な状態になっている。[Function] Generally, a chelate complex, as shown in FIG.
It can be classified into four generations, 0th generation to 3rd generation.
First, the 0th generation complex is one having an electric charge and an unsaturated coordination number. Examples of specific compounds are complex a in the figure.
Is. The central metal of the complex a is Al, which has a coordination number of 6 and is a trivalent cation. On the other hand, the ligand is azomethine, which is a divalent anion with three donor groups. Complex a
Is a 1: 1 complex of a metal ion and a ligand as described above, and therefore has a positive charge, and the coordination number is also in an unsaturated state.
【００１２】第１世代の錯体とは電荷が中性で、配位数
が不飽和なものである。具体的な化合物の例は図中の錯
体ｂである。錯体ｂの中心金属はＺｎであり、配位数が
４で２価の陽イオンである。一方、配位子はアゾメチン
は、ドナーの数が３で２価の陰イオンである。錯体ｂは
上記のような金属イオンと配位子との１対１の錯体であ
るため、電荷は中性であるが、配位数は不飽和な状態に
なっている。The first-generation complex has a neutral charge and an unsaturated coordination number. An example of a specific compound is the complex b in the figure. The central metal of the complex b is Zn, which has a coordination number of 4 and is a divalent cation. On the other hand, the ligand, azomethine, is a divalent anion with three donors. Since the complex b is a 1: 1 complex of a metal ion and a ligand as described above, the charge is neutral, but the coordination number is in an unsaturated state.
【００１３】第２世代の錯体とは電荷が中性で、配位数
が飽和なものである。一般にこのような状態（電荷が中
性、配位数が飽和）の錯体を分子内錯塩と称する。具体
的な化合物の例は図中の錯体ｃである。錯体ｃは、中心
金属が配位数が４で２価の陽イオンであるＺｎであり、
配位子が２価の陰イオンで配位数４のアゾメチンであ
る。上記のような配位子と中心金属との１対１の錯体で
あるので、電荷が中性で、且つ、配位数も飽和な状態に
なっている。The second-generation complex has a neutral charge and a saturated coordination number. Generally, a complex in such a state (neutral charge and saturated coordination number) is called an intramolecular complex salt. An example of a specific compound is the complex c in the figure. In the complex c, the central metal is Zn having a coordination number of 4 and a divalent cation,
The ligand is azomethine having a divalent anion and a coordination number of 4. Since it is a one-to-one complex of the ligand and the central metal as described above, the charge is neutral and the coordination number is saturated.
【００１４】第３世代の錯体も、電荷が中性で、配位数
が飽和な分子内錯塩である。具体的には図中の錯体ｄで
あり、Ｚｎ金属錯体は中心金属が配位数４で２価の陽イ
オンである。配位子はドナー基の数が３で、２価の陰イ
オンのアゾメチンと、ドナー基の数が１で電荷が中性の
ピコリンである。錯体ｄはこれら金属イオンと配位子と
の１対１対１の錯体であり、電荷が中性で配位数の飽和
になっている。The third-generation complex is also an intramolecular complex salt having a neutral charge and a saturated coordination number. Specifically, it is the complex d in the figure, and the central metal of the Zn metal complex is a divalent cation having a coordination number of 4. The ligand is azomethine, which is a divalent anion and has 3 donor groups, and picoline, which has 1 donor group and is neutral in charge. The complex d is a one-to-one-one complex of these metal ions and a ligand, and has a neutral charge and a saturated coordination number.
【００１５】第２世代、第３世代何れも電荷、配位数が
飽和な分子内錯塩であるが、以下のような違いがある。
第２世代の中心金属イオンの配位数及び電荷と一致する
ドナー基の数と電荷を有する１種類の配位子を用いて錯
体（分子構造内の配位子の種類は１種類）を形成させた
ものある。一方、第３世代は、すでに形成している錯体
が電荷を帯びているか、または中心金属イオンの配位数
が不飽和な場合、その錯体を構成している配位子とは別
種の配位子を中心金属に配位させ、電荷の中和及び配位
数の飽和を図ることによって形成された錯体（分子構造
内の配位子の種類は２種類以上。）である。Both the second generation and the third generation are intramolecular complex salts with saturated charges and coordination numbers, but have the following differences.
A complex (one kind of ligand in the molecular structure is one kind) is formed by using one kind of ligand having the number and the number of donor groups that match the coordination number and charge of the second-generation central metal ion. There is something I let you do. On the other hand, in the 3rd generation, when the complex already formed is charged or the coordination number of the central metal ion is unsaturated, the coordination of a different species from the ligand constituting the complex It is a complex (two or more kinds of ligands in the molecular structure) formed by coordinating the child with the central metal to neutralize the charge and saturate the coordination number.
【００１６】それぞれの世代のキレート錯体について発
光材料としての評価を行ってみると、先ず、第０世代の
錯体は、水溶液中では強い螢光を持っているが極性が高
いために固体が得られず、発光材料としては用いること
ができない。第１世代の錯体については、第０世代と比
較すると極性は低く、螢光性の固体は得られるが、まだ
極性が高く、昇華性がなく、発光材料として用いること
ができない。When the chelate complex of each generation was evaluated as a light-emitting material, first, the 0th generation complex had strong fluorescence in an aqueous solution, but a solid was obtained because of its high polarity. Therefore, it cannot be used as a light emitting material. The first-generation complex has a lower polarity than that of the 0-th generation, and a fluorescent solid is obtained, but it is still high in polarity and has no sublimation property and cannot be used as a light emitting material.
【００１７】第２世代の錯体は、螢光性の固体で、しか
も極性が低いために昇華性があり、発光材料として用い
ることができる。しかしながら、この第２世代の錯体の
分子構造内に存在する配位子の種類は１種類であり、１
種類の配位子で中心金属の電界を中和し、配位数を飽和
させためには、使用される配位子が限定され、結果とし
て発光材料として用いることのできる化合物の選択の幅
を広げるにはいたらない。The second-generation complex is a fluorescent solid and has sublimability because it has a low polarity and can be used as a light-emitting material. However, there is one kind of ligand present in the molecular structure of this second generation complex, and
In order to neutralize the electric field of the central metal and saturate the coordination number with various kinds of ligands, the ligands used are limited, and as a result, the range of selection of compounds that can be used as the light emitting material is limited. It's useless to unfold.
【００１８】本発明の発光材料として用いられる第３世
代の錯体は、上記したように、第２世代と同様に、電荷
は中性で、配位数も飽和であるため、螢光性固体が得ら
れ、昇華性も高く、発光材料として用いることができ
る。この錯体は、分子構造内に２種類の配位子を有して
いることにより、一種類の配位子を用いた錯体では、中
心金属イオンの配位数と、電荷を飽和することができな
い配位子も、他の種類の配位子と組み合わせることによ
って用いることができるようになり、配位子の選択の自
由度は高まる。この結果、発光材料として用いることの
できる材料の種類を増やすことができ、発光材料の選択
の幅が広がる。As described above, the third-generation complex used as the light-emitting material of the present invention has a neutral charge and a saturated coordination number, as in the second-generation complex. It is obtained and has a high sublimation property and can be used as a light emitting material. Since this complex has two kinds of ligands in the molecular structure, the coordination number of the central metal ion and the charge cannot be saturated in the complex using one kind of ligand. A ligand can also be used by combining it with another type of ligand, and the degree of freedom in selecting a ligand is increased. As a result, the types of materials that can be used as the light emitting material can be increased, and the range of selection of the light emitting material can be widened.
【００１９】また、分子内錯塩は、電子輸送性を有して
おり、電子輸送層の材料として用いることができる。特
に、発光層の材料にも分子内錯塩を用いて素子を作成し
た場合、類似の分子構造をもつ化合物を材料に用いるこ
ととなり、電子輸送層と有機発光層との界面接合状態が
良好になり、発光特性が向上するものと考えられる。さ
らに、この分子内錯塩は製膜後の安定性が高いために、
結晶の析出がおこり難く、保存特性が向上するものと考
えられる。The intramolecular complex salt has an electron transporting property and can be used as a material for the electron transporting layer. In particular, when an element is created using an intramolecular complex salt as the material of the light emitting layer, a compound having a similar molecular structure is used as the material, and the interface bonding state between the electron transport layer and the organic light emitting layer is improved. It is considered that the light emission characteristics are improved. Furthermore, since this intramolecular complex salt has high stability after film formation,
It is considered that the precipitation of crystals hardly occurs and the storage characteristics are improved.
【００２０】[0020]
（第一実施例） （実施例１）図１は、本発明の実施例１に係る電界発光
素子の断面図であり、ガラス基板１上にはホール注入電
極２と、有機ホール輸送層３（厚み ５００Å）と、有
機発光層４（厚み ５００Å）と、電子注入電極５（厚
み ２０００Å）とが順に形成されている。(First Example) (Example 1) FIG. 1 is a cross-sectional view of an electroluminescent device according to a first example of the present invention, in which a hole injection electrode 2 and an organic hole transport layer 3 ( A thickness of 500Å), an organic light emitting layer 4 (thickness of 500Å), and an electron injection electrode 5 (thickness of 2000Å) are sequentially formed.
【００２１】上記構造の素子において、ホール注入電極
２の材料としてはインジウム−スズ酸化物（ＩＴＯ）
が、有機ホール輸送層３の材料としてはジアミン誘導体
（ＴＰＤ 下記化１に示す）が、有機発光層４の材料と
してはアゾメチン−ピコリン−亜鉛から構成される分子
内体錯塩（下記化２に示す）が、電子注入電極５の材料
としてはＭｇＩｎ合金（比率１０対１）がそれぞれ用い
られている。In the element having the above structure, the material of the hole injecting electrode 2 is indium-tin oxide (ITO).
However, a diamine derivative (TPD shown in the following chemical formula 1) is used as the material of the organic hole transport layer 3, and an azomethine-picoline-zinc is used as the material of the organic light-emitting layer 4 in the intramolecular complex salt (shown in the chemical formula 2 below). ), MgIn alloy (ratio 10: 1) is used as the material of the electron injection electrode 5.
【００２２】[0022]
【化１】 [Chemical 1]
【００２３】[0023]
【化２】 [Chemical 2]
【００２４】ここで、上記構造の電界発光素子を以下の
ようにして作製した。先ず、ガラス基板１上にホール注
入電極２であるインジウム−スズ酸化物膜（ＩＴＯ）が
形成された基板を中性洗剤により洗浄したのち、アセト
ン中で２０分間、エタノール中で２０分間超音波洗浄を
行った。次いで上記基板を沸騰したエタノール中に約１
分間入れ取り出した後、すぐに送風乾燥を行った。この
後、上記ＩＴＯからなるホール注入電極２上にＴＰＤを
真空蒸着して有機ホール輸送層３を形成した。続いて、
この有機ホール輸送層３上にアゾメチン−ピコリン−亜
鉛の分子内錯塩を真空蒸着して有機発光層４を形成し、
さらにその上にＭｇＩｎ合金からなる電子注入電極５を
形成した。尚、これらの蒸着は何れも真空度１×１０-6
Ｔｏｒｒ、基板温度２０℃、有機層の蒸着速度２Å／ｓ
ｅｃという条件下で行なった。 （合成方法１）有機発光層３の材料として用いたアゾメ
チン−ピコリン−亜鉛から構成された分子内錯塩は以下
のようにして行なった。Here, an electroluminescent device having the above structure was manufactured as follows. First, a substrate in which the indium-tin oxide film (ITO) that is the hole injecting electrode 2 is formed on the glass substrate 1 is washed with a neutral detergent, and then ultrasonic cleaning is performed in acetone for 20 minutes and in ethanol for 20 minutes. I went. Then, the above substrate was placed in boiling ethanol for about 1
Immediately after putting in and taking out for a minute, blast drying was performed. Then, TPD was vacuum-deposited on the hole injection electrode 2 made of ITO to form the organic hole transport layer 3. continue,
An azomethine-picoline-zinc intramolecular complex salt is vacuum-deposited on the organic hole transport layer 3 to form an organic light emitting layer 4,
Further, an electron injection electrode 5 made of a MgIn alloy was formed thereon. All of these vapor depositions have a vacuum degree of 1 × 10 −6.
Torr, substrate temperature 20 ° C., deposition rate of organic layer 2Å / s
It was performed under the condition of ec. (Synthesis Method 1) The intramolecular complex salt composed of azomethine-picoline-zinc used as the material for the organic light emitting layer 3 was prepared as follows.
【００２５】先ず、ＤＬロイシン１５．２５ｍｍｏｌを
メタノール２０ｍｌ中に入れ、少し加温しながら溶解さ
せた。次に、サリチルアルデヒド１５．２５ｍｍｏｌと
ピコリン３ｍｌをこの反応系に添加すると、黄濁した。
さらにこの系に酢酸亜鉛１５．２５ｍｍｏｌを含有した
メタノール溶液３０ｍｌを入れて、２時間還流すると、
強い青色の螢光を持ったアゾメチン−ピコリン−亜鉛か
ら構成される分子内錯塩が生成された。この分子内錯塩
は、メタノールに完全に溶解するので、水を加えて、錯
体を沈澱させた。精製は昇華精製法を用いて行った。First, 15.25 mmol of DL leucine was put into 20 ml of methanol and dissolved while slightly heating. Next, when 15.25 mmol of salicylaldehyde and 3 ml of picoline were added to this reaction system, it became cloudy.
Furthermore, 30 ml of a methanol solution containing 15.25 mmol of zinc acetate was added to this system, and the mixture was refluxed for 2 hours.
An intramolecular complex composed of azomethine-picoline-zinc with strong blue fluorescence was formed. Since this intramolecular complex salt was completely dissolved in methanol, water was added to precipitate the complex. Purification was performed using the sublimation purification method.
【００２６】この錯体において、中心金属の亜鉛は２価
の陽イオン、配位数４であり、配位子アゾメチンは２価
の陰イオン、ドナー基の数が３個、配位子ピコリンは電
荷は中性、ドナー基の数が１個であるため、錯体全体と
して、分子内錯塩を形成している。従って、この分子内
錯塩は極性が低く、固体状態で発光し、昇華が可能で電
界発光素子を作製することができる。In this complex, the central metal zinc is a divalent cation with a coordination number of 4, the ligand azomethine is a divalent anion, the number of donor groups is 3, and the ligand picoline is a charge. Since is neutral and has one donor group, the complex as a whole forms an intramolecular complex salt. Therefore, this intramolecular complex salt has a low polarity, emits light in a solid state, is capable of sublimation, and is capable of producing an electroluminescence device.
【００２７】このように作製した素子を以下、（ａ1 ）
素子と称する。 （実施例２）素子構造をホール注入電極と電子注入電極
との間に有機ホール注入輸送層（厚み ５００Å）と、
有機発光層（厚み １００Å）と、有機電子輸送層（厚
み４００Å）とが順に形成された３層構造とし、有機発
光層の材料として下記化３に示すＥｕ（ＴＴＡ）3 （ｐ
ｈｅｎ）（ＴＴＡ＝２−テノイルトリフルオロアセト
ン、ｐｈｅｎ＝１，１０−フェナントロリン）を用い、
有機電子輸送層の材料として下記化４に示すＯＸＤ−７
を用いた以外は、上記実施例１と同様に素子を作成し
た。The element thus produced is referred to below as (a 1 )
It is called an element. (Example 2) An organic hole injecting and transporting layer (thickness 500Å) is provided between a hole injecting electrode and an electron injecting electrode, and
The organic light-emitting layer (thickness 100 Å) and the organic electron transport layer (thickness 400 Å) are sequentially formed to have a three-layer structure, and the material of the organic light-emitting layer is Eu (TTA) 3 (p
hen) (TTA = 2-thenoyltrifluoroacetone, phen = 1,10-phenanthroline),
As a material of the organic electron transport layer, OXD-7 shown in the following chemical formula 4
A device was prepared in the same manner as in Example 1 except that was used.
【００２８】[0028]
【化３】 [Chemical 3]
【００２９】[0029]
【化４】 [Chemical 4]
【００３０】（合成方法２）実施例２のＥｕ（ＴＴＡ）
3 （ｐｈｅｎ）は以下の方法で合成を行った。ＴＴＡ９
ｍｍｏｌとｐｈｅｎ３ｍｍｏｌとをエタノール２０ｍｌ
に室温で溶解させた。さらに１ＮのＮａＯＨ水溶液３ｍ
ｌを加えて、反応系を６０℃に加熱しながら、ＥｕＣｌ
3 ・６Ｈ2 Ｏ ３ｍｍｏｌを１０ｍｌの水に溶解させた
ものを滴下ロートより、開放系で滴下した。滴下終了
後、６０℃に保ちながら１時間攪拌した。生成した沈澱
物を吸引ろ過した後、昇華精製を行った。(Synthesis Method 2) Eu (TTA) of Example 2
3 (phen) was synthesized by the following method. TTA9
mmol and phen3 mmol in ethanol 20 ml
Dissolved at room temperature. 1m NaOH aqueous solution 3m
1 was added to the reaction system while heating the reaction system to 60 ° C.
Than 3 · 6H 2 O 3mmol dropping those dissolved in 10ml of water funnel, was added dropwise in an open system. After completion of the dropping, the mixture was stirred for 1 hour while maintaining the temperature at 60 ° C. The precipitate formed was suction filtered and then purified by sublimation.
【００３１】この錯体において、中心金属のユーロピウ
ムは３価の陽イオンであり、配位数は８である。一方、
配位子の２−テノイルトリフルオロアセトンは、ドーナ
基の数が２、電荷が１価の陰イオンであり、１、１０−
フェナントロリンはドナー基の数が２で電荷が中性であ
る。したがって、錯体全体として、配位数、及び、電荷
はそれぞれ中性、飽和であり、分子内錯塩を形成してい
る。In this complex, the central metal europium is a trivalent cation and has a coordination number of 8. on the other hand,
The ligand 2-thenoyltrifluoroacetone is an anion having two donor groups and a monovalent charge, and is 1,10-
Phenanthroline has two donor groups and a neutral charge. Therefore, the coordination number and the charge of the complex as a whole are neutral and saturated, respectively, and form an intramolecular complex salt.
【００３２】このように作製した素子を以下、（ａ2 ）
素子と称する。 （実験）本実施例の（ａ1 ）素子、（ａ2 ）素子を用い
て、ホール注入電極をプラス、電子注入電極をマイナス
にバイアスして、電圧を印加し、素子の発光特性を調べ
たので下記表１にその結果を示す。The element thus produced is referred to below as (a 2 )
It is called an element. (Experiment) Using the (a 1 ) element and the (a 2 ) element of the present example, the hole injection electrode was positively biased and the electron injection electrode was negatively biased, and a voltage was applied to examine the emission characteristics of the element. The results are shown in Table 1 below.
【００３３】[0033]
【表１】 [Table 1]
【００３４】表１から明らかなように、（ａ1 ）素子、
（ａ2 ）素子それぞれ青色、赤色の発光を呈した。 （第２実施例） （実施例）有機発光層にアゾメチン−ピコリン−亜鉛か
ら構成された分子内錯塩（上記化２に示す）、有機電子
輸送層にアゾメチン−ピリジン−亜鉛から構成された分
子内錯塩（下記化５に示す）を用いた以外は、上記実施
例２と同様に素子を作成した。As is clear from Table 1, (a 1 ) element,
The (a 2 ) device exhibited blue light emission and red light emission, respectively. (Second Example) (Example) Intramolecular complex salt composed of azomethine-picoline-zinc (shown in Chemical Formula 2 above) in the organic light-emitting layer, and intramolecular complex salt composed of azomethine-pyridine-zinc in the organic electron transport layer. An element was prepared in the same manner as in Example 2 except that a complex salt (shown in Chemical Formula 5 below) was used.
【００３５】このように作成した素子を、以下（ｂ）素
子と称する。The element thus produced is hereinafter referred to as (b) element.
【００３６】[0036]
【化５】 [Chemical 5]
【００３７】（比較例）有機電子輸送層にｔＢｕ−ＰＢ
Ｄ（下記化６に示す）を用いた以外は上記実施例と同様
に素子を作成した。Comparative Example tBu-PB was added to the organic electron transport layer.
A device was prepared in the same manner as in the above-mentioned example except that D (shown in the following chemical formula 6) was used.
【００３８】[0038]
【化６】 [Chemical 6]
【００３９】このように作成した素子を、以下（ｙ）素
子と称する。 （実験）本実施例の（ｂ）素子と比較例の（ｙ）素子を
用いて、発光輝度、発光ピーク波長、発光色、さらに、
保存特性を調べたので下記表２にその結果を示す。The element thus prepared is hereinafter referred to as (y) element. (Experiment) Using the device (b) of this example and the device (y) of the comparative example, the emission luminance, emission peak wavelength, emission color, and
The storage characteristics were examined, and the results are shown in Table 2 below.
【００４０】[0040]
【表２】 [Table 2]
【００４１】表１から明らかなように、本実施例の
（ｂ）素子の方が、低電圧、低電流密度でありながら高
輝度発光を呈した。これは、有機電子輸送層に有機発光
層と類似の分子構造を持つ分子内錯塩を用いることによ
り、電子輸送層と発光層との界面接合状態が良好にな
り、発光特性が向上したものと考えられる。また、比較
例の（ｙ）素子は保存３日後には光らなくなったが、本
実施例の（ｂ）素子は保存１週間後にも良好な発光を示
した。これは、ｔＢｕ−ＰＢＤと比較して分子内錯塩は
製膜後の安定が高いために、結晶の析出が起こらず、保
存性が向上したものと考えられる。As is clear from Table 1, the device (b) of this example exhibited higher luminance light emission with a lower voltage and a lower current density. It is considered that the use of an intramolecular complex salt having a molecular structure similar to that of the organic light-emitting layer for the organic electron-transporting layer improved the interface bonding state between the electron-transporting layer and the light-emitting layer and improved the light-emitting characteristics. To be Further, the element (y) of the comparative example did not illuminate after 3 days of storage, whereas the element (b) of this example showed good light emission even after 1 week of storage. This is considered to be because the intramolecular complex salt has higher stability after film formation as compared with tBu-PBD, so that crystal precipitation does not occur and storage stability is improved.
【００４２】（その他の事項）配位子の種類や分子内錯
塩が有する配位子の種類の数等は上記実施例に限定され
るものではない。(Other Matters) The types of ligands, the number of types of ligands in the intramolecular complex salt, etc. are not limited to those in the above examples.
【００４３】[0043]
【発明の効果】以上説明したように、本発明によれば、
固体状態で発光し、しかも昇華性の高い分子内錯塩のう
ち、分子構造内に２種類以上の配位子を有した分子内錯
塩を発光材料として用いることにより、配位子の種類が
１種類の分子内錯塩と比較して配位子の自由度が広が
り、結果として発光材料となるキレート錯体の種類が増
え、材料選択の幅が広がるという効果を奏した。As described above, according to the present invention,
Among the intramolecular complex salts that emit light in the solid state and have high sublimation properties, the use of an intramolecular complex salt having two or more types of ligands in the molecular structure as the light emitting material results in one type of ligand. As compared with the intramolecular complex salt of (3), the degree of freedom of the ligand is widened, and as a result, the number of types of chelate complexes as light emitting materials is increased, and the range of material selection is widened.
【図１】本発明の一例に係る電界発光素子の断面図であ
る。FIG. 1 is a cross-sectional view of an electroluminescent device according to an example of the present invention.
【図２】キレート錯体についての説明を行うための図で
ある。FIG. 2 is a diagram for explaining a chelate complex.
１ ガラス基板 ２ ホール注入電極 ３ 有機ホール輸送層 ４ 有機発光層 ５ 電子注入電極 1 Glass Substrate 2 Hole Injection Electrode 3 Organic Hole Transport Layer 4 Organic Light Emitting Layer 5 Electron Injection Electrode
───────────────────────────────────────────────────── フロントページの続き (72)発明者 藤井 孝則 守口市京阪本通２丁目18番地 三洋電機株 式会社内 (72)発明者 西尾 佳高 守口市京阪本通２丁目18番地 三洋電機株 式会社内 (72)発明者 柴田 賢一 守口市京阪本通２丁目18番地 三洋電機株 式会社内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takanori Fujii 2-18 Keihan Hondori, Moriguchi Sanyo Electric Co., Ltd. (72) Inventor Yoshitaka Nishio 2-18 Keihan Hondori, Moriguchi Sanyo Electric Co., Ltd. In-company (72) Inventor Kenichi Shibata 2-18-18 Keihan Hondori, Moriguchi Sanyo Electric Co., Ltd.
Claims (3)
に少なくとも有機発光層を含む有機薄膜層を有する電界
発光素子において、 上記有機薄膜層の材料として、２種類以上の配位子を含
む分子内錯塩が用いられていることを特徴とする電界発
光素子。1. An electroluminescent device having an organic thin film layer including at least an organic light emitting layer between a hole injecting electrode and an electron injecting electrode, wherein the organic thin film layer contains two or more kinds of ligands. An electroluminescent device, characterized in that an intramolecular complex salt is used.
れていることを特徴とする請求項１記載の電界発光素
子。2. The electroluminescent device according to claim 1, wherein the intramolecular complex salt is used in an organic light emitting layer.
膜層が更に有機電子輸送層を有しており、当該有機電子
輸送層に分子内錯塩を用いたことを特徴とする請求項２
記載の電界発光素子。3. The electroluminescent device according to claim 2, wherein the organic thin film layer further has an organic electron transport layer, and an intramolecular complex salt is used for the organic electron transport layer.
The electroluminescent element described.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP06700293A JP3253404B2 (en) | 1993-03-25 | 1993-03-25 | EL device |
| US08/203,942 US5529853A (en) | 1993-03-17 | 1994-03-01 | Organic electroluminescent element |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP06700293A JP3253404B2 (en) | 1993-03-25 | 1993-03-25 | EL device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06283267A true JPH06283267A (en) | 1994-10-07 |
| JP3253404B2 JP3253404B2 (en) | 2002-02-04 |
Family
ID=13332300
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP06700293A Expired - Lifetime JP3253404B2 (en) | 1993-03-17 | 1993-03-25 | EL device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3253404B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6264805B1 (en) | 1994-12-13 | 2001-07-24 | The Trustees Of Princeton University | Method of fabricating transparent contacts for organic devices |
| US6358631B1 (en) | 1994-12-13 | 2002-03-19 | The Trustees Of Princeton University | Mixed vapor deposited films for electroluminescent devices |
| US6365270B2 (en) | 1994-12-13 | 2002-04-02 | The Trustees Of Princeton University | Organic light emitting devices |
-
1993
- 1993-03-25 JP JP06700293A patent/JP3253404B2/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6264805B1 (en) | 1994-12-13 | 2001-07-24 | The Trustees Of Princeton University | Method of fabricating transparent contacts for organic devices |
| US6358631B1 (en) | 1994-12-13 | 2002-03-19 | The Trustees Of Princeton University | Mixed vapor deposited films for electroluminescent devices |
| US6365270B2 (en) | 1994-12-13 | 2002-04-02 | The Trustees Of Princeton University | Organic light emitting devices |
| US6596134B2 (en) * | 1994-12-13 | 2003-07-22 | The Trustees Of Princeton University | Method of fabricating transparent contacts for organic devices |
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| JP3253404B2 (en) | 2002-02-04 |
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