JP5803692B2 - ORGANIC ELECTROLUMINESCENT ELEMENT AND LIGHTING DEVICE - Google Patents

Description

  The present invention relates to an organic electroluminescence element and a lighting device.

Conventionally, an organic electroluminescence element (hereinafter abbreviated as an OLED element, an organic EL element, etc.) can be driven at a low voltage of several V to several tens V, and has a wide viewing angle and is visually recognizable because it is a self-luminous type. It is a thin film type complete element solid, and is attracting attention from the viewpoint of space saving, energy saving, and portability as a display or lighting application, and is used in the main display of mobile phones. Has begun to spread.
However, for the realization and widespread use of large screen displays or lighting that replaces cold cathode fluorescent lamps, the luminous efficiency is dramatically higher than the current situation, the luminous lifetime is long, and there are no defects such as discoloration of the luminescent color over time. Development of devices is desired.

In recent years, phosphorescent materials have been actively studied as a technique for increasing luminous efficiency.
Phosphorescent materials are attracting much attention as illumination applications because they may have almost the same luminous efficiency as cold cathode fluorescent lamps.
Although this is a very high potential method, in organic EL devices using phosphorescent materials, the method of controlling the position of the emission center, in particular, recombination of carriers inside the light emitting layer, how to stabilize the light emission. From the viewpoint of luminous efficiency and lifetime of the device, it is an important technical problem how to improve the luminous performance of the phosphorescent material itself.

As luminescent materials for blue phosphorescence used in OLED elements, iridium complexes having phenylpyrazole-based, imidazophenanthridine-based, and phenylimidazole-based ligands are known. Great challenges remain to satisfy wavelength emission (blue compatibility) and high durability at the same time.
Although it has been disclosed that the iridium complex of phenylimidazole is a material having a relatively short emission wavelength (see, for example, Patent Documents 1, 2, and 3), the lifetime of the emission color is further changed, and the color of the emitted color changes over time. It was hard to say that the problem was completely solved.
In addition, some attempts have been made to provide short-wavelength emission (blue compatibility) by disposing an electron-withdrawing group as a substituent at a specific position on phenylimidazole. (For example, see Patent Documents 4 and 5) However, the trade-off with the light emission lifetime has not been completely eliminated.
Furthermore, an iridium complex aimed at improving thermal stability by binding the ligands of the complex to form a tetradentate or higher polydentate ligand is disclosed. (For example, refer to Patent Documents 6 and 7) With this technology, there is a certain effect with respect to the improvement of the lifetime, but it is difficult to say that the problem is completely solved in the discoloration of the luminescent color over time.

On the other hand, because of demands for large area, low cost, and high productivity, there is a great expectation for a wet method (also called a wet process method), and film formation can be performed at a lower temperature than film formation by a vacuum process. In addition, it is possible to reduce the damage of the lower organic layer, and there are great expectations from the viewpoint of improving the light emission efficiency and the device life.
However, in order to realize wet film formation in an organic EL element using blue phosphorescence, a light emitting material contained in the light emitting layer is particularly problematic, and from a practical viewpoint, currently known light emitting materials. However, in terms of low voltage driving, reduction of dark spots, suppression of occurrence of luminance unevenness of light emission, etc., it has been found that further improvement techniques are indispensable.

International Publication No. 2006/046980 US Patent Publication No. 2011/0057559 Specification US Patent Publication No. 2011/02034333 JP 2008-069221 A JP 2008-074921 A International Publication No. 2004/81017 Specification International Publication No. 2005/113563

  The present invention has been made in view of the above problems and situations, and the problem to be solved is to provide an organic electroluminescence device having high luminous efficiency, excellent luminous lifetime, and little change in luminescent color over time. An organic electroluminescence element preferably formed by wet film formation, comprising an organic electroluminescence element having a low driving voltage, reduced dark spots, and suppressed occurrence of luminance unevenness of light emission, and the organic electroluminescence element It is providing the illuminating device.

In order to solve the above-mentioned problems, the present inventor pays attention to the organic EL element material used for the light-emitting layer of the organic EL element in the process of examining the cause of the above-mentioned problem, particularly about the organometallic complex compound used as the phosphorescent dopant. Various studies were made. And, as a result of intensive studies aimed at further improving luminous efficiency and durability by optimizing the molecular structure of the ligand of the metal complex having a phenylimidazole ligand, the present inventor has found that the general formula of the present invention It reached the structure of (1)-(3), and it discovered that luminous efficiency and element lifetime were improved.
That is, the above-described problem according to the present invention is solved by the following means . In particular, according to the present invention, in the configuration 3, in the general formulas (11) to (13), “M” represents iridium or rhodium. Features. In the configuration 4, in the general formulas (14) to (20), “M” represents iridium or rhodium.
1. In an organic electroluminescence device having an anode, a cathode, and an organic layer composed of a single layer or a plurality of layers having a light emitting layer, and the organic layer is sandwiched between the anode and the cathode,
A phosphorescent organometallic complex having at least one compound represented by the general formulas (1) to (3) as a ligand is contained in at least one of the organic layers. Organic electroluminescence device.

〔一般式（１）〜（３）中、「Ｒａ」及び「Ｒｂ」はそれぞれ独立にアルキル基、シクロアルキル基、アルケニル基、アルキニル基、アリール基、ヘテロアリール基または非芳香族複素環基を表す。
一般式（１）〜（３）中、「Ｒｃ」及び「Ｒｄ」はそれぞれ独立に、水素原子、アルキル基、シクロアルキル基、アルケニル基、アルキニル基、アリール基、ヘテロアリール基または非芳香族複素環基を表す。
一般式（１）〜（３）中、「Ｖ_１〜Ｖ_４」はそれぞれ独立に、アルキル基、シクロアルキル基、アルケニル基、アルキニル基、アリール基、ヘテロアリール基または非芳香族複素環基を表す。
一般式（１）〜（３）中、「ＥＷＧ_１」及び「ＥＷＧ_２」はそれぞれ独立にハメットの置換基定数σｐ値が０．０５以上１．１０以下の基を表す。
一般式（１）〜（３）中、「Ｑ_１〜Ｑ_１１」はそれぞれ独立に窒素原子またはＣ−Ｒ_１〜Ｃ−Ｒ_１１を表す。
「Ｒ_１〜Ｒ_１１」はそれぞれ独立に、水素原子、アルキル基、アリール基、シクロアルキル基、アルケニル基、アルキニル基、アルコキシ基、シクロアルコキシ基、アリールオキシ基、アルキルチオ基、シクロアルキルチオ基、アリールチオ基、アルコキシカルボニル基、アリールオキシカルボニル基、スルファモイル基、アシル基、アシルオキシ基、アミド基、ウレイド基、カルバモイル基、スルフィニル基、アルキルスルホニル基、アリールスルホニル基、アミノ基、ハロゲン原子、パーフルオロアルキル基、シアノ基、ニトロ基、ヒドロキシ基、メルカプト基、シリル基または非芳香族複素環基を表す。
一般式（１）〜（３）で表される化合物は各々、連結基を介して、２量体、または３量体を形成してもよい。〕

[In the general formulas (1) to (3), “Ra” and “Rb” each independently represents an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group or a non-aromatic heterocyclic group. Represent.
In the general formulas (1) to (3), “Rc” and “Rd” are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group or a non-aromatic heterocycle. Represents a cyclic group.
In the general formulas (1) to (3), “V _{1 to} V ₄ ” each independently represents an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group or a non-aromatic heterocyclic group. Represent.
In the general formulas (1) to (3), “EWG ₁ ” and “EWG ₂ ” each independently represent a group having a Hammett's substituent constant σp value of 0.05 to 1.10.
In General Formulas (1) to (3), “Q _{1 to} Q ₁₁ ” each independently represent a nitrogen atom or C—R _{1 to} C—R ₁₁ .
“R _{1 to} R ₁₁ ” are each independently a hydrogen atom, alkyl group, aryl group, cycloalkyl group, alkenyl group, alkynyl group, alkoxy group, cycloalkoxy group, aryloxy group, alkylthio group, cycloalkylthio group, arylthio group. Group, alkoxycarbonyl group, aryloxycarbonyl group, sulfamoyl group, acyl group, acyloxy group, amide group, ureido group, carbamoyl group, sulfinyl group, alkylsulfonyl group, arylsulfonyl group, amino group, halogen atom, perfluoroalkyl group , A cyano group, a nitro group, a hydroxy group, a mercapto group, a silyl group or a non-aromatic heterocyclic group.
Each of the compounds represented by the general formulas (1) to (3) may form a dimer or a trimer via a linking group. ]

2. 2. The organic electroluminescent device according to item 1, wherein the compounds represented by the general formulas (1) to (3) are represented by the following general formulas (4) to (10).

〔一般式（４）〜（１０）中、「Ｒａ」及び「Ｒｂ」はそれぞれ独立にアルキル基、シクロアルキル基、アルケニル基、アルキニル基、アリール基、ヘテロアリール基または非芳香族複素環基を表す。
一般式（４）〜（１０）中、「Ｒｃ」及び「Ｒｄ」はそれぞれ独立に、水素原子、アルキル基、シクロアルキル基、アルケニル基、アルキニル基、アリール基、ヘテロアリール基または非芳香族複素環基を表す。
一般式（４）〜（１０）中、「Ｖ_１〜Ｖ_４」はそれぞれ独立に、アルキル基、シクロアルキル基、アルケニル基、アルキニル基、アリール基、ヘテロアリール基または非芳香族複素環基を表す。
一般式（４）〜（１０）中、「ＥＷＧ_１」及び「ＥＷＧ_２」はそれぞれ独立にハメットの置換基定数σｐ値が０．０５以上１．１０以下の基を表す。
一般式（４）〜（１０）中、「Ｒｘ」及び「Ｒｙ」は水素原子、若しくは、アルキル基を表す。複数の「Ｒｘ」及び「Ｒｙ」は同じであっても異なっていてもよい。
一般式（４）〜（１０）中、ｌ、ｍ、ｎは１以上６以下の整数を表し、ｌ、ｍ、ｎは同じであっても、異なっていてもよい。
一般式（４）〜（１０）中、「Ｑ_１〜Ｑ_１１」はそれぞれ独立に窒素原子またはＣ−Ｒ_１〜Ｃ−Ｒ_１１を表す。
「Ｒ_１〜Ｒ_１１」はそれぞれ独立に、水素原子、アルキル基、アリール基、シクロアルキル基、アルケニル基、アルキニル基、アルコキシ基、シクロアルコキシ基、アリールオキシ基、アルキルチオ基、シクロアルキルチオ基、アリールチオ基、アルコキシカルボニル基、アリールオキシカルボニル基、スルファモイル基、アシル基、アシルオキシ基、アミド基、ウレイド基、カルバモイル基、スルフィニル基、アルキルスルホニル基、アリールスルホニル基、アミノ基、ハロゲン原子、パーフルオロアルキル基、シアノ基、ニトロ基、ヒドロキシ基、メルカプト基、シリル基または非芳香族複素環基を表す。
一般式（４）〜（１０）中、Ｖは窒素原子、リン原子、ホウ素原子、シリル基、フォスフィンオキシド基、アルキレン基、シクロアルキレン基、アリーレン基、ヘテロアリーレン基、非芳香族複素環基、アルキレンオキシ基、シクロアルキレンオキシ基、アリーレンオキシ基、ヘテロアリーレンオキシ基、非芳香族複素環オキシ基を表す。〕

[In the general formulas (4) to (10), “Ra” and “Rb” each independently represents an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group or a non-aromatic heterocyclic group. Represent.
In the general formulas (4) to (10), “Rc” and “Rd” each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group or a non-aromatic heterocycle. Represents a cyclic group.
In the general formulas (4) to (10), “V _{1 to} V ₄ ” each independently represents an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group or a non-aromatic heterocyclic group. Represent.
In the general formulas (4) to (10), “EWG ₁ ” and “EWG ₂ ” each independently represent a group having a Hammett's substituent constant σp value of 0.05 to 1.10.
In the general formulas (4) to (10), “Rx” and “Ry” represent a hydrogen atom or an alkyl group. A plurality of “Rx” and “Ry” may be the same or different.
In general formulas (4) to (10), l, m, and n represent an integer of 1 to 6, and l, m, and n may be the same or different.
In General Formulas (4) to (10), “Q _{1 to} Q ₁₁ ” each independently represent a nitrogen atom or C—R _{1 to} C—R ₁₁ .
“R _{1 to} R ₁₁ ” are each independently a hydrogen atom, alkyl group, aryl group, cycloalkyl group, alkenyl group, alkynyl group, alkoxy group, cycloalkoxy group, aryloxy group, alkylthio group, cycloalkylthio group, arylthio group. Group, alkoxycarbonyl group, aryloxycarbonyl group, sulfamoyl group, acyl group, acyloxy group, amide group, ureido group, carbamoyl group, sulfinyl group, alkylsulfonyl group, arylsulfonyl group, amino group, halogen atom, perfluoroalkyl group , A cyano group, a nitro group, a hydroxy group, a mercapto group, a silyl group or a non-aromatic heterocyclic group.
In general formulas (4) to (10), V represents a nitrogen atom, a phosphorus atom, a boron atom, a silyl group, a phosphine oxide group, an alkylene group, a cycloalkylene group, an arylene group, a heteroarylene group, or a non-aromatic heterocyclic group. Represents an alkyleneoxy group, a cycloalkyleneoxy group, an aryleneoxy group, a heteroaryleneoxy group, or a non-aromatic heterocyclic oxy group. ]

〔一般式（１１）〜（１３）中、「Ｒａ」及び「Ｒｂ」はそれぞれ独立にアルキル基、シクロアルキル基、アルケニル基、アルキニル基、アリール基、ヘテロアリール基または非芳香族複素環基を表す。
一般式（１１）〜（１３）中、「Ｒｃ」及び「Ｒｄ」はそれぞれ独立に、水素原子、アルキル基、シクロアルキル基、アルケニル基、アルキニル基、アリール基、ヘテロアリール基または非芳香族複素環基を表す。
一般式（１１）〜（１３）中、「Ｖ_１〜Ｖ_４」はそれぞれ独立に、アルキル基、シクロアルキル基、アルケニル基、アルキニル基、アリール基、ヘテロアリール基または非芳香族複素環基を表す。
一般式（１１）〜（１３）中、「ＥＷＧ_１」及び「ＥＷＧ_２」はそれぞれ独立にハメットの置換基定数σｐ値が０．０５以上１．１０以下の基を表す。
一般式（１１）〜（１３）中、「Ｑ_１〜Ｑ_１１」はそれぞれ独立に窒素原子またはＣ−Ｒ_１〜Ｃ−Ｒ_１１を表す。
「Ｒ_１〜Ｒ_１１」はそれぞれ独立に、水素原子、アルキル基、アリール基、シクロアルキル基、アルケニル基、アルキニル基、アルコキシ基、シクロアルコキシ基、アリールオキシ基、アルキルチオ基、シクロアルキルチオ基、アリールチオ基、アルコキシカルボニル基、アリールオキシカルボニル基、スルファモイル基、アシル基、アシルオキシ基、アミド基、ウレイド基、カルバモイル基、スルフィニル基、アルキルスルホニル基、アリールスルホニル基、アミノ基、ハロゲン原子、パーフルオロアルキル基、シアノ基、ニトロ基、ヒドロキシ基、メルカプト基、シリル基または非芳香族複素環基を表す。
一般式（１１）〜（１３）中、「Ｌ」はＭに配位したモノアニオン性の二座配位子であり、「Ｍ」は原子番号が４０以上でかつ元素周期表における８〜１０族の遷移金属原子を表し、「ｎ」は０〜２の整数を表す。〕 3. In an organic electroluminescence device having an anode, a cathode, and an organic layer composed of a single layer or a plurality of layers having a light emitting layer, and the organic layer is sandwiched between the anode and the cathode,
At least one layer of the phosphorescent organic metal complex represented by the general formulas (11) to (13) is contained in at least one layer of the organic layer.

[In the general formulas (11) to (13), “Ra” and “Rb” each independently represents an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group or a non-aromatic heterocyclic group. Represent.
In the general formulas (11) to (13), “Rc” and “Rd” are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group or a non-aromatic heterocycle. Represents a cyclic group.
In the general formulas (11) to (13), “V _{1 to} V ₄ ” each independently represents an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group or a non-aromatic heterocyclic group. Represent.
In the general formulas (11) to (13), “EWG ₁ ” and “EWG ₂ ” each independently represent a group having a Hammett's substituent constant σp value of 0.05 to 1.10.
In general formulas (11) to (13), “Q _{1 to} Q ₁₁ ” each independently represents a nitrogen atom or C—R _{1 to} C—R ₁₁ .
“R _{1 to} R ₁₁ ” are each independently a hydrogen atom, alkyl group, aryl group, cycloalkyl group, alkenyl group, alkynyl group, alkoxy group, cycloalkoxy group, aryloxy group, alkylthio group, cycloalkylthio group, arylthio group. Group, alkoxycarbonyl group, aryloxycarbonyl group, sulfamoyl group, acyl group, acyloxy group, amide group, ureido group, carbamoyl group, sulfinyl group, alkylsulfonyl group, arylsulfonyl group, amino group, halogen atom, perfluoroalkyl group , A cyano group, a nitro group, a hydroxy group, a mercapto group, a silyl group or a non-aromatic heterocyclic group.
In the general formulas (11) to (13), “L” is a monoanionic bidentate ligand coordinated to M, and “M” has an atomic number of 40 or more and 8 to 10 in the periodic table of elements. Represents a transition metal atom of the group, and “n” represents an integer of 0 to 2. ]

4). In an organic electroluminescence device having an anode, a cathode, and an organic layer composed of a single layer or a plurality of layers having a light emitting layer, and the organic layer is sandwiched between the anode and the cathode,
At least one of the organic layers contains at least one phosphorescent organometallic complex represented by general formulas (14) to (20).

[In the general formulas (14) to (20), “Ra” and “Rb” each independently represents an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group or a non-aromatic heterocyclic group. Represent.
In the general formulas (14) to (20), “Rc” and “Rd” each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group or a non-aromatic heterocycle. Represents a cyclic group.
In the general formulas (14) to (20), “V _{1 to} V ₄ ” each independently represents an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group or a non-aromatic heterocyclic group. Represent.
In the general formulas (14) to (20), “EWG ₁ ” and “EWG ₂ ” each independently represent a group having a Hammett's substituent constant σp value of 0.05 to 1.10.
In the general formulas (14) to (20), “Rx” and “Ry” represent a hydrogen atom or an alkyl group. A plurality of “Rx” and “Ry” may be the same or different.
In the general formulas (14) to (20), l, m, and n represent an integer of 1 to 6, and l, m, and n may be the same or different.
In General Formulas (14) to (20), “Q _{1 to} Q ₁₁ ” each independently represent a nitrogen atom or C—R _{1 to} C—R ₁₁ .
“R _{1 to} R ₁₁ ” are each independently a hydrogen atom, alkyl group, aryl group, cycloalkyl group, alkenyl group, alkynyl group, alkoxy group, cycloalkoxy group, aryloxy group, alkylthio group, cycloalkylthio group, arylthio group. Group, alkoxycarbonyl group, aryloxycarbonyl group, sulfamoyl group, acyl group, acyloxy group, amide group, ureido group, carbamoyl group, sulfinyl group, alkylsulfonyl group, arylsulfonyl group, amino group, halogen atom, perfluoroalkyl group , A cyano group, a nitro group, a hydroxy group, a mercapto group, a silyl group or a non-aromatic heterocyclic group.
In general formulas (14) to (20), V represents a nitrogen atom, a phosphorus atom, a boron atom, a silyl group, a phosphine oxide group, an alkylene group, a cycloalkylene group, an arylene group, a heteroarylene group, or a non-aromatic heterocyclic group. Represents an alkyleneoxy group, a cycloalkyleneoxy group, an aryleneoxy group, a heteroaryleneoxy group, or a non-aromatic heterocyclic oxy group.
In the general formulas (14) to (20), “M” represents a transition metal atom having an atomic number of 40 or more and a group 8 to 10 in the periodic table.
In the general formulas (14) to (20), * represents a bonding point with M. ]

  5. In the general formulas (11) to (20), “M” is iridium, or the organic electroluminescence device according to the third or fourth item.

  6). An illuminating device comprising the organic electroluminescent element according to any one of Items 1 to 5.

By the above means of the present invention, it is possible to provide an organic electroluminescence device having high light emission efficiency, excellent light emission lifetime, and little change in emission color over time. Further, in particular, an organic electroluminescence element formed by wet film formation, in which a driving voltage is low, dark spots are reduced, and generation of luminance unevenness of light emission is suppressed, and the organic electroluminescence element It is possible to provide an illumination device including
The expression mechanism or action mechanism of the effect of the present invention is not clear, but is presumed as follows.
In the phosphorescent organometallic complex of the present invention (hereinafter abbreviated as a metal complex), the biaryl structure having an electron-withdrawing group at a specific position improves luminous efficiency and material robustness. Estimated.
In the metal complex according to the present invention, the combination of the ligands coordinated to the transition metal element M and the introduction of a specific substituent into the ligand allows the emission wavelength of the compound to be in a desired region. Can be controlled.
The “ligand” here is a portion obtained by removing the transition metal element M from the metal complex represented by the general formulas (1) to (3).
The conventionally known monoanionic bidentate ligand that can be used for forming the metal complex according to the present invention will be described in detail later.
Among the metal complexes of the present invention, a metal complex whose central metal is iridium is preferable. By using the iridium metal complex of the present invention, an organic EL element formed by wet film formation in particular has a low initial driving voltage, reduced dark spots, reduced emission unevenness (luminance unevenness), and high We were able to provide a quality lighting device.

It is the schematic diagram which showed an example of the display apparatus comprised from an organic EL element. It is a schematic diagram of the display part of the display apparatus of FIG. It is a schematic diagram of the pixel of the display apparatus of FIG. It is a schematic diagram of a passive matrix type full-color display device. It is the schematic of an illuminating device. It is a schematic diagram of an illuminating device.

The organic electroluminescence device of the present invention includes an anode, a cathode, and an organic layer composed of a single layer or a plurality of layers having a light emitting layer, and the organic layer is sandwiched between the anode and the cathode. An electroluminescence element, wherein at least one layer of the organic layer includes a phosphorescent organometallic complex having at least one compound represented by the general formulas (1) to (3) as a ligand. It is contained. This feature is a technical feature common to the inventions according to claims 1 to 5.
As an embodiment of the present invention, the compounds represented by the general formulas (1) to (3) may be represented by the general formulas (4) to (10) from the viewpoint of manifesting the effects of the present invention. It is preferable from the viewpoints of high luminous efficiency, long emission lifetime, little change in emission color with time, few dark spots, driving at low voltage, and suppression of luminance unevenness of emission.

  According to another aspect of the present invention, an anode, a cathode, and an organic layer composed of a single layer or a plurality of layers having a light emitting layer are provided, and the organic layer is sandwiched between the anode and the cathode. In the organic electroluminescence device thus formed, at least one of the organic layers contains at least one phosphorescent organometallic complex represented by the general formulas (11) to (13). Features. As a result, it is possible to obtain an effect that the light emission efficiency is high, the light emission life is long, the change in the emission color with time is small, the dark spots are few, the drive is possible at a low voltage, and the luminance unevenness of light emission is suppressed.

  According to another aspect of the present invention, an anode, a cathode, and an organic layer composed of a single layer or a plurality of layers having a light emitting layer are provided, and the organic layer is sandwiched between the anode and the cathode. The organic electroluminescence device is characterized in that at least one of the organic layers contains at least one phosphorescent organometallic complex represented by the general formulas (14) to (20). It is characterized by. As a result, it is possible to obtain an effect that the light emission efficiency is high, the light emission life is long, the change in the emission color with time is small, the dark spots are few, the drive is possible at a low voltage, and the luminance unevenness of light emission is suppressed.

  In addition, in the general formulas (11) to (20), it is preferable that “M” is iridium because the light emission efficiency is high, the color of the light emission color is preferably blue, and the change in the light emission color with time is reduced. Is preferable.

  Further, the illumination device of the present invention includes the organic electroluminescence element, and the initial drive voltage is low, the dark spot is reduced, the occurrence of light emission unevenness (luminance unevenness) is suppressed, and the high-quality illumination device is provided. Is preferable.

  Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described in detail. In addition, in this application, "-" is used in the meaning which includes the numerical value described before and behind that as a lower limit and an upper limit.

The organic electroluminescence element (referred to as an organic EL element) of the present invention will be described.
[Organic EL device]
<Constitutional layer of organic EL element>
The constituent layers of the organic EL element of the present invention will be described.
The organic EL device of the present invention preferably has a light emitting layer between the anode and the cathode, and preferably has a layer containing the phosphorescent organometallic complex of the present invention between the anode and the cathode. A mode in which the layer containing the light-emitting organometallic complex is a light-emitting layer is a preferable mode.
That is, the phosphorescent organometallic complex according to the present invention is preferably an embodiment that functions as a light-emitting dopant described below.
In this invention, although the preferable specific example of the layer structure of an organic EL element is shown below, this invention is not limited to these. In this embodiment, the layer between the anode and the cathode corresponds to the organic layer.
(I) anode / light emitting layer / cathode (ii) anode / light emitting layer / electron transport layer / cathode (iii) anode / hole transport layer / light emitting layer / electron transport layer / cathode (iv) anode / hole transport layer / Light emitting layer / hole blocking layer / electron transport layer / cathode (v) anode / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / cathode (vi) anode / anode buffer layer / positive Hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / cathode (vii) anode / hole transport layer / electron blocking layer / light emitting layer / hole blocking layer / electron transport layer / cathode In the organic EL element, the light emitting maximum wavelength of the blue light emitting layer is preferably 430 to 480 nm, the green light emitting layer has a light emitting maximum wavelength of 510 to 550 nm, and the red light emitting layer has a light emitting maximum wavelength of 600 to 640 nm. Preferably a certain monochromatic light emitting layer, these A display device using is preferable.
Further, a white light emitting layer may be formed by laminating at least three of these light emitting layers, and an illumination device using these may be used.
Further, a non-light emitting intermediate layer may be provided between the light emitting layers.

Each layer which comprises the organic EL element of this invention is demonstrated.
<Light emitting layer>
The light-emitting layer according to the present invention is a layer that emits light by recombination of injected electrons and holes, and the light-emitting portion is the interface between the light-emitting layer and the adjacent layer even within the light-emitting layer. May be.
The total film thickness of the light emitting layer is not particularly limited, but it is 2 nm to from the viewpoint of preventing the application of a high voltage unnecessary for the film homogeneity and light emission and improving the stability of the emission color with respect to the drive current. It is preferable to adjust to the range of 5 micrometers, More preferably, it adjusts to the range of 2 nm-200 nm, Most preferably, it is the range of 10 nm-20 nm.
For the production of the light-emitting layer, a light-emitting dopant or a host compound, which will be described later, is formed by a known thinning method such as a vacuum deposition method, a spin coating method, a casting method, an LB method, or an ink-jet method. it can.
The light emitting layer of the organic EL device of the present invention contains a host compound and at least one kind of light emitting dopant (such as a phosphorescent dopant (also referred to as a phosphorescent dopant) or a fluorescent dopant).
As the luminescent dopant, it is preferable to use the metal complex of the present invention.
Moreover, it becomes possible to mix different light emission by using multiple types of the metal complex of this invention used as said phosphorescence dopant, and / or a conventionally well-known compound, and, thereby, arbitrary luminescent colors can be obtained.

<Host compound (also called luminescent host)>
In the present invention, the host compound has a mass ratio of 20% or more among the compounds contained in the light emitting layer, and a phosphorescence quantum yield of phosphorescence emission is 0 at room temperature (25 ° C.). Defined as less than 1 compound. The phosphorescence quantum yield is preferably less than 0.01. Moreover, it is preferable that the mass ratio in the layer is 20% or more among the compounds contained in a light emitting layer.
There is no restriction | limiting in particular as a light emission host which can be used for this invention, The compound conventionally used with an organic EL element can be used. Typically, a carbazole derivative, a triarylamine derivative, an aromatic derivative, a nitrogen-containing heterocyclic compound, a thiophene derivative, a furan derivative, an oligoarylene compound or the like having a basic skeleton, or a carboline derivative or a diazacarbazole derivative (here And the diazacarbazole derivative represents one in which at least one carbon atom of the hydrocarbon ring constituting the carboline ring of the carboline derivative is substituted with a nitrogen atom.
As the known light-emitting host that can be used in the present invention, a compound that has a hole transporting ability and an electron transporting ability, prevents the emission of light from becoming longer, and has a high Tg (glass transition temperature) is preferable.
In the present invention, conventionally known light-emitting hosts may be used alone or in combination of two or more.
By using a plurality of types of light-emitting hosts, the movement of charges can be adjusted, and the organic EL element can be made highly efficient.
In addition, the light emitting host used in the present invention may be a low molecular compound, a high molecular compound having a repeating unit, or a low molecular compound having a polymerizable group such as a vinyl group or an epoxy group (polymerizable light emitting host). Of course, one or more of such compounds may be used.
Specific examples of the known light-emitting host include compounds described in the following documents.
JP-A-2001-257076, 2002-308855, 2001-313179, 2002-319491, 2001-357777, 2002-334786, 2002-8860, 2002-334787, 2002-15871, 2002-334788, 2002-43056, 2002-334789, 2002-75645, 2002-338579, 2002-105445 gazette, 2002-343568 gazette, 2002-141173 gazette, 2002-352957 gazette, 2002-203683 gazette, 2002-363227 gazette, 2002-231453 gazette, No. 003-3165, No. 2002-234888, No. 2003-27048, No. 2002-255934, No. 2002-286061, No. 2002-280183, No. 2002-299060, No. 2002. -302516, 2002-305083, 2002-305084, 2002-308837, and the like.

  Hereinafter, although the specific example used as a light emission host of the light emitting layer of the organic EL element of this invention is given, this invention is not limited to these.

<Phosphorescent dopant>
The phosphorescent dopant is a compound in which light emission from an excited triplet is observed. Specifically, the phosphorescent dopant is a compound that emits phosphorescence at room temperature (25 ° C.). Although defined as being a compound of 01 or more, a preferable phosphorescence quantum yield is 0.1 or more.
The phosphorescence quantum yield can be measured by the method described in Spectroscopic II, page 398 (1992 edition, Maruzen) of Experimental Chemistry Course 4 of the 4th edition. Although the phosphorescence quantum yield in a solution can be measured using various solvents, the phosphorescence dopant according to the present invention achieves the phosphorescence quantum yield (0.01 or more) in any solvent. That's fine.
There are two types of light emission of the phosphorescent dopant in principle.
One is energy transfer that recombination of carriers occurs on the host compound to which carriers are transported to generate an excited state of the host compound, and this energy is transferred to the phosphorescent dopant to obtain light emission from the phosphorescent dopant. It is a type.
The other is a carrier trap type in which a phosphorescent dopant becomes a carrier trap, and carrier recombination occurs on the phosphorescent dopant, and light emission from the phosphorescent dopant is obtained.
In any case, it is a condition that the excited state energy of the phosphorescent dopant is lower than the excited state energy of the host compound.

<Ligand and phosphorescent organometallic complex>
In the present embodiment, the light emitting layer of the organic layer contains a phosphorescent organometallic complex having the compound represented by the general formulas (1) to (3) as a ligand as a phosphorescent dopant. ing.

(1) Ligands represented by general formulas (1) to (3)

In the general formula, “Ra” and “Rb” each independently represents an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group or a non-aromatic heterocyclic group.
Specific examples of Ra and Rb include alkyl groups (eg, methyl group, ethyl group, propyl group, isopropyl group, tert-butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group). Group), cycloalkyl group (for example, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (for example, vinyl group, allyl group, 1-propenyl group, 2-butenyl group, 1,3-butadienyl group, 2-pentenyl group) , Isopropenyl group etc.), alkenyl group (eg vinyl group, allyl group, 1-propenyl group, 2-butenyl group, 1,3-butadienyl group, 2-pentenyl group, isopropenyl group etc.), alkynyl group (eg Ethynyl group, propargyl group, etc.), aryl group (for example, phenyl group, chlorophenyl group, Cytyl group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group, etc.) and heteroaryl groups include, for example, pyridyl group, pyrimidyl group Group, furyl group, pyrrolyl group, imidazolyl group, benzimidazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, 1,2,4-triazol-1-yl group, 1,2,3-triazol-1-yl group) Etc.)), oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, thienyl group, quinolyl group, benzofuryl group, dibenzofuryl group, benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl Group, Carborini Groups, diazacarbolyl groups (wherein one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom), quinoxalinyl groups, triazinyl groups, quinazolinyl groups, phthalazinyl groups, etc. Group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.).
Ra and Rb are preferably an alkyl group or a cycloalkyl group, and more preferably an isopropyl group, a cyclopentyl group, or a cyclohexyl group.
Ra and Rb are particularly preferably both an alkyl group or a cycloalkyl group, and most preferably both are isopropyl groups.

In the general formula, “Rc” and “Rd” each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group or a non-aromatic heterocyclic group. Is the same as listed for Ra or Rb.
Rc and Rd are preferably a hydrogen atom or an alkyl group, and particularly preferably both are hydrogen atoms.

In the general formula, each of “V _{1 to} V ₄ ” independently represents an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, or a non-aromatic heterocyclic group, and specific examples thereof include Ra Or it is the same as that of Rb. “V _{1 to} V ₄ ” are preferably an alkyl group or a cycloalkyl group, and more preferably a methyl group or an ethyl group. In particular, this is the case when all of “V _{1 to} V ₄ ” are methyl groups.

In the general formula, “EWG ₁ ” and “EWG ₂ ” each independently represent a group having a Hammett's substituent constant σp value of 0.05 to 1.10.

  Hammett's σp value refers to Hammett's substituent constant σp. Hammett's substituent constant σp is a substituent constant determined by Hammett et al. From the electronic effect of the substituent on the hydrolysis of ethyl benzoate. “Structure-activity relationship of drugs” (Nanedo: 1979) , "Substituent Constants for Correlation Analysis in chemistry and biology" (C. Hansch and A. Leo, John Wiley & Sons, New York, 1979) and the like can be cited.

Here, the preferable Hammett σp value range is 0.05 to 1.0, more preferably 0.2 to 1.0, and most preferably 0.5 to 1.0.
Here, although the example of a typical electron withdrawing group is shown, this invention is not limited to these.
σp value F 0.06
Cl 0.23
Br 0.23
I 0.18
COCH ₃ 0.50
CO ₂ CH ₃ 0.45
COC ₆ H ₅ 0.41
SH 0.15
SC ₆ H ₅ 0.18
OCF ₃ 0.35
OCOCH ₃ 0.31
C ₆ F ₅ 0.41
C (CF ₃ ) 0.53
CF ₃ 0.54
PO (C ₆ H ₅ ) ₂ 0.53
SO ₂ C ₆ H ₅ 0.70
SO ₂ CH ₃ 0.72
SO ₂ CF ₃ 0.93
CN 0.66
NO ₂ 0.78
N = C = O 0.19
N = C = S 0.38
N (CF ₃ ) ₂ 0.53

  Of the substituents of 0.5 <σp <1.0, the most preferred substituent is a cyano group, an alkylsulfonyl group, an arylsulfonyl group, or a trifluoromethyl group.

In the general formula, “Q _{1 to} Q ₁₁ ” each independently represents a nitrogen atom or C—R _{1 to} C—R ₁₁ .
Preferably, Q _{1 to} Q ₁₁ are all C—R _{1 to} C—R ₁₁ .
When a nitrogen atom is present in Q _{1 to} Q ₁₁ , the number of nitrogen atoms is preferably 2 or less, more preferably both or any one of Q ₃ and Q ₇ is a nitrogen atom.

“R _{1 to} R ₁₁ ” are each independently a hydrogen atom, alkyl group, aryl group, cycloalkyl group, alkenyl group, alkynyl group, alkoxy group, cycloalkoxy group, aryloxy group, alkylthio group, cycloalkylthio group, arylthio group. Group, alkoxycarbonyl group, aryloxycarbonyl group, sulfamoyl group, acyl group, acyloxy group, amide group, ureido group, carbamoyl group, sulfinyl group, alkylsulfonyl group, arylsulfonyl group, amino group, halogen atom, perfluoroalkyl group , A cyano group, a nitro group, a hydroxy group, a mercapto group, a silyl group or a non-aromatic heterocyclic group.
Specific examples of R _{1 to} R ₁₁ include alkyl groups (for example, methyl group, ethyl group, propyl group, isopropyl group, tert-butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group). , Pentadecyl group, etc.), aryl group (for example, phenyl group, chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, Biphenylyl group), cycloalkyl group (for example, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (for example, vinyl group, allyl group, 1-propenyl group, 2-butenyl group, 1,3-butadienyl group, 2-pentenyl group) Group, isopropenyl group, etc.), alkenyl group (for example, Vinyl group, allyl group, 1-propenyl group, 2-butenyl group, 1,3-butadienyl group, 2-pentenyl group, isopropenyl group, etc.), alkynyl group (for example, ethynyl group, propargyl group, etc.), alkoxy group ( For example, methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group, octyloxy group, dodecyloxy group, etc.), cycloalkoxy group (for example, cyclopentyloxy group, cyclohexyloxy group, etc.), aryloxy group ( For example, phenoxy group, naphthyloxy group, etc.), alkylthio group (eg, methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio group (eg, cyclopentylthio group, cyclohexyl) Thio group, etc. An arylthio group (eg, phenylthio group, naphthylthio group, etc.), an alkoxycarbonyl group (eg, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl Group (for example, phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (for example, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, Octylaminosulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), a Sil group (for example, acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc. ), An acyloxy group (for example, acetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, acryloyl group, methacryloyl group, etc.), acyloxy group (for example, acetyl) Oxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, acrylic group Yl group, methacryloyl group, etc.), ureido group (for example, methylureido group, ethylureido group, pentylureido group, cyclohexylureido group, octylureido group, dodecylureido group, phenylureido group, naphthylureido group, 2-pyridylaminoureido group, etc. ), Carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylamino) A carbonyl group, a phenylaminocarbonyl group, a naphthylaminocarbonyl group, a 2-pyridylaminocarbonyl group, etc.), a sulfinyl group (for example, a methylsulfinyl group, Tylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group, phenylsulfinyl group, naphthylsulfinyl group, 2-pyridylsulfinyl group, etc.), alkylsulfonyl group (for example, methylsulfonyl group, ethylsulfonyl group) Group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group, etc.), arylsulfonyl group or heteroarylsulfonyl group (for example, phenylsulfonyl group, naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.), aryl Sulfonyl group (2-naphthylsulfonyl group, phenylsulfonyl group, 2-pyridylsulfonyl group, etc.), amino group (for example, amino group, ethylamino group, di Tilamino group, butylamino group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, anilino group, phenylamino group, diphenylamino group, naphthylamino group, 2-pyridylamino group, etc.), halogen atom (for example, fluorine atom) Chlorine atom, bromine atom, etc.), perfluoroalkyl group (eg, trifluoromethyl group, pentafluoroethyl group, etc.), silyl group (eg, trimethylsilyl group, triisopropylsilyl group, triphenylsilyl group, phenyldiethylsilyl group) And non-aromatic heterocyclic groups (for example, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.).

R _{1 to} R ₁₁ are preferably an alkyl group, an aryl group, a silyl group, or a cyano group.
Each of the compounds represented by the general formulas (1) to (3) may form a dimer or a trimer through a linking group, but a preferable structure is a general formula (4) described later. ) To (10).

(2) Ligands represented by general formulas (4) to (10)

In the general formulas (4) to (10), “Ra”, “Rb”, “Rc”, “Rd”, “Q _{1 to} Q ₁₁ (including R _{1 to} R ₁₁ )”, “V _{1 to} V _4”. ”And“ EWG _{1 to} EWG ₂ ”include Ra, Rb, Rc, Rd, Q _{1 to} Q ₁₁ (including R _{1 to} R ₁₁ ), and V ₁ to R 3 in the general formulas (1) to (3). The contents of V ₄ and EWG _{1 to} EWG ₂ are the same.
In the general formulas (4) to (10), “Rx” and “Ry” represent a hydrogen atom or an alkyl group. A plurality of “Rx” and “Ry” may be the same or different. Preferably, they are hydrogen atoms, and a plurality of “Rx” and “Ry” are the same.
In general formulas (4) to (10), l, m, and n represent an integer of 1 to 6, and l, m, and n may be the same or different. l, m and n are preferably the same, and preferably 2 or 3.
In general formulas (4) to (10), V represents a nitrogen atom, a phosphorus atom, a boron atom, a silyl group, a phosphine oxide group, an alkylene group, a cycloalkylene group, an arylene group, a heteroarylene group, or a non-aromatic heterocyclic group. Represents an alkyleneoxy group, a cycloalkyleneoxy group, an aryleneoxy group, a heteroaryleneoxy group, or a non-aromatic heterocyclic oxy group. An alkylene group, an arylene group, and an aryleneoxy group are preferable.

(3) Phosphorescent organometallic complexes represented by general formulas (11) to (13)

In the general formulas (11) to (13), “Ra”, “Rb”, “Rc”, “Rd”, “Q _{1 to} Q ₁₁ (including R _{1 to} R ₁₁ )”, “V _{1 to} V _4”. ”And“ EWG _{1 to} EWG ₂ ”include Ra, Rb, Rc, Rd, Q _{1 to} Q ₁₁ (including R _{1 to} R ₁₁ ), and V ₁ to R 3 in the general formulas (1) to (3). The contents of V ₄ and EWG _{1 to} EWG ₂ are the same.
In the general formulas (11) to (13), “L” represents a monoanionic bidentate ligand coordinated to M.
Specific examples of L include a ligand of the general formula (2L).

In General Formula (2L), “Rd ′”, “Rd ″”, and “Rd ′ ″” represent a hydrogen atom or a substituent.
The substituents represented by Rd ′, Rd ″, and Rd ′ ″ are synonymous with the groups represented by R _{1 to} R ₁₁ in the general formulas (1) to (3).

In the general formulas (11) to (13), “M” represents an atomic number of 40 or more and represents a transition metal atom of Group 8 to 10 in the periodic table, preferably Os, Ir, or Pt, more preferably Ir. is there.
In general formula (11)-(13), "n" represents the integer of 0-2, Preferably it is 0.

(4) Phosphorescent organometallic complexes represented by general formulas (14) to (20)

In the general formulas (14) to (20), “Ra”, “Rb”, “Rc”, “Rd”, “Q _{1 to} Q ₁₁ (including R _{1 to} R ₁₁ )”, “V _{1 to} V _4”. ”And“ EWG _{1 to} EWG ₂ ”include Ra, Rb, Rc, Rd, Q _{1 to} Q ₁₁ (including R _{1 to} R ₁₁ ), and V ₁ to R 3 in the general formulas (1) to (3). The contents of V ₄ and EWG _{1 to} EWG ₂ are the same.
In the general formulas (14) to (20), “Rx” and “Ry” represent a hydrogen atom or an alkyl group. A plurality of “Rx” and “Ry” may be the same or different. Preferably, they are hydrogen atoms, and a plurality of “Rx” and “Ry” are the same.
In the general formulas (14) to (20), l, m, and n represent an integer of 1 to 6, and l, m, and n may be the same or different. l, m and n are preferably the same, and preferably 2 or 3.
In general formulas (14) to (20), V represents a nitrogen atom, a phosphorus atom, a boron atom, a silyl group, a phosphine oxide group, an alkylene group, a cycloalkylene group, an arylene group, a heteroarylene group, or a non-aromatic heterocyclic group. Represents an alkyleneoxy group, a cycloalkyleneoxy group, an aryleneoxy group, a heteroaryleneoxy group, or a non-aromatic heterocyclic oxy group. An alkylene group, an arylene group, and an aryleneoxy group are preferable.
In the general formulas (14) to (20), M ”represents an atomic number of 40 or more and represents a transition metal atom of Group 8 to 10 in the periodic table, preferably Os, Ir, Pt, and more preferably Ir. is there.
In the general formulas (14) to (20), * represents a bonding point with M.

(5) Specific examples Hereinafter, specific examples of the phosphorescent organometallic complex of the present invention will be given, but the present invention is not limited thereto.
(5.1) Specific example of general formula (11)

(5.2) Specific example of general formula (12)

なお、表１〜表３において、「Ｌ」の欄に示されたＬ−１〜Ｌ−６は、下記化合物を示す。

(5.3) Specific example of general formula (13)

In Tables 1 to 3, L-1 to L-6 shown in the “L” column represent the following compounds.

(5.4) Specific example of general formula (14)

(5.5) Specific example of general formula (15)

(5.6) Specific example of general formula (16)

(5.7) Specific example of general formula (17)

(5.8) Specific example of general formula (18)

(5.9) Specific example of general formula (19)

なお、表４〜表１０において、「Ｖ」の欄に示されたＡ〜Ｋは、下記化合物を示す。

(5.10) Specific example of general formula (20)

In Tables 4 to 10, A to K shown in the column “V” represent the following compounds.

(6) Synthesis example Hereinafter, although the synthesis example of the phosphorescence-emitting organometallic complex of this invention is given, this invention is not limited to these.

(6.1) Synthesis Example 1: Synthesis of Compound D-3 Under nitrogen flow, cyanoboronic acid ester intermediate (a) 2.57 g (10.0 mmol) Pd (dba) ₂ 460 mg (0.40 mmol), S-Phos 1.46 g (0.80 mmol) 3.58 g (16.4 mmol) of potassium phosphate was mixed, and 60 ml of toluene and 6 ml of water were added to form a suspension. This was heated and stirred at an internal temperature of 90 ° C. for 5 hours. The toluene layer of the reaction solution was separated and washed with water three times. Thereafter, concentration under reduced pressure was performed, and the residue was purified by silica gel column chromatography (developing solvent: heptane: ethyl acetate = 5: 1) to obtain 4.10 g of intermediate (c) (yield 95%).
Next, under nitrogen flow, 4.33 g (10.0 mmol) of the intermediate (c) was dissolved in a mixture of 150 ml of ethoxyethanol and 50 ml of water, and 1.40 g (4.0 mmol) of iridium trichloride trihydrate was added. The mixture was heated and refluxed for 6 hours. After cooling to room temperature, it was sufficiently diluted with methanol, and the precipitated crystals were separated by filtration and thoroughly washed with methanol. μ complex (d) was obtained in 2.75 g (yield 63%).
Next, under nitrogen flow, (d) 1.00 g (0.46 mmol), (c) 0.80 g (1.84 mmol), silver trifluoroacetate 0.30 g (1.38 mol), trishydroxyethylamine 0.41 g (2.76 mmol) was dispersed in 60 ml of PhOAc and stirred with heating at an internal temperature of 130 ° C. for 6 hours. The insoluble material was filtered off, concentrated under reduced pressure, methanol was added, and the crystals were filtered off. By sublimation purification of the crystals under reduced pressure. 450 mg (yield 61%) of the target product D-3 was identified, and the structure was identified by NMR and MASS spectra.
Other complexes of the present invention can be easily synthesized by the same method as described above.

<Other phosphorescent dopants>
In this invention, the phosphorescence dopant which can be used together can be suitably selected from the well-known things used for the light emitting layer of an organic EL element, and can be used. Specific examples include compounds described in the following patent publications.
WO 00/70655 pamphlet, JP 2002-280178, JP 2001-181616, JP 2002-280179, JP 2001-181617, JP 2002-280180, JP 2001-247859, JP 2002-299060, JP 2001-313178, JP 2002-302671, JP 2001-345183, JP 2002-324679, International Publication No. 02/15645 pamphlet, JP 2002-332291 A, JP 2002-50484 A, JP 2002-332292 A, JP 2002-83684 A, JP 2002-540572 A, JP 2002-2002 A. No. 117978, JP 20 JP-A-2-338588, JP-A-2002-170684, JP-A-2002-352960, WO01 / 93642, JP-A-2002-50483, JP-A-2002-1000047, JP-A-2002. No. -173744, JP-A No. 2002-359082, JP-A No. 2002-17584, JP-A No. 2002-363552, JP-A No. 2002-184582, JP-A No. 2003-7469, JP-T-2002-525808. Gazette, JP2003-7471, JP2002-525833, JP2003-31366, JP2002-226495, JP2002-234894, JP2002-2335076 JP 2002-241751 A JP 2001-319779, JP 2001-319780, JP 2002-62824, JP 2002-1000047, JP 2002-203679, JP 2002-343572, JP 2002-203678 gazette etc.
Moreover, you may use together a conventionally well-known light emission dopant as shown below.

<Fluorescent dopant (also called fluorescent compound)>
In the present invention, the fluorescent dopants that can be used in combination include coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, pyrylium dyes, Examples include perylene dyes, stilbene dyes, polythiophene dyes, and rare earth complex phosphors.

  Next, an injection layer, a blocking layer, a hole transport layer, an electron transport layer, and the like used as a constituent layer of the organic EL element of the present invention will be described.

<Injection layer: electron injection layer, hole injection layer>
The injection layer is provided as necessary, and there are an electron injection layer and a hole injection layer, and as described above, it exists between the anode and the light emitting layer or the hole transport layer and between the cathode and the light emitting layer or the electron transport layer. May be.
An injection layer is a layer provided between an electrode and an organic layer in order to reduce drive voltage and improve light emission luminance. “Organic EL element and its forefront of industrialization (issued by NTT Corporation on November 30, 1998) 2), Chapter 2, “Electrode Materials” (pages 123 to 166) in detail, and includes a hole injection layer (anode buffer layer) and an electron injection layer (cathode buffer layer).
The details of the anode buffer layer (hole injection layer) are described in JP-A-9-45479, JP-A-9-260062, JP-A-8-288069 and the like. As a specific example, copper phthalocyanine is used. Examples thereof include a phthalocyanine buffer layer represented by an oxide, an oxide buffer layer represented by vanadium oxide, an amorphous carbon buffer layer, and a polymer buffer layer using a conductive polymer such as polyaniline (emeraldine) or polythiophene.
The details of the cathode buffer layer (electron injection layer) are described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like. Specifically, strontium, aluminum, etc. Metal buffer layer typified by lithium, alkali metal compound buffer layer typified by lithium fluoride, alkaline earth metal compound buffer layer typified by magnesium fluoride, oxide buffer layer typified by aluminum oxide, etc. .
The injection layer can be formed by thinning the above material by a known method such as a vacuum deposition method, a spin coating method, a casting method, an ink jet method, or an LB method.
The buffer layer (injection layer) is preferably a very thin film, and the film thickness is preferably in the range of 0.1 nm to 5 μm although it depends on the material.
The injection layer may have a single layer structure composed of one or more of the above materials.

<Blocking layer: hole blocking layer, electron blocking layer>
The blocking layer is provided as necessary in addition to the basic constituent layer of the organic compound thin film as described above. For example, it is described in JP-A Nos. 11-204258, 11-204359, and “Organic EL elements and their forefront of industrialization” (issued by NTT, Inc. on November 30, 1998). There is a hole blocking (hole blocking) layer.
The hole blocking layer has a function of an electron transport layer in a broad sense, and is made of a hole blocking material that has a function of transporting electrons and has a remarkably small ability to transport holes. The probability of recombination of electrons and holes can be improved by blocking. Moreover, the structure of the electron carrying layer mentioned later can be used as a hole-blocking layer as needed.
The hole blocking layer preferably contains a carbazole derivative, a carboline derivative, or a diazacarbazole derivative (in which one of carbon atoms constituting the carboline ring of the carboline derivative is replaced with a nitrogen atom).
Further, in the present invention, when a plurality of light emitting layers having different light emission colors are provided, it is preferable that the light emitting layer whose emission maximum wavelength is the shortest is the closest to the anode among all the light emitting layers. In this case, it is preferable that a hole blocking layer is additionally provided between the shortest wave layer and the light emitting layer next to the anode next to the shortest wave layer. Furthermore, it is preferable that 50% by mass or more of the compound contained in the hole blocking layer provided at the position has an ionization potential of 0.3 eV or more larger than the host compound of the shortest wave emitting layer.
The ionization potential is defined by the energy required to emit electrons at the HOMO (highest occupied molecular orbital) level of the compound to the vacuum level, and can be determined by, for example, the following method.
A low energy electron spectrometer “Model AC-1” manufactured by Riken Keiki Co., Ltd. or a method known as ultraviolet photoelectron spectroscopy can be suitably used.

On the other hand, the electron blocking layer has a function of a hole transport layer in a broad sense, and is made of a material that has a function of transporting holes and has an extremely small ability to transport electrons, and transports electrons while transporting holes. By blocking, the recombination probability of electrons and holes can be improved.
Moreover, the structure of the positive hole transport layer mentioned later can be used as an electron blocking layer as needed. The film thickness of the hole blocking layer and the electron blocking layer is preferably 3 nm to 100 nm, and more preferably 5 nm to 30 nm.

<Hole transport layer>
The hole transport layer is made of a hole transport material having a function of transporting holes, and in a broad sense, the hole injection layer and the electron blocking layer also have the function of a hole transport layer. The hole transport layer can be provided as a single layer or a plurality of layers.
The hole transport material has any one of hole injection or transport and electron barrier properties, and may be either organic or inorganic. For example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, Examples thereof include stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers, particularly thiophene oligomers.
The above-mentioned materials can be used as the hole transport material, but it is preferable to use a porphyrin compound, an aromatic tertiary amine compound and a styrylamine compound, particularly an aromatic tertiary amine compound.
Representative examples of aromatic tertiary amine compounds and styrylamine compounds include N, N, N ′, N′-tetraphenyl-4,4′-diaminophenyl, N, N′-diphenyl-N, N′— Bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine (TPD), 2,2-bis (4-di-p-tolylaminophenyl) propane, 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane, N, N, N ′, N′-tetra-p-tolyl-4,4′-diaminobiphenyl, 1,1-bis (4-di-p-tolyl) Aminophenyl) -4-phenylcyclohexane, bis (4-dimethylamino-2-methylphenyl) phenylmethane, bis (4-di-p-tolylaminophenyl) phenylmethane, N, N'-diphenyl-N, N ' − (4-methoxyphenyl) -4,4'-diaminobiphenyl, N, N, N ', N'-tetraphenyl-4,4'-diaminodiphenyl ether, 4,4'-bis (diphenylamino) quadriphenyl, N, N, N-tri (p-tolyl) amine, 4- (di-p-tolylamino) -4 '-[4- (di-p-tolylamino) styryl] stilbene, 4-N, N-diphenylamino ( 2-diphenylvinyl) benzene, 3-methoxy-4'-N, N-diphenylaminostilbenzene, N-phenylcarbazole and also two condensations described in US Pat. No. 5,061,569 Those having an aromatic ring in the molecule, for example, 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-30868 No. 4,4 ′, 4 ″ -tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine (MTDATA) in which three triphenylamine units described in the publication No. 1 are linked in a starburst type ) And the like.
Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used. In addition, inorganic compounds such as p-type-Si and p-type-SiC can also be used as the hole injection material and the hole transport material.
JP-A-11-251067, J. Org. Huang et. al. A so-called p-type hole transport material as described in a book (Applied Physics Letters 80 (2002), p. 139) can also be used. In the present invention, these materials are preferably used because a light-emitting element with higher efficiency can be obtained.

The hole transport layer can be formed by thinning the hole transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. it can. Although there is no restriction | limiting in particular about the film thickness of a positive hole transport layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. The hole transport layer may have a single layer structure composed of one or more of the above materials.
Alternatively, a hole transport layer having a high p property doped with impurities can be used. Examples thereof include JP-A-4-297076, JP-A-2000-196140, 2001-102175, J. Pat. Appl. Phys. 95, 5773 (2004), and the like.
In the present invention, it is preferable to use a hole transport layer having such a high p property because a device with lower power consumption can be produced.

<Electron transport layer>
The electron transport layer is made of a material having a function of transporting electrons, and in a broad sense, an electron injection layer and a hole blocking layer are also included in the electron transport layer.
The electron transport layer can be provided as a single layer or a plurality of layers.
Conventionally, in the case of a single electron transport layer and a plurality of layers, an electron transport material (also serving as a hole blocking material) used for an electron transport layer adjacent to the light emitting layer on the cathode side is injected from the cathode. As long as it has a function of transferring electrons to the light-emitting layer, any material can be selected and used from among conventionally known compounds. For example, nitro-substituted fluorene derivatives, diphenylquinone derivatives Thiopyrandioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives and the like.
Furthermore, in the above oxadiazole derivative, a thiadiazole derivative in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and a quinoxaline derivative having a quinoxaline ring known as an electron withdrawing group can also be used as an electron transport material. Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.
In addition, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) aluminum Tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), and the like, and the central metals of these metal complexes are In, Mg, Metal complexes replaced with Cu, Ca, Sn, Ga or Pb can also be used as the electron transport material.
In addition, metal-free or metal phthalocyanine, or those having terminal ends substituted with an alkyl group or a sulfonic acid group can be preferably used as the electron transporting material. In addition, the distyrylpyrazine derivative exemplified as the material of the light emitting layer can also be used as an electron transport material, and an inorganic semiconductor such as n-type-Si, n-type-SiC, etc. as in the case of the hole injection layer and the hole transport layer. Can also be used as an electron transporting material.

The electron transport layer can be formed by thinning the electron transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. Although there is no restriction | limiting in particular about the film thickness of an electron carrying layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5 nm-200 nm.
The electron transport layer may have a single layer structure composed of one or more of the above materials.
Further, an electron transport layer having a high n property doped with impurities can also be used. Examples thereof include JP-A-4-297076, JP-A-10-270172, JP-A-2000-196140, 2001-102175, J.A. Appl. Phys. 95, 5773 (2004), and the like.
The use of such an n-type electron transport layer is preferable because an element with lower power consumption can be manufactured.

<Anode>
As the anode in the organic EL element, an electrode material made of a metal, an alloy, an electrically conductive compound, or a mixture thereof having a high work function (4 eV or more) is preferably used. Specific examples of such electrode materials include metals such as Au, and conductive transparent materials such as CuI, indium tin oxide (ITO), SnO ₂ , and ZnO. Alternatively, an amorphous material such as IDIXO (In ₂ O ₃ —ZnO) capable of forming a transparent conductive film may be used.
For the anode, these electrode materials may be formed into a thin film by a method such as vapor deposition or sputtering, and a pattern having a desired shape may be formed by a photolithography method, or when pattern accuracy is not so high (about 100 μm or more) A pattern may be formed through a mask having a desired shape at the time of vapor deposition or sputtering of the electrode material. Or when using the substance which can be apply | coated like an organic electroconductivity compound, wet film-forming methods, such as a printing system and a coating system, can also be used.
When light emission is extracted from the anode, it is desirable that the transmittance be greater than 10%, and the sheet resistance as the anode is preferably several hundred Ω / □ or less.
Further, although the film thickness depends on the material, it is usually selected in the range of 10 nm to 1000 nm, preferably 10 nm to 200 nm.

<Cathode>
On the other hand, as the cathode, a material having a low work function (4 eV or less) metal (referred to as an electron injecting metal), an alloy, an electrically conductive compound, and a mixture thereof as an electrode material is used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) Mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like.
Among these, from the point of durability against electron injection and oxidation, etc., a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function than this, for example, a magnesium / silver mixture, Magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al ₂ O ₃ ) mixtures, lithium / aluminum mixtures, aluminum and the like are preferred.
The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering.
The sheet resistance as a cathode is preferably several hundred Ω / □ or less, and the film thickness is usually selected in the range of 10 nm to 5 μm, preferably 50 nm to 200 nm.
In order to transmit the emitted light, if either the anode or the cathode of the organic EL element is transparent or translucent, the light emission luminance is improved and it is convenient.
In addition, a transparent or translucent cathode can be produced by producing the conductive transparent material mentioned in the description of the anode on the cathode after producing the metal with a thickness of 1 nm to 20 nm on the cathode, and applying this. Thus, an element in which both the anode and the cathode are transmissive can be manufactured.

<Support substrate>
As a support substrate (hereinafter also referred to as a substrate, substrate, substrate, support, etc.) that can be used in the organic EL device of the present invention, there is no particular limitation on the type of glass, plastic, etc., and it is transparent. May be opaque. When extracting light from the support substrate side, the support substrate is preferably transparent. Examples of the transparent support substrate preferably used include glass, quartz, and a transparent resin film. A particularly preferable support substrate is a resin film capable of giving flexibility to the organic EL element.
Examples of the resin film include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, cellulose acetate propionate (CAP), Cellulose esters such as cellulose acetate phthalate (TAC) and cellulose nitrate or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide , Polyethersulfone (PES), polyphenylene sulfide, polysulfones Polyetherimide, polyether ketone imide, polyamide, fluorine resin, nylon, polymethyl methacrylate, acrylic or polyarylates, and cycloolefin resins such as ARTON (manufactured by JSR) or APEL (manufactured by Mitsui Chemicals).

On the surface of the resin film, an inorganic film, an organic film, or a hybrid film of both may be formed. Water vapor permeability (25 ± 0.5 ° C.) measured by a method according to JIS K 7129-1992. , Relative humidity (90 ± 2)% RH) is preferably 0.01 g / (m ² · 24 h) or less, and more preferably oxygen permeability measured by a method according to JIS K 7126-1987. A high barrier property film having a degree of 10 ⁻³ ml / (m ² · 24 h · atm) or less and a water vapor permeability of 10 ⁻⁵ g / (m ² · 24 h) or less is preferable.
As a material for forming the barrier film, any material may be used as long as it has a function of suppressing entry of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like can be used. Further, in order to improve the brittleness of the film, it is more preferable to have a laminated structure of these inorganic layers and organic material layers. Although there is no restriction | limiting in particular about the lamination | stacking order of an inorganic layer and an organic layer, It is preferable to laminate | stack both alternately several times.

The method for forming the barrier film is not particularly limited. For example, vacuum deposition, sputtering, reactive sputtering, molecular beam epitaxy, cluster ion beam, ion plating, plasma polymerization, atmospheric pressure plasma polymerization A plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used, but an atmospheric pressure plasma polymerization method as described in JP-A-2004-68143 is particularly preferable.
Examples of the opaque support substrate include metal plates such as aluminum and stainless steel, films, opaque resin substrates, and ceramic substrates.

The external extraction quantum efficiency at room temperature of light emission of the organic EL device of the present invention is preferably 1% or more, more preferably 5% or more.
Here, the external extraction quantum efficiency (%) = the number of photons emitted to the outside of the organic EL element / the number of electrons sent to the organic EL element × 100.

  In addition, a hue improvement filter such as a color filter may be used in combination, or a color conversion filter that converts the emission color from the organic EL element into multiple colors using a phosphor. In the case of using a color conversion filter, the λmax of light emission of the organic EL element is preferably 480 nm or less.

<Sealing>
The organic EL device of the present invention is preferably sealed by sealing with a sealing member in order to seal the anode, the cathode, and the layer between the cathode and the anode from the outside air.
As a sealing means used for this invention, the method of adhere | attaching a sealing member, an electrode, and a support substrate with an adhesive agent can be mentioned, for example.
As a sealing member, it should just be arrange | positioned so that the display area | region of an organic EL element may be covered, and concave plate shape or flat plate shape may be sufficient. Further, transparency and electrical insulation are not particularly limited.
Specific examples include a glass plate, a polymer plate / film, and a metal plate / film. Examples of the glass plate include soda-lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz. Examples of the polymer plate include polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, and polysulfone. Examples of the metal plate include those made of one or more metals or alloys selected from the group consisting of stainless steel, iron, copper, aluminum, magnesium, nickel, zinc, chromium, titanium, molybdenum, silicon, germanium, and tantalum.
In the present invention, a polymer film and a metal film can be preferably used because the element can be thinned. Furthermore, the polymer film has an oxygen permeability of 1 × 10 ⁻³ ml / (m ² · 24 h · atm) or less measured by a method according to JIS K 7126-1987, and a method according to JIS K 7129-1992. It is preferable that the water vapor permeability (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) measured in (1) is 1 × 10 ⁻³ g / (m ² · 24 h) or less.
For processing the sealing member into a concave shape, sandblasting, chemical etching, or the like is used.

Specific examples of the adhesive include photocuring and thermosetting adhesives having reactive vinyl groups such as acrylic acid oligomers and methacrylic acid oligomers, and moisture curing adhesives such as 2-cyanoacrylates. be able to. Moreover, heat | fever and chemical curing types (two-component mixing), such as an epoxy type, can be mentioned. Moreover, hot-melt type polyamide, polyester, and polyolefin can be mentioned. Moreover, a cationic curing type ultraviolet curing epoxy resin adhesive can be mentioned.
In addition, since an organic EL element may deteriorate by heat processing, what can be adhesively cured from room temperature to 80 degreeC is preferable. A desiccant may be dispersed in the adhesive.
Application | coating of the adhesive agent to a sealing part may use commercially available dispenser, and may print like screen printing.
In addition, it is also preferable to form an inorganic or organic layer on the outer side of the electrode on the side facing the support substrate with the organic layer interposed therebetween, and form an inorganic or organic layer in contact with the support substrate to form a sealing film. it can.
In this case, the material for forming the film may be any material that has a function of suppressing intrusion of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like may be used. it can.
Further, in order to improve the brittleness of the film, it is preferable to have a laminated structure of these inorganic layers and layers made of organic materials. There are no particular limitations on the method of forming these films. For example, vacuum deposition, sputtering, reactive sputtering, molecular beam epitaxy, cluster ion beam, ion plating, plasma polymerization, atmospheric pressure plasma A combination method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used.

In the gap between the sealing member and the display area of the organic EL element, an inert gas such as nitrogen or argon, or an inert liquid such as fluorinated hydrocarbon or silicon oil can be injected in the gas phase and liquid phase. preferable. A vacuum can also be used. Moreover, a hygroscopic compound can also be enclosed inside.
Examples of the hygroscopic compound include metal oxides (for example, sodium oxide, potassium oxide, calcium oxide, barium oxide, magnesium oxide, aluminum oxide) and sulfates (for example, sodium sulfate, calcium sulfate, magnesium sulfate, cobalt sulfate). Etc.), metal halides (eg calcium chloride, magnesium chloride, cesium fluoride, tantalum fluoride, cerium bromide, magnesium bromide, barium iodide, magnesium iodide etc.), perchloric acids (eg perchloric acid) Barium, magnesium perchlorate and the like), and anhydrous salts are preferably used in sulfates, metal halides and perchloric acids.

<Protective film, protective plate>
In order to increase the mechanical strength of the element, a protective film or a protective plate may be provided on the outer side of the sealing film on the side facing the support substrate with the organic layer interposed therebetween or on the sealing film. In particular, when the sealing is performed by the sealing film, the mechanical strength is not necessarily high, and thus it is preferable to provide such a protective film and a protective plate.
As a material that can be used for this, the same glass plate, polymer plate / film, metal plate / film, and the like used for the sealing can be used. Is preferably used.

<Light extraction>
The organic EL element emits light inside a layer having a refractive index higher than that of air (refractive index is about 1.7 to 2.1) and can extract only about 15% to 20% of the light generated in the light emitting layer. It is generally said. This is because light incident on the interface (interface between the transparent substrate and air) at an angle θ greater than the critical angle causes total reflection and cannot be taken out of the device, or between the transparent electrode or light emitting layer and the transparent substrate. This is because the light is totally reflected between the light and the light is guided through the transparent electrode or the light emitting layer, and as a result, the light escapes in the direction of the element side surface.
As a method for improving the light extraction efficiency, for example, a method of forming irregularities on the surface of the transparent substrate to prevent total reflection at the interface between the transparent substrate and the air (US Pat. No. 4,774,435), A method of improving efficiency by providing a light collecting property to a substrate (Japanese Patent Laid-Open No. 63-314795), a method of forming a reflective surface on a side surface of an element (Japanese Patent Laid-Open No. 1-220394), and light emission from a substrate A method of forming an antireflection film by introducing a flat layer having an intermediate refractive index between the bodies (Japanese Patent Laid-Open No. 62-172691), a flat having a lower refractive index between the substrate and the light emitter than the substrate A method of introducing a layer (Japanese Patent Laid-Open No. 2001-202827), a method of forming a diffraction grating between any one of a substrate, a transparent electrode layer and a light emitting layer (including between the substrate and the outside) (Japanese Patent Laid-Open No. 11-283951) Gazette).

In the present invention, these methods can be used in combination with the organic EL device of the present invention. However, a method of introducing a flat layer having a lower refractive index than the substrate between the substrate and the light emitter, or a substrate, transparent A method of forming a diffraction grating between any layers of the electrode layer and the light emitting layer (including between the substrate and the outside) can be suitably used.
In the present invention, by combining these means, it is possible to obtain an element having higher luminance or durability.
When a medium having a low refractive index is formed between the transparent electrode and the transparent substrate with a thickness longer than the wavelength of light, the light extracted from the transparent electrode has a higher extraction efficiency to the outside as the refractive index of the medium is lower.
Examples of the low refractive index layer include aerogel, porous silica, magnesium fluoride, and a fluorine-based polymer. Since the refractive index of the transparent substrate is generally about 1.5 to 1.7, the low refractive index layer preferably has a refractive index of about 1.5 or less. Further, it is preferably 1.35 or less.
The thickness of the low refractive index medium is preferably at least twice the wavelength in the medium. This is because the effect of the low refractive index layer is diminished when the thickness of the low refractive index medium is about the wavelength of light and the electromagnetic wave that has exuded by evanescent enters the substrate.

The method of introducing a diffraction grating into an interface or any medium that causes total reflection is characterized by a high effect of improving light extraction efficiency. This method uses the property that the diffraction grating can change the direction of light to a specific direction different from refraction by so-called Bragg diffraction such as first-order diffraction and second-order diffraction. Of these, light that cannot be emitted due to total reflection between layers, etc. is diffracted by introducing a diffraction grating into any layer or medium (in a transparent substrate or transparent electrode), and the light is I want to take it out.
The introduced diffraction grating desirably has a two-dimensional periodic refractive index. This is because light emitted from the light-emitting layer is randomly generated in all directions, so in a general one-dimensional diffraction grating having a periodic refractive index distribution only in a certain direction, only light traveling in a specific direction is diffracted. Therefore, the light extraction efficiency does not increase so much.
However, by making the refractive index distribution a two-dimensional distribution, light traveling in all directions is diffracted, and light extraction efficiency is increased.
As described above, the position where the diffraction grating is introduced may be in any of the layers or in the medium (in the transparent substrate or the transparent electrode), but is preferably in the vicinity of the organic light emitting layer where light is generated.
At this time, the period of the diffraction grating is preferably about 1/2 to 3 times the wavelength of light in the medium. The arrangement of the diffraction grating is preferably two-dimensionally repeated, such as a square lattice, a triangular lattice, or a honeycomb lattice.

<Condensing sheet>
The organic EL device of the present invention is processed on the light extraction side of the substrate so as to provide, for example, a microlens array structure, or combined with a so-called condensing sheet, for example, with respect to a specific direction, for example, the device light emitting surface. By condensing in the front direction, the luminance in a specific direction can be increased.
As an example of the microlens array, quadrangular pyramids having a side of 30 μm and an apex angle of 90 degrees are two-dimensionally arranged on the light extraction side of the substrate. One side is preferably 10 μm to 100 μm. If it becomes smaller than this, the effect of diffraction will generate | occur | produce and color, and if too large, thickness will become thick and is not preferable.
As the condensing sheet, for example, a sheet that is put into practical use in an LED backlight of a liquid crystal display device can be used. As such a sheet, for example, Sumitomo 3M brightness enhancement film (BEF) can be used. As the shape of the prism sheet, for example, the base material may be formed by forming a △ -shaped stripe having a vertex angle of 90 degrees and a pitch of 50 μm, or the vertex angle is rounded and the pitch is changed randomly. Other shapes may be used.
Moreover, in order to control the light emission angle from a light emitting element, you may use together a light diffusing plate and a film with a condensing sheet. For example, a diffusion film (light-up) manufactured by Kimoto Co., Ltd. can be used.

<Method for producing organic EL element>
As an example of the method for producing the organic EL device of the present invention, a method for producing an organic EL device comprising an anode / hole injection layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode will be described.
First, a desired electrode material, for example, a thin film made of an anode material is formed on a suitable substrate so as to have a film thickness of 1 μm or less, preferably 10 nm to 200 nm, by vapor deposition, sputtering, or the like to produce an anode. .
Next, organic compound thin films (organic layers) such as a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, and an electron transport layer, which are organic EL element materials, are formed thereon.
Methods for forming these layers include the vapor deposition method and the wet process (spin coating method, casting method, ink jet method, printing method, etc.) as described above, but it is easy to obtain a uniform film and pinholes are generated. In view of difficulty, etc., film formation by vapor deposition, spin coating, ink jet, or printing is preferred in the present invention.
Further, a different film forming method may be applied for each layer.

When a vapor deposition method is employed for film formation, the vapor deposition conditions vary depending on the type of compound used, but generally a boat heating temperature of 50 ° C. to 450 ° C., a vacuum degree of 10 ⁻⁶ Pa to 10 ⁻² Pa, and a vapor deposition rate of 0. It is desirable to select appropriately within the range of 0.01 nm / second to 50 nm / second, substrate temperature of −50 ° C. to 300 ° C., and film thickness of 0.1 μm to 5 μm.

  When the layer is formed by a wet process, examples of the liquid medium for dissolving or dispersing the organic EL material according to the present invention include ketones such as methyl ethyl ketone and cyclohexanone, fatty acid esters such as ethyl acetate, and halogens such as dichlorobenzene. Hydrocarbons, aromatic hydrocarbons such as toluene, xylene, mesitylene and cyclohexylbenzene, aliphatic hydrocarbons such as cyclohexane, decalin and dodecane, and organic solvents such as DMF and DMSO can be used. Moreover, as a dispersion method, it can disperse | distribute by dispersion methods, such as an ultrasonic wave, high shear force dispersion | distribution, and media dispersion | distribution.

After forming these layers, a thin film made of a cathode material is formed thereon by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably in the range of 50 nm to 200 nm. By providing, a desired organic EL element can be obtained.
The organic EL device is preferably manufactured from the hole injection layer to the cathode consistently by a single vacuum, but may be taken out halfway and subjected to different film forming methods. At that time, it is necessary to consider that the work is performed in a dry inert gas atmosphere.

<Application>
The organic EL element of the present invention can be used as a display device, a display, and various light emission sources. For example, lighting devices (home lighting, interior lighting), clock and liquid crystal backlights, billboard advertisements, traffic lights, light sources of optical storage media, light sources of electrophotographic copying machines, light sources of optical communication processors, light Although the light source of a sensor etc. are mentioned, It is not limited to this, Especially, it can use effectively for the use as a backlight of a liquid crystal display device, and a light source for illumination.
In the organic EL element of the present invention, patterning may be performed by a metal mask, an ink jet printing method, or the like as needed during film formation. In the case of patterning, only the electrode may be patterned, the electrode and the light emitting layer may be patterned, or the entire layer of the element may be patterned, and a conventionally known method may be used in the fabrication of the element. it can.
The light emission color of the organic EL element of the present invention and the compound according to the present invention is shown in FIG. It is determined by the color when the result measured with the total CS-1000 (manufactured by Konica Minolta Sensing) is applied to the CIE chromaticity coordinates.
When the organic EL element of the present invention is a white element, white means that the chromaticity in the CIE 1931 color system at 1000 cd / m ² is X = It is in the region of 0.33 ± 0.07, Y = 0.33 ± 0.1.

<Display device>
A display device using the present invention will be described.
A display device using the present invention has the organic EL element.
The display device using the present invention may be single color or multicolor, but here, the multicolor display device will be described. In the case of a multicolor display device, a shadow mask is provided only at the time of forming a light emitting layer, and a film can be formed on one surface by vapor deposition, casting, spin coating, ink jet, printing, or the like.
When patterning is performed only on the light-emitting layer, the method is not limited, but a vapor deposition method, an inkjet method, and a printing method are preferable. In the case of using a vapor deposition method, patterning using a shadow mask is preferable.
Moreover, it is also possible to reverse the production order to produce the cathode, the electron transport layer, the hole blocking layer, the light emitting layer, the hole transport layer, and the anode in this order.
When a DC voltage is applied to the multicolor display device thus obtained, light emission can be observed when a voltage of about 2 V to 40 V is applied with the positive polarity of the anode and the negative polarity of the cathode. Further, even when a voltage is applied with the opposite polarity, no current flows and no light emission occurs.
Further, when an AC voltage is applied, light is emitted only when the anode is in the + state and the cathode is in the-state. The alternating current waveform to be applied may be arbitrary.

The multicolor display device can be used as a display device, a display, and various light emission sources. In a display device or display, full-color display is possible by using three types of organic EL elements of blue, red, and green light emission.
Examples of the display device and display include a television, a personal computer, a mobile device, an AV device, a character broadcast display, and an information display in an automobile. In particular, it may be used as a display device for reproducing still images and moving images, and the driving method when used as a display device for reproducing moving images may be either a simple matrix (passive matrix) method or an active matrix method.
Light sources include home lighting, interior lighting, clock and liquid crystal backlights, billboard advertisements, traffic lights, light sources for optical storage media, light sources for electrophotographic copying machines, light sources for optical communication processors, light sources for optical sensors, etc. For example, it is not limited to this.

The organic EL element of the present invention may be used as a kind of lamp for illumination or an exposure light source, a projection device that projects an image, or a display device that directly recognizes a still image or a moving image ( It may be used as a display.
The driving method when used as a display device for moving image reproduction may be either a simple matrix (passive matrix) method or an active matrix method. Alternatively, a full-color display device can be manufactured by using two or more organic EL elements of the present invention having different emission colors.

Hereinafter, an example of a display device having the organic EL element of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view showing an example of a display device composed of organic EL elements.
FIG. 1 is a schematic diagram of a display such as a mobile phone that displays image information by light emission of an organic EL element.
As shown in FIG. 1, the display 1 includes a display unit A having a plurality of pixels, a control unit B that performs image scanning of the display unit A based on image information, and the like.
The control unit B is electrically connected to the display unit A.
The control unit B sends a scanning signal and an image data signal to each of a plurality of pixels based on image information from the outside, and the pixels for each scanning line sequentially emit light according to the image data signal by the scanning signal to perform image scanning. The image information is displayed on the display unit A.

FIG. 2 is a schematic diagram of the display unit A.
As shown in FIG. 2, the display unit A includes a wiring unit including a plurality of scanning lines 5 and data lines 6, a plurality of pixels 3 and the like on a substrate.
The main members of the display unit A will be described below.
FIG. 2 shows a case where the light emitted from the pixel 3 is extracted in the direction of the white arrow (downward).
Each of the scanning lines 5 and the plurality of data lines 6 in the wiring portion is made of a conductive material.
The scanning lines 5 and the data lines 6 are orthogonal to each other in a lattice pattern, and are connected to the pixels 3 at the orthogonal positions (details are not shown).
When a scanning signal is applied from the scanning line 5, the pixel 3 receives an image data signal from the data line 6 and emits light according to the received image data.
In the display unit A, full-color display can be performed by appropriately arranging pixels in which the emission color is a red region, a green region, and a blue region on the same substrate.

Next, the light emission process of the pixel will be described.
FIG. 3 is a schematic diagram of a pixel.
As shown in FIG. 3, the pixel includes an organic EL element 10, a switching transistor 11, a driving transistor 12, a capacitor 13, and the like.
In a plurality of pixels, red, green, and blue light emitting organic EL elements are used as the organic EL elements 10, and full color display can be performed by arranging them in parallel on the same substrate.
In FIG. 3, an image data signal is applied from the control unit B to the drain of the switching transistor 11 through the data line 6. When a scanning signal is applied from the control unit B to the gate of the switching transistor 11 via the scanning line 5, the driving of the switching transistor 11 is turned on, and the image data signal applied to the drain is supplied to the capacitor 13 and the driving transistor 12. Is transmitted to the gate.
By transmitting the image data signal, the capacitor 13 is charged according to the potential of the image data signal, and the drive of the drive transistor 12 is turned on. The drive transistor 12 has a drain connected to the power supply line 7 and a source connected to the electrode of the organic EL element 10, and the power supply line 7 connects to the organic EL element 10 according to the potential of the image data signal applied to the gate. Current is supplied.
When the scanning signal is moved to the next scanning line 5 by the sequential scanning of the control unit B, the driving of the switching transistor 11 is turned off. However, even if the driving of the switching transistor 11 is turned off, the capacitor 13 maintains the potential of the charged image data signal, so that the driving of the driving transistor 12 is kept on and the next scanning signal is applied. Until then, the light emission of the organic EL element 10 continues. When the scanning signal is next applied by sequential scanning, the driving transistor 12 is driven according to the potential of the next image data signal synchronized with the scanning signal, and the organic EL element 10 emits light.
That is, the light emission of the organic EL element 10 is performed by providing the switching transistor 11 and the drive transistor 12 which are active elements with respect to the organic EL element 10 of each of the plurality of pixels, and the light emission of the organic EL element 10 of each of the plurality of pixels 3. It is carried out. Such a light emitting method is called an active matrix method.
Here, the light emission of the organic EL element 10 may be light emission of a plurality of gradations by a multi-value image data signal having a plurality of gradation potentials, or by turning on / off a predetermined light emission amount by a binary image data signal. Good. The potential of the capacitor 13 may be maintained until the next scanning signal is applied, or may be discharged immediately before the next scanning signal is applied.
In the present invention, not only the active matrix method described above, but also a passive matrix light emission drive in which the organic EL element emits light according to the data signal only when the scanning signal is scanned.

FIG. 4 is a schematic diagram of a passive matrix display device.
In FIG. 4, a plurality of scanning lines 5 and a plurality of image data lines 6 are provided in a lattice shape so as to face each other with the pixel 3 interposed therebetween.
When the scanning signal of the scanning line 5 is applied by sequential scanning, the pixels 3 connected to the applied scanning line 5 emit light according to the image data signal.
In the passive matrix system, the pixel 3 has no active element, and the manufacturing cost can be reduced.

[Lighting device]
The organic EL material of the present invention can be applied to an organic EL element that emits substantially white light as a lighting device. A plurality of light emitting colors are simultaneously emitted by a plurality of light emitting materials to obtain white light emission by color mixing. The combination of a plurality of emission colors may include three emission maximum wavelengths of the three primary colors of red, green and blue, or two using the complementary colors such as blue and yellow, blue green and orange. The thing containing the light emission maximum wavelength may be used.
In addition, a combination of light emitting materials for obtaining a plurality of emission colors is a combination of a plurality of phosphorescent or fluorescent materials, a light emitting material that emits fluorescence or phosphorescence, and light from the light emitting material as excitation light. Any of those combined with a dye material that emits light may be used, but in the white organic EL device according to the present invention, only a combination of a plurality of light-emitting dopants may be mixed.
It is only necessary to provide a mask only when forming the light emitting layer, hole transport layer, electron transport layer, etc. In addition, for example, an electrode film can be formed by a vapor deposition method, a cast method, a spin coating method, an ink jet method, a printing method, etc., and productivity is also improved. According to this method, unlike a white organic EL device in which light emitting elements of a plurality of colors are arranged in parallel in an array, the elements themselves are luminescent white.

<One aspect of lighting device of the present invention>
One aspect of the lighting device of the present invention that includes the organic EL element of the present invention will be described.
The non-light emitting surface of the organic EL device of the present invention is covered with a glass case, a 300 μm thick glass substrate is used as a sealing substrate, and an epoxy photocurable adhesive (LUX The track LC0629B) is applied, and this is overlaid on the cathode and brought into close contact with the transparent support substrate, irradiated with UV light from the glass substrate side, cured, sealed, and illuminated as shown in FIGS. A device can be formed.
FIG. 5 shows a schematic diagram of the illumination device.
As shown in FIG. 5, the organic EL element 101 is covered with a glass cover 102.
The sealing operation with the glass cover 102 is preferably performed in a glove box (in an atmosphere of high purity nitrogen gas having a purity of 99.999% or more) in a nitrogen atmosphere without bringing the organic EL element 101 into contact with the atmosphere.
FIG. 6 shows a cross-sectional view of the lighting device.
As shown in FIG. 6, the lighting device mainly includes a cathode 105, an organic EL layer 106, and a glass substrate 107 with a transparent electrode, and these members are covered with a glass cover 102.
The glass cover 102 is filled with nitrogen gas 108 and a water catching agent 109 is provided.

EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these.
In addition, compounds used for manufacturing the device are shown below.

[Example 1]
<Preparation of Organic EL Element 1-1>
Transparent support provided with this ITO transparent electrode after patterning on a substrate (NA Techno Glass NA45) with a 100 nm ITO (indium tin oxide) film formed on a 100 mm × 100 mm × 1.1 mm glass substrate as an anode The substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes.

  This transparent support substrate is fixed to a substrate holder of a commercially available vacuum deposition apparatus, while 200 mg of HIL-1 is put in a molybdenum resistance heating boat, and 200 mg of HTL-1 is put in another molybdenum resistance heating boat, and another molybdenum resistance is added. 200 mg of OC-33 was put into a heating boat, 200 mg of D-D-1 was put into another resistance heating boat made of molybdenum, and 200 mg of ETL-1 was put into another resistance heating boat made of molybdenum, and attached to a vacuum deposition apparatus.

The vacuum chamber was then depressurized to 4 × 10 ⁻⁴ Pa, heated by energizing the heating boat containing HIL-1, and deposited on a transparent support substrate at a deposition rate of 0.1 nm / sec. An injection layer was provided.
Further, the heating boat containing HTL-1 was energized and heated, and was deposited on the hole injection layer at a deposition rate of 0.1 nm / second to provide a 20 nm hole transport layer.

  Further, the heating boat containing OC-33 and D-1 was energized and heated, and co-deposited on the hole transport layer at a deposition rate of 0.1 nm / second and 0.006 nm / second, respectively, to emit light of 40 nm. A layer was provided.

  Furthermore, it supplied with electricity to the said heating boat containing ETL-1, and heated, and it vapor-deposited on the said light emitting layer with the vapor deposition rate of 0.1 nm / sec, and provided the 40-nm electron carrying layer.

  Subsequently, 0.5 nm of lithium fluoride was vapor-deposited as a cathode buffer layer, and further, 110 nm of aluminum was vapor-deposited to form a cathode, and “organic EL element 1-1” was produced.

  Thereafter, the non-light emitting surface of the organic EL element 1-1 is covered with a glass case, an epoxy photocurable adhesive (manufactured by Toagosei Co., Ltd.) is used as a sealing material around a glass substrate having a thickness of 300 μm as a sealing substrate. LUX TRACK LC0629B) is applied, and this is overlaid on the cathode and brought into close contact with the transparent support substrate, irradiated with UV light from the glass substrate side, cured, and sealed, as shown in FIGS. The lighting device as shown was formed and used as a sample for evaluation (the same applies to organic EL elements 1-2 to 1-40 described later).

<Preparation of organic EL elements 1-2 to 1-40>
In production of the organic EL element 1-1, the dopant compound was changed to the dopant compounds shown in Table 11.
Other than that was carried out similarly to preparation of the organic EL element 1-1, and produced "organic EL element 1-2 to 1-40."

<Evaluation of the organic EL elements 1-1 to 1-40>
The following evaluations were performed on the organic EL elements 1-1 to 1-40 produced as described above. The results are shown in Tables 1 and 2.

(1) Luminous efficiency (also called external extraction quantum efficiency)
For each organic EL element, the external extraction quantum efficiency (%) when a constant current of ^2.5 mA / cm ² was applied at 23 ° C. in a dry nitrogen gas atmosphere was measured and used as an index of luminous efficiency. For the measurement, a spectral radiance meter CS-1000 (manufactured by Konica Minolta Sensing) was used.
In Table 11, the measurement result of the external extraction quantum efficiency was expressed as a relative value when the measurement value of the organic EL element 1-1 was 100.

(2) 50 ° C drive life (half life at high temperature storage)
Each organic EL element is driven at a constant current with a current that gives an initial luminance of 1000 cd / m ² under a constant condition of 50 ° C., and a time that is ½ (500 cd / m ² ) of the initial luminance is obtained. It was used as a measure of life and as an index of durability.
In Table 11, the 50 ° C. drive life is expressed as a relative value when the organic EL element 1-1 is set to 100.

(3) Discoloration of luminescent color over time Each organic EL element is driven at a constant current with a current that gives an initial luminance of 600 cd / m ² under a constant condition of 50 ° C., to 2/3 of initial luminance (400 cd / m ² ). The change in emission color was visually observed, and the following four ranks were evaluated.
◎: No discoloration is observed ○: Slightly yellowish △: Yellowish ×: Extremely yellowish

(4) Summary As shown in Table 11, the organic EL elements 1-1 to 1-31 of the present invention have higher luminous efficiency than the comparative organic EL elements 1-32 to 1-40, and emit light. It is clear that the lifetime is long and the luminescent color changes little over time.

[Example 2]
<Preparation of organic EL element 2-1>
Patterning was performed on a substrate (NAV-45, manufactured by AvanStrate Co., Ltd.) in which an ITO (indium tin oxide) film having a thickness of 100 nm was formed on a 100 mm × 100 mm × 1.1 mm glass substrate as an anode. Thereafter, the transparent support substrate provided with the ITO transparent electrode was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes.

On this transparent support substrate, a solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, manufactured by Bayer, Baytron P Al 4083) to 70% with pure water, 3000 rpm, 30 After forming a film by spin coating under the condition of seconds, the film was dried at 200 ° C. for 1 hour to provide a first hole transport layer having a thickness of 20 nm.
On this first hole transport layer, 50 mg of hole transport material Poly (N, N′-bis (4-butylphenyl) -N, N′-bis (phenyl)) benzidine (manufactured by American Dye Source, A solution of ADS-254) dissolved in 10 ml of chlorobenzene was deposited by spin coating under conditions of 1500 rpm and 30 seconds. It heat-dried at 150 degreeC for 1 hour, and provided the 2nd hole transport layer with a film thickness of 40 nm.

  On this second hole transport layer, a solution prepared by dissolving 100 mg of host compound OC-29 and 13 mg of dopant compound D-3 in 10 ml of butyl acetate was formed by spin coating at 1000 rpm for 30 seconds. A film was formed and vacuum-dried at 100 ° C. for 1 hour to provide a light-emitting layer having a thickness of 40 nm.

  On this light emitting layer, a solution of 50 mg of the electron transport material ETL-2 dissolved in 10 ml of 1-butanol was formed into a film by spin coating under conditions of 1000 rpm and 30 seconds, and dried under vacuum heating at 60 ° C. for 1 hour. Then, an electron transport layer having a thickness of 20 nm was provided.

This was attached to a vacuum deposition apparatus, and the vacuum chamber was depressurized to 4 × 10 ⁻⁴ Pa.
Next, 0.4 nm of lithium fluoride was deposited as an electron injection layer and 110 nm of aluminum was deposited as a cathode, and “organic EL element 2-1” was produced.

  Thereafter, the non-light emitting surface of the organic EL element 2-1 is covered with a glass case, and a 300 μm thick glass substrate is used as a sealing substrate, and an epoxy-based photocurable adhesive (manufactured by Toagosei Co., Ltd.) is used as a sealing material around. LUX TRACK LC0629B) is applied, and this is overlaid on the cathode and brought into close contact with the transparent support substrate, irradiated with UV light from the glass substrate side, cured, and sealed, as shown in FIGS. The lighting device as shown was formed and used as a sample for evaluation (the same applies to organic EL elements 2-2 to 2-21 described later).

<< Production of Organic EL Elements 2-2 to 2-21 >>
In production of the organic EL element 2-1, the dopant compound D-3 in the light emitting layer was replaced with the compounds shown in Table 12.
Other than that was carried out similarly to preparation of the organic EL element 2-1, and each "organic EL element 2-2 to 2-21" was produced.

<< Evaluation of organic EL elements >>
The organic EL elements 2-1 to 2-21 produced as described above were evaluated as follows. The results are shown in Table 12.

(1) Luminous efficiency (also called external extraction quantum efficiency)
For each organic EL element, the external extraction quantum efficiency (%) when a constant current of ^2.5 mA / cm ² was applied at 23 ° C. in a dry nitrogen gas atmosphere was measured and used as an index of luminous efficiency. Similarly, a spectral radiance meter CS-1000 (manufactured by Konica Minolta Sensing) was used for the measurement.
In Table 12, the measurement result of the external extraction quantum efficiency was expressed as a relative value when the measurement value of the organic EL element 2-1 was 100.

(2) 50 ° C drive life (half life at high temperature storage)
Each organic EL element is driven at a constant current with a current that gives an initial luminance of 1000 cd / m ² under a constant condition of 50 ° C., and a time that is ½ (500 cd / m ² ) of the initial luminance is obtained. It was used as a measure of life and as an index of durability.
In Table 12, the 50 ° C. drive life is expressed as a relative value when the organic EL element 2-1 is 100.

(3) Discoloration of luminescent color over time Each organic EL element is driven at a constant current with a current that gives an initial luminance of 600 cd / m ² under a constant condition of 50 ° C., to 2/3 of initial luminance (400 cd / m ² ). The change in emission color was visually observed, and the following four ranks were evaluated.
◎: No discoloration is observed ○: Slightly yellowish △: Yellowish ×: Extremely yellowish

(4) Dark spot The light emitting surface when each organic EL element was continuously lit under a constant current condition of room temperature (about 23 ° C. to 25 ° C.) and ^2.5 mA / cm ² was visually evaluated.
The following rank evaluation was performed by visual evaluation by 10 people extracted at random, and used as an index of the dark spot generation prevention effect.
In Table 3, the criteria for ○, Δ, and × were as follows.
○: The number of people who confirmed dark spots is 0. △: The number of people confirmed dark spots is 1 to 4. ×: The number of people confirmed dark spots is 5 or more.

(5) Drive voltage The voltage when each organic EL element was driven at room temperature (about 23 ° C. to 25 ° C.) and a constant current of ^2.5 mA / cm ² was determined.
In Table 12, the drive voltage of each organic EL element is shown as a relative value with the organic EL element 2-1 being 100 according to the following formula.
Drive voltage = (drive voltage of each element / drive voltage of the organic EL element 2-1) × 100
Note that a smaller drive voltage value indicates a lower drive voltage for comparison.

(6) Luminance unevenness of light emission Each organic EL element is driven under a constant current of room temperature (about 23 ° C. to 25 ° C.) and an initial luminance of 2000 cd / m ² , and the light emission luminance after 150 hours has passed is measured by a spectral radiance meter CS−. 1000 (manufactured by Konica Minolta Sensing) was used for measurement.
20 arbitrary points on the light emitting surface were measured, and from the measured value at this time, the luminance unevenness of light emission was calculated as in-plane minimum luminance / maximum luminance, and the three-level rank evaluation was performed as follows.
○: Luminance unevenness of light emission is 0.90 or more Δ: Luminance unevenness of light emission is 0.86 or more and less than 0.90 ×: Luminance unevenness of light emission is less than 0.86

(7) Summary As shown in Table 12, the organic EL elements 2-1 to 2-12 of the present invention have higher luminous efficiency and light emission lifetime than the comparative organic EL elements 2-13 to 2-21. It can be seen that the light emission color changes little with time, there are few dark spots, it can be driven at a low voltage, and the luminance unevenness of light emission is suppressed.

[Example 3]
<Preparation of White Light-Emitting Organic EL Element 3-1>
Transparent support provided with this ITO transparent electrode after patterning on a substrate (NA Techno Glass NA45) with a 100 nm ITO (indium tin oxide) film formed on a 100 mm × 100 mm × 1.1 mm glass substrate as an anode The substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes.

  This transparent support substrate is fixed to a substrate holder of a commercially available vacuum deposition apparatus, while 200 mg of HIL-1 is put in a molybdenum resistance heating boat, and 200 mg of HTL-1 is put in another molybdenum resistance heating boat, and another molybdenum resistance is added. Put 200 mg of OC-33 into a heating boat, put 200 mg of D-3 into another resistance heating boat made of molybdenum, put 200 mg of ETL-2 into another resistance heating boat made of molybdenum, and put GD- into another molybdenum resistance heating boat. 200 mg of 1 was placed, 200 mg of RD-1 was placed in another molybdenum resistance heating boat, and attached to a vacuum deposition apparatus.

The vacuum chamber was then depressurized to 4 × 10 ⁻⁴ Pa, heated by energizing the heating boat containing HIL-1, and deposited on a transparent support substrate at a deposition rate of 0.1 nm / sec. An injection layer was provided.
Further, the heating boat containing HTL-1 was energized and heated, and was deposited on the hole injection layer at a deposition rate of 0.1 nm / second to provide a 20 nm hole transport layer.

  Further, the heating boat containing OC-33, D-3, GD-1 and RD-1 was heated by energization, and the deposition rates were 0.1 nm / second, 0.025 nm / second, 0.0007 nm / second and A light-emitting layer having a thickness of 60 nm was formed by co-evaporation on the hole transport layer at 0.0002 nm / second.

Further, the heating boat containing ETL-2 was energized and heated, and was deposited on the light emitting layer at a deposition rate of 0.1 nm / second to provide a 20 nm electron transport layer.
Then, 0.5 nm of potassium fluoride was vapor-deposited as a cathode buffer layer, and also aluminum 110nm was vapor-deposited, the cathode was formed, and "organic EL element 3-1" was produced.

  Thereafter, the non-light-emitting surface of the organic EL element 3-1 is covered with a glass case, an epoxy-based photocurable adhesive (manufactured by Toagosei Co., Ltd.) is used as a sealing material around a glass substrate having a thickness of 300 μm as a sealing substrate. LUX TRACK LC0629B) is applied, and this is overlaid on the cathode and brought into close contact with the transparent support substrate, irradiated with UV light from the glass substrate side, cured, and sealed, as shown in FIGS. The lighting device as shown was formed and used as a sample for evaluation (the same applies to organic EL elements 3-2 to 3-21 described later).

<< Production of White Light-Emitting Organic EL Elements 3-2 to 3-21 >>
In the production of the organic EL element 3-1, the dopant compound D-3 in the light emitting layer was replaced with a compound shown in Table 13.
Other than that was carried out similarly to preparation of the organic EL element 3-1, and each "organic EL element 3-2-3-21" was produced.

<< Evaluation of organic EL elements >>
The following evaluations were performed on the organic EL elements 3-1 to 3-21 manufactured as described above. The results are shown in Table 13.

(1) Luminous efficiency (also called external extraction quantum efficiency)
For each organic EL element, the external extraction quantum efficiency (%) when a constant current of ^2.5 mA / cm ² was applied at 23 ° C. in a dry nitrogen gas atmosphere was measured and used as an index of luminous efficiency. Similarly, a spectral radiance meter CS-1000 (manufactured by Konica Minolta Sensing) was used for the measurement.
In Table 13, the measurement result of the external extraction quantum efficiency was expressed as a relative value when the measured value of the organic EL element 3-1 was 100.

(2) 50 ° C drive life (half life at high temperature storage)
Each organic EL element is driven at a constant current with a current that gives an initial luminance of 1000 cd / m ² under a constant condition of 50 ° C., and a time that is ½ (500 cd / m ² ) of the initial luminance is obtained. It was used as a measure of life and as an index of durability.
In Table 13, the 50 ° C. drive life is expressed as a relative value when the organic EL element 3-1 is taken as 100.

(3) Discoloration of luminescent color over time Each organic EL element is driven at a constant current with a current that gives an initial luminance of 600 cd / m ² under a constant condition of 50 ° C., to 2/3 of initial luminance (400 cd / m ² ). The change in emission color was visually observed, and the following four ranks were evaluated.
◎: No discoloration is observed ○: Slightly yellowish △: Yellowish ×: Extremely yellowish

(4) Summary As shown in Table 13, the organic EL elements 3-1 to 3-12 of the present invention have higher luminous efficiency and light emission than the comparative organic EL elements 3-13 to 3-21. It is clear that the lifetime is long and the luminescent color changes little over time.

[Example 4]
<Preparation of white light-emitting organic EL element 4-1>
Patterning was performed on a substrate (NAV-45, manufactured by AvanStrate Co., Ltd.) in which an ITO (indium tin oxide) film having a thickness of 100 nm was formed on a 100 mm × 100 mm × 1.1 mm glass substrate as an anode. Thereafter, the transparent support substrate provided with the ITO transparent electrode was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes.

On this transparent support substrate, a solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, manufactured by Bayer, Baytron P Al 4083) to 70% with pure water, 3000 rpm, 30 After forming a film by spin coating under the condition of seconds, the film was dried at 200 ° C. for 1 hour to provide a first hole transport layer having a thickness of 20 nm.
On this first hole transport layer, 50 mg of hole transport material Poly (N, N′-bis (4-butylphenyl) -N, N′-bis (phenyl)) benzidine (manufactured by American Dye Source, A solution of ADS-254) dissolved in 10 ml of chlorobenzene was deposited by spin coating under conditions of 1500 rpm and 30 seconds. It heat-dried at 150 degreeC for 1 hour, and provided the 2nd hole transport layer with a film thickness of 40 nm.

  On this second hole transport layer, 100 mg of the host compound OC-2, 20 mg of the dopant compound D-4, 0.5 mg of the dopant compound GD-1, and 0.2 mg of the dopant compound RD-1 were added with 10 ml of acetic acid. A solution dissolved in butyl was formed into a film by spin coating under conditions of 600 rpm and 30 seconds, and dried by heating under vacuum at 100 ° C. for 1 hour to provide a light emitting layer having a thickness of 70 nm.

On this light emitting layer, a solution of 50 mg of electron transport material ETL-1 dissolved in 10 ml of 1-butanol was formed into a film by spin coating under conditions of 1000 rpm and 30 seconds, and dried by heating under vacuum at 60 ° C. for 1 hour. Then, an electron transport layer having a thickness of 20 nm was provided.
This was attached to a vacuum deposition apparatus, and the vacuum chamber was depressurized to 4 × 10 ⁻⁴ Pa.
Next, 0.4 nm of lithium fluoride was deposited as an electron injection layer and 110 nm of aluminum was deposited as a cathode, and “organic EL element 4-1” was produced.

  Thereafter, the non-light-emitting surface of the organic EL element 4-1 is covered with a glass case, an epoxy photo-curing adhesive (manufactured by Toagosei Co., Ltd.) is used as a sealing material around a glass substrate having a thickness of 300 μm as a sealing substrate. LUX TRACK LC0629B) is applied, and this is overlaid on the cathode and brought into close contact with the transparent support substrate, irradiated with UV light from the glass substrate side, cured, and sealed, as shown in FIGS. The lighting device as shown was formed and used as a sample for evaluation (the same applies to organic EL elements 4-2 to 4-21 described later).

<< Production of Organic EL Elements 4-2 to 4-21 >>
In the production of the organic EL element 4-1, the dopant compound D-4 in the light emitting layer was replaced with a compound shown in Table 14.
Other than that was carried out similarly to preparation of the organic EL element 4-1, and each "organic EL element 4-2 to 4-21" was produced.

<< Evaluation of organic EL elements >>
The following evaluation was performed on the organic EL elements 4-1 to 4-21 produced as described above. The results are shown in Table 14.

(1) Luminous efficiency (also called external extraction quantum efficiency)
For each organic EL element, the external extraction quantum efficiency (%) when a constant current of ^2.5 mA / cm ² was applied at 23 ° C. in a dry nitrogen gas atmosphere was measured and used as an index of luminous efficiency. Similarly, a spectral radiance meter CS-1000 (manufactured by Konica Minolta Sensing) was used for the measurement.
In Table 14, the measurement result of the external extraction quantum efficiency was expressed as a relative value when the measurement value of the organic EL element 4-1 was 100.

(2) 50 ° C drive life (half life at high temperature storage)
Each organic EL element is driven at a constant current with a current that gives an initial luminance of 1000 cd / m ² under a constant condition of 50 ° C., and a time that is ½ (500 cd / m ² ) of the initial luminance is obtained. It was used as a measure of life and as an index of durability.
In Table 14, the 50 ° C. drive life is expressed as a relative value when the organic EL element 4-1 is 100.

(3) Discoloration of luminescent color over time Each organic EL element is driven at a constant current with a current that gives an initial luminance of 600 cd / m ² under a constant condition of 50 ° C., to 2/3 of initial luminance (400 cd / m ² ). The change in emission color was visually observed, and the following four ranks were evaluated.
◎: No discoloration is observed ○: Slightly yellowish △: Yellowish ×: Extremely yellowish

(4) Dark spot The light emitting surface when each organic EL element was continuously lit under a constant current condition of room temperature (about 23 ° C. to 25 ° C.) and ^2.5 mA / cm ² was visually evaluated.
The following rank evaluation was performed by visual evaluation by 10 people extracted at random, and used as an index of the dark spot generation prevention effect.
In Table 14, the criteria for ○, Δ, and × were as follows.
○: The number of people who confirmed dark spots is 0. △: The number of people confirmed dark spots is 1 to 4. ×: The number of people confirmed dark spots is 5 or more.

(5) Drive voltage The voltage when each organic EL element was driven at room temperature (about 23 ° C. to 25 ° C.) and a constant current of ^2.5 mA / cm ² was determined.
In Table 14, the drive voltage of each organic EL element is shown as a relative value with the organic EL element 4-1 as 100 according to the following formula.
Drive voltage = (drive voltage of each element / drive voltage of organic EL element 4-1) × 100
Note that a smaller drive voltage value indicates a lower drive voltage for comparison.

(6) Luminance unevenness of light emission Each organic EL element is driven under a constant current of room temperature (about 23 ° C. to 25 ° C.) and an initial luminance of 2000 cd / m ² , and the light emission luminance after 150 hours has passed is measured by a spectral radiance meter CS−. 1000 (manufactured by Konica Minolta Sensing) was used for measurement.
20 arbitrary points on the light emitting surface were measured, and from the measured value at this time, the luminance unevenness of light emission was calculated as in-plane minimum luminance / maximum luminance, and the three-level rank evaluation was performed as follows.
○: Luminance unevenness of light emission is 0.90 or more Δ: Luminance unevenness of light emission is 0.86 or more and less than 0.90 ×: Luminance unevenness of light emission is less than 0.86

(7) Summary As shown in Table 14, the organic EL elements 4-1 to 4-12 of the present invention have higher luminous efficiency and light emission lifetime than the comparative organic EL elements 2-13 to 4-21. It can be seen that the light emission color changes little with time, there are few dark spots, it can be driven at a low voltage, and the luminance unevenness of light emission is suppressed.

DESCRIPTION OF SYMBOLS 1 Display 3 Pixel 5 Scan line 6 Data line 7 Power supply line 10 Organic EL element 11 Switching transistor 12 Drive transistor 13 Capacitor A Display part B Control part 107 Glass substrate with a transparent electrode 106 Organic EL layer 105 Cathode 102 Glass cover 108 Nitrogen gas 109 Water catcher

Claims (4)

In an organic electroluminescence device having an anode, a cathode, and an organic layer composed of a single layer or a plurality of layers having a light emitting layer, and the organic layer is sandwiched between the anode and the cathode,
At least one layer of the phosphorescent organic metal complex represented by the general formulas (11) to (13) is contained in at least one layer of the organic layer.

[In the general formulas (11) to (13), “Ra” and “Rb” each independently represents an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group or a non-aromatic heterocyclic group. Represent.
In the general formulas (11) to (13), “Rc” and “Rd” are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group or a non-aromatic heterocycle. Represents a cyclic group.
In the general formulas (11) to (13), “V _{1 to} V ₄ ” each independently represents an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group or a non-aromatic heterocyclic group. Represent.
In the general formulas (11) to (13), “EWG ₁ ” and “EWG ₂ ” each independently represent a group having a Hammett's substituent constant σp value of 0.05 to 1.10.
In general formulas (11) to (13), “Q _{1 to} Q ₁₁ ” each independently represents a nitrogen atom or C—R _{1 to} C—R ₁₁ .
“R _{1 to} R ₁₁ ” are each independently a hydrogen atom, alkyl group, aryl group, cycloalkyl group, alkenyl group, alkynyl group, alkoxy group, cycloalkoxy group, aryloxy group, alkylthio group, cycloalkylthio group, arylthio group. Group, alkoxycarbonyl group, aryloxycarbonyl group, sulfamoyl group, acyl group, acyloxy group, amide group, ureido group, carbamoyl group, sulfinyl group, alkylsulfonyl group, arylsulfonyl group, amino group, halogen atom, perfluoroalkyl group , A cyano group, a nitro group, a hydroxy group, a mercapto group, a silyl group or a non-aromatic heterocyclic group.
In the general formulas (11) to (13), “L” is a monoanionic bidentate ligand coordinated to M, “M” represents iridium or rhodium , and “n” represents 0 to 2 Represents an integer. ] In an organic electroluminescence device having an anode, a cathode, and an organic layer composed of a single layer or a plurality of layers having a light emitting layer, and the organic layer is sandwiched between the anode and the cathode,
At least one of the organic layers contains at least one phosphorescent organometallic complex represented by general formulas (14) to (20).

[In the general formulas (14) to (20), “Ra” and “Rb” each independently represents an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group or a non-aromatic heterocyclic group. Represent.
In the general formulas (14) to (20), “Rc” and “Rd” each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group or a non-aromatic heterocycle. Represents a cyclic group.
In the general formulas (14) to (20), “V _{1 to} V ₄ ” each independently represents an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group or a non-aromatic heterocyclic group. Represent.
In the general formulas (14) to (20), “EWG ₁ ” and “EWG ₂ ” each independently represent a group having a Hammett's substituent constant σp value of 0.05 to 1.10.
In the general formulas (14) to (20), “Rx” and “Ry” represent a hydrogen atom or an alkyl group. A plurality of “Rx” and “Ry” may be the same or different.
In the general formulas (14) to (20), l, m, and n represent an integer of 1 to 6, and l, m, and n may be the same or different.
In General Formulas (14) to (20), “Q _{1 to} Q ₁₁ ” each independently represent a nitrogen atom or C—R _{1 to} C—R ₁₁ .
“R _{1 to} R ₁₁ ” are each independently a hydrogen atom, alkyl group, aryl group, cycloalkyl group, alkenyl group, alkynyl group, alkoxy group, cycloalkoxy group, aryloxy group, alkylthio group, cycloalkylthio group, arylthio group. Group, alkoxycarbonyl group, aryloxycarbonyl group, sulfamoyl group, acyl group, acyloxy group, amide group, ureido group, carbamoyl group, sulfinyl group, alkylsulfonyl group, arylsulfonyl group, amino group, halogen atom, perfluoroalkyl group , A cyano group, a nitro group, a hydroxy group, a mercapto group, a silyl group or a non-aromatic heterocyclic group.
In general formulas (14) to (20), V represents a nitrogen atom, a phosphorus atom, a boron atom, a silyl group, a phosphine oxide group, an alkylene group, a cycloalkylene group, an arylene group, a heteroarylene group, or a non-aromatic heterocyclic group. Represents an alkyleneoxy group, a cycloalkyleneoxy group, an aryleneoxy group, a heteroaryleneoxy group, or a non-aromatic heterocyclic oxy group.
In the general formulas (14) to (20), “M” represents iridium or rhodium .
In the general formulas (14) to (20), * represents a bonding point with M. ] In the organic electroluminescent element according to claim 1 or 2 ,
In the general formulas (11) to (20), “M” is iridium, and the organic electroluminescence element. An illuminating device comprising the organic electroluminescence element according to any one of claims 1 to 3 .

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