JP6119375B2 - Organic electroluminescence element, display device and lighting device - Google Patents

Description

  The present invention relates to an organic electroluminescence element, a display device including the same, and a lighting device.

  An organic electroluminescence element (hereinafter also referred to as an organic EL element) has a configuration in which a light-emitting layer containing a light-emitting compound is sandwiched between a cathode and an anode, and a positive electrode injected from the anode by applying an electric field. This is a light emitting device that uses the emission of light (fluorescence / phosphorescence) when excitons are generated by recombining electrons injected from holes and cathodes in the light emitting layer to generate excitons. is there. The organic EL element is an all-solid-state element composed of an organic material film having a thickness of only a submicron between the electrodes, and can emit light at a voltage of several volts to several tens of volts. It is expected to be used for next-generation flat display and lighting.

  As for the development of organic EL elements for practical use, Princeton University has reported organic EL elements that use phosphorescence emission from excited triplets, and since then, active research has been conducted on materials that exhibit phosphorescence at room temperature. It is becoming. In addition, organic EL elements that utilize phosphorescence can in principle achieve a light emission efficiency that is approximately four times that of organic EL elements that utilize previous fluorescence. Research and development of device layer configurations and electrodes are performed all over the world.

  Among them, many organometallic complexes using heavy metals such as iridium have been studied from the viewpoint of high luminous efficiency and long luminous lifetime, but there is still room for improvement.

  For example, in Patent Documents 1, 2, and 3, a metal complex having a specific structure in which two rings constituting a bidentate ligand are further bonded with a linking group having 2 atoms or 3 to 20 atoms. Is presented. This enhances the bond between the two rings constituting the ligand and improves the stability of the ligand itself.

  However, further investigations have led to the discovery of new issues that differ from the stability of the ligand itself as described above.

  When an organic EL element using the organometallic complex as a light emitting material was prepared and used at a high temperature, the external quantum efficiency was reduced and the light emission life was shortened. That is, there is a problem that the performance of the organic EL element is likely to fluctuate greatly as the temperature of the external environment in which the element is used increases. Such a problem is a big problem especially when using an organic EL element in an environment where the temperature tends to be high, such as in a car.

International Publication No. 2010/86089 International Publication No. 2011/134013 JP 2004-131463 A

  The present invention has been made in view of the above-described problems and situations, and the problem to be solved is that even when used at high temperatures, the light emission efficiency is high, the light emission lifetime is long, the drive voltage is low, and the drive voltage changes with time. Is to provide an organic EL device having a small size. Moreover, it is providing the display apparatus and illuminating device with which the said organic EL element was comprised.

  In order to solve the above problems, the present inventor, in the process of studying the cause of the above problems, etc., by incorporating the phosphorescent organic metal complex according to the present invention into the organic layer of the organic EL element, The present inventors have found that performance fluctuations with respect to temperature changes can be improved, and have reached the present invention.

（式中、Ａ_１２及びＡ_１３は、Ｃ又はＮを表し、Ａ_１４〜Ａ_１６は、各々独立に、置換基を有していてもよいＣ、Ｎ、Ｏ又はＳのいずれか１つを表す。Ｂ_１２及びＢ_１３は、Ｃ又はＮを表す。Ｂ_１４〜Ｂ_１６は、各々独立に、置換基を有していてもよいＣ、Ｎ、Ｏ又はＳのいずれか一つを表す。ｋ１及びｋ２は、０又は１を表し、０の場合はＡ_１４とＡ_１５、又は、Ｂ_１４とＢ_１５が直接結合している。Ａ_１２〜Ａ_１６及びＮで形成される環は、ｋ１が１であるとき非芳香族複素環を表し、ｋ１が０であるとき複素環を表す。Ｂ_１２〜Ｂ_１６及びＮで形成される環は、複素環を表す。Ｘ_１１〜Ｘ_１３は、各々、置換基を有していてもよいＣ、Ｏ、Ｓ、Ｎ、Ｓｉ、Ｂ又はＰ原子を表す。ｋ４は、０又は１以上の整数を表し、ｋ４が２以上の場合、Ｘ_１２は各々同じでも異なっていてもよい。ｋ４が０の場合は、Ｘ１１とＸ１３が直接結合している。Ｍはイリジウム又は白金を表す。Ｌは、モノアニオン性の二座配位子を表す。ｍは、０〜２の整数を表し、ｎは、１〜３の整数を表す。）

（式中、Ａ_２２及びＡ_２３は、Ｃ又はＮを表し、Ａ_２４〜Ａ_２６は、各々独立に、置換基を有していてもよいＣ、Ｎ、Ｏ又はＳのいずれか１つを表す。Ｂ_２２及びＢ_２３は、Ｃ又はＮを表す。Ｂ_２４及びＢ_２５は、各々独立に、置換基を有していてもよいＣ、Ｎ、Ｏ又はＳのいずれか一つを表す。ｋ３は、０又は１を表し、０の場合はＡ_２４とＡ_２５が直接結合している。Ａ_２２〜Ａ_２６及びＣで形成される環は、炭化水素環又は複素環を表し、Ｂ_２２〜Ｂ_２５及びＣで形成される環は、複素環を表す。ｋ４は、１〜３の整数を表す。Ｘ_１１〜Ｘ_１３、Ｍ，Ｌ，ｍ及びｎは一般式（１）におけるＸ_１１〜Ｘ_１３、Ｍ，Ｌ，ｍ及びｎと同義である。） 1. An organic electroluminescent element in which an organic layer including at least a light emitting layer is sandwiched between an anode and a cathode, wherein at least one of the organic layers contains a neutral phosphorescent organic material containing a transition metal as a central metal An organic electroluminescence device comprising a metal complex, wherein the phosphorescent organometallic complex is a compound having a structure represented by the following general formula (1) or (2).

(In the formula, A ₁₂ and A ₁₃ represent C or N, and A _{14 to} A ₁₆ each independently represents any one of C, N, O or S which may have a substituent. B ₁₂ and B ₁₃ each represent C or N. B _{14 to} B ₁₆ each independently represent any one of C, N, O or S which may have a substituent. k1 and k2 represent 0 or 1, and in the case of 0, A ₁₄ and A ₁₅ or B ₁₄ and B ₁₅ are directly bonded to each other, and the ring formed by A _{12 to} A ₁₆ and N is k1 Represents a non-aromatic heterocyclic ring when 1 is 1, and represents a heterocyclic ring when k1 is 0. The ring formed by B _{12 to} B ₁₆ and N represents a heterocyclic ring, and X _{11 to} X ₁₃ are Each represents a C, O, S, N, Si, B or P atom which may have a substituent, k4 represents 0 or an integer of 1 or more, k For but 2 or more, if X ₁₂ each may be the same or different. K4 is 0, .L representing a. M is iridium or platinum X11 and X13 are bonded directly, monoanionic Represents a bidentate ligand, m represents an integer of 0 to 2, and n represents an integer of 1 to 3)

(In the formula, A ₂₂ and A ₂₃ represent C or N, and A _{24 to} A ₂₆ each independently represents any one of C, N, O or S which may have a substituent. B ₂₂ and B ₂₃ each represent C or N. B ₂₄ and B ₂₅ each independently represent any one of C, N, O or S which may have a substituent. k3 represents 0 or 1, and in the case of 0, A ₂₄ and A ₂₅ are directly bonded to each other, and the ring formed by A _{22 to} A ₂₆ and C represents a hydrocarbon ring or a heterocyclic ring, and B ₂₂ ring formed by .about.B ₂₅ and C, .K4 representing a heterocyclic ring, _.X 11 _{to X} 13 representing the integer of 1 to 3., M, L, _X in m and n are the general formula (1) ₁₁ To X ₁₃ , M, L, m and n.

2 . 2. The organic electroluminescence device according to item 1, wherein at least one of X _{11 to} X ₁₃ is an sp3 carbon atom.

3 . In the general formula (1), k1 represents 1. The organic electroluminescence element according to item 1 or 2 , wherein k1 represents 1 .

4 . In Formula (1), k2 is an organic electroluminescence device according to paragraph 1 or 2, characterized in that represents 0.

5 . In Formula (1), A ₁₄ ~A ₁₆ are each independently any one of the first term you characterized by representing a C or N which may have a substituent to paragraph 4 The organic electroluminescence device according to one item.

6 . In the general formula (1), B ₁₄ ~B ₁₆ are each independently, any one of the first term you characterized by representing a C or N which may have a substituent to paragraph 5 The organic electroluminescence device according to one item.

7 . In the general formula (2), k3 represents 1. The organic electroluminescent element according to item 1 or 2 , wherein k3 represents 1 .

8 . In the general formula _{(2), A} 24 _{~A 26} are each independently, the first term you characterized by representing a C or N which may have a substituent, paragraph 2 or paragraph 7 Organic electroluminescent element as described in any one of these.

9 . In the general formula (2), B ₂₄ and B ₂₅ each independently represent C or N which may have a substituent, wherein the first , second , seventh , or The organic electroluminescent element according to any one of the eighth aspect .

10 . Oite the general formula (1) or (2), X ₁₁ to X ₁₃ is any one of the first term, characterized in that to represent the carbon atoms which may have a substituent to paragraph 9 The organic electroluminescence device according to one item.

11 . Oite the general formula (1), k4 is, the organic electroluminescence device according to paragraph 1 you characterized in that represents an integer of 1-3.

12 . The organic electroluminescence element according to any one of items 1 to 11 , wherein the emission color is white.

13 . A display device comprising the organic electroluminescence element according to any one of items 1 to 12 .

14 . An illuminating device comprising the organic electroluminescent element according to any one of items 1 to 12 .

  The above-described means of the present invention can provide an organic EL device that has high luminous efficiency, long luminous lifetime, low driving voltage, and small change with time in driving voltage even when used at high temperatures. In addition, a display device and a lighting device including the organic EL element can be provided.

  The expression mechanism or action mechanism of the effect of the present invention is not clear, but is presumed as follows.

  It is well known that the bond between atoms vibrates, and therefore the bond distance and bond angle between atoms change. However, the higher the temperature, the greater the amplitude of the vibration, and the change in bond distance and bond angle. Is also big.

  In the aforementioned Patent Documents 1 to 3, two different atoms, C atom and N atom, are used as atoms that are covalently and coordinately bonded to the central metal. If the atoms are different, the vibrations are different, and especially at high temperatures, the difference in bond distance and bond angle between each other appears greatly.

  For this reason, the entire structure of the metal complex is distorted mainly at the bond between the central metal and the bonding atom at higher temperatures than at room temperature, resulting in a decrease in emission intensity from the complex, resulting in a decrease in the luminous efficiency of the organic EL device. it is conceivable that. Further, it is assumed that when the change in the bond (distance / angle) increases, the ligand easily deviates from the central metal, and as a result, the emission lifetime is shortened and the driving voltage is increased as the change with time.

  Therefore, in the present invention, the common atom and the atom coordinated to the central metal are the same atom such as N atom and N atom, or C atom and C atom. As a result, changes in the bond distance and bond angle between the central metal and the coordinating atoms can be reduced, and as a result, it has become possible to provide an organic EL device with little performance fluctuation even at high temperatures.

  Further, a linking group is selected such that the ring structure formed when the two rings constituting the ligand (ring A and ring B in the present invention) are joined together by a linking group is non-aromatic. As a result, the durability of the ligand itself can be improved without unnecessarily extending the resonance structure.

  Furthermore, when the number of atoms of the linking group contained in the ring structure formed by the linking group and a part of the ring A and ring B is 3 to 5 (when k4 in the general formula (O) is 1 to 3) It was found that fluctuations in the bond distance and bond angle between the central metal and coordinating atoms caused by temperature changes tend to be more relaxed.

  Furthermore, when sp3 carbon atoms were present in the linking group, the effect of suppressing aggregation between organometallic complexes was also observed due to the space volume of two hydrogen atoms or substituents not involved in the junction with ring A and ring B.

Schematic diagram showing an example of a display device composed of organic EL elements Schematic diagram of display section A in FIG. Pixel circuit diagram Schematic diagram of passive matrix type full color display device Schematic of lighting device Schematic diagram of lighting device

  The organic electroluminescence device of the present invention is an organic electroluminescence device in which an organic layer including at least a light emitting layer is sandwiched between an anode and a cathode, and at least one layer of the organic layer contains a transition metal complex as a central metal A ring A containing a neutral phosphorescent organometallic complex as a ligand of the complex, and an atom covalently bonded to the central metal as a constituent atom, and an atom coordinated to the central metal The ring B included as a constituent atom is directly bonded, the covalently bonded atom of the ring A is identical to the coordination bond atom of the ring B, and the ring A and the ring B is joined by a linking group represented by the general formula (0), and the ring structure newly formed by the linking group and a part of ring A and ring B is non-aromatic. It is characterized by.

  This feature is a technical feature common to the inventions according to claims 1 to 15.

As an embodiment of the present invention, the transition metal complex contains a phosphorescent organometallic complex having a structure represented by the general formula (1) or (2) from the viewpoint of manifesting the effect of the present invention. It is preferable to do. Further, at least one of X _{11 to} X ₁₃ is an sp3 carbon atom, and the aggregation of organometallic complexes is caused by the space volume of two hydrogen atoms or substituents that are not involved in the junction with ring A and ring B. Since the effect which suppresses is acquired, it is preferable.

  Furthermore, in this invention, it is preferable that k1 of the said General formula (1) represents 1. Thereby, the effect of reducing the distortion of the structure of the metal complex is obtained. Moreover, it is preferable that k2 of the general formula (1) represents 0 because an effect of reducing the distortion of the structure of the metal complex is obtained.

Also, A ₁₄ to A ₁₆ in the general formula (1) represent each may have a substituent group independently C or N is obtained the effect of reducing the distortion of the overall structure of the metal complex This is preferable. Further, B ₁₄ .about.B ₁₆ in the general formula (1) represent each may have a substituent group independently C or N is obtained the effect of reducing the distortion of the overall structure of the metal complex This is preferable.

Furthermore, when k3 in the general formula (2) represents 1, an effect of reducing the distortion of the structure of the metal complex at a high temperature can be obtained. Also, the A ₂₄ to A ₂₆ in formula (2) is to represent each may have a substituent group independently C or N is, to reduce the distortion of the structure of a metal complex at high temperature effect Is preferable. In addition, B ₂₄ and B _{25 in} the general formula (2) each independently represent C or N which may have a substituent, thereby reducing the distortion of the structure of the metal complex at a high temperature. Is preferable.

Furthermore, two hydrogen atoms which do not participate in the junction with the ring A and the ring B by X _{11 to} X _{13 in the} general formula (1) or (2) representing a carbon atom which may have a substituent. Or the effect of the aggregation suppression of organometallic complexes is acquired by the space volume of a substituent. In addition, when k4 in the general formula (1) or (2) represents any integer of 1 to 3, fluctuations in the bond distance and bond angle between the central metal and the coordinating atoms caused by temperature change are more relaxed. It is preferable because the effect obtained is obtained.

  The organic electroluminescent device of the present invention can be applied to a white light emitting organic electroluminescent device to provide an organic electroluminescent device with excellent white light emitting properties.

  The organic electroluminescence element of the present invention can be suitably included in a display device and a lighting device.

  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.

《Organic electroluminescence device》
The organic electroluminescence device of the present invention is an organic electroluminescence device in which an organic layer including at least a light emitting layer is sandwiched between an anode and a cathode, and at least one layer of the organic layer contains a transition metal as a central metal A ring A containing a neutral phosphorescent organometallic complex, wherein the ligand of the complex includes an atom covalently bonded to the central metal as a constituent atom, and an atom coordinated to the central metal. The ring B included as a constituent atom has a direct bond structure, the covalently bonded atom of the ring A is the same as the coordination bond atom of the ring B, and the ring A and the ring B Are bonded by a linking group represented by the following general formula (0), and the ring structure newly formed by the linking group and a part of ring A and ring B is non-aromatic. And

Formula _{(0): * -X 11 -} (X 12) k4 -X 13 - **
(In the formula, X ₁₁ , X ₁₂ and X ₁₃ each represents a C, O, S, N, Si, B or P atom which may have a substituent, and k4 is 0 or 1 or more. Represents an integer, * represents a bonding site with ring A, and ** represents a bonding site with ring B.)
The phosphorescent organometallic complex preferably has a structure represented by the following general formula (1) or (2).

<< Phosphorescent Metal Organic Complex Represented by Formulas (1) and (2) >>
The phosphorescent organometallic complex represented by the general formulas (1) and (2), which is contained in the organic EL element of the present invention as an organic EL element material, will be described.

一般式（１）において、Ａ_１２、Ａ_１３はＣ又はＮを表し、Ａ_１４〜Ａ_１６は、各々独立に置換基を有していてもよいＣ、Ｎ、Ｏ又はＳのいずれか１つを表す。 << Phosphorescent Metal Organic Complex Represented by Formula (1) >>

In the general formula _{(1), A 12, A} 13 represents C or _N, A 14 _{to A 16} is any one of each may have a substituent group independently C, N, O or S Represents.

B ₁₂ and B ₁₃ represent C or N. B ₁₄ .about.B ₁₆ represent each independently may have a substituent group C, N, any one of O or S.

Preferably, A _{14 to} A ₁₆ each independently represent any one of C or N optionally having a substituent.

_Preferably, B 14 _{.about.B 16} each independently represent any one of a C or N which may have a substituent.

It is preferable that the substituents of B _{14 to} B ₁₆ do not form a ring structure by linking with X _{11 to} X ₁₃ .

  k1 and k2 represent 0 or 1.

The ring formed by A _{12 to} A ₁₆ and N represents a non-aromatic heterocycle when k1 is 1, and represents a heterocycle when k1 is 0.

The ring formed by B _{12 to} B ₁₆ and N represents a heterocyclic ring.

In the present invention, the heterocyclic ring includes a non-aromatic heterocyclic ring and an aromatic heterocyclic ring. The hydrocarbon ring includes a non-aromatic hydrocarbon ring and an aromatic hydrocarbon ring.
X _{11 to} X ₁₃ each represent a C, O, S, N, Si, B, or P atom that may have a substituent.

A ring formed by A _{12 to} A ₁₆ and N (ring A) and a ring formed by B _{12 to} B ₁₆ and N (ring B) and a ring structure newly formed by X _{11 to} X ₁₃ are non- Aromatic.

The bond between X ₁₁ and X ₁₂ and X ₁₂ and X ₁₃ is not particularly limited, and may be a single bond, a double bond, or a triple bond.

At least one of X _{11 to} X ₁₃ is preferably an sp3 carbon atom.

k4 represents 0 or an integer of 1 or more, and when k4 is 2 or more, X ₁₂ may be the same or different.

Preferably, X _{11 to} X ₁₃ are each a C atom that may have a substituent. Preferably, k4 is an integer of 1 to 3, and more preferably 1.

  M represents iridium or platinum. L represents a monoanionic bidentate ligand. m represents an integer of 0 to 2, and n represents an integer of 1 to 3.

  When M is iridium, m + n is 3, m is preferably 0 or 1, and more preferably m is 0. When M is platinum, m + n is 2 and m is preferably 0.

Examples of the substituent for A _{14 to} A ₁₆ , B _{14 to} B ₁₆ and X _{11 to} X ₁₃ include a hydrogen atom, a halogen atom (for example, a chlorine atom, a bromine atom, an iodine atom, a fluorine atom, etc.), a cyano group, and an alkyl group. Group (for example, methyl group, ethyl group, propyl group, isopropyl group, (t) butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, benzyl group, etc.), alkenyl group (For example, vinyl group, allyl group, etc.), alkynyl group (for example, propargyl group, etc.), alkoxy group (for example, methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group, octyloxy group, dodecyloxy group) Group), aryloxy group (for example, phenoxy group, naphthyloxy group, etc.), alkylthio group ( For example, methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.), arylthio group (eg, phenylthio group, naphthylthio group, etc.), amino group (eg, amino group, ethylamino group, Dimethylamino group, butylamino group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, anilino group, diarylamino group (for example, diphenylamino group, dinaphthylamino group, phenylnaphthylamino group, etc.), naphthylamino group , 2-pyridylamino group, etc.), silyl groups (eg, trimethylsilyl group, triethylsilyl group, (t) butyldimethylsilyl group, triisopropylsilyl group, (t) butyldiphenylsilyl group, triphenylsilyl group, trinaphthylsilyl Group, 2-pyridylsilyl group, etc.), phosphino group (dimethylphosphino group, diethylphosphino group, dicyclohexylphosphino group, methylphenylphosphino group, diphenylphosphino group, dinaphthylphosphino group, di (2-pyridyl group) ) Phosphosphino group), phosphoryl group (dimethylphosphoryl group, diethylphosphoryl group, dicyclohexylphosphoryl group, methylphenylphosphoryl group, diphenylphosphoryl group, dinaphthylphosphoryl group, di (2-pyridyl) phosphoryl group), aryl group (for example, phenyl) Group, p-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), heteroaryl Group (pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzoimidazolyl 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, dibenzo Thienyl group, indolyl group, indoloindolyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group (indicating that one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom), quinoxalinyl group , Pyridazinyl group, triazinyl group, quina Zolinyl group, phthalazinyl group, etc.), halogen atom (eg, chlorine atom, bromine atom, iodine atom, fluorine atom etc.), alkoxyl group (eg, methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group, Octyloxy group, dodecyloxy group, etc.), cycloalkoxyl group (eg, cyclopentyloxy group, cyclohexyloxy group, etc.), aryloxy group (eg, phenoxy group, naphthyloxy group, etc.), non-aromatic hydrocarbon ring group (eg, Cycloalkyl group (eg, cyclopentyl group, cyclohexyl group, etc.), cycloalkoxy group (eg, cyclopentyloxy group, cyclohexyloxy group, etc.), cycloalkylthio group (eg, cyclopentylthio group, cyclohexylthio group, etc.), cyclohexylaminosulfuryl Nyl group, tetrahydronaphthyl group, 9,10-dihydroanthryl group, biphenylyl group, etc.), non-aromatic heterocyclic group (for example, epoxy ring, aziridine ring, thiirane ring, oxetane ring, azetidine ring, thietane ring, tetrahydrofuran ring) , Dioxolane ring, pyrrolidine ring, pyrazolidine ring, imidazolidine ring, oxazolidine ring, tetrahydrothiophene ring, sulfolane ring, thiazolidine ring, ε-caprolactone ring, ε-caprolactam ring, piperidine ring, hexahydropyridazine ring, hexahydropyrimidine ring, Piperazine ring, morpholine ring, tetrahydropyran ring, 1,3-dioxane ring, 1,4-dioxane ring, trioxane ring, tetrahydrothiopyran ring, thiomorpholine ring, thiomorpholine-1,1-dioxide ring, pyranose ring, di- Zabishikuro [2,2,2] - represents any group selected from octane ring). Here, a group other than the hydrogen atom is referred to as a substituent. These substituents may further have a substituent.

Are shown below, but an example of the structure represented by X ₁₁ to X _13, but is not limited thereto.

In the formula, A and B represent A ₁₃ and B ₁₃ , or A ₂₃ and B ₂₃ . R _{1Q to} R _6Q represent a hydrogen atom or a substituent. R _{1Q to} R _6Q may be linked to each other to form a ring. The substituents are the same as the substituents of the _{A 14 ~A 16, B 14 ~B} 16 and _X 11 _{to X 13.}

一般式（２）において、
Ａ_２２、Ａ_２３はＣ又はＮを表し、Ａ_２４〜Ａ_２６は、各々独立に置換基を有していてもよいＣ、Ｎ、Ｏ又はＳのいずれか１つを表す。 << Phosphorescent Metal Organic Complex Represented by Formula (2) >>

In general formula (2),
A ₂₂ and A ₂₃ represent C or N, and A _{24 to} A ₂₆ each independently represent any one of C, N, O, or S which may have a substituent.

B ₂₂ and B ₂₃ represent C or N. B ₂₄ and B ₂₅ each independently represent any one of C, N, O or S which may have a substituent.

A ₂₄ to A ₂₆ represents any one of a C or N which may have independently a substituent.

B ₂₄ and B ₂₅ each independently represent any one of C or N optionally having a substituent.

k3 represents 0 or 1, and in the case of 0, A ₂₄ and A ₂₅ are directly bonded.

The ring formed by A _{22 to} A ₂₆ and C represents a hydrocarbon ring or a heterocyclic ring, and the ring formed from B _{22 to} B ₂₅ and C represents a heterocyclic ring. It is preferable that the substituents of B _{14 to} B ₁₆ do not form a ring structure by linking with X _{11 to} X ₁₃ .

_{X 11 ~X 13, k4, M} , L, m, n, _{substituents, X 11 ~X 13, k4,} M, L, m, n, is synonymous with the substituent group in the general formula (1).

"Concrete example"
Specific examples of the phosphorescent metal complex represented by the general formulas (1) and (2) are given below, but the present invention is not limited thereto.

<< Constitutional layer of organic EL element >>
The constituent layers of the organic EL element will be described. 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.
(I) Anode / light emitting layer unit / electron transport layer / cathode (ii) Anode / hole transport layer / light emitting layer unit / electron transport layer / cathode (iii) Anode / hole transport layer / light emitting layer unit / hole blocking Layer / electron transport layer / cathode (iv) anode / hole transport layer / light emitting layer unit / hole blocking layer / electron transport layer / cathode buffer layer / cathode (v) anode / anode buffer layer / hole transport layer / light emission Layer unit / hole blocking layer / electron transport layer / cathode buffer layer / cathode In addition to the hole blocking layer, an electron blocking layer can also be used as the blocking layer.

  When a plurality of light emitting layers are included, a non-light emitting intermediate layer may be provided between the light emitting layers. In addition, among the above layer structures, an organic layer including a light emitting layer excluding an anode and a cathode can be used as one light emitting unit, and a plurality of light emitting units can be stacked. The plurality of stacked light emitting units may have a non-light emitting intermediate layer between the light emitting units, and the intermediate layer may further include a charge generation layer.

  The organic EL element of the present invention is preferably a white light emitting layer, and is preferably an illumination device or a display device using these. That is, the organic EL element preferably emits white light.

  Each layer which comprises the organic EL element of this invention is demonstrated.

《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, a hole injection layer and an electron blocking layer are also included in the 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 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.

  Further, azatriphenylene derivatives such as those described in JP-T-2003-519432 and JP-A-2006-135145 can also be used as a hole transport material.

  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-diphenylaminostilbene; N-phenylcarbazole and also two condensations described in US Pat. No. 5,061,569 Having an aromatic ring in the molecule, for example, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-308688 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine (MTDATA) in which three triphenylamine units described in the publication are linked in a starburst type Etc.

  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, it exists in the range of 5 nm-5 micrometers, Preferably it exists in the range of 5-200 nm. This 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 with a single layer or a plurality of layers.

  The electron transport layer only needs to have a function of transmitting electrons injected from the cathode to the light emitting layer. As a constituent material of the electron transport layer, any conventionally known compound may be selected and used in combination. Is possible.

  Examples of conventionally known materials used for the electron transport layer (hereinafter referred to as electron transport materials) include polycyclic aromatic hydrocarbons such as nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, naphthalene perylene, Ring tetracarboxylic anhydride, carbodiimide, fluorenylidenemethane derivative, anthraquinodimethane and anthrone derivative, oxadiazole derivative, carboline derivative, or at least carbon atoms of the hydrocarbon ring constituting the carboline ring of the carboline derivative Derivatives having a ring structure, one of which is substituted with a nitrogen atom, hexaazatriphenylene 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, or a quinoxaline derivative having a quinoxaline ring known as an electron-withdrawing group can also be used as an electron transport material.

  It is also possible to use a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain.

  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 a terminal substituted with an alkyl group or a sulfonic acid group can also be used as the electron transport material. In addition, inorganic semiconductors such as n-type-Si and n-type-SiC can also be used as the electron transport material.

  The electron transport layer is made of an electron transport material such as a vacuum deposition method, a wet method (also referred to as a wet process, such as a spin coating method, a casting method, a die coating method, a blade coating method, a roll coating method, an ink jet method, a printing method, or a spraying method. The film is preferably formed by thinning by a coating method, a curtain coating method, an LB method (such as Langmuir Brodgett method)).

  Although there is no restriction | limiting in particular about the film thickness of an electron carrying layer, Usually, it exists in the range of 5-5000 nm, Preferably it exists in the range of 5-200 nm. The electron transport layer may have a single layer structure composed of one or more of the above materials.

  Further, an n-type dopant such as a metal compound such as a metal complex or a metal halide may be doped.

  As a conventionally well-known compound (electron transport material) preferably used for formation of the electron carrying layer of the organic EL element of this invention, the compound of ET-1-ET-43 of Unexamined-Japanese-Patent No. 2012-164731 is mentioned, for example. For example, but not limited to.

<Light emitting layer>
The light-emitting layer is a layer that emits light by recombination of electrons and holes injected from the electrode or the electron transport layer and the hole transport layer. It may be an interface with an adjacent layer.

  The total thickness of the light emitting layer is not particularly limited, but from the viewpoint of improving the uniformity of the film, preventing application of unnecessary high voltage during light emission, and improving the stability of the emission color with respect to the drive current. It is preferably adjusted to a range of 2 nm to 5 μm, more preferably adjusted to a range of 2 to 200 nm, and particularly preferably adjusted to a range of 5 to 100 nm.

  For the production of the light-emitting layer, a light-emitting dopant or a host compound, which will be described later, is used, for example, a vacuum deposition method, a wet method (also referred to as a wet process, for example, a spin coating method, a casting method, a die coating method, a blade coating method, a roll coating). And the like, the inkjet method, the printing method, the spray coating method, the curtain coating method, the LB method (Langmuir-Blodgett method, etc.). In addition, when using the phosphorescent organometallic complex used for this invention as a material of a light emitting layer, it is preferable to form into a film by a wet process.

In the light emitting layer of the organic EL device of the present invention, a light emitting dopant (phosphorescent dopant (also referred to as phosphorescent metal organic complex, phosphorescent dopant, phosphorescent dopant group) or fluorescent dopant) compound, A luminescent host compound,
At least one phosphorescent organic metal complex represented by the above general formulas (1) and (2) is contained.

(Luminescent dopant compound)
A light-emitting dopant compound (a light-emitting dopant, a dopant compound, or simply referred to as a dopant) will be described. As the luminescent dopant compound, the phosphorescent organometallic complex according to the present invention (a kind of phosphorescent dopant) is used.

  Examples of the dopant compound that may be used in combination with the phosphorescent organometallic complex include a fluorescent dopant (also referred to as a fluorescent compound), and a phosphorescent dopant other than the phosphorescent organometallic complex (phosphorescent metal organic complex). , Phosphorescent emitters, phosphorescent compounds, phosphorescent compounds, and the like) can be used.

(Phosphorescent dopant)
A phosphorescent dopant (also referred to as a phosphorescent dopant) is a compound in which light emission from an excited triplet is observed, specifically a compound that emits phosphorescence at room temperature (25 ° C.). Although the yield is defined to be a compound of 0.01 or more at 25 ° C., the preferred 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 the recombination of carriers on the host compound to which carriers are transported to generate an excited state of the luminescent host compound, and this energy is used as the phosphorescent dopant. It is an energy transfer type in which light emission from a phosphorescent dopant is obtained by moving to. The other is a carrier trap type in which a phosphorescent dopant serves as a carrier trap, carrier recombination occurs on the phosphorescent dopant, and light emission from the phosphorescent dopant compound 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.

  Moreover, you may use together the compound etc. which are described in the following patent gazettes in a light emitting layer.

  For example, International Publication No. 00/70655, JP 2002-280178, JP 2001-181616, JP 2002-280179, JP 2001-181617, JP 2002-280180, JP 2001-247859 A, JP 2002-299060 A, JP 2001-313178 A, JP 2002-302671 A, JP 2001-345183 A, JP 2002-324679 A, International Publication. No. 02/15645, 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, Japanese Patent Application Laid-Open No. 2002-33858 JP, JP-A-2002-170684, JP-A-2002-352960, WO01 / 93642, JP-A-2002-50483, JP-A-2002-1000047, JP-A-2002-173684. JP-A-2002-359082, JP-A-2002-175484, JP-A-2002-363552, JP-A-2002-184582, JP-A-2003-7469, JP-A-2002-525808, JP 2003-7471, JP 2002-525833, JP 2003-31366, JP 2002-226495, JP 2002-234894, JP 2002-2335076, JP 2002 No. 2411751, JP 2001-319779 A. JP, 2001-319780, 2002-62824, 2002-100474, 2002-203679, 2002-343572, 2002-203678, etc. It is.

(Fluorescent dopant)
Fluorescent dopants (also referred to as fluorescent compounds) include coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, pyrylium dyes. Perylene dyes, stilbene dyes, polythiophene dyes, rare earth complex phosphors, and compounds having a high fluorescence quantum yield such as laser dyes.

  In the present invention, the light-emitting dopant may be used in combination with a plurality of types of compounds as long as the effect is not affected, and a combination of phosphorescent dopants having different structures or a combination of a phosphorescent dopant and a fluorescent dopant. It may be used.

  Specific examples of preferable known phosphorescent dopant compounds that can be used in combination with the phosphorescent organometallic complex according to the present invention include, for example, D-1 to D- described in JP2012-195554A. 47 compounds and the following D-48 and D-49 compounds are exemplified, but not limited thereto.

(Luminescent host compound)
There is no restriction | limiting in particular as a light emission host (it is also mentioned a host compound) which can be used for this invention, The compound conventionally used with an organic EL element can be used.

  Conventionally known compounds typically include those having a basic skeleton such as carbazole derivatives, triarylamine derivatives, aromatic derivatives, nitrogen-containing heterocyclic compounds, thiophene derivatives, furan derivatives, oligoarylene compounds, or carboline derivatives. And diazacarbazole derivatives (herein, diazacarbazole derivatives are those 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). .

  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.

  In addition, as a specific example used as a well-known light emission host of the light emitting layer of the organic EL element of this invention, although the compound of OC-1 to OC-32 of Unexamined-Japanese-Patent No. 2012-164731 is mentioned, for example, It is not limited to these.

  Furthermore, as a particularly preferable light emitting host of the light emitting layer of the organic EL device of the present invention, for example, compounds 1 to 56 which are compounds of the general formula (B) described in JP 2012-164731 A can be mentioned. However, it is not limited to these.

<< Injection layer: hole injection layer (anode buffer layer), electron injection layer (cathode buffer layer) >>
The injection layer is a layer provided between the electrode and the organic layer for reducing the driving voltage and improving the light emission luminance as required. “The organic EL element and its industrialization front line (November 30, 1998 2) Chapter 2 “Electrode Materials” (pages 123 to 166) of the second edition of “TS Co., Ltd.”), 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. Representative phthalocyanine buffer layer, hexaazatriphenylene derivative buffer layer, oxide buffer layer typified by vanadium oxide, amorphous carbon buffer layer, polyaniline as described in JP-T-2003-519432 and JP-A-2006-135145 Examples thereof include a polymer buffer layer using a conductive polymer such as (emeraldine) or polythiophene, an ortho-metalated complex layer represented by tris (2-phenylpyridine) iridium complex, and the like.

  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, alkali metal compound buffer layer typified by lithium fluoride and potassium fluoride, alkaline earth metal compound buffer layer typified by magnesium fluoride and cesium fluoride, typified by aluminum oxide Examples thereof include an oxide buffer layer. 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.

<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 concerning this invention as needed.

  The hole blocking layer of the organic EL device of the present invention is preferably provided adjacent to the light emitting layer.

  The hole blocking layer includes a carbazole derivative, a carboline derivative, a diazacarbazole derivative (the diazacarbazole derivative is a nitrogen atom in which any one of carbon atoms constituting the carboline ring is mentioned as the host compound described above. It is preferable to contain (represented by).

  Further, in the present invention, when a plurality of light emitting layers having different emission colors are provided, the light emitting layer having the shortest wavelength of the light emission maximum wavelength (shortest wave layer) is closest to the anode among all the light emitting layers. preferable. In such a case, it is preferable to additionally provide a hole blocking layer between the shortest wave layer and the light emitting layer next to the anode next to the shortest wave layer.

  The film thickness of the hole blocking layer and the electron transport layer that can be used in the present invention is preferably in the range of 3 to 100 nm, and more preferably in the range of 5 to 30 nm.

《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 with a single layer or a plurality of layers.

  The electron transport layer only needs to have a function of transmitting electrons injected from the cathode to the light emitting layer. As a constituent material of the electron transport layer, any conventionally known compound may be selected and used in combination. Is possible.

  Examples of conventionally known materials used for the electron transport layer (hereinafter referred to as electron transport materials) include polycyclic aromatic hydrocarbons such as nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, naphthalene perylene, Ring tetracarboxylic anhydride, carbodiimide, fluorenylidenemethane derivative, anthraquinodimethane and anthrone derivative, oxadiazole derivative, carboline derivative, or at least carbon atoms of the hydrocarbon ring constituting the carboline ring of the carboline derivative Derivatives having a ring structure, one of which is substituted with a nitrogen atom, hexaazatriphenylene 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, or a quinoxaline derivative having a quinoxaline ring known as an electron-withdrawing group can also be used as an electron transport material.

  It is also possible to use a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain.

  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 a terminal substituted with an alkyl group or a sulfonic acid group can also be used as the electron transport material. In addition, inorganic semiconductors such as n-type-Si and n-type-SiC can also be used as the electron transport material.

  The electron transport layer is made of an electron transport material such as a vacuum deposition method, a wet method (also referred to as a wet process, such as a spin coating method, a casting method, a die coating method, a blade coating method, a roll coating method, an ink jet method, a printing method, or a spraying method. The film is preferably formed by thinning by a coating method, a curtain coating method, an LB method (such as Langmuir Brodgett method)).

  Although there is no restriction | limiting in particular about the film thickness of an electron carrying layer, Usually, it exists in the range of 5-5000 nm, Preferably it exists in the range of 5-200 nm. The electron transport layer may have a single layer structure composed of one or more of the above materials.

  Further, an n-type dopant such as a metal compound such as a metal complex or a metal halide may be doped.

  As a conventionally well-known compound (electron transport material) preferably used for formation of the electron carrying layer of the organic EL element of this invention, the compound of ET-1-ET-43 of Unexamined-Japanese-Patent No. 2012-164731 is mentioned, for example. For example, but not limited to.

"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 the 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 to 200 nm.
In order to transmit the emitted light, if either one of the anode or the cathode of the organic EL element is transparent or translucent, the emission luminance is advantageously improved.

  Moreover, after producing the metal with a film thickness in the range of 1 nm to 20 nm on the cathode, a transparent or semitransparent cathode is produced by producing a conductive transparent material mentioned in the description of the anode described later on the cathode. By applying this, an element in which both the anode and the cathode are transmissive 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 within the range of 10 to 1000 nm, preferably within the range of 10 to 200 nm.

《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.

<< Method for producing organic EL element >>
As an example of a method for producing an organic EL element, from anode / hole injection layer (anode buffer layer) / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / electron injection layer (cathode buffer layer) / cathode A method for manufacturing the element will be described.

  First, a thin film made of a desired electrode material, for example, an anode material, is formed on a suitable substrate so as to have a thickness of 1 μm or less, preferably in the range of 10 to 200 nm, to produce an anode.

  Next, a thin film containing an organic compound such as a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer, which is a device material, is formed thereon.

  As a method for forming the thin film, for example, the thin film can be formed by a vacuum deposition method, a wet method (also referred to as a wet process), or the like. However, in the present invention, it is preferable to produce an organic EL element by a wet process. By producing it by a wet process, it is possible to obtain an effect such that a homogeneous film can be easily obtained and pinholes are hardly generated.

  Wet methods include spin coating, casting, die coating, blade coating, roll coating, ink jet, printing, spray coating, curtain coating, and LB, but precise thin films can be formed. In view of high productivity, a method having high suitability for a roll-to-roll method such as a die coating method, a roll coating method, an ink jet method, or a spray coating method is preferable. Different film formation methods may be applied for each layer.

  Examples of the liquid medium for dissolving or dispersing the organic EL material that can be used in the present invention include ketones such as methyl ethyl ketone and cyclohexanone, fatty acid esters such as ethyl acetate, halogenated hydrocarbons such as dichlorobenzene, toluene, Aromatic hydrocarbons such as 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 the formation of these layers, a thin film made of a cathode material is formed thereon so as to have a thickness of 1 μm or less, preferably in the range of 50 to 200 nm, and a desired organic EL device can be obtained by providing a cathode. .

  Alternatively, the cathode, electron injection layer, electron transport layer, hole blocking layer, light emitting layer, hole transport layer, hole injection layer, and anode can be formed in this order in the reverse order.

The organic EL device of the present invention is preferably produced from the hole injection layer to the cathode consistently by a single evacuation, but it may be taken out halfway and subjected to different film forming methods. At that time, it is preferable to perform the work in a dry inert gas atmosphere.
<Sealing>
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.

  For processing the sealing member into a concave shape, sandblasting, chemical etching, or the like is used.

  In addition, it is also preferable that the electrode and the organic layer are coated on the outside of the electrode facing the support substrate with the organic layer interposed therebetween, and an inorganic or organic layer is formed in contact with the support substrate to form a sealing film. .

《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, but the polymer film is light and thin. Is preferably used.

《Light extraction》
The organic EL element emits light inside a layer having a refractive index higher than that of air (with a refractive index in the range of 1.7 to 2.1), and light of about 15% to 20% of the light generated in the light emitting layer. It is generally said that it can only be taken out. 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.
《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 within a range of 10 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.

  In addition, the “supporting substrate”, “sealing”, “protective film, protective plate”, “light extraction”, “light condensing” other than the characteristic portions of the present invention regarding the “each layer constituting the organic EL element” described above. The other details of the “sheet” and the like are the same as those described in known documents such as Japanese Patent Application Laid-Open Nos. 2012-164731 and 2012-156299.

<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 device may be patterned. Can do.
The light emission color of the organic EL device of the present invention and the compound according to the present invention is shown in FIG. 4.16 on page 108 of “New Color Science Handbook” (edited by the Japan Color Society, University of Tokyo Press, 1985). It is determined by the color when the result measured with a total CS-1000 (Konica Minolta Sensing Co., Ltd.) 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 CIE1931 color system at 1000 cd / m ² is X when the 2 ° viewing angle front luminance is measured by the above method. = 0.33 ± 0.07 and Y = 0.33 ± 0.1.
<Display device>
The display device of the present invention will be described. The display device of the present invention comprises the organic EL element of the present invention. Although the display device of the present invention may be single color or multicolor, the multicolor display device will be described here.

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.
In the case of patterning only the light emitting layer, the method is not limited. However, the vapor deposition method, the ink jet method, the spin coating method, and the printing method are preferable.
The configuration of the organic EL element provided in the display device is selected from the above-described configuration examples of the organic EL element as necessary.

  Moreover, the manufacturing method of an organic EL element is as having shown to the one aspect | mode of manufacture of the organic EL element of said invention.

  When a DC voltage is applied to the multicolor display device thus obtained, light emission can be observed by applying a voltage in the range of 2 to 40 V 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. The present invention is not limited to these examples.

  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. It is a schematic diagram of a display such as a mobile phone that displays image information by light emission of an organic EL element.

  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, and 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 respond to the image data signal by the scanning signal. The image information is sequentially emitted to scan the image and display the image information on the display unit A.

  FIG. 2 is a schematic diagram of the display unit A.

  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).

  The scanning line 5 and the plurality of data lines 6 in the wiring portion are each made of a conductive material, and the scanning lines 5 and the data lines 6 are orthogonal to each other in a grid pattern and are connected to the pixels 3 at the orthogonal positions (details are illustrated). Not)

  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. Full-color display is possible by appropriately arranging pixels in the red region, the green region, and the blue region on the same substrate.

  Next, the light emission process of the pixel will be described. FIG. 3 is a circuit diagram of the pixel. The pixel includes an organic EL element 10, a switching transistor 11, a driving transistor 12, a capacitor 13, and the like. A full color display can be performed by using red, green, and blue light emitting organic EL elements as the organic EL elements 10 in a plurality of pixels, and juxtaposing them 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 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. The power supply line 7 connects the organic EL element 10 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, since the capacitor 13 holds the charged potential of the image data signal even when the driving of the switching transistor 11 is turned off, 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 organic EL element 10 emits light by the switching transistor 11 and the drive transistor 12 that are active elements for the organic EL elements 10 of the plurality of pixels, and the organic EL elements 10 of the plurality of pixels 3 emit light. 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 held continuously 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 lighting device of the present invention will be described. The lighting device of the present invention comprises the organic EL element of the present invention. The organic EL element of the present invention may be used as an organic EL element having a resonator structure. The purpose of use of the organic EL element having such a resonator structure is as follows. The light source of a machine, the light source of an optical communication processing machine, the light source of a photosensor, etc. are mentioned, However It is not limited to these. Moreover, you may use for the said use by making a laser oscillation.

  Further, the organic EL element of the present invention may be used as a kind of lamp for illumination or exposure light source, a projection device for projecting an image, or a display for directly viewing a still image or a moving image. It may be used as a device (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, it is possible to produce a full-color display device by using two or more organic EL elements of the present invention having different emission colors.

  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 a light emitting layer, a hole transport layer, an electron transport layer, etc., and simply arrange them separately by coating with the mask. Since other layers are common, patterning of the mask or the like is not necessary. 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, or the like, 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. There is no restriction | limiting in particular as a luminescent material used for a light emitting layer, For example, if it is a backlight in a liquid crystal display device, the metal complex which concerns on this invention so that it may suit the wavelength range corresponding to CF (color filter) characteristic, Any one of known luminescent materials may be selected and combined to whiten.

<< One Embodiment 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 element of the present invention is covered with a glass case, and a glass substrate is used as a sealing substrate, and an epoxy photocurable adhesive (Lux Track LC0629B manufactured by Toagosei Co., Ltd.) is used as a sealing material around This is applied, stacked 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 to form an illumination device as shown in FIGS. be able to.

  FIG. 5 shows a schematic diagram of a lighting device, and the organic EL element 101 of the present invention is covered with a glass cover 102 (in addition, the sealing operation with the glass cover is to bring the organic EL element 101 into contact with the atmosphere. And a glove box under a nitrogen atmosphere (in an atmosphere of high-purity nitrogen gas having a purity of 99.999% or more).

  FIG. 6 shows a cross-sectional view of the lighting device. In FIG. 6, 105 denotes a cathode, 106 denotes an organic EL layer, and 107 denotes a glass substrate with a transparent electrode. The glass cover 102 is filled with nitrogen gas 108 and a water catching agent 109 is provided.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "part by mass" or "mass%" is represented.

  Compounds other than the compounds according to the present invention used in the following examples are shown.

[Example 1]
<< Production of Organic EL Element 1-1 >>
An ITO (indium tin oxide) film having a thickness of 100 nm is formed on a glass substrate of 100 mm × 100 mm × 1.1 mm on a substrate (NA45 manufactured by NH Techno Glass), and then this ITO transparent electrode is provided. The transparent support substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes.

  A solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, manufactured by HC Starck Co., Ltd., CLEVIO P VP AI 4083) with pure water on this transparent support substrate to 70%. After forming a thin film by spin coating at 3000 rpm for 30 seconds, the film was dried at 200 ° C. for 1 hour to provide a first hole transport layer having a thickness of 20 nm.

  This transparent support substrate is fixed to a substrate holder of a commercially available vacuum vapor deposition apparatus. On the other hand, 200 mg of α-NPD is placed as a hole transport material, and 200 mg of H-1 is placed as a host compound in another molybdenum resistance heating boat. 200 mg of ET-8 as an electron transport material was placed in a molybdenum resistance heating boat, and 100 mg of Comparative Compound D-101 as a dopant compound was placed in another molybdenum resistance heating boat, and attached to a vacuum evaporation apparatus.

Then, after reducing the vacuum chamber to 4 × 10 ⁻⁴ Pa, the heating boat containing α-NPD was energized and heated, and a film thickness of 20 nm was formed on the first hole transport layer at 0.1 nm / second. A second hole transport layer was provided.

  Furthermore, the second boat is heated by energizing the heating boat containing H-1 as a host compound and comparative compound D-101 as a dopant compound, and the deposition rate is 0.1 nm / second and 0.025 nm / second, respectively. A light emitting layer having a thickness of 30 nm was provided by co-evaporation on the transport layer.

  Further, the heating boat containing ET-8 was energized and heated, and deposited on the light emitting layer at a deposition rate of 0.1 nm / second to provide an electron transport layer having a thickness of 30 nm. In addition, the substrate temperature at the time of vapor deposition was room temperature.

  Subsequently, lithium fluoride was vapor-deposited to form a cathode buffer layer having a thickness of 0.5 nm, and aluminum was further vapor-deposited to form a cathode having a thickness of 110 nm. Thus, a comparative organic EL element 1-1 was produced.

<< Production of Organic EL Elements 1-2 to 1-20 >>
In the production of the organic EL element 1-1, organic EL elements 1-2 to 1-20 were produced in the same manner except that the dopant compound of the light emitting layer was changed to the compounds shown in Table 1.

<< Evaluation of Organic EL Elements 1-1 to 1-20 >>
When evaluating the obtained organic EL elements 1-1 to 1-20, the non-light-emitting surface of each organic EL element after production was covered with a glass case, and a glass substrate having a thickness of 300 μm was used as a sealing substrate. An epoxy photo-curing adhesive (Lux Track LC0629B manufactured by Toagosei Co., Ltd.) is applied as a sealant around the periphery, and this is placed on the cathode so as to be in close contact with the transparent support substrate and irradiated with UV light from the glass substrate side. Then, it was cured and sealed, and a lighting device as shown in FIGS. 5 and 6 was produced and evaluated.

  The following evaluation was performed for each sample thus prepared. The evaluation results are shown in Table 1.

(1) Half-life The half-life was evaluated according to the measurement method shown below.

Each organic EL device driven with a constant current at a current giving an initial luminance 1000 cd / ^{m 2,} obtains the time to be 1/2 (500cd / ^{m 2)} of the initial luminance, which was used as a measure of the half-life.

  The half life was expressed as a relative value with the organic EL element 1-1 as 100.

  Larger values are preferred for longer life.

(2) Driving voltage Relative with the organic EL element 1-1 being 100 by measuring the voltage when the organic EL element was driven at room temperature (about 23 to 25 ° C.) and a constant current of ^2.5 mA / cm ^2. Expressed by value.

  The smaller the value, the lower the drive voltage and the better.

(3) Change in drive voltage over time The organic EL element is continuously lit under a constant current condition of room temperature (about 23 to 25 ° C.) and 2.5 mA / cm 2 to drive when the brightness reaches 70% of the initial brightness. Each voltage was measured. The measurement results are shown as relative values so that the organic EL element 1-1 (comparison) becomes 100 as shown below. In addition, it shows that the one where a value is small is small with respect to a comparison, and is excellent.

Drive voltage change 1 = (drive voltage when the luminance of the organic EL element 1-1 is 70%) / (initial drive voltage of the organic EL element 1-1)
Change in drive voltage of each element = (drive voltage at 70% luminance of each element) / (initial drive voltage of each element)
Drive voltage change = (Drive voltage change of each element) / (Drive voltage change 1)
(4) Change in external extraction quantum efficiency at high temperature The organic EL element is turned on at room temperature (about 23 to 25 ° C.) under a constant current condition of ^2.5 mA / cm ² , and light emission luminance immediately after the start of lighting (L1) The external extraction quantum efficiency (η1) was calculated by measuring [cd / m ² ]. Furthermore, the organic EL element was similarly measured at 50 ° C., and the external extraction efficiency (η2) was calculated from the light emission luminance (L2).

  The measurement results are shown as relative values so that the organic EL element 1-1 (comparison) becomes 100 as shown below.

  Here, the measurement of emission luminance was performed using CS-1000 (manufactured by Konica Minolta Sensing), and the external extraction quantum efficiency was expressed as a relative value where the organic EL element 1-1 was 100.

A larger value indicates better comparison.
External extraction quantum efficiency change of each element at high temperature = (η2 of each organic EL element) / (η1 of each organic EL element)

  From Table 1, the organic EL elements 1-8 to 1-20 of the present invention have a longer emission lifetime, lower driving voltage, and lower driving voltage than the organic EL elements 1-1 to 1-7 of the comparative example. It can be seen that the change in the aging and the external extraction quantum efficiency fluctuation at high temperature are small, and the characteristics as the device are improved.

[Example 2]
<< Production of Organic EL Elements 2-1 to 2-16 >>
In the organic EL device 1-1 of Example 1, the host compound H-1 was changed to H-2, and the light emitting layer dopant compound was changed to the compounds shown in Table 2 in the same manner. EL elements 2-1 to 2-16 were produced. The obtained organic EL elements 2-1 to 2-16 were prepared in the same manner as in Example 1, with (1) half-life (2) driving voltage (3) change over time in driving voltage and (4) external at high temperature. The extraction quantum efficiency change was evaluated, and each was represented by a relative value where the organic EL element 2-1 was 100.

  From Table 2, the organic EL elements 2-6 to 2-16 of the present invention have a longer emission lifetime, lower driving voltage, and lower driving voltage than the organic EL elements 2-1 to 2-5 of the comparative example. It can be seen that the change in the aging and the external extraction quantum efficiency fluctuation at high temperature are small, and the characteristics as the device are improved.

[Example 3]
<< Production of Organic EL Elements 3-1 to 3-15 >>
In the organic EL element 1-1 of Example 1, ET-8 of the electron transport layer was changed to ET-9, and the dopant compound of the light emitting layer was changed to the compounds shown in Table 3, and was the same as Example 1. In this way, organic EL elements 3-1 to 3-15 were produced.

  The obtained organic EL elements 3-1 to 3-15 were prepared in the same manner as in Example 1, with (1) half-life (2) driving voltage (3) change over time in driving voltage and (4) external at high temperature. The extracted quantum efficiency change was evaluated, and each was represented by a relative value where the organic EL element 3-1 was 100.

  From Table 3, the organic EL elements 3-8 to 3-15 of the present invention have a longer emission lifetime, lower driving voltage, and lower driving voltage than the organic EL elements 3-1 to 3-7 of the comparative example. It can be seen that the change in the aging and the external extraction quantum efficiency fluctuation at high temperature are small, and the characteristics as the device are improved.

[Example 4]
In the organic EL device 1-1 of Example 1, H-1 of the host compound is changed to H-2, ET-8 of the electron transport layer is changed to ET-9, and dopant compounds of the light emitting layer are shown in Table 4. Organic EL elements 4-1 to 4-12 were produced in the same manner as in Example 1 except that the compounds described were changed.

  The obtained organic EL elements 4-1 to 4-12 were prepared in the same manner as in Example 1, with (1) half-life (2) driving voltage (3) change over time in driving voltage and (4) external at high temperature. The extraction quantum efficiency change was evaluated, and each was represented by a relative value where the organic EL element 4-1 was 100.

  From Table 4, the organic EL elements 4-6 to 4-12 of the present invention have a longer emission lifetime, lower driving voltage, and lower driving voltage than the organic EL elements 4-1 to 4-5 of the comparative example. It can be seen that the change in the aging and the external extraction quantum efficiency fluctuation at high temperature are small, and the characteristics as the device are improved.

[Example 5]
In the organic EL element 1-1 of Example 1, H-1 of the host compound was changed to H-3, and the dopant compound of the light emitting layer was changed to the compounds described in Table 5 as in Example 1. The organic EL elements 5-1 to 5-14 were produced by a simple method.

  The obtained organic EL elements 5-1 to 5-14 were prepared in the same manner as in Example 1, with (1) half-life (2) driving voltage (3) change over time in driving voltage and (4) external at high temperature. The extraction quantum efficiency change was evaluated, and each was represented by a relative value where the organic EL element 5-1 was 100.

  From Table 5, the organic EL elements 5-5 to 5-14 of the present invention have a longer emission lifetime, lower drive voltage, and lower drive voltage than the organic EL elements 5-1 to 5-4 of the comparative example. It can be seen that the change in the aging and the external extraction quantum efficiency fluctuation at high temperature are small, and the characteristics as the device are improved.

[Example 6]
<< Production of Organic EL Elements 6-1 to 6-15 >>
In the organic EL device 1-1 of Example 1, H-1 of the host compound was changed to H-3, ET-8 of the electron transport layer was changed to ET-9, and dopant compounds of the light emitting layer are shown in Table 6. Organic EL elements 6-1 to 6-15 were produced in the same manner as in Example 1 except that the compounds described were changed.

  The obtained organic EL elements 6-1 to 6-15 were prepared in the same manner as in Example 1, with (1) half-life (2) driving voltage (3) change over time in driving voltage and (4) external at high temperature. The extraction quantum efficiency change was evaluated, and each was represented by a relative value where the organic EL element 6-1 was 100.

  From Table 6, the organic EL elements 6-5 to 6-15 of the present invention have a longer emission lifetime, lower drive voltage, and lower drive voltage than the organic EL elements 6-1 to 6-4 of the comparative example. It can be seen that the change in the aging and the external extraction quantum efficiency fluctuation at high temperature are small, and the characteristics as the device are improved.

[Example 7]
<< Preparation of White Light-Emitting Organic EL Element 7-1 >>
This ITO transparent electrode was formed by patterning a substrate (NH45 manufactured by NH Techno Glass Co., Ltd.) on which a film of ITO (indium tin oxide) having a thickness of 100 nm was formed as an anode on a glass substrate of 100 mm × 100 mm × 1.1 mm. The transparent support substrate provided with 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 vapor deposition apparatus. Meanwhile, 200 mg of α-NPD as a hole transport material is placed in a molybdenum resistance heating boat, and the host compound is used as a host compound in another molybdenum resistance heating boat. 200 mg of H-1 was added, 200 mg of ET-8 as an electron transport material was put into another molybdenum resistance heating boat, and 100 mg of the compound 1A-9 of the present invention was added as a dopant compound to another resistance heating boat made of molybdenum. 100 mg of D-10 as a dopant compound was placed in a molybdenum resistance heating boat and attached to a vacuum deposition apparatus.

Next, after reducing the vacuum tank to 4 × 10 ⁻⁴ Pa, each of the heating boats containing α-NPD was separately energized and deposited on the transparent support substrate at a deposition rate of 0.1 nm / second. A first hole transport layer was provided.

  Furthermore, the heating boat containing the host compound H-1 as the host compound, the heating boat containing the compound 1A-9 of the present invention as the dopant compound, and the heating boat containing D-10 as the dopant compound. The light-emitting layer having a film thickness of 30 nm was provided by applying current and heating, adjusting the deposition rate to 100: 5: 0.6.

  Furthermore, it supplied with electricity to the said heating boat containing ET-8, it heated, and it vapor-deposited on the said light emitting layer with the vapor deposition rate of 0.1 nm / sec, and provided the electron carrying layer with a film thickness of 30 nm. In addition, the substrate temperature at the time of vapor deposition was room temperature.

  Subsequently, lithium fluoride was vapor-deposited to form a cathode buffer layer having a thickness of 0.5 nm, and aluminum was further vapor-deposited to form a cathode having a thickness of 110 nm. Thus, an organic EL element 7-1 was produced.

  When the produced organic EL element 7-1 was energized, almost white light was obtained, and it was found that it could be used as a lighting device.

<< Production of Organic EL Element 7-2 >>
In the production of the organic EL element 7-1, an organic EL element 7-2 was produced in the same manner except that the dopant compound 1A-9 used for the light emitting layer was changed to 2B-6. When the produced organic EL elements 7-1 and 7-2 were energized, almost white light was obtained, and it was found that they could be used as a lighting device.

A Display unit B Control unit 3 Pixel 5 Scan line 6 Data line 10 Organic EL element 11 Switching transistor 12 Drive transistor 12
13 Capacitor 101 Illumination Device 102 Glass Case 105 Cathode 106 Organic EL Layer 107 Glass Substrate 108 Nitrogen Gas 109 Water Capture Agent L Light

Claims (14)

An organic electroluminescent element in which an organic layer including at least a light emitting layer is sandwiched between an anode and a cathode, wherein at least one of the organic layers contains a neutral phosphorescent organic material containing a transition metal as a central metal Contains a metal complex,
The phosphorescent organometallic complex is a compound having a structure represented by the following general formula (1) or (2).

(In the formula, A ₁₂ and A ₁₃ represent C or N, and A _{14 to} A ₁₆ each independently represents any one of C, N, O or S which may have a substituent. B ₁₂ and B ₁₃ each represent C or N. B _{14 to} B ₁₆ each independently represent any one of C, N, O or S which may have a substituent. k1 and k2 represent 0 or 1, and in the case of 0, A ₁₄ and A ₁₅ or B ₁₄ and B ₁₅ are directly bonded to each other, and the ring formed by A _{12 to} A ₁₆ and N is k1 Represents a non-aromatic heterocyclic ring when 1 is 1, and represents a heterocyclic ring when k1 is 0. The ring formed by B _{12 to} B ₁₆ and N represents a heterocyclic ring, and X _{11 to} X ₁₃ are Each represents a C, O, S, N, Si, B or P atom which may have a substituent, k4 represents 0 or an integer of 1 or more, k For but 2 or more, if X ₁₂ each may be the same or different. K4 is 0, .L representing a. M is iridium or platinum X11 and X13 are bonded directly, monoanionic Represents a bidentate ligand, m represents an integer of 0 to 2, and n represents an integer of 1 to 3)

(In the formula, A ₂₂ and A ₂₃ represent C or N, and A _{24 to} A ₂₆ each independently represents any one of C, N, O or S which may have a substituent. B ₂₂ and B ₂₃ each represent C or N. B ₂₄ and B ₂₅ each independently represent any one of C, N, O or S which may have a substituent. k3 represents 0 or 1, and in the case of 0, A ₂₄ and A ₂₅ are directly bonded to each other, and the ring formed by A _{22 to} A ₂₆ and C represents a hydrocarbon ring or a heterocyclic ring, and B ₂₂ ring formed by .about.B ₂₅ and C, .K4 representing a heterocyclic ring, _.X 11 _{to X} 13 representing the integer of 1 to 3., M, L, _X in m and n are the general formula (1) ₁₁ To X ₁₃ , M, L, m and n. At least one of said _X 11 _{to X 13,} but the organic electroluminescent device according to claim 1, characterized in that the sp3 carbon atom.   In the said General formula (1), k1 represents 1, The organic electroluminescent element of Claim 1 or Claim 2 characterized by the above-mentioned.   In the said General formula (1), k2 represents 0, The organic electroluminescent element of Claim 1 or Claim 2 characterized by the above-mentioned. In the general formula (1), A ₁₄ ~A ₁₆ are each independently any one of claims 1, characterized in that represent a C or N which may have a substituent to claim 4 one The organic electroluminescent element of the item. In Formula (1), B ₁₄ ~B ₁₆ are each independently, any one of the preceding claims, characterized in that represent a C or N which may have a substituent to claim 5 one The organic electroluminescent element of the item.   In the said General formula (2), k3 represents 1, The organic electroluminescent element of Claim 1 or Claim 2 characterized by the above-mentioned. In the general formula (2), A ₂₄ ~A ₂₆ are each independently claim 1, characterized in that represent a C or N which may have a substituent, according to claim 2 or claim 7 The organic electroluminescent element as described in any one. In the general formula (2), B ₂₄ and B ₂₅ are each independently claim 1, characterized in that represent a C or N which may have a substituent, claim 2, claim 7 or The organic electroluminescent element according to claim 8. In the general formula (1) or (2), X ₁₁ to X ₁₃ are any one of claims 1 to 9, characterized in that to represent the carbon atoms which may have a substituent The organic electroluminescent element of description.   In the said General formula (1), k4 represents the integer in any one of 1-3, The organic electroluminescent element of Claim 1 characterized by the above-mentioned.   The organic electroluminescence device according to any one of claims 1 to 11, wherein the emission color is white.   A display device comprising the organic electroluminescence element according to any one of claims 1 to 12.   An illuminating device comprising the organic electroluminescent element according to any one of claims 1 to 12.

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