JP2015153984A - organic light-emitting element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic light-emitting element that is stable even in the atmosphere.SOLUTION: An organic light-emitting element has a positive electrode and a negative electrode, a luminous layer arranged between the positive electrode and negative electrode, and an organic compound layer provided between the negative electrode and luminous layer and in contact with the negative electrode. The organic compound layer has a compound represented by following general formula (1). (In the formula (1),*represents the condensation position of naphthylene skeleton, phenantrylene skeleton, and pyrenylene skeleton).

Description

  The present invention relates to an organic light emitting device.

  An organic light emitting element (an organic electroluminescence element, an organic EL element) is an electronic element having a pair of electrodes and an organic compound layer disposed between these electrodes. When electrons and holes are injected from the pair of electrodes and the electrons and holes are recombined in the organic compound layer, excitons of the light-emitting organic compound are generated, and the excitons return to the ground state. In addition, the organic light emitting device emits light.

  One of the layers constituting the organic light emitting element is an electron injection layer having a function of injecting charges (electrons) injected from an electrode (cathode) into an organic compound layer such as a light emitting layer. Examples of the constituent material of the electron injection layer include an alkali metal or alkaline earth metal derivative in addition to an electron transporting organic compound. As described above, as an organic light emitting device including an alkali metal or alkaline earth metal derivative in an electron injection layer, for example, there is an organic light emitting device disclosed in Patent Document 1. In the organic light-emitting device disclosed in Patent Document 1, the electron injection layer constituting the device includes a nitrogen-containing heterocyclic compound having a chelate structure typified by a phenanthroline skeleton as a host and an alkali metal or alkali as a dopant. It is a layer containing an earth metal derivative.

  By the way, alkali metals and alkaline earth metals are all elements having a small work function, and their derivatives as well as simple metals exhibit good electron injection properties. However, an electron injection layer composed of a nitrogen-containing heterocyclic compound containing a plurality of nitrogen atoms and having a chelate structure and an alkali metal or alkaline earth metal derivative is greatly affected by moisture in the atmosphere. Therefore, at present, it is necessary to strictly seal the organic light emitting device so that the electron injection layer does not deteriorate due to moisture in the atmosphere. Apart from this, research and development for overcoming the instability of the electron injection layer with respect to moisture and the like in the atmosphere, that is, research and development on an organic light-emitting element that is stable in the atmosphere has also been made.

  As one method for improving the stability of the organic light emitting device against moisture in the atmosphere, for example, as in Patent Document 2, an electron donating compound (BTQBT) and an electron accepting compound (PTCDA) are mixed. The method of using the layer formed as an electron injection layer is mentioned. This is due to the generation of charges (electrons) due to the donation of electrons to the electron accepting compound by the electron donating compound and the formation of a polarized DA complex due to the strong interaction between the electron donating compound and the electron accepting compound. This is because it effectively acts against electron injection into the light emitting layer or the like.

JP 2003-338377 A US Patent Application Publication No. 2005/0110005 JP-A-2005-53806 US Patent Application Publication No. 2010/061952 JP 2012-36096 A

  However, since the electron-accepting compound (PTCDA) used in Patent Document 2 has a deep LUMO (the LUMO is located in a direction farther from the vacuum level), the energy level of the DA complex is also deep. Therefore, when the electron-accepting compound of Patent Document 2 is used as a constituent material of the electron injection layer constituting the organic light-emitting device, it is possible to inject electrons from the electrode even though it is possible to inject electrons into the shallow LUMO light-emitting layer. Due to the large barrier, good light emission could not be obtained.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide an organic light-emitting element that is stable even in the atmosphere.

An anode and a cathode;
A light emitting layer disposed between the anode and the cathode;
An organic compound layer provided between the cathode and the light emitting layer and in contact with the cathode;
The organic compound layer has a compound represented by the following general formula [1].

(In the formula [1], R _{1 to} R ₆ each represent a hydrogen atom, a fluorine atom, an alkyl group or an aryl group. When any of R _{1 to} R ₆ is an alkyl group, At least part of the hydrogen atoms contained may be substituted with fluorine atoms, and when any of R _{1 to} R ₆ is an aryl group, the aryl group further has a fluorine atom or an alkyl group. * Represents a bond for bonding to the skeleton represented by any one of the following general formulas [2-1] to [2-3], and an anthraquinone skeleton represented by the formula [1] A 5-membered ring is formed by the bond to the skeleton represented by any one of the following general formulas [2-1] to [2-3].

(In the formulas [2-1] to [2-3], R _{7 to} R ₂₈ each represent a hydrogen atom, a fluorine atom, an alkyl group or an aryl group. Note that any one of R _{7 to} R ₂₈ is an alkyl group. In this case, at least a part of hydrogen atoms contained in the alkyl group may be substituted with fluorine atoms, and when any of R _{7 to} R ₂₈ is an aryl group, the aryl group (It may have an atom or an alkyl group. * Represents a bond for bonding to the anthraquinone skeleton represented by the general formula [1].))

  According to the present invention, an organic light-emitting element that is stable even in the atmosphere can be provided.

It is a cross-sectional schematic diagram which shows an example of the display apparatus which has the organic light emitting element of this invention, and the active element connected to this organic light emitting element. It is a schematic diagram which shows the example of the image forming apparatus which has the organic light emitting element which concerns on this invention. FIGS. 4A and 4B are schematic plan views showing a specific example of an exposure light source constituting the image forming apparatus of FIG. 2, and FIG. 4C is a specific example of a photoconductor constituting the image forming apparatus of FIG. FIG. It is a schematic diagram which shows the example of the illuminating device which has the organic light emitting element which concerns on this invention.

  The organic light emitting device of the present invention includes an anode, a cathode, a light emitting layer disposed between the anode and the cathode, an organic compound layer provided between the cathode and the organic light emitting layer, and in contact with the cathode. Have. In the present invention, the organic compound layer has a compound represented by the following general formula [1].

  The details of the compound represented by the general formula [1] will be described later.

[Organic light emitting device]
First, the organic light emitting device of the present invention will be described. The organic light emitting device of the present invention has at least a light emitting layer and an organic compound layer in contact with the cathode between the anode and the cathode. Thus, in the present invention, since the organic compound layer is a layer in contact with the cathode, it is a layer having a function of injecting electrons injected from the cathode into the light emitting layer (for example, an electron injection layer).

Examples of the configuration of the organic light emitting device of the present invention include the following (a) to (k).
(A) (substrate /) anode / light emitting layer / electron injection layer / cathode (b) (substrate /) anode / hole injection layer / light emitting layer / electron injection layer / cathode (c) (substrate /) anode / hole Transport layer / light emitting layer / electron injection layer / cathode (d) (substrate /) anode / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode (e) (substrate /) anode / hole injection layer / Hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode (f) (substrate /) anode / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / electron injection layer / cathode ( g) (substrate /) anode / hole injection layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / electron injection layer / cathode (h) (substrate /) anode / hole transport layer / electron Block layer / light emitting layer / electron transport layer / electron injection layer / cathode (i) (substrate /) anode / hole injection layer / hole transport layer / electron block layer / light emitting layer / electron transport layer / Child injection layer / cathode (j) (substrate /) anode / hole transport layer / electron blocking layer / light emitting layer / hole blocking layer / electron transport layer / electron injection layer / cathode (k) (substrate /) anode / positive Hole injection layer / hole transport layer / electron block layer / light emitting layer / hole block layer / electron transport layer / electron injection layer / cathode

  However, the structure of the organic light emitting device of the present invention is not limited to the structures (a) to (k) described above. For example, an insulating layer, an adhesive layer or an interference layer is provided at the interface between an electrode (cathode) and an organic compound layer (electron injection layer), and an electron transport layer or a hole transport layer is formed of a plurality of layers having different ionization potentials. Various layer configurations such as a body can be taken.

  In the present invention, the light extraction configuration of the organic light emitting device may be a top emission method in which light is extracted from the electrode on the side opposite to the substrate, or a bottom emission method in which light is extracted from the substrate side. Moreover, the structure taken out from both sides (a board | substrate side and the opposite side to a board | substrate) may be sufficient, respectively.

[Constituent material of organic compound layer (anthraquinone derivative)]
Next, the constituent material of the organic compound layer in contact with the cathode will be described. The organic compound layer in contact with the cathode contains a compound represented by the following general formula [1].

In the formula [1], R _{1 to} R ₆ each represent a hydrogen atom, a fluorine atom, an alkyl group, or an aryl group.

Examples of the alkyl group represented by R _{1 to} R ₆ include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, and a tert-butyl group.

By the way, the alkyl group is effective for forming a high-quality amorphous film. Moreover, since the alkyl group has an electron donating effect, the value of the reduction potential can be further reduced. However, since the molecular weight increases and the sublimation purification becomes difficult as the number of carbon atoms increases, the alkyl group represented by R _{1 to} R ₆ is preferably an alkyl group having 1 to 12 carbon atoms.

When any of R _{1 to} R ₆ is an alkyl group, at least a part of hydrogen atoms contained in the alkyl group may be substituted with a fluorine atom. In this way, when some of the hydrogen atoms contained in the alkyl group are substituted with fluorine atoms, the hydrophobic and oleophobic effects of the fluorine atoms cause deterioration of the organic compound layer due to reaction with moisture and oxygen in the atmosphere. And the sublimation property of the compound itself can be improved.

Examples of the aryl group represented by R _{1 to} R ₆ include a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, and a phenanthryl group.

The aryl group represented by R _{1 to} R ₆ is preferably an aryl stalk having 6 to 18 carbon atoms. This is because sublimation purification becomes difficult as the molecular weight increases.

When any of R _{1 to} R ₆ is an aryl group, the aryl group is further a fluorine atom or a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group. , May have an alkyl group such as a tert-butyl group.

  In the formula [1], * represents a bond for binding to a skeleton represented by any of the following general formulas [2-1] to [2-3]. A 5-membered ring is formed by the bond between the anthraquinone skeleton represented by the formula [1] and the skeleton represented by any one of the following general formulas [2-1] to [2-3].

In the formulas [2-1] to [2-3], R _{7 to} R ₂₈ each represent a hydrogen atom, a fluorine atom, an alkyl group, or an aryl group. Specific examples of the alkyl group represented by R _{7 to} R ₂₈ are the same as the specific examples of the alkyl group represented by R _{1 to} R ₆ in the formula [1]. Specific examples of the aryl group represented by R _{7 to} R ₂₈ are the same as the specific examples of the alkyl group represented by R _{1 to} R ₆ in the formula [1].

When any of R _{7 to} R ₂₈ is an alkyl group, at least a part of hydrogen atoms contained in the alkyl group may be substituted with a fluorine atom. When any of R _{7 to} R ₂₈ is an aryl group, the aryl group is further a fluorine atom or a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group. And may have an alkyl group such as a tert-butyl group.

  In the formulas [2-1] to [2-3], * represents a bond for binding to the anthraquinone skeleton represented by the general formula [1].

  As described above, the compound represented by the general formula [1] is specifically any one of the compounds represented by the following formulas [1A] to [1F].

  In addition, due to the symmetry of the molecule, the compound of the formula [1A] is the same as the compound of the formula [1B], the compound of the formula [1C] is the same as the compound of the formula [1D], and the compound of the formula [1E] Is the same as the compound of formula [1F].

  In the present invention, the compound of the formula [1A] is preferably a compound represented by the following general formula [5].

In the formula [5], R _{31 to} R ₃₆ are each a substituent selected from a hydrogen atom, a fluorine atom and an alkyl group. Specific examples of the alkyl group represented by R _{31 to} R ₃₆ are the same as the specific examples of the alkyl group represented by R _{1 to} R ₆ in the formula [1].

When any of R _{31 to} R ₃₆ is an alkyl group, at least a part of hydrogen atoms contained in the alkyl group may be substituted with a fluorine atom.

In the formula [5], R _{37 to} R ₄₂ are each a substituent selected from a hydrogen atom, a fluorine atom, an alkyl group, and an aryl group. Specific examples of the alkyl group represented by R _{37 to} R ₄₂ are the same as the specific examples of the alkyl group represented by R _{1 to} R ₆ in the formula [1]. Specific examples of the aryl group represented by R _{37 to} R ₄₂ are the same as the specific examples of the aryl group represented by R _{1 to} R ₆ in the formula [1].

When any of R _{37 to} R ₄₂ is an alkyl group, at least a part of hydrogen atoms contained in the alkyl group may be substituted with a fluorine atom. When any of R _{37 to} R ₄₂ is an aryl group, the aryl group is further a fluorine atom or a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, You may have alkyl group alkyl groups, such as a tert- butyl group.

  In the present invention, the compound of the formula [1C] is preferably a compound represented by the following general formula [6].

In the formula [6], R _{31 to} R ₃₆ are each a substituent selected from a hydrogen atom, a fluorine atom and an alkyl group. Specific examples of the alkyl group represented by R _{31 to} R ₃₆ are the same as the specific examples of the alkyl group represented by R _{1 to} R ₆ in the formula [1].

When any of R _{31 to} R ₃₆ is an alkyl group, at least a part of hydrogen atoms contained in the alkyl group may be substituted with a fluorine atom.

In the formula [6], R _{43 to} R ₅₀ are each a substituent selected from a hydrogen atom, a fluorine atom, an alkyl group, and an aryl group. Specific examples of the alkyl group represented by R _{43 to} R ₅₀ are the same as the specific examples of the alkyl group represented by R _{1 to} R ₆ in the formula [1]. Specific examples of the aryl group represented by R _{43 to} R ₅₀ are the same as the specific examples of the aryl group represented by R _{1 to} R ₆ in the formula [1].

When any of R _{43 to} R ₅₀ is an alkyl group, at least a part of hydrogen atoms contained in the alkyl group may be substituted with a fluorine atom. When any of R _{43 to} R ₅₀ is an aryl group, the aryl group is further a fluorine atom or a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, You may have alkyl groups, such as a tert- butyl group.

  In the present invention, the compound of the formula [1E] is preferably a compound represented by the following general formula [7].

In the formula [7], R _{31 to} R ₃₆ are each a substituent selected from a hydrogen atom, a fluorine atom and an alkyl group. Specific examples of the alkyl group represented by R _{31 to} R ₃₆ are the same as the specific examples of the alkyl group represented by R _{1 to} R ₆ in the formula [1].

When any of R _{31 to} R ₃₆ is an alkyl group, at least a part of hydrogen atoms contained in the alkyl group may be substituted with a fluorine atom.

In the formula [7], R _{51 to} R ₅₈ are each a substituent selected from a hydrogen atom, a fluorine atom, an alkyl group, and an aryl group.

When any of R _{51 to} R ₅₈ is an alkyl group, at least a part of hydrogen atoms contained in the alkyl group may be substituted with a fluorine atom. When any of R _{51 to} R ₅₈ is an aryl group, the aryl group is further a fluorine atom or a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, You may have alkyl groups, such as a tert- butyl group.

By the way, the compound represented by the general formula [1] can be obtained by appropriately changing the substituents (R _{1 to} R ₂₈ ) of the basic skeleton so that the physical properties of the compound itself, specifically, the reduction potential, film property, heat Stability, sublimation, etc. can be finely adjusted as appropriate.

For example, R ₃ , R ₄ , R ₉ and R ₁₀ (R ₃₃ , R ₃₄ , R ₃₉ and R ₄₀ in the formula [5]) greatly contribute to the reduction potential reduction in the compound of the formula [1A]. is there. In the compound of the formula [1C], R ₃ , R ₄ and R ₁₇ (R ₃₃ , R ₃₄ and R ₄₇ in the formula [6]) greatly contribute to the reduction potential change. In the compound of the formula [1E], R ₃ , R ₄ , R ₂₄ and R ₂₇ (R ₃₃ , R ₃₄ , R ₅₄ and R ₅₇ in the formula [7]) greatly contribute to the reduction potential change. When an electron-donating substituent is substituted for these substituents, the value of the reduction potential of the compound itself becomes small. On the other hand, when an electron-withdrawing substituent is substituted for these substituents, the value of the reduction potential of the compound itself increases.

[Specific examples of anthraquinone derivatives]
Specific examples of the anthraquinone derivative (compound of general formula [1]) included as a constituent material of the organic light-emitting device of the present invention are shown below. However, the present invention is not limited to these specific examples.

[Constituent material of organic compound layer (electron-donating compound)]
In the present invention, the organic compound layer in contact with the cathode is a layer containing at least the compound of the general formula [1], but preferably further includes a compound different from the compound of the general formula [1]. Here, when the organic compound layer includes a compound of the general formula [1] and a compound different from the compound of the general formula [1], the compound of the general formula [1] is preferably an electron accepting compound. Yes, the compound different from the compound of the general formula [1] is an electron donating compound. Here, when the compound of the general formula [1] is an electron-accepting compound, the compound to be an electron-donating compound is an organic compound or an organometallic compound containing a transition metal.

  Here, when the electron donating compound is an organic compound, the corresponding compound is an organic compound having a property that electrons are easily extracted. As the organic compound capable of donating electrons to the electron-accepting compound (compound represented by the general formula [1]), an organic compound known to form a charge transfer complex system can be used. . Specific examples of the organic compound that can form a charge transfer complex by interaction with the compound represented by the general formula [1] include aniline derivatives, phenazine derivatives, viologen derivatives, thiophene derivatives, and thiopyran derivatives. More specifically, examples include the compounds shown below, but the present invention is not limited thereto.

[Redox potential of components]
Thus, when the organic compound layer contains an electron accepting compound and an electron donating compound, it is preferable that the relationship of the following formula [3] is satisfied with respect to the oxidation-reduction potential of both compounds.
| V _red −V _ox | ≦ 1.0 V [3]
In the formula [3], V _red represents the first reduction potential value of the electron accepting compound, and V _ox represents the first oxidation potential value of the electron donating compound. V _red and V _ox are oxidation-reduction potentials measured under the same conditions in cyclic voltammetry (CV). Here, the same condition means that the conditions for CV measurement, specifically, the solvent, the electrolyte, the working electrode, the reference electrode, the counter electrode, the temperature and the concentration are the same. The oxidation-reduction potential is a half-wave potential value (E ^1/2 ) of a generally used oxidation-reduction wave.

Moreover, it is more preferable that the relationship of the following formula [4] is satisfied for the oxidation-reduction potentials of both compounds.
| V _red −V _ox | ≦ 0.5 V [4]

In the formula [4], V _red represents the first reduction potential value of the electron accepting compound, and V _ox represents the first oxidation potential value of the electron donating compound. Incidentally, V _red and V _ox in the formula [4] is a consent Zorezore, V _red in the formula [3], and V _ox.

  As described above, the organic compound layer contains an electron-accepting compound (anthraquinone derivative of the general formula [1]) and an electron-donating compound, and is represented by the formula [3] (preferably the formula [4]). Suppose the relationship is satisfied. In such a case, the electron-accepting compound contained in the organic compound layer is preferably an anthraquinone derivative represented by any one of the general formulas [5] to [7].

[Function of the compound of general formula [1] (anthraquinone derivative)]
The organic light emitting device of the present invention has an organic compound layer (an electron injection layer or the like) in which an anthraquinone derivative condensed with a five-membered ring structure (compound of general formula [1]) is in contact with the cathode as an electron accepting compound Layer). In particular, in the present invention, this organic compound layer is used as a mixed film of the electron accepting compound and the electron donating compound and as an electron injection layer (or a layer functioning as an electron injection layer) constituting the organic light emitting device. An effective effect can be obtained.

Here, the electron injection layer constituting the organic light emitting element is required to have three performances listed in the following (1) to (3).
(1) Ability to receive electrons from an electrode (2) Ability to inject electrons into layers (for example, an electron transport layer, a hole blocking layer, and a light emitting layer) on the side opposite to the cathode among the layers constituting the organic light emitting device. (3) Ability to transport charges

  If these are not satisfied, good light emission cannot be obtained from the light emitting layer constituting the organic light emitting device.

In general, there is a large energy barrier between a cathode and a layer (for example, an electron transport layer, a hole blocking layer, and a light emitting layer) provided between the anode and the cathode. Here, the HOMO of the electron-donating compound (BTQBT) and the LUMO of the electron-accepting molecule PTCDA disclosed in Patent Document 2 are −4.5 eV, which is generally used for the aluminum constituting the cathode. It is almost equivalent to the work function (4.3 eV). Therefore, for example, the energy barrier with the LUMO (-3.3 eV) of Alq ₃ that is typically used in organic light-emitting elements is large. As a result, even when the DA complex described in Patent Document 2 is used for the electron transport layer of the organic light emitting device, the voltage becomes high and good light emission from the light emitting layer cannot be obtained.

On the other hand, the LUMO of the anthraquinone derivative of the general formula [1] is around −3.6 eV. For example, the energy barrier with the LUMO (−3.3 eV) of Alq _{3 described} above is small, and the organic light emitting device is configured. The electron injection property to the layer (electron transport layer etc.) which improves is improved.

  Further, the anthraquinone derivative of the general formula [1] can receive electrons from the cathode, for example, by combining with an electron donating compound (electron donating compound).

As an electron receiving mechanism from the cathode by the combination of the anthraquinone derivative (electron accepting compound) of the general formula [1] and the electron donating compound, a series of processes leading to the following (i) to (ii) is assumed. .
(I) Charge transfer from an electron-donating compound to an electron-accepting compound (anthraquinone derivative) (ii) Formation of a polarized DA complex by the interaction between the electron-donating compound and the electron-accepting compound

  The process from (i) to (ii) is caused by the interaction between the electron-donating compound and the electron-accepting compound. This interaction is caused by the HOMO of the electron-donating compound and the electron-accepting compound. It happens with LUMO. Moreover, the organic compound layer which touches an electrode (cathode) can receive an electron from this electrode by the process from said (i) to (ii). Moreover, since carriers are generated in the DA complex, the charge mobility of the organic compound layer is high. For this reason, in this invention, the organic compound layer which contact | connects an electrode (cathode) also has an electron transport capability.

  By the way, a nitrogen-containing heterocyclic compound having a chelate structure represented by a phenanthroline skeleton, which has been conventionally used as a constituent material of an electron injection layer, has a plurality of (for example, two) nitrogen atoms. There is a strong possibility of forming hydrogen bonds in water molecules. For this reason, a nitrogen-containing heterocyclic compound having a chelate structure is easily affected by moisture in the atmosphere because it easily interacts with water molecules. On the other hand, the anthraquinone derivative (compound of general formula [1]) constituting the organic compound layer constituting the organic light-emitting device of the present invention does not have a nitrogen-containing heterocyclic group containing the chelate structure. Therefore, since the anthraquinone derivative has reduced interaction with water molecules, the organic compound layer in contact with the cathode constituting the organic light-emitting device becomes a stable layer in the atmosphere.

  As described above, the organic light-emitting device of the present invention has a good electron injecting property from the cathode and is stable in the atmosphere.

  In the organic light-emitting device of the present invention, a known compound can be used as a constituent material included in the device, in addition to the above-described electron-donating compound and electron-accepting compound (the compound of the general formula [1]). Examples of these compounds are given below.

  As the hole injecting and transporting material, a material having a high hole mobility is preferable so that the injection of holes from the anode can be facilitated and the injected holes can be transported to the light emitting layer. In order to prevent deterioration of film quality such as crystallization in the organic light emitting device, a material having a high glass transition temperature is preferable. Low molecular and high molecular weight materials having hole injection and transport performance include triarylamine derivatives, arylcarbazole derivatives, phenylenediamine derivatives, stilbene derivatives, phthalocyanine derivatives, porphyrin derivatives, poly (vinylcarbazole), poly (thiophene), Other examples include conductive polymers. Further, the hole injecting / transporting material is also preferably used for the electron blocking layer.

  Specific examples of the compound used as the hole injecting and transporting material are shown below, but the present invention is not limited to these.

  Among the constituent materials of the light emitting layer, light emitting materials mainly related to the light emitting function include condensed ring compounds (eg, fluorene derivatives, naphthalene derivatives, pyrene derivatives, perylene derivatives, tetracene derivatives, anthracene derivatives, rubrene, etc.), quinacridone derivatives, coumarins. Derivatives, stilbene derivatives, organoaluminum complexes such as tris (8-quinolinolato) aluminum, iridium complexes, platinum complexes, rhenium complexes, copper complexes, europium complexes, ruthenium complexes, and poly (phenylene vinylene) derivatives, poly (fluorene) derivatives, And polymer derivatives such as poly (phenylene) derivatives.

  Although the specific example of the compound used as a luminescent material is shown below, of course, it is not limited to these.

  Examples of the host or assist material (light emission assist material) contained in the light emitting layer include aromatic hydrocarbon compounds or derivatives thereof, as well as organoaluminum complexes such as carbazole derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, and tris (8-quinolinolato) aluminum. And organic beryllium complexes.

  Specific examples of the compound used as the light emitting layer host or the light emission assist material contained in the light emitting layer are shown below, but of course not limited thereto.

  The compounds listed here (compounds used as a host or assist material) are also preferably used as a constituent material of the hole blocking layer.

  The electron transporting material can be arbitrarily selected from those capable of transporting electrons injected from the cathode to the light emitting layer, and is appropriately selected in consideration of the balance with the hole mobility of the hole transporting material. Selected. Materials having electron transport performance include oxadiazole derivatives, oxazole derivatives, pyrazine derivatives, triazole derivatives, triazine derivatives, quinoline derivatives, quinoxaline derivatives, phenanthroline derivatives, organoaluminum complexes, condensed compounds (for example, fluorene derivatives, naphthalene derivatives, Chrysene derivatives, anthracene derivatives, etc.). Furthermore, the above electron transporting material is also suitably used for a hole blocking layer (hole / exciton blocking layer).

  Specific examples of the compound used as the electron transporting material are shown below, but of course not limited thereto.

  In the present invention, an electron injecting material other than the compound of the general formula [1] (anthraquinone derivative) may be used. The electron injecting material other than the compound of general formula [1] (anthraquinone derivative) can be arbitrarily selected from those capable of easily injecting electrons from the cathode, considering the balance with the hole injecting property and the like. Selected. Specific examples include an n-type dopant and a reducing dopant which are electron-donating organic compounds used by mixing with the electron-accepting anthraquinone derivative of the general formula [1].

  As the material for the anode, a material having a work function as large as possible is preferable. For example, simple metals such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium, tungsten, etc., or an alloy combining them, tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), zinc oxide Metal oxides such as indium can be used. In addition, conductive polymers such as polyaniline, polypyrrole, and polythiophene can also be used.

  These electrode materials may be used alone or in combination of two or more. Moreover, the anode may be composed of a single layer or a plurality of layers.

  On the other hand, the material constituting the cathode is preferably a material having a small work function. Examples thereof include alkali metals such as lithium, alkaline earth metals such as calcium, and simple metals such as aluminum, titanium, manganese, silver, lead, and chromium. Or the alloy which combined these metal single-piece | units can also be used. For example, magnesium-silver, aluminum-lithium, aluminum-magnesium, etc. can be used. A metal oxide such as indium tin oxide (ITO) can also be used. These electrode materials may be used alone or in combination of two or more. The cathode may have a single layer structure or a multilayer structure.

  The layers constituting the organic light emitting device of the present invention (hole injection layer, hole transport layer, electron block layer, light emitting layer, hole block layer, electron transport layer, electron injection layer, etc.) are formed by the method shown below. Is done.

  The layer constituting the organic light-emitting device of the present invention can use a dry process such as a vacuum deposition method, an ionization deposition method, sputtering, or plasma. In place of the dry process, a wet process in which a layer is formed by a known coating method (for example, spin coating, dipping, casting method, LB method, ink jet method, etc.) after dissolving in an appropriate solvent may be used.

  Here, when a layer is formed by a vacuum deposition method, a solution coating method, or the like, crystallization or the like hardly occurs and the temporal stability is excellent. Moreover, when forming into a film by the apply | coating method, a film | membrane can also be formed combining with a suitable binder resin.

  Examples of the binder resin include, but are not limited to, polyvinyl carbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicon resin, urea resin, and the like. .

  Moreover, these binder resins may be used alone as a homopolymer or a copolymer, or may be used in combination of two or more. Furthermore, you may use together additives, such as a well-known plasticizer, antioxidant, and an ultraviolet absorber, as needed.

[Applications of organic light-emitting elements]
The organic light-emitting element of the present invention can be used as a constituent member of a display device or a lighting device. In addition, there are uses such as an exposure light source of an electrophotographic image forming apparatus, a backlight of a liquid crystal display device, and a light emitting device having a color filter in a white light source. Examples of the color filter include filters that transmit three colors of red, green, and blue.

  The display device of the present invention has the organic light emitting device of the present invention in a display portion. This display unit has a plurality of pixels.

  The pixel includes the organic light emitting device of the present invention and a transistor which is an example of an active device (switching device) or an amplifying device for controlling light emission luminance. The anode or cathode of the organic light emitting device and the transistor A drain electrode or a source electrode is electrically connected. Here, the display device can be used as an image display device such as a PC. An example of the transistor is a TFT element, and this TFT element is provided on, for example, an insulating surface of a substrate.

  The display device may be an information processing device that includes an image input unit that inputs image information from an area CCD, linear CCD, memory card, or the like, and displays the input image on the display unit.

  In addition, a display unit included in the imaging device or the inkjet printer may have a touch panel function. The driving method of the touch panel function is not particularly limited.

  The display device may be used for a display unit of a multifunction printer.

  The lighting device is, for example, a device that illuminates a room. The lighting device may emit white light (color temperature is 4200K), day white light (color temperature is 5000K), or any other color from blue to red.

  The lighting device of the present invention includes the organic light-emitting element of the present invention, an AC / DC converter circuit (a circuit that converts an AC voltage into a DC voltage) that is connected to the organic light-emitting element and supplies a drive voltage to the organic light-emitting element. have. In addition, this illuminating device may further have a color filter.

  The image forming apparatus of the present invention comprises a photosensitive member, a charging unit for charging the surface of the photosensitive member, an exposure unit for exposing the photosensitive member to form a negative electrostatic image, and a static image formed on the surface of the photosensitive member. An image forming apparatus having a developing device for developing an electrostatic latent image. Here, the exposure means provided in the image forming apparatus includes the organic light emitting device of the present invention.

  The organic light-emitting device of the present invention can be used as a constituent member of an exposure apparatus for exposing a photoreceptor. The exposure apparatus having the organic light emitting element of the present invention includes, for example, an exposure apparatus in which the organic light emitting elements of the present invention are arranged in rows along a predetermined direction.

  Next, the display device of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an example of a display device having an organic light emitting element and a TFT element connected to the organic light emitting element. In addition, the organic light emitting element of this invention is used as an organic light emitting element which comprises the display apparatus 1 of FIG.

  The display device 1 in FIG. 1 includes a substrate 11 made of glass or the like and a moisture-proof film 12 for protecting the TFT element or the organic compound layer on the substrate 11. Reference numeral 13 denotes a metal gate electrode 13. Reference numeral 14 denotes a gate insulating film 14 and reference numeral 15 denotes a semiconductor layer.

  The TFT element 18 includes a semiconductor layer 15, a drain electrode 16, and a source electrode 17. An insulating film 19 is provided on the TFT element 18. The anode 21 and the source electrode 17 constituting the organic light emitting element are connected via the contact hole 20.

  The method of electrical connection between the electrodes (anode and cathode) included in the organic light emitting element and the electrodes (source electrode and drain electrode) included in the TFT is not limited to the mode shown in FIG. That is, it is only necessary that either one of the anode or the cathode is electrically connected to either the TFT element source electrode or the drain electrode.

  In the display device 1 of FIG. 1, the multiple organic compound layers are illustrated as one layer, but the organic compound layer 22 may be a plurality of layers. On the cathode 23, the 1st protective layer 24 and the 2nd protective layer 25 for suppressing deterioration of an organic light emitting element are provided.

  When the display device 1 in FIG. 1 is a display device that emits white light, the light emitting layer included in the organic compound layer 22 in FIG. 1 may be a layer formed by mixing a red light emitting material, a green light emitting material, and a blue light emitting material. . Alternatively, a layered light emitting layer in which a layer made of a red light emitting material, a layer made of a green light emitting material, and a layer made of a blue light emitting material are laminated may be used. Furthermore, as another method, a mode in which a layer is formed in one light emitting layer by arranging a layer made of a red light emitting material, a layer made of a green light emitting material, and a layer made of a blue light emitting material side by side.

  In the display device 1 of FIG. 1, a transistor is used as a switching element, but an MIM element may be used as a switching element instead.

  1 is not limited to a transistor using a single crystal silicon wafer, but may be a thin film transistor having an active layer on an insulating surface of a substrate. Thin film transistor using single crystal silicon as active layer, thin film transistor using non-single crystal silicon such as amorphous silicon or microcrystalline silicon as active layer, non-single crystal oxidation such as indium zinc oxide or indium gallium zinc oxide as active layer A thin film transistor using a physical semiconductor may be used. The thin film transistor is also called a TFT element.

  The switching element according to this embodiment may have an oxide semiconductor in its channel portion. In this switching element, the oxide semiconductor portion may be amorphous, crystalline, or a mixture of both. The crystal may be a single crystal, a microcrystal, a crystal in which a specific axis such as the C axis is oriented, or a mixture of at least any two of them.

  The organic light emitting element having such a switching element may be used in an image display device in which each organic light emitting element is provided as a pixel. Alternatively, it may be used as an exposure unit that exposes a photoreceptor of an electrophotographic image forming apparatus such as an illumination device, a laser beam printer, or a copying machine.

  The transistor included in the display device 1 of FIG. 1 may be formed in a substrate such as a Si substrate. Here, being formed in the substrate means that a transistor is manufactured by processing the substrate itself such as a Si substrate. In other words, having a transistor in a substrate can be regarded as the substrate and the transistor being integrally formed.

  Whether or not the transistor is provided in the substrate is selected depending on the definition. For example, in the case of a definition of about 1 inch and QVGA, it is preferable to provide an organic light emitting element in the Si substrate.

  As described above, by driving the display device using the organic light emitting device of the present invention, stable display can be performed for a long time with good image quality.

  Next, other uses of the organic light emitting device of the present invention will be described. FIG. 2 is a schematic view showing an example of an image forming apparatus having the organic light emitting device according to the present invention. The image forming apparatus 26 of FIG. 2 includes a photoreceptor 27, an exposure light source 28, a developing device 30, a charging unit 31, a transfer device 32, a transport roller 33, and a fixing device 33.

  In the image forming apparatus 26 in FIG. 2, light 29 is irradiated from the exposure light source 28 toward the photoconductor 27, and an electrostatic latent image is formed on the surface of the photoconductor 27. In the image forming apparatus 26 of FIG. 2, the exposure light source 28 includes the organic light emitting element according to the present invention. Further, in the image forming apparatus 26 of FIG. 2, the developing device 30 has toner or the like. In the image forming apparatus 26 of FIG. 2, the charging unit 31 is provided for charging the photoconductor 27. In the image forming apparatus 26 of FIG. 2, the transfer device 32 is provided for transferring the developed image to a recording medium 34 such as paper. Note that the recording medium 34 is conveyed to the subordinate 32 by the conveying roller 33. In the image forming apparatus 26 of FIG. 2, the fixing device 35 is provided for fixing the image formed on the recording medium 34.

  3A and 3B are schematic plan views showing a specific example of the exposure light source (exposure device) constituting the image forming apparatus 26 of FIG. 2, and FIG. 3C is a plan view of FIG. 3 is a schematic view showing a specific example of a photoconductor that constitutes the image forming apparatus 26. FIG. 3 (a) and 3 (b) are common in that a plurality of light emitting portions 36 including organic light emitting elements in the exposure light source 28 are arranged on the long substrate 28a. An arrow with reference numeral 37 represents the column direction in which the light emitting sections 36 are arranged. This row direction is the same as the direction of the axis around which the photoconductor 27 rotates.

  Incidentally, in FIG. 3A, the light emitting unit 36 is arranged along the axial direction of the photoconductor 27. On the other hand, FIG. 3B shows a form in which the light emitting units 36 are alternately arranged in the column direction in each of the first column α and the second column β. In FIG. 3B, the first column α and the second column β are arranged at different positions in the row direction.

  In FIG. 3B, in the first column α, a plurality of light emitting units 36α are arranged with a certain interval, while the second column β is a light emitting unit included in the first column α. The light emitting unit 36β is provided at a position corresponding to the interval between the 36α. That is, in the exposure light source of FIG. 3B, a plurality of light emitting units are arranged with a certain interval in the row direction.

  In addition, the exposure light source of FIG.3 (b) can also be paraphrased in the state which has arrange | positioned the light emission parts (36 (alpha), 36 (beta)) which comprise an exposure light source, for example in a grid | lattice form, a staggered pattern, or a checkered pattern.

  FIG. 4 is a schematic view showing an example of a lighting device having an organic light emitting element according to the present invention. The illuminating device in FIG. 4 includes an organic light emitting element 38 provided on a substrate (not shown) and an AC / DC converter circuit 39. 4 has a heat sink (not shown) corresponding to a heat dissipating part for releasing heat in the apparatus to the outside, for example, a substrate surface opposite to the side on which the organic light emitting element 38 is placed. You may have.

  The anthraquinone derivative that is a constituent material of the organic light-emitting device of the present invention can be synthesized by an existing method. Specifically, it can be synthesized by the methods described in Patent Documents 3 to 5. In addition, the anthraquinone derivative which is a constituent material of the organic light emitting device of the present invention is an intermediate compound used when a compound having an anthracene skeleton is synthesized.

The synthesized anthraquinone derivatives are shown below.
(I) Compound represented by general formula [5]: Exemplified compounds A1, A4, A6
(Ii) Compound represented by general formula [6]: Exemplified compounds B1, B4, B6
(Iii) Compound represented by general formula [7]: Exemplified compounds C1, C3, C4

Further, CV measurement was performed on the above-described anthraquinone derivatives. The measurement conditions for CV measurement are shown below.
Measurement environment (gas atmosphere): Nitrogen gas atmosphere Solution used: 0.1 M tetrabutylammonium perchlorate in DMF solution Reference electrode: Ag / Ag ⁺
Counter electrode: Pt
Working electrode: Glassy carbon insertion speed: 0.1 V / s
Measuring device: Electrochemical analyzer (Model 660, manufactured by ALS)
Table 2 shows the oxidation potential and reduction potential of each compound obtained from CV measurement.

[Example 1]
In this example, an organic light emitting device in which an anode, a hole transport layer, an electron blocking layer, a light emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a cathode are formed in this order on a substrate. It was produced by the method described below.

  An anode was formed by depositing indium tin oxide (ITO) on a glass substrate by sputtering. At this time, the film thickness of the anode was set to 120 nm. Next, the substrate on which the anode was formed was sequentially ultrasonically cleaned with acetone and isopropyl alcohol (IPA), then boiled and cleaned with IPA, and then dried. Further, UV / ozone cleaning was performed. The substrate processed by the above method was used in the next step as a transparent conductive support substrate (ITO substrate).

Next, an organic compound layer and an electrode layer shown in Table 1 below were continuously formed on the ITO substrate by vacuum evaporation by resistance heating in a 10 ⁻⁵ Pa vacuum chamber. At this time, the opposing electrode area was 3 mm ² .

When the obtained organic light emitting device was driven to have a luminance of 100 cd / m ² , the light emission efficiency was 3.0 cd / A and red light emission was observed.

[Example 2]
In Example 1, the following steps were performed after the formation of the electron injection layer and before the formation of the metal electrode layer.

[Exposure process]
After the formation of the electron injection layer, the vacuum state was released and the atmosphere was sent into the film forming apparatus, and the substrate formed up to the electron injection layer was exposed to the atmosphere for 10 minutes. Next, the inside of the film forming apparatus was again returned to a vacuum state of 10 ⁻⁵ Pa. After the inside of the film forming apparatus was in a vacuum state (10 ⁻⁵ Pa), a metal electrode was formed.

  Except for this, an organic light emitting device was fabricated in the same manner as in Example 1. About the obtained organic light emitting element, the performance was evaluated by the same method as Example 1. The results are shown in Table 2.

[Example 3 to Example 12]
In Example 2, the constituent materials of the hole blocking layer, the electron transport layer, and the electron injection layer were appropriately changed as shown in Table 3 described later. Except for this, an organic light emitting device was fabricated in the same manner as in Example 1. About the obtained organic light emitting element, the performance was evaluated by the same method as Example 1. The results are shown in Table 2.

[Comparative Example 1]
In Example 2, as the electron-accepting compound (Compound X), the compound R1 shown below is used instead of the exemplified compound A1, and the Liq shown below is used instead of the compound D3 as the electron-donating compound (Compound Y). Each was used.

  Except for these, an organic light emitting device was produced in the same manner as in Example 2. About the obtained organic light emitting element, the performance was evaluated by the same method as Example 1. The results are shown in Table 2.

[Comparative Example 2]
In Example 2, an organic light emitting device was produced in the same manner as in Example 2 except that Compound R1 was used instead of Exemplary Compound A1 as the electron accepting compound (Compound X). About the obtained organic light emitting element, the performance was evaluated by the same method as Example 1. The results are shown in Table 2.

[Comparative Example 3]
In Example 7, an organic light emitting device was produced in the same manner as in Example 7 except that the compound R2 shown below was used instead of the exemplified compound B4 as the electron accepting compound (compound X). .

  About the obtained organic light emitting element, the performance was evaluated by the same method as Example 1. The results are shown in Table 2.

[Example 13 to Example 16]
In Example 2, an organic light emitting device was produced in the same manner as in Example 2 except that the constituent material of the light emitting layer was changed as shown in Table 3 below. About the obtained organic light emitting element, the performance was evaluated by the same method as Example 1. The results are shown in Table 3.

[Results and discussion]
From the examples, a film (mixed film) containing an anthraquinone derivative of the general formula [1], which is an electron-accepting compound, and an electron-donating compound is used as an electron-injecting layer. Electrons can be injected into the light emitting layer, and light emission from the light emitting layer can be obtained. Further, from the results of Examples 1 and 2, even when an element having the same configuration was manufactured, even when the vacuum was once released before the metal electrode (cathode) was formed and the electron injection layer was exposed to the atmosphere, It showed the same performance as the device manufactured by vacuum consistent. For this reason, it turned out that the electron injection layer which comprises the organic light emitting element of this invention is a thin film stable with respect to air | atmosphere.

  On the other hand, from Comparative Example 1, when an electron injection layer is formed using an alkali metal complex (Liq) generally used as an electron injection transport material and a nitrogen-containing heterocyclic compound (compound R1) having a chelate structure The light emission intensity of the obtained organic light emitting device was weak. From this result, it can be said that the electron injection layer containing the alkali metal complex and the nitrogen-containing heterocyclic compound having a chelate structure deteriorated the performance (electron injection performance) of the film itself when exposed to the atmosphere.

  Moreover, from the comparative example 2, when compound R1 which is compounds other than the anthraquinone derivative of General formula [1] was included in the electron injection layer as an electron-accepting compound, the produced organic light emitting element did not light-emit. This is a compound in which the electron donating compound (compound D3) does not contain an alkali metal, and since the reduction potential of the compound R1 is small, charge (electrons) is transferred from the electron donating compound to the electron accepting compound. This is because no problem occurred.

  Moreover, even if it was a compound containing an anthraquinone frame | skeleton, the organic light emitting element of the comparative example 3 which used the compound R2 which does not correspond to the anthraquinone derivative of General formula [1] as an electron-accepting compound did not light-emit. This is because the compound R2 does not have a 5-membered ring structure formed by the condensation of an anthraquinone skeleton and a condensed ring skeleton, so that the reduction potential value is smaller than that of the anthraquinone derivative of the general formula [1], and the electron donating compound This is because it is not sufficient to cause the charge transfer.

  As described above, unlike the alkali metal and alkaline earth metal derivatives, the anthraquinone derivative of the general formula [1] is stable even when exposed to the atmosphere, and has a structure of a layer in contact with the cathode (such as an electron injection layer). It was found to be useful as a material.

  18: TFT element, 21: anode, 22: organic compound layer, 23: cathode

Claims (15)

An anode and a cathode;
A light emitting layer disposed between the anode and the cathode;
An organic compound layer provided between the cathode and the light emitting layer and in contact with the cathode;
The organic light-emitting element, wherein the organic compound layer has a compound represented by the following general formula [1].

(In the formula [1], R _{1 to} R ₆ each represent a hydrogen atom, a fluorine atom, an alkyl group or an aryl group. When any of R _{1 to} R ₆ is an alkyl group, At least part of the hydrogen atoms contained may be substituted with fluorine atoms, and when any of R _{1 to} R ₆ is an aryl group, the aryl group further has a fluorine atom or an alkyl group. * Represents a bond for bonding to the skeleton represented by any one of the following general formulas [2-1] to [2-3], and an anthraquinone skeleton represented by the formula [1] A 5-membered ring is formed by the bond to the skeleton represented by any one of the following general formulas [2-1] to [2-3].

(In the formulas [2-1] to [2-3], R _{7 to} R ₂₈ each represent a hydrogen atom, a fluorine atom, an alkyl group or an aryl group. Note that any one of R _{7 to} R ₂₈ is an alkyl group. In this case, at least a part of hydrogen atoms contained in the alkyl group may be substituted with fluorine atoms, and when any of R _{7 to} R ₂₈ is an aryl group, the aryl group (It may have an atom or an alkyl group. * Represents a bond for bonding to the anthraquinone skeleton represented by the general formula [1].))   The organic light emitting device according to claim 1, wherein the organic compound layer has a compound different from the compound represented by the general formula [1].   The organic light-emitting device according to claim 2, wherein the compound represented by the general formula [1] is an electron-accepting compound, and the compound different from the general formula [1] is an electron-donating compound. The organic light-emitting device according to claim 3, wherein the electron-accepting compound and the electron-donating compound satisfy the following formula [3].
| V _red −V _ox | ≦ 1.0 V [3]
(In Formula [3], V _red represents the first reduction potential value of the electron-accepting compound, and V _ox represents the first oxidation potential value of the electron-donating compound.) The organic light-emitting device according to claim 2, wherein the following formula [4] is satisfied.
| V _red −V _ox | ≦ 0.5 V [4]
(In Formula [4], V _red represents the first reduction potential value of the electron-accepting compound, and V _ox represents the first oxidation potential value of the electron-donating compound.) The organic light-emitting device according to any one of claims 2 to 5, wherein the electron-accepting compound X is represented by the general formula [5].

(In the formula [5], R _{31 to} R ₃₆ are each a substituent selected from a hydrogen atom, a fluorine atom, and an alkyl group. When any of R _{31 to} R ₃₆ is an alkyl group, At least some of the hydrogen atoms contained in the alkyl group may be substituted with fluorine atoms, and R _{37 to} R ₄₂ are each a substituent selected from a hydrogen atom, a fluorine atom, an alkyl group, and an aryl group. . Note that if any of R ₃₇ to R ₄₂ is an alkyl group, either at least part of the hydrogen atoms contained in the alkyl group may be substituted by a fluorine atom. in addition the R ₃₇ to R ₄₂ When is an aryl group, the aryl group may further have a fluorine atom or an alkyl group.) The organic light-emitting device according to any one of claims 2 to 5, wherein the electron-accepting compound X is represented by the general formula [6].

(In the formula [6], R _{31 to} R ₃₆ are each a substituent selected from a hydrogen atom, a fluorine atom and an alkyl group. When any of R _{31 to} R ₃₆ is an alkyl group, At least some of the hydrogen atoms contained in the alkyl group may be substituted with fluorine atoms, and R _{43 to} R ₅₀ are each a substituent selected from a hydrogen atom, a fluorine atom, an alkyl group, and an aryl group. . Note that if any of R ₄₃ to R ₅₀ is an alkyl group, at least some of the hydrogen atoms contained in the alkyl group may be substituted by a fluorine atom. in addition any of R ₄₃ to R ₅₀ When is an aryl group, the aryl group may further have a fluorine atom or an alkyl group.) The organic light-emitting device according to any one of claims 2 to 5, wherein the electron-accepting compound X is represented by the general formula [7].

(In the formula [7], R _{31 to} R ₃₆ are each a substituent selected from a hydrogen atom, a fluorine atom and an alkyl group. When any of R _{31 to} R ₃₆ is an alkyl group, At least part of the hydrogen atoms contained in the alkyl group may be substituted with fluorine atoms, and R _{51 to} R ₅₈ are each a substituent selected from a hydrogen atom, a fluorine atom, an alkyl group, and an aryl group. . Note that if any of R ₅₁ to R ₅₈ is an alkyl group, either at least part of the hydrogen atoms contained in the alkyl group may be substituted by a fluorine atom. in addition the R ₅₁ to R ₅₈ When is an aryl group, the aryl group may further have a fluorine atom or an alkyl group.) Having a plurality of pixels,
At least one of the plurality of pixels includes the organic light emitting element according to any one of claims 1 to 8 and an active element connected to the organic light emitting element. apparatus. The active element is a transistor;
The display device according to claim 9, wherein the transistor includes an oxide semiconductor in an active layer. An input unit for inputting image information and a display unit for displaying an image;
The information processing apparatus, wherein the display unit is the display apparatus according to claim 9 or 10.   9. An illuminating device comprising: the organic light emitting device according to claim 1; and an AC / DC converter circuit for supplying a driving voltage to the organic light emitting device.   An illuminating device comprising: the organic light-emitting element according to claim 1; and a heat radiating unit that releases heat in the device to the outside. A charging unit that charges the surface of the photosensitive member and the photosensitive member;
An exposure unit for exposing the photoreceptor;
A developing unit that develops the electrostatic latent image formed on the surface of the photoreceptor,
The image forming apparatus, wherein the exposure unit includes the organic light-emitting element according to claim 1.   9. An exposure apparatus, wherein the organic light-emitting elements according to claim 1 are arranged in a row, and the organic light-emitting elements expose a photosensitive member.

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