JP2014073965A - Novel benzoindolocarbazole compound, organic light-emitting element containing the same, display device, image information processor, lighting device, image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel compound having low S1 energy and shallow HOMO level, an organic light-emitting element having high luminous efficiency and capable of being driven at low voltage, and to provide a display device, an image information processor, lighting device and image forming device using the same.SOLUTION: There is provided a benzoindolocarbazole compound. [1] where Rto Rare selected from a hydrogen atom, an alkyl group and a group represented by the formula [2]. [2]

Description

  The present invention relates to a novel benzoindolocarbazole compound, an organic light emitting device having the compound, a display device, an image information processing device, a lighting device, and an image forming device.

  An organic light emitting element is an element having a pair of electrodes (anode and cathode) and an organic compound layer disposed between the electrodes. Holes and electrons injected from each electrode recombine in the organic compound layer to generate excitons, and light is emitted when the excitons return to the ground state.

  As a technique for improving the light emission efficiency of such an organic light emitting element, an organic light emitting element using phosphorescence has been developed.

  Patent Document 1 describes the following compounds A1 and A2 as materials used for the light emitting layer of the organic light emitting device using phosphorescence emission.

JP 2010-087496 A

  However, since the compounds A1 and A2 described in Patent Document 1 are both compounds having indolocarbazole as the main skeleton, the HOMO level is deep (the ionization potential is large) and the S1 energy is large. Therefore, the organic light emitting device having the compounds A1 and A2 in the light emitting layer has a problem that it becomes an organic light emitting device having a high driving voltage.

  Accordingly, the present invention provides a benzoindolocarbazole compound represented by the following formula [1].

[In the formula [1], R _{1 to} R ₄ are each independently selected from a hydrogen atom, an alkyl group, and a group represented by the following formula [2]. However, at least one of R _{1 to} R ₄ is a group represented by the following formula [2]. ]

[In the formula [2], Ar ₁ represents a divalent hydrocarbon aromatic group having a substituent, an unsubstituted divalent hydrocarbon aromatic group, a divalent heteroaromatic group having a substituent, and Ar ₂ is selected from a substituted divalent heteroaromatic group, and Ar ₂ is a monovalent hydrocarbon aromatic group having a substituent, an unsubstituted monovalent hydrocarbon aromatic group, or a monovalent complex having a substituent. It is selected from an aromatic group and an unsubstituted monovalent heteroaromatic group. a is an integer of 0 to 2. When a is 2, two Ar ₁ may be the same or different. ]

  According to the present invention, a novel benzoindolocarbazole compound having a shallow HOMO level and low S1 energy can be provided. In addition, it is possible to provide an organic light-emitting element that has high luminous efficiency and can be driven at a low voltage, and a display device, an image information processing device, a lighting device, and an image forming device using the organic light-emitting device.

It is a cross-sectional schematic diagram showing the white organic light emitting element which concerns on embodiment of this invention. It is a cross-sectional schematic diagram showing the display apparatus which concerns on embodiment of this invention.

  The benzoindolocarbazole compound according to the present invention is represented by the following formula [1].

[In the formula [1], R _{1 to} R ₄ are each independently selected from a hydrogen atom, an alkyl group, and a group represented by the following formula [2]. However, at least one of R _{1 to} R ₄ is a group represented by the following formula [2]. ]

[In the formula [2], Ar ₁ represents a divalent hydrocarbon aromatic group having a substituent, an unsubstituted divalent hydrocarbon aromatic group, a divalent heteroaromatic group having a substituent, and Ar ₂ is selected from a substituted divalent heteroaromatic group, and Ar ₂ is a monovalent hydrocarbon aromatic group having a substituent, an unsubstituted monovalent hydrocarbon aromatic group, or a monovalent complex having a substituent. It is selected from an aromatic group and an unsubstituted monovalent heteroaromatic group. a is an integer of 0 to 2. When a is 2, two Ar ₁ may be the same or different. ]

  In the following description of this specification, the group represented by the formula [2] may be represented as A.

  The benzoindolocarbazole compound represented by the formula [1] has a benzo [b] indolo [3,2,1-jk] carbazole ring in the main skeleton. In the present invention and the present embodiment, the main skeleton of the compound is a partial structure that greatly affects the physical property value of the compound among the structures of the compound, specifically, S1 energy, T1 energy, HOMO. It is a partial structure that mainly determines physical properties such as levels and LUMO levels. On the other hand, the sub skeleton is a partial structure that does not greatly affect the physical properties of the compound, and the physical properties such as film properties, S1 energy, and charge transport properties of the compound are finely adjusted by selecting the sub skeleton. be able to.

  The benzo [b] indolocarbazole ring has a lower S1 energy than the other isomers of indolocarbazole and benzoindolocarbazole, as shown in the calculated values of S1 energy and HOMO level in Table 1. The rank is shallow. Here, the shallow HOMO level means that the absolute value of the HOMO level (negative value) is small when the vacuum level is 0, or the ionization potential is small.

  In addition, the actual value of the ionization potential of the benzoindolocarbazole compound represented by the formula [1] can be measured by the following method, for example.

The compound represented by the formula [1] is heat-deposited on an AlNd substrate to obtain a deposited thin film having a thickness of 30 nm. About this vapor deposition thin film, ionization potential is measured on the following measurement conditions with photoelectron spectrometer AC-3 (made by Riken Keiki Co., Ltd.).
Measurement environment: room temperature, under nitrogen Measurement light intensity: 0.5 nW
Measurement energy range: 5.0 to 7.0 eV
Step: 0.05eV
Measurement time: 10sec / 1 energy point

  As a host material of the light emitting layer of the organic light emitting element, it is preferable to use a compound having a low S1 energy and a shallow HOMO level. The reason is described below.

  Generally, in an organic light emitting device, the smaller the HOMO level difference between the hole transport layer and the light emitting layer, the smaller the hole injection barrier and the lower the driving voltage of the organic light emitting device. Since the hole transport layer is often composed of a compound having a shallow HOMO level such as an arylamine compound, the hole injection barrier is reduced by using a compound having a shallow HOMO level as the host material that is the main component of the light-emitting layer. be able to.

  Similarly, the smaller the LUMO level difference between the electron transport layer and the light emitting layer, the smaller the electron injection barrier, and the driving voltage of the organic light emitting device further decreases.

  In general, since the electron transport layer is often made of a compound having a deep LUMO level (high electron affinity), the deeper the LUMO level of the host material of the light emitting layer, the smaller the electron injection barrier and the lower the voltage. Good electron injection below can be expected.

  Since the level difference between HOMO and LUMO is almost equal to the S1 energy, a compound having a shallow HOMO level and a deep LUMO level, which is preferable for use as a host material of the light-emitting layer, can be said to be a compound having a low S1 energy.

Note that in a phosphorescent light-emitting element that uses a phosphorescent light-emitting material as a guest material for the light-emitting layer, it is preferable to reduce the HOMO level of the host material in order to improve the carrier balance and expand the light-emitting region (carrier recombination region). . Many phosphorescent guest materials including iridium complexes such as Ir (ppy) ₃ have shallow HOMO levels. When the HOMO level of the guest material is shallow and the HOMO level of the host material is deep, the HOMO level of the guest material becomes a hole trap level in the light emitting layer, and the hole transport property may be greatly reduced. . In such a case, the holes injected from the hole transport layer are not sufficiently transported to the inside of the light emitting layer and are unevenly distributed on the hole transport layer side, so that the carrier balance between holes and electrons deteriorates, The light emitting region may be localized, leading to a decrease in the light emission efficiency of the organic light emitting device and a deterioration in the durability life.

  Therefore, in the phosphorescent light-emitting element, by reducing the HOMO level of the host material, the HOMO level difference from the guest material can be reduced and the light-emitting region in the light-emitting layer can be expanded. As a result, it is possible to achieve high luminous efficiency and long life of the light emitting element.

  Moreover, the benzo [b] indolocarbazole ring has high chemical stability.

  The benzo [b] indolocarbazole ring includes a naphthalene ring and a carbazole ring, a carbon-nitrogen bond (hereinafter referred to as a carbazole type CN bond) and a carbon-carbon bond as an aryl-aryl bond (hereinafter referred to as an aryl type C). It can be regarded as a compound crosslinked by two bonds of -C bond).

  In general, carbazole type C—N bonds are considered to have lower bond energy and lower chemical stability than aryl type C—C bonds. In the benzo [b] indolocarbazole ring, as shown in the following formula [3-1], even if the carbazole type C—N bond is cleaved by a radical bond due to excitation energy, the aryl type C—C bond causes a naphthalene ring. And the carbazole ring is retained.

  Therefore, even if radical bond cleavage occurs, the two radicals are close to each other in the same molecule, and thus there is a high probability that the carbazole type C—N bond will be regenerated.

  That is, it can be said that the benzo [b] indolocarbazole ring hardly deteriorates, and the benzoindolo compound represented by the formula [1] has high chemical stability.

  In addition, in the case of 9-naphthylcarbazole having only a carbazole type C—N bond, as shown in the following formula [3-2], once bond cleavage occurs, the naphthalene ring and the carbazole ring are dissociated into a bimolecular form in the system. , 9-naphthylcarbazole structure becomes difficult to maintain.

  Furthermore, since the dissociated radicals are recombined and the probability that the carbazole-type C—N bond is regenerated is low, the deterioration of the compound via such a radical state is promoted. That is, the compound having such a weak bond is likely to cause structural deterioration of the compound during driving of the organic light emitting device, and adversely affects the durability life of the light emitting device.

In the formula [1], R _{1 to} R ₄ are each independently selected from a hydrogen atom, an alkyl group, and a group represented by the formula [2] (that is, A), and at least one of R _{1 to} R ₄ Is A. The carbon position of the benzo [b] indolocarbazole ring to which R _{1 to} R ₄ are bonded is the substitution position on the benzo [b] indolocarbazole ring, which is easily regioselectively synthesized. It is.

When at least one of R _{1 to} R ₄ in Formula [1] is A, the π-conjugated system of the benzo [b] indolocarbazole ring is expanded, compared with a case where it is a hydrogen atom or an alkyl group. , A compound having a smaller S1 energy and a shallower HOMO level.

At least one of R _{1 to} R ₄ may be A, but R ₁ is preferably A, more preferably R ₁ is A, and R _{2 to} R ₄ are each independently hydrogen. This is a case selected from an atom or an alkyl group. More preferably, R ₁ is A and R _{2 to} R ₄ are hydrogen.

Note that when A is one reason why it is preferable that R ₁ of R ₁ through R ₄ is less.

  The benzoindolocarbazole ring has 13 substitution positions, and the substitution position numbers are shown below.

  As described above, with respect to the substitution positions of the benzoindolocarbazole ring, regioselective synthesis can be easily performed at four positions of 2, 5, 11, and 12, and a phenyl group is substituted at these positions. When molecular orbital calculation is performed on the compound thus obtained, the calculated value of the HOMO level is as shown in Table 2.

  From Table 2, it can be seen that the HOMO level of the compound is the shallowest when the substitution position is the 12th position of the benzoindolocarbazole ring.

Thus, if A compound represented by the formula [1] has is one, it is preferred R ₁ of R ₁ through R ₄ is A.

  The alkyl group is preferably an alkyl group having 1 to 6 carbon atoms, and examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, Examples thereof include n-butyl group, iso-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, iso-pentyl group, tert-pentyl group, neopentyl group, n-hexyl group and cyclohexyl group.

Ar ₁ in A is a divalent hydrocarbon aromatic group having a substituent, an unsubstituted divalent hydrocarbon aromatic group, a divalent heteroaromatic group having a substituent, and an unsubstituted divalent group. Selected from the following hydrocarbon aromatic groups. Ar ₂ represents a monovalent hydrocarbon aromatic group having a substituent, an unsubstituted monovalent hydrocarbon aromatic group, a monovalent heteroaromatic group having a substituent, and an unsubstituted monovalent hydrocarbon group. Heteroaromatic group. Among them, the hydrocarbon aromatic group and the heteroaromatic group in Ar ₁ and Ar ₂ are a hydrocarbon aromatic group having 6 to 22 carbon atoms and a heteroaromatic group having 4 to 22 carbon atoms. Preferably there is. This is because the number of carbon atoms in the main skeleton benzoindolocarbazole ring is 22, and the hydrocarbon aromatic group or heteroaromatic group in Ar ₁ and Ar ₂ has a size less than or equal to that of the benzoindolocarbazole ring. This is because it preferably comprises only an aromatic ring.

  Examples of the unsubstituted monovalent hydrocarbon aromatic group having 6 to 22 carbon atoms include phenyl group, naphthyl group, phenanthryl group, anthryl group, benzo [a] anthryl group, fluorenyl group, benzo [a]. Fluorenyl group, benzo [b] fluorenyl group, benzo [c] fluorenyl group, dibenzo [a, c] fluorenyl group, dibenzo [b, h] fluorenyl group, dibenzo [c, g] fluorenyl group, biphenylenyl group, acenaphthylenyl group, Chrycenyl group, benzo [b] chrycenyl group, pyrenyl group, benzo [e] pyrenyl group, triphenylenyl group, benzo [a] triphenylenyl group, benzo [b] triphenylenyl group, picenyl group, fluoranthenyl group, benzo [a] full Oranthenyl group, benzo [b] fluoranthenyl group, benzo [j] fluor Nteniru group, benzo [k] fluoranthenyl group, perylenyl group, naphthacenyl group, a biphenyl group and a terphenyl group.

  Among these monovalent hydrocarbon aromatic groups, a naphthyl group or a fluorenyl group is preferable.

  Examples of the unsubstituted divalent hydrocarbon aromatic group having 6 to 22 carbon atoms include divalent groups corresponding to the examples of the monovalent hydrocarbon aromatic group having 6 to 22 carbon atoms. (In other words, the hydrocarbon aromatic group mentioned in the example of the monovalent hydrocarbon aromatic group having 6 to 22 carbon atoms is divalent). Among these divalent hydrocarbon aromatic groups, a naphthalenediyl group or a fluorenediyl group is preferable as in the case of the monovalent group.

  Examples of the unsubstituted monovalent heteroaromatic group having 4 to 22 carbon atoms include thienyl group, pyrrolyl group, pyrazinyl group, pyridyl group, bipyridyl group, indolyl group, quinolyl group, isoquinolyl group, naphthyridinyl group. Group, acridinyl group, phenanthrolinyl, etc., carbazolyl group, benzo [a] carbazolyl group, benzo [b] carbazolyl group, benzo [c] carbazolyl group, phenazinyl group, phenoxazinyl group, phenothiazinyl group, benzothiophenyl group, Examples thereof include a dibenzothiophenyl group, a benzofuranyl group, a dibenzofuranyl group, an oxazolyl group, an oxadiazolyl group, an indolo [3,2,1-kl] phenoxazinyl group, and an indolo [3,2,1-jk] carbazolyl group.

  Examples of the unsubstituted divalent heteroaromatic group having 4 to 22 carbon atoms include divalent groups corresponding to the above examples of the monovalent heteroaromatic group having 4 to 22 carbon atoms (in other words, For example, the heteroaromatic group mentioned in the example of the monovalent heteroaromatic group having 4 to 22 carbon atoms is divalent).

In Ar ₁ and Ar ₂ , the substituent when the hydrocarbon aromatic group or the heteroaromatic group has a substituent is not limited, but an alkyl group, an arylamino group, an alkoxy group, a cyano group, a trifluoromethyl group A group selected from a monovalent hydrocarbon aromatic group and a monovalent heteroaromatic group is preferable.

When the substituent is an alkyl group, it is preferably an alkyl group having 1 to 6 carbon atoms. Specific examples thereof are the same as those exemplified in the examples of the alkyl group having 1 to 6 carbon atoms of R _{1 to} R ₄ in the formula [1], and include a methyl group, an ethyl group, an n-propyl group, an iso group. -Propyl group, n-butyl group, iso-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, iso-pentyl group, tert-pentyl group, neopentyl group, n-hexyl group, cyclohexyl group Can be mentioned. Among these alkyl groups, a methyl group or a tert-butyl group is more preferable.

  Examples of the arylamino group when the substituent is an arylamino group include the groups shown below.

  Examples of the alkoxy group when the substituent is an alkoxy group include a methoxy group, an ethoxy group, an isopropoxy group, and a tert-butoxy group. Among these alkoxy groups, a methoxy group is preferable.

When the substituent is a monovalent hydrocarbon aromatic group, it is preferably an unsubstituted monovalent hydrocarbon aromatic group having 6 to 22 carbon atoms. Specific examples thereof are the same as those exemplified in the examples of the unsubstituted monovalent hydrocarbon aromatic group having 6 to 22 carbon atoms of Ar ₁ and Ar ₂ in A.

When the substituent is a monovalent heteroaromatic group, it is preferably an unsubstituted monovalent heteroaromatic group having 4 to 22 carbon atoms. Specific examples thereof are the same as those exemplified in the examples of the unsubstituted monovalent heteroaromatic group having 4 to 22 carbon atoms of Ar ₁ and Ar ₂ in A.

  When the substituent is a monovalent hydrocarbon aromatic group or a monovalent heteroaromatic group, as compared with any of an alkyl group, an arylamino group, an alkoxy group, a cyano group, and a trifluoromethyl group, The π-conjugated system of the benzo [b] indolocarbazole ring is expanded, has a smaller S1 energy, and has a shallower HOMO level.

  In addition, the compound represented by the formula [1] according to the present invention is preferably used as a host material using a red phosphorescent material as a guest material. This is because the T1 energy in the benzoindolocarbazole monocycle is 527 nm in terms of wavelength. In the present invention and the present embodiment, the red phosphorescent light-emitting material is defined as having a maximum emission peak wavelength of a phosphorescence emission spectrum in a dilute solution in a range of 580 nm to 630 nm.

When the compound represented by the formula [1] according to the present invention is used as a host material using a red phosphorescent material as a guest material, the wavelength converted value of T1 energy of A is preferably less than 527 nm. That is, at least the T1 energy of the aromatic ring constituting the hydrocarbon aromatic group or heteroaromatic group in Ar ₁ and Ar ₂ is preferably less than 527 nm in terms of wavelength. This is because the T1 energy magnitude relationship is preferably host material> guest material so that T1 excitons are not quenched in the light emitting layer.

Table 3 shows T1 energy (wavelength conversion value) of typical aromatic rings. Among the aromatic rings shown in Table 3, the aromatic ring whose T1 energy wavelength conversion value is less than 527 nm is benzene or chrysene. That is, when the compound represented by the formula [1] according to the present invention is used as a host material using a red phosphorescent material as a guest material, the aromatic ring and heteroaromatic group of the hydrocarbon aromatic group in Ar ₁ and Ar ₂ Among the aromatic rings shown in Table 3, benzene, carbazole, dibenzothiophene, dibenzofuran, fluorene, triphenylene, biphenyl, phenanthroline, phenoxazine, anthraquinone, phenanthrene, indolophenoxazine, quinoline, naphthalene, picene , Preferably selected from chrysene.

  When the substituent is a monovalent hydrocarbon aromatic group or a monovalent heteroaromatic group, the aromatic ring of the monovalent hydrocarbon aromatic group and the monovalent heteroaromatic group The heteroaromatic ring is also preferably selected from benzene, carbazole, dibenzothiophene, dibenzofuran, fluorene, triphenylene, biphenyl, phenanthroline, phenoxazine, anthraquinone, phenanthrene, indolophenoxazine, quinoline, naphthalene, picene, and chrysene.

  The compound represented by the formula [1] according to the present invention can also be used as a host material of a light emitting layer using a fluorescent material as a guest material. In such a case, it is preferable to appropriately select a benzoindolocarbazole compound having S1 energy suitable for the emission wavelength of the fluorescent material that is the guest material, but there is no particular limitation on T1 energy. Therefore, a benzoindolocarbazole compound containing an aromatic ring having a T1 energy lower than that of a benzoindolocarbazole monocycle can also be used as a host material for a light-emitting layer using a fluorescent material as a guest material.

(Examples of benzoindolocarbazole compounds according to the present invention)
Specific structural formulas of the benzoindolocarbazole compound according to the present invention are exemplified below.

Among the exemplified compounds, the compounds represented by 101 to 157 have A at only the 12-position of the benzoindolocarbazole ring among the compounds represented by the formula [1], and Ar ₁ and Ar ₂ constituting A are both It is a hydrocarbon aromatic group which may have a substituent, and is a compound which does not have an aromatic ring having a T1 energy lower than that of the main skeleton benzoindolocarbazole ring. These first group compounds have a low S1 energy and a shallow HOMO level. Further, the T1 energy value is suitable for a host material of a light emitting layer using a red phosphorescent light emitting material as a guest material.

Among the exemplified compounds, the compounds represented by 201 to 226 have A at only the 12-position of the benzoindolocarbazole ring and at least of Ar ₁ and Ar ₂ constituting A among the compounds represented by the formula [1]. One of the compounds is a heteroaromatic group which may have a substituent. Since these second group compounds have at least one heteroaromatic ring in the molecule, the carrier mobility and the HOMO level can be easily fine-tuned. As in the first group, the red phosphorescent light emitting material is used as the guest material. It is suitable as a host material for the light emitting layer.

  Among the exemplified compounds, the compounds represented by 301 to 320 have A at least one of the 2-position, 5-position, and 11-position of the benzoindolocarbazole ring among the benzoindolocarbazole compounds represented by the formula [1]. A compound. Similar to the compounds of the first group, these third group compounds are also suitable as a host material for a light emitting layer having a low S1 energy and a low HOMO level and a T1 energy value of which a red phosphorescent material is a guest material. .

  Among the exemplified compounds, the compounds represented by 401 to 411 are compounds having A at the 12-position of the benzoindolocarbazole ring among the compounds represented by the formula [1], and have a T1 higher than that of the main skeleton benzoindolocarbazole ring. It is a compound containing an aromatic ring with low energy. Although these S4 energies are low and the HOMO levels are shallow, the fourth group compounds are also suitable as the host material of the light emitting layer using the fluorescent light emitting material as the guest material because of the low T1 energy value. .

Among the exemplified compounds, the compounds represented by 501 to 507 include, among the benzoindolocarbazole compounds represented by the formula [1], at least one of Ar ₁ and Ar ₂ constituting A has an arylamino group as a substituent. It is a compound. These fifth group compounds are suitable for the material of the hole injecting and transporting layer because they have a shallower HOMO level than the first to fourth group compounds.

(Method for synthesizing benzoindolocarbazole compound according to the present invention)
Next, a method for synthesizing the benzoindolocarbazole compound represented by the formula [1] according to the present invention will be described.

  As shown in the following formula [4], the benzoindolocarbazole compound represented by the formula [1] according to the present invention constructs a benzoindolocarbazole ring by intramolecular cyclization of a chloro derivative of 9-naphthylcarbazole by Heck reaction. Synthesized.

In [Equation [4], _{R 1} to _{R 4} are equal to _{R 1} to _{R 4} in the formula [1], respectively _{Z 1} to _{Z 4} is equal to _{R 1} to _{R 4,} the _{R 1} to _{R 4} Reactive groups necessary for introduction are shown. ]

The site where R _{1 to} R ₄ are introduced into the benzoindolocarbazole ring after cyclization, that is, Z _{1 to} Z ₄ in formula [4], is the desired R _{1 to} R ₄ , or R ₁ to R after the cyclization reaction. A reactive group for introducing ₄ may be introduced in advance before the cyclization reaction. A desired benzoindolocarbazole compound of the present invention can be synthesized by appropriately selecting Z _{1 to} Z ₄ .

  The reactive group for introducing A after the cyclization reaction is preferably a methoxy group. When a methoxy group is used as a reactive group, for example, one of the benzoindolocarbazole compounds according to the present invention can be synthesized as shown in the following formula [5].

[In Formula [5], A is equal to the group shown in Formula [2]. ]

  Further, when the compound according to the present invention is used in an organic light emitting device, sublimation purification is preferred as the last purification. This is because sublimation purification has a large purification effect in purifying organic compounds. In such sublimation purification, in general, the higher the molecular weight of the organic compound, the higher the sublimation temperature, which tends to cause thermal decomposition at a high temperature. Therefore, when the compound represented by the formula [1] according to the present invention is used in an organic light emitting device, the molecular weight of the compound represented by the formula [1] is 1000 or less so that sublimation purification can be performed without excessive heating. It is preferable that

(About the organic light emitting device according to the present invention)
Next, the organic light emitting device according to the present invention will be described.

  The organic light emitting device according to the present invention is an organic light emitting device having a pair of electrodes (anode and cathode) facing each other and an organic compound layer disposed between the pair of electrodes, wherein the organic compound layer is represented by the formula [1]. It has the benzoindolocarbazole compound shown in the above.

  The organic compound layer may be a single layer or a plurality of layers.

As an element structure of the organic light emitting element according to the present invention, a multilayer element structure in which the following layers are sequentially laminated on a substrate can be given.
(1) Anode / light emitting layer / cathode (2) Anode / hole transport layer / light emitting layer / electron transport layer / cathode (3) Anode / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode ( 4) Anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / cathode (5) Anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode ( 6) Anode / hole transport layer / electron blocking layer / light emitting layer / hole blocking layer / electron transport layer / cathode However, these device configuration examples are very basic device configurations, and the compounds according to the present invention are used. However, the structure of the organic light emitting device is not limited to these.

  For example, an insulating layer is provided at the interface between the electrode and the organic compound layer, an adhesive layer or an interference layer is provided, the electron transport layer or the hole transport layer is composed of two layers having different ionization potentials, and the light emitting layer has a different light emitting material. Various layer configurations such as two layers can be adopted.

  In this case, the element form may be a so-called bottom emission method in which light is extracted from an electrode on the substrate side, a so-called top emission method in which light is extracted from the opposite side of the substrate, or a double-sided extraction configuration.

  Of the above element configurations, the configuration (6) having both an electron blocking layer and a hole blocking layer is preferably used. In the configuration (6), since both the hole and electron carriers can be confined in the light emitting layer, a light emitting element having no light leakage and high light emission efficiency can be obtained.

  Among the organic compound layers, a layer having a light emitting material is a light emitting layer. The light emitting layer may be composed of one type of compound or may be composed of a plurality of types of compounds. When the light emitting layer is composed of a plurality of types of compounds, the compound having the largest weight ratio among all the compounds constituting the light emitting layer can be referred to as a main component, and components other than the main component can be referred to as subcomponents. Can be called. The main component may be called a host material. Examples of subcomponents include guest (dopant) materials, light emission assist materials, and charge injection materials.

  Here, the host material is a compound that exists as a matrix around the guest material in the light emitting layer, and is a compound that plays a role of transporting carriers to the guest material or supplying excitation energy to the guest material. The guest material is a compound responsible for main light emission as an element in the light emitting layer. The light emission assist material is a compound having a weight ratio smaller than that of the host material in the light emitting layer and assisting the light emission of the guest material, and is also referred to as a second host material.

  The concentration of the guest material with respect to the host material is 0.01 wt% or more and 50 wt% or less, preferably 0.1 wt% or more and 20 wt% or less with respect to the total weight of all the materials constituting the light emitting layer. More preferably, it is 0.1 wt% or more and 10 wt% or less in order to prevent concentration quenching.

  The benzoindolocarbazole compound represented by the formula [1] is any of a light emitting layer, a hole injection layer, a hole transport layer, an electron blocking layer, a hole blocking layer, an electron transport layer, or an electron injection layer of an organic light emitting device. Although it may be used for this layer, it is preferably used for the light emitting layer. Of the benzoindolocarbazole compounds represented by the formula [1], those preferably used as the hole injection layer or the hole transport layer are as shown in the fifth group of the exemplary compounds of the present invention described above. A compound having an arylamino substituent and a shallow HOMO level.

  Further, the benzoindolocarbazole compound represented by the formula [1] is preferably used as a host material of the light emitting layer, and more preferably used as a host material of the light emitting layer using a phosphorescent light emitting material as a guest material. In such a case, the guest material is preferably selected from metal complexes such as an iridium complex, a platinum complex, a rhenium complex, a copper complex, a europium complex, and a ruthenium complex. Among these, an iridium complex having strong phosphorescence intensity Is particularly preferred. Among these, a red phosphorescent material having an emission peak wavelength in the range of 580 nm to 630 nm is preferable. In addition, the light emitting layer may include a plurality of phosphorescent materials for the purpose of assisting the transmission of excitons and carriers.

  Specific examples of the iridium complex that can be used as the phosphorescent material of the organic light emitting device according to the present invention are shown below, but the present invention is not limited thereto.

  Examples of guest materials other than the above metal complexes include condensed ring compounds (eg, fluorene derivatives, naphthalene derivatives, pyrene derivatives, perylene derivatives, tetracene derivatives, anthracene derivatives, rubrene, etc.), quinacridone derivatives, coumarin derivatives, stilbene derivatives. And organic aluminum complexes such as tris (8-quinolinolato) aluminum, organic beryllium complexes, and polymer derivatives such as poly (phenylene vinylene) derivatives, poly (fluorene) derivatives, poly (phenylene) derivatives, and the like.

  The light emitting layer included in the organic light emitting device according to the present embodiment includes a light emitting layer in which the guest material and the host material are uniformly present throughout the light emitting layer, or the guest material and the host material have a concentration gradient independently of each other. It may exist in the inside.

  The hole injection layer is a layer adjacent to the anode and into which holes are injected from the anode, and the hole transport layer is a layer for transporting holes to the light emitting layer. The compounds possessed by these layers include low molecular weight compounds such as triarylamine derivatives, phenylenediamine derivatives, stilbene derivatives, phthalocyanine derivatives, porphyrin derivatives, and conductive polymers such as poly (vinylcarbazole) and poly (thiophene). Is mentioned.

  The electron injection layer is a layer adjacent to the cathode and into which electrons are injected from the cathode, and the electron transport layer is a layer for transporting electrons to the light emitting layer. Examples of the compound included in these layers include oxadiazole derivatives, oxazole derivatives, pyrazine derivatives, triazole derivatives, triazine derivatives, quinoline derivatives, quinoxaline derivatives, phenanthroline derivatives, and organoaluminum complexes.

  The anode is preferably a material having a large work function. 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 Examples thereof include metal oxides such as indium and conductive polymers such as polyaniline, polypyrrole, and polythiophene. The anode may be made of one kind of material, or may be made of a mixture of two or more kinds of materials. Moreover, the anode may be composed of a single layer or a plurality of layers.

  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, simple metals such as aluminum, titanium, manganese, silver, lead, and chromium, and alloys obtained by combining these simple metals. Examples of the alloy include magnesium-silver, aluminum-lithium, aluminum-magnesium and the like. Moreover, you may use metal oxides, such as an indium tin oxide (ITO), as a material which comprises a cathode. The cathode may be made of one kind of material or may be made of a material obtained by mixing two or more kinds of materials. Moreover, the cathode may be composed of a single layer or a plurality of layers.

  The organic light emitting device according to the present embodiment preferably emits red phosphorescence, but the organic light emitting device according to the present invention may emit other colors (green, blue, etc.) or emit white light. Good.

When the organic light emitting device according to the present embodiment is a white light emitting device, the light emitting layer can be configured as shown in the following examples, but is not limited thereto.
(1) Single layer: element containing blue, green and red light emitting materials (2) Single layer: element containing light blue and yellow light emitting materials (3) Two layers: including blue light emitting layer and green and red light emitting materials Light emitting layer or laminated element of red light emitting layer and light emitting layer containing blue and green light emitting materials (4) 2 layers: laminated element of light emitting layer and yellow light emitting layer (5) 3 layers: blue light emitting layer and green Laminated element of light emitting layer and red light emitting layer

  The white color according to the present embodiment includes pure white (color temperature is 4200K), day white (color temperature is 5000K), and the like. Further, the color temperature of white according to the present embodiment is not less than 3000K and not more than 9500K. The emission color of the white organic light emitting device according to this embodiment is C.I. I. E. In the chromaticity coordinates, x is in the range of 0.25 to 0.50, and y is in the range of 0.30 to 0.42.

  In the organic light emitting device according to the present invention, the layer containing the organic compound according to the present invention and the layer made of other organic compounds are known by being dissolved in a vacuum deposition method, ionization deposition method, sputtering, plasma, or an appropriate solvent. The coating method (for example, spin coating, dipping, casting method, LB method, ink jet method, etc.) can be used.

  When a layer is formed by a vacuum vapor deposition method, a solution coating method, or the like, crystallization 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.

  FIG. 1 is an example of a white organic light emitting device according to this embodiment, and is a schematic cross-sectional view of an organic light emitting device having a configuration in which light emitting layers are stacked. In the drawing, an organic light emitting device in which three light emitting layers emit different colors is illustrated.

  A substrate such as glass has an anode 1, a hole injection layer 2, a hole transport layer 3, a blue light emitting layer 4, a green light emitting layer 5, a red light emitting layer 6, an electron transport layer 7, an electron injection layer 8, and a cathode 9. Arranged in order.

  In the organic light emitting device that emits white light according to the present embodiment, the light emitting layer is arranged in order of the blue light emitting layer, the green light emitting layer, and the red light emitting layer from the anode side. The order of stacking is not limited.

  The organic light emitting element that emits white light according to the present embodiment is not limited to a configuration in which a plurality of light emitting layers are stacked and may be arranged side by side. When a plurality of light emitting layers are arranged side by side, any light emitting layer may be arranged in contact with a common hole transport layer and / or electron transport layer.

(Applications of organic light emitting devices)
The organic light emitting device according to this embodiment includes a display unit of a display device, an image information processing device, a light source of an illumination device, an exposure light source of an electrophotographic image forming device, a backlight of a liquid crystal display device, and a white color using a color filter. It can be used as a light emitting part of a light source.

  The display device according to the present embodiment includes a plurality of pixels in the display unit, and at least one of the plurality of pixels is connected to the organic light emitting element according to the present embodiment and the organic light emitting element. An element.

  The active element controls the light emission luminance of the display unit, and examples thereof include transistors such as TFT elements and MIM elements. When the active element is a transistor, the anode or cathode of the organic light emitting element and the drain electrode or source electrode of the transistor are connected.

  Examples of such display devices include image display devices such as PCs, head mounted displays, and mobile phones. The displayed image may be a two-dimensional image or a three-dimensional image.

  FIG. 2 is a schematic cross-sectional view of the display device according to the present embodiment. The display device of this figure has two organic light emitting elements and two TFT elements (thin film transistor elements), one organic light emitting element is connected to one TFT element, and the other organic light emitting element is the other. Connected to the TFT element.

  2, 30 is a display device, 31 is a substrate, 32 is a moisture-proof layer, 33 is a gate electrode, 34 is a gate insulating layer, 35 is a semiconductor layer, 36 is a drain electrode, 37 is a source electrode, and 38 is a switching element. A TFT element, 39 is an insulating layer, and 40 is an organic light emitting element. Further, 310 is a contact hole, 311 is an anode, 312 is an organic compound layer, 313 is a cathode, 314 is a first protective layer, and 315 is a second protective layer.

  The display device 30 includes a substrate 31, a moisture-proof layer 32 present on the surface of the substrate 31, a TFT element 38 present in contact with the moisture-proof layer 32, an organic light-emitting element 40 connected to the TFT element 38, and a TFT element 38. And a first protective layer 314 and a second protective layer 315 having a function of protecting the organic light emitting element 40.

  The substrate 31 is a member that supports the display device 30.

  The moisture-proof layer 32 protects the TFT element 38 and the organic light emitting element 40. Examples of the moisture-proof layer 32 include silicon oxide and a composite of silicon oxide and silicon nitride. When the substrate 31 also functions as the moisture-proof layer 32, such as when the material constituting the substrate 31 is the same as the material that constitutes the moisture-proof layer 32, the moisture-proof layer 32 may not be present.

  The TFT element 38 includes a gate electrode 33, a gate insulating layer 34, a semiconductor layer 35, a drain electrode 36, and a source electrode 37.

  The gate electrode 33 is present on the surface of the moisture-proof layer 32. Examples of the material constituting the gate electrode include metals such as Cr. The gate electrode 33 can be formed by a method such as sputtering.

  The gate insulating layer 34 is present so as to cover the gate electrode 33. Examples of the material constituting the gate insulating layer 34 include silicon oxide. The gate insulating layer 34 can be formed by a plasma CVD method or a catalytic chemical vapor deposition method (cat-CVD method).

  The semiconductor layer 35 exists on the surface of the gate insulating film 34. The semiconductor layer 35 may be made of any material of an inorganic semiconductor material, an organic semiconductor material, and a hybrid material of an inorganic semiconductor material and an organic semiconductor material. When the semiconductor layer 35 is made of silicon, which is an inorganic semiconductor material, silicon is formed by plasma CVD or the like (in some cases, annealed at a temperature of, for example, 290 ° C. or higher) and patterned according to the circuit shape. It can also be obtained.

  The drain electrode 36 and the source electrode 37 are in contact with the semiconductor layer 35. Examples of the material constituting the drain electrode 36 and the source electrode 37 include Cr, platinum, and gold. The organic light emitting device 40 includes an anode 311, an organic compound layer 312, and a cathode 313.

  The insulating layer 39 exists between the TFT element 38 and the organic light emitting element 40. Examples of the material constituting the insulating layer 39 include silicon oxide. A contact hole (through hole) 310 is provided in the insulating layer 39, and the presence of the contact hole 310 connects the anode 311 of the organic light emitting element 40 and the source electrode 37.

  The first protective layer 314 and the second protective layer 315 may be present to prevent deterioration of the organic light emitting element 40. The materials of the first protective layer 314 and the second protective layer 315 can be independently selected from inorganic materials and organic materials. The inorganic material is, for example, silicon oxide or aluminum oxide. The organic material is, for example, a polymer material. The first protective layer 314 and the second protective layer 315 may be the same or different.

  The organic light emitting element according to this embodiment included in the display device according to this embodiment is any one of a red light emitting element, a green light emitting element, a blue light emitting element, and a white light emitting element. Among these, a red light emitting element is preferable, and a red light emitting element having a red phosphorescent light emitting material as a guest material is more preferable. In addition, when the organic light-emitting element according to this embodiment included in the display device according to this embodiment is a white light-emitting element, the red component constituting white is caused by a red phosphorescent light-emitting material that is a guest material. Is preferred.

  The image information processing apparatus according to this embodiment includes the display device described above as a display unit that displays an input image, and an input for inputting image information from an area CCD, a linear CCD, a memory card, or the like to the display device. An image information processing apparatus having a unit. Examples of such an image information processing apparatus include a digital camera and a digital video camera. In these cases, an imaging unit having an imaging optical system for imaging can be referred to as an input unit. Note that the display unit included in the image information processing apparatus may have a touch panel function. When the image information processing apparatus has a touch panel function, the driving method of the touch panel function is not particularly limited. The image information processing apparatus may be a multi-function printer having a display unit.

  The lighting device according to the present embodiment includes an organic light emitting element and an AD converter circuit for supplying a driving voltage to the organic light emitting element. The illuminating device may illuminate the room or illuminate the outdoors. The lighting device may emit white, day white, or any other color from blue to red. The lighting device may have a color filter. Here, the AD converter circuit is a circuit that converts an AC voltage into a DC voltage. When the lighting device emits white, the light emitting layer of the organic light emitting element has a plurality of layers, the layer in which the benzoindolocarbazole compound according to the present invention is present emits red, and the other layers emit other than red. , Emits white as an element.

  An image forming apparatus according to the present embodiment includes a photosensitive member, a charging unit that charges the surface of the photosensitive member, an exposure unit that exposes the photosensitive member, and a developer that develops an electrostatic latent image formed on the surface of the photosensitive member. The exposure unit includes the organic light emitting element according to the present embodiment. The exposure unit includes a plurality of organic light emitting devices according to the present embodiment arranged in a line, and each organic light emitting device is independently controlled by a control unit.

  The light emitting luminance of the organic light emitting device according to this embodiment is controlled by a TFT device which is an example of a switching device. By providing a plurality of organic light emitting elements in the plane, an image can be displayed according to the light emission luminance of each organic light emitting element.

  The switching element included in the organic light emitting element according to the present embodiment is not limited to the TFT element, and an active matrix driver is formed on a substrate such as a transistor, an MIM element, or a Si substrate, and the organic light emitting element is provided on the active matrix driver. Form may be sufficient.

  This is selected depending on the definition. For example, in the case of a definition of 1 inch and QVGA, it is preferable to provide an organic light emitting element on the Si substrate.

  By driving the display device using the organic light emitting element according to the present embodiment, it is possible to perform stable display even with long-time display with good image quality.

<Example 1> (Synthesis of Exemplified Compound No. 117)
(1) Synthesis of intermediate BICz-OTf

The following reagents and solvents were put into a 300 mL eggplant flask.
1-chlorocarbazole: 6.00 g (29.8 mmol)
2-Bromo-6-methoxynaphthalene: 7.76 g (32.7 mmol)
Tris (dibenzylideneacetone) dipalladium: 1.37 g (1.49 mmol)
Tri-tert-butylphosphine: 0.602 g (2.98 mmol)
tert-Butoxy sodium: 4.29 g (44.6 mmol)
Toluene: 180 mL
The reaction solution was heated at 100 ° C. for 5 hours with stirring under nitrogen. After completion of the reaction, the reaction solution was washed with a saturated aqueous sodium chloride solution, dried over sodium sulfate and then concentrated to obtain a crude product. Next, this crude product was dissolved by heating in a toluene solvent, gel-filtered with a small amount of silica gel to remove the Pd catalyst, and then purified by recrystallization with a mixed solvent of toluene / heptane = 1/1. 8.22 g of chloro-9 (6-methoxynaphthalen-2-yl) carbazole was obtained (yield 77%).

Subsequently, the reagent shown below was put into a 300 mL eggplant flask and the inside of the eggplant flask was replaced with nitrogen.
1-chloro-9 (6-methoxynaphthalen-2-yl) carbazole: 7.70 g (21.5 mmol)
Palladium acetate: 194 mg (0.863 mmol)
Tricyclohexylphosphonium tetrafluoroborate: 636 mg (1.73 mmol)
Potassium carbonate: 5.97 g (43.2 mmol)

  Next, 120 mL of N, N-dimethylacetamide that had been bubbled with nitrogen was added, and the reaction solution was heated at 130 ° C. for 5 hours with stirring under nitrogen. After cooling the reaction solution, water was added and stirred, and the precipitated crystals were collected by filtration to obtain a crude product. Next, this crude product was dissolved by heating in a toluene solvent, gel-filtered with a small amount of silica gel to remove the Pd catalyst, purified by recrystallization from a toluene / heptane mixed solvent, and the intermediate BICz- Obtained 5.72 g of OMe (82% yield).

Subsequently, the following reagents and solvent were charged into a 500 mL eggplant flask.
BICz-OMe: 5.08 g (15.8 mmol)
Dehydrated dichloromethane: 300 mL
To this reaction solution, 19.0 mL (19.0 mmol) of BBr ₃ (1M dichloromethane solution) was added dropwise over 2 minutes while stirring under nitrogen, and stirring was continued overnight at room temperature. Then, methanol was added to stop the reaction. Next, dichloromethane was distilled off from the reaction solution and concentrated, and the resulting precipitate was collected by filtration and washed with methanol on a filter to obtain 3.73 g of intermediate BICz-OH (yield 77%).

Subsequently, the following reagents and solvent were charged into a 500 mL eggplant flask.
BICz-OH: 3.47 g (11.3 mmol)
Pyridine: 1.79 g (22.6 mmol)
Dehydrated dichloromethane: 210 mL
The reaction solution was cooled to 0 ° C. with stirring under nitrogen, and a solution obtained by diluting 2.47 mL (14.7 mmol) of trifluoromethanesulfonic anhydride with 30 mL of dichloromethane was added dropwise from a dropping funnel over 10 minutes. Added to the reaction solution. After completion of the dropwise addition, stirring was further continued at 0 ° C. for 1 hour, and then water was added to stop the reaction. Subsequently, the reaction solution was washed with a saturated aqueous sodium chloride solution, dried over sodium sulfate, and then concentrated to obtain a crude product. Next, this crude product was purified by silica gel column chromatography (developing solvent: heptane / toluene = 1/1) to obtain 4.67 g of intermediate BICz-OTf (yield 94%).

Further, BICz-OTf was identified by ¹ H-NMR measurement.
[ ¹ H-NMR (400 MHz, CDCl ₃ )]
δ 8.97 (s, 1H), 8.90 (s, 1H), 8.41 (d, 1H), 8.37-8.23 (m, 5H), 7.72 (d, 1H), 7.71-7.65 (m, 2H), 7.46 (t, 1H).

  (2) Exemplified Compound No. Synthesis of 117

The following reagents and solvents were put into a 100 mL eggplant flask.
BICz-OTf: 500 mg (1.14 mmol)
Bpin-1: 433 mg (1.14 mmol)
Tetrakis (triphenylphosphine) palladium (0): 39 mg (34 μmol)
Toluene: 16 mL
Ethanol: 8mL
10wt% sodium carbonate aqueous solution: 8mL
The reaction solution was heated to reflux for 3 hours with stirring under nitrogen. After completion of the reaction, water was added to the reaction solution and stirred, and the precipitated crystals were collected by filtration and washed with water, methanol and acetone to obtain a crude product. Next, the crude product is dissolved in xylene with heating, and gel-filtered with a small amount of silica gel while hot. The filtrate is concentrated and recrystallized with a xylene solvent, and the obtained crystals are vacuum-dried at 150 ° C. 383 mg of Exemplified Compound No. 117 was obtained (synthesis yield 62%). Subsequently, sublimation purification was performed under conditions of 10 ⁻⁴ Pa and 380 ° C., and high-purity Example Compound No. 338 mg of 117 was obtained.

The obtained compound was identified by mass spectrometry.
[MALDI-TOF-MS (Matrix Assisted Ionization-Time of Flight Mass Spectrometry)]
Actual value: m / z = 543.19 Calculated value: C ₄₂ H ₂₅ N = 543.20

Next, Exemplified Compound No. About 117, S1 energy was measured with the following method.
Exemplified Compound No. 117 was heated and deposited on a glass substrate to obtain a deposited thin film having a thickness of 30 nm. About this vapor deposition thin film, the absorption spectrum was measured using the ultraviolet visible spectrophotometer (JASCO Corporation V-560). The absorption edge of the obtained absorption spectrum was determined to be 443 nm. The S1 energy of 117 was 2.80 eV.

  Furthermore, Exemplified Compound No. For 117, the ionization potential was measured by the following method.

Next, Exemplified Compound No. For 117, the ionization potential was measured by the following method. Exemplified Compound No. 117 was heated and deposited on an AlNd substrate to obtain a deposited thin film having a thickness of 30 nm. About this vapor deposition thin film, ionization potential was measured on the following measurement conditions with photoelectron spectrometer AC-3 (made by Riken Keiki Co., Ltd.).
Measurement environment: room temperature, under nitrogen Measurement light intensity: 0.5 nW
Measurement energy range: 5.0 to 7.0 eV
Step: 0.05eV
Measurement time: 10sec / 1 energy point
As a result of the measurement, Exemplified Compound No. The ionization potential of 117 was 5.80 eV.

  <Example 2> (Synthesis of Exemplified Compound No. 131)

The following reagents and solvents were put into a 100 mL eggplant flask.
BICz-OTf: 700 mg (1.59 mmol)
Bpin-2: 841 mg (1.64 mmol)
Tetrakis (triphenylphosphine) palladium (0): 55 mg (48 μmol)
Toluene: 20 mL
Ethanol: 10mL
10 wt% sodium carbonate aqueous solution: 10 mL
The reaction solution was heated to reflux for 2 hours and half with stirring under nitrogen. After completion of the reaction, water was added to the reaction solution and stirred, and the precipitated crystals were collected by filtration and washed with water, ethanol and hexane to obtain a crude product. Next, this crude product was dissolved in 200 mL of toluene by heating, and then gel-filtered with a small amount of silica gel while hot. The filtrate was concentrated and recrystallized with a xylene solvent, and the resulting crystals were vacuum-dried at 150 ° C. 826 mg of Exemplified Compound No. 131 was obtained (synthesis yield 77%). Some of them were purified by sublimation under conditions of 10 ⁻⁴ Pa and 380 ° C. 290 mg of 131 was obtained.

The obtained compound was identified by mass spectrometry.
[MALDI-TOF-MS]
Actual value: m / z = 675.36 Calculated value: C ₅₂ H ₃₇ N = 675.29

  In addition, Exemplified Compound No. 131 was measured for S1 energy in the same manner as in Example 1. As a result, the absorption edge of the absorption spectrum was 432 nm. The energy gap of 131 was 2.87 eV.

  Furthermore, Exemplified Compound No. When the ionization potential of No. 131 was measured in the same manner as in Example 1, Exemplified Compound No. 131 was used. The ionization potential of 131 was 5.74 eV.

  <Example 3> (Synthesis of Exemplified Compound No. 202)

The following reagents and solvents were put into a 50 mL eggplant flask.
BICz-OTf: 300 mg (0.683 mmol)
4-Dibenzothiopheneboronic acid: 163 mg (0.717 mmol)
Tetrakis (triphenylphosphine) palladium (0): 24 mg (20 μmol)
Toluene: 10 mL
Ethanol: 5mL
10wt% sodium carbonate aqueous solution: 5mL
The reaction solution was heated to reflux for 4 hours with stirring under nitrogen. After completion of the reaction, water and ethanol were added to the reaction solution and stirred, and the precipitated crystals were collected by filtration and washed with water, ethanol and hexane to obtain a crude product. Next, this crude product is heated and dissolved in toluene, gel-filtered while hot using a small amount of silica gel, the filtrate is concentrated, recrystallized with a toluene solvent, and the obtained crystals are vacuum-dried at 120 ° C. 233 mg of Exemplified Compound No. 202 was obtained (synthesis yield 72%). Subsequently, sublimation purification was performed under conditions of 10 ⁻⁴ Pa and 330 ° C., and high-purity Example Compound No. 150 mg of 202 was obtained.

The obtained compound was identified by mass spectrometry.
[MALDI-TOF-MS]
Actual value: m / z = 475.30 Calculated value: C ₃₄ H ₂₁ NS = 475.14

In addition, Exemplified Compound No. For S202, S1 energy was measured in the same manner as in Example 1. As a result, the absorption edge of the absorption spectrum was 427 nm. The energy gap of 202 was 2.90 eV.
Furthermore, Exemplified Compound No. When the ionization potential was measured in the same manner as in Example 1 for 202, Exemplified Compound No. The ionization potential of 202 was 5.88 eV.

  <Example 4> (Synthesis of Exemplified Compound No. 220)

The following reagents and solvents were put into a 100 mL eggplant flask.
BICz-OTf: 613 mg (1.39 mmol)
Bpin-3: 660 mg (1.44 mmol)
Tetrakis (triphenylphosphine) palladium (0): 48 mg (42 μmol)
Toluene: 20 mL
Ethanol: 10mL
10 wt% sodium carbonate aqueous solution: 10 mL
The reaction solution was heated to reflux for 4 hours with stirring under nitrogen. After completion of the reaction, water was added to the reaction solution and stirred, and the precipitated crystals were collected by filtration and washed with water, methanol and acetone to obtain a crude product. Next, this crude product was dissolved by heating in 500 mL of DMA and filtered while hot. After cooling the filtrate, the precipitated crystals were collected by filtration, and the obtained crystals were purified by recrystallization using a chlorobenzene solvent. The obtained crystals were vacuum dried at 150 ° C. to give 354 mg of Exemplified Compound No. 220 was obtained (synthesis yield 41%). Subsequently, sublimation purification was performed under conditions of 10 ⁻⁴ Pa and 400 ° C., and high-purity Example Compound No. 158 mg of 220 was obtained.

The obtained compound was identified by mass spectrometry.
[MALDI-TOF-MS]
Actual value: m / z = 622.36 Calculated value: C ₄₆ H ₂₆ N ₂ O = 622.20

  In addition, Exemplified Compound No. When S1 energy was measured for 220 in the same manner as in Example 1, the absorption edge of the absorption spectrum was 444 nm. The energy gap of 220 was 2.79 eV.

  Furthermore, Exemplified Compound No. When the ionization potential of No. 220 was measured in the same manner as in Example 1, Exemplified Compound No. The ionization potential of 220 was 5.73 eV.

  <Example 5> (Synthesis of Exemplified Compound No. 405)

The following reagents and solvents were put into a 50 mL eggplant flask.
BICz-OTf: 300 mg (0.683 mmol)
Bpin-4: 271 mg (0.717 mmol)
Tetrakis (triphenylphosphine) palladium (0): 24 mg (20 μmol)
Toluene: 10 mL
Ethanol: 5mL
10wt% sodium carbonate aqueous solution: 5mL
The reaction solution was heated to reflux for 3 hours with stirring under nitrogen. After completion of the reaction, Exemplified Compound Nos. Post-treatment and purification similar to the synthesis of 202 were performed, and 245 mg of Exemplified Compound No. 405 crystals were obtained (synthesis yield 66%). Subsequently, sublimation purification was performed under conditions of 10 ⁻⁴ Pa and 350 ° C., and high-purity Example Compound No. 161 mg of 405 was obtained.

The obtained compound was identified by mass spectrometry.
[MALDI-TOF-MS]
Actual value: m / z = 543.34 Calculated value: C ₄₂ H ₂₅ N = 543.20

  In addition, Exemplified Compound No. When S1 energy was measured for 405 in the same manner as in Example 1, the absorption edge of the absorption spectrum was 524 nm. The energy gap of 405 was 2.36 eV.

  Furthermore, Exemplified Compound No. When the ionization potential of 405 was measured by the same method as in Example 1, Exemplified Compound No. 405 was obtained. The ionization potential of 405 was 5.59 eV.

<Example 6> (Synthesis of Exemplified Compound No. 502)
(1) Synthesis of intermediate BICz-Bpin

The following reagents and solvents were put into a 100 mL eggplant flask.
BICz-OTf: 1.00 g (2.28 mmol)
Bis (pinacolato) diboron: 868 mg (3.42 mmol)
Bis (dibenzylideneacetone) dipalladium (0): 66 mg (0.114 mmol)
Tricyclohexylphosphine: 96 mg (0.342 mmol)
Potassium acetate: 0.67 g (6.84 mmol)
1,4-dioxane: 40 mL
The reaction solution was stirred at 92 ° C. for 5 hours under nitrogen. After completion of the reaction, toluene was added to the reaction solution, the salt was removed by filtration, the filtrate was washed with water, dried over sodium sulfate and concentrated to obtain a crude product. Next, this crude product was purified by silica gel column chromatography (developing solvent: toluene / heptane = 2/1) to obtain 810 mg of intermediate BICz-Bpin (yield 85%).

  (2) Exemplified Compound No. Synthesis of 502

The following reagents and solvents were put into a 50 mL eggplant flask.
BICz-Bpin: 400 mg (0.959 mmol)
DPFLAm-Br: 402 mg (0.913 mmol)
Tetrakis (triphenylphosphine) palladium (0): 32 mg (27 μmol)
Toluene: 12 mL
Ethanol: 6mL
10wt% sodium carbonate aqueous solution: 6mL
The reaction solution was heated to reflux for 5 hours with stirring under nitrogen. After completion of the reaction, Exemplified Compound Nos. Post-treatment and purification similar to the synthesis of 202 were performed, and 430 mg of Exemplified Compound No. 502 crystals were obtained (synthesis yield 69%). Subsequently, sublimation purification was performed under conditions of 10 ⁻⁴ Pa and 360 ° C., and high-purity Example Compound No. 311 mg of 502 was obtained.

The obtained compound was identified by mass spectrometry.
[MALDI-TOF-MS]
Actual measurement value: m / z = 650.38 Calculation value: C ₄₉ H ₃₄ N ₂ = 650.27
In addition, Exemplified Compound No. For 502, S1 energy was measured in the same manner as in Example 1. As a result, the absorption edge of the absorption spectrum was 444 nm. The energy gap of 502 was 2.79 eV.
Furthermore, Exemplified Compound No. When the ionization potential was measured in the same manner as in Example 1 for 502, Exemplified Compound No. The ionization potential of 502 was 5.59 eV.

  <Example 7> (Synthesis of Exemplified Compound No. 148)

(1) Synthesis of DtBuBICz-OTf In Example 1 (1), 3,6-di-tert-butyl-1-chlorocarbazole was used instead of 1-chlorocarbazole, and other than this, Example 1 (1) and The intermediate DtBuBICz-OTf was synthesized by the same method.

(2) Exemplified Compound No. Synthesis of 148 The following reagents and solvent were charged into a 100 mL eggplant flask.
DtBuBICz-OTf: 300 mg (0.544 mmol)
Bpin-2: 293 mg (0.571 mmol)
Tetrakis (triphenylphosphine) palladium (0): 19 mg (16 μmol)
Toluene: 10 mL
Ethanol: 5mL
10wt% sodium carbonate aqueous solution: 5mL
The reaction solution was heated to reflux for 3 hours with stirring under nitrogen. After completion of the reaction, Exemplified Compound Nos. Post-treatment and purification similar to the synthesis of 131 were performed, and 347 mg of Exemplified Compound No. 148 crystals were obtained (81% synthesis yield). Subsequently, sublimation purification was performed under conditions of 10 ⁻⁴ Pa and 365 ° C., and high-purity Example Compound No. 270 mg of 148 was obtained.

The obtained compound was identified by mass spectrometry.
[MALDI-TOF-MS]
Actual value: m / z = 787.52 Calculated value: C ₆₀ H ₅₃ N = 787.42
In addition, Exemplified Compound No. 148 was measured for S1 energy in the same manner as in Example 1. As a result, the absorption edge of the absorption spectrum was 436 nm. The energy gap of 148 was 2.84 eV.
Furthermore, Exemplified Compound No. When the ionization potential was measured for 148 in the same manner as in Example 1, Exemplified Compound No. 148 was measured. The ionization potential of 148 was 5.64 eV.

  <Example 8> (Synthesis of Exemplified Compound No. 305)

(1) Synthesis of Intermediate IM-305-1 The following reagents and solvent were charged into a 100 mL eggplant flask.
3,6-dibromocarbazole: 500 mg (1.54 mmol)
Bpin-5: 1.03 g (3.23 mmol)
Tetrakis (triphenylphosphine) palladium (0): 89 mg (77 μmol)
Toluene: 30 mL
Ethanol: 15mL
10 wt% sodium carbonate aqueous solution: 15 mL
The reaction solution was heated to reflux for 4 hours with stirring under nitrogen. After completion of the reaction, water and ethanol were added to the reaction solution and stirred, and the precipitated crystals were separated by filtration and washed with water, ethanol and hexane to obtain a crude product. Next, this crude product was heated and dissolved in toluene, and then subjected to gel filtration while hot using a small amount of silica gel. The filtrate was concentrated and then recrystallized with a toluene solvent to obtain 721 mg of IM-305-1 (synthesis). Yield 85%).

(2) Synthesis of Intermediate IM-305-2 The following reagents and solvent were charged into a 100 mL eggplant flask.
IM-305-1: 500 mg (0.906 mmol)
2,3-Dibromonaphthalene: 285 mg (0.997 mmol)
Tris (dibenzylideneacetone) dipalladium: 41 mg (45 μmol)
Tri-tert-butylphosphine: 18 mg (91 μmol)
tert-Butoxy sodium: 131 mg (1.36 mmol)
Toluene: 20 mL
The reaction solution was heated at 100 ° C. for 3 hours with stirring under nitrogen. After completion of the reaction, the reaction solution was washed with a saturated aqueous sodium chloride solution, dried over sodium sulfate and then concentrated to obtain a crude product. Next, this crude product was dissolved by heating in a toluene solvent, gel-filtered with a small amount of silica gel to remove the Pd catalyst, and then purified by recrystallization with toluene to obtain 424 mg of IM-305-2 ( Yield 62%).

(3) Exemplified Compound No. Synthesis of 305 The reagent shown below was put into a 50 mL eggplant flask and the inside of the eggplant flask was replaced with nitrogen.
IM-305-2: 424 mg (0.560 mmol)
Palladium acetate: 3.8 mg (17 μmol)
Tricyclohexylphosphonium tetrafluoroborate: 12.4 mg (34 μmol)
Potassium carbonate: 155 mg (1.12 mmol)

Next, 8 mL of N, N-dimethylacetamide that had been bubbled with nitrogen was added, and the reaction solution was heated at 130 ° C. for 4 hours with stirring under nitrogen. After cooling the reaction solution, water was added and stirred, and the precipitated crystals were collected by filtration to obtain a crude product. Next, this crude product was dissolved by heating in a toluene solvent, gel-filtered using a small amount of silica gel to remove the Pd catalyst, and then purified by recrystallization from a toluene solvent. 305 crystals were obtained (synthesis yield 80%). Subsequently, sublimation purification was performed under conditions of 10 ⁻⁴ Pa and 380 ° C., and high-purity Example Compound No. 210 mg of 305 was obtained.

The obtained compound was identified by mass spectrometry.
[MALDI-TOF-MS]
Actual value: m / z = 675.44 Calculated value: C ₅₂ H ₃₇ N = 675.29

  In addition, Exemplified Compound No. When S1 energy was measured for 305 in the same manner as in Example 1, the absorption edge of the absorption spectrum was 440 nm. The energy gap of 305 was 2.82 eV.

  Furthermore, Exemplified Compound No. When the ionization potential was measured in the same manner as in Example 1 for 305, Exemplified Compound No. 305 was measured. The ionization potential of 305 was 5.72 eV.

<Comparative Example 1> (Comparison of T1 energy and ionization potential)
For the comparative compounds CBP and A2 shown below, S1 energy and ionization potential were measured in the same manner as in Example 1. The results are shown in Table 4 together with the results of Examples 1 to 8.

  From Table 4, the exemplary compounds of the present invention have low S1 energy and low ionization potential (shallow HOMO level). And the exemplary compound of this invention has S1 energy smaller than the comparison compounds CBP and A2, and its ionization potential is also small. This difference is the difference in the main skeleton of the molecule. The benzoindolocarbazole, which is the main skeleton of the compound of the present invention, has an S1 energy lower than that of the carbazole main skeleton (CBP) or indolocarbazole (A2), and has a HOMO level. This is due to the shallow main skeleton.

<Example 9>
In this example, an organic light emitting device having a structure in which an anode / hole transport layer / electron blocking layer / light emitting layer / hole blocking layer / electron transport layer / cathode were sequentially provided on a substrate was produced by the following method. .

A transparent conductive support substrate (IZO substrate) obtained by depositing IZO as a positive electrode with a film thickness of 100 nm on a glass substrate was used. On this IZO substrate, the following organic compound layer and electrode layer were continuously formed by vacuum evaporation by resistance heating in a vacuum chamber of 10 ⁻⁵ Pa. At this time, the opposing electrode area was 3 mm ² .
Hole transport layer (50 nm) HTL-1
Electron blocking layer (10 nm) EBL-1
Light emitting layer (30 nm) Host material: Exemplified Compound No. 117, Guest material: Ir-1 (4 vol%)
Hole blocking layer (10 nm) HBL-1
Electron transport layer (50 nm) ETL-1
Metal electrode layer 1 (0.5 nm) LiF
Metal electrode layer 2 (100 nm) Al

  Next, the organic light emitting device was covered with a protective glass plate in a dry air atmosphere and sealed with an acrylic resin adhesive so that the device did not deteriorate due to moisture adsorption. An organic light emitting device was obtained as described above.

About the obtained organic light emitting device, when an applied voltage of 5.6 V was applied with the IZO electrode as the positive electrode and the Al electrode as the negative electrode, red light emission with a luminance of 2000 cd / m ^{2 with} a luminous efficiency of 10.4 cd / A was observed. It was done. In this device, the CIE chromaticity coordinates were (x, y) = (0.68, 0.32). Furthermore, in this light-emitting element, the luminance half life at a constant current density of 100 mA / cm ² was 320 hours.

<Examples 10 to 14, Comparative Examples 2 and 3>
A device was prepared and evaluated in the same manner as in Example 9 except that the compounds used in the hole transport layer, the electron blocking layer, and the light emitting layer were changed to the compounds shown in Table 5. The results obtained are shown in Table 5.

  As described above, the benzoindolocarbazole compound according to the present invention has high chemical stability, low S1 energy, and a shallow HOMO level. Therefore, when it is used for a light emitting layer host of an organic phosphorescent light emitting device, it emits high light with a low driving voltage. An efficient light emitting device is obtained. Furthermore, in Examples 9 to 11, the benzoindolocarbazole compound according to the present invention has no carbazole-type C—N bond and high chemical stability, so that it has a longer lifetime than the case where the CBP of Comparative Example 2 is used as the light emitting layer host. A light-emitting element can be obtained.

<Example 15>
In this example, an organic light emitting device having a structure in which an anode / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode were sequentially provided on a substrate was produced by the method described below.

On the IZO substrate produced by the same method as in Example 9, the following organic compound layer and electrode layer were continuously formed by vacuum evaporation by resistance heating in a 10 ⁻⁵ Pa vacuum chamber. At this time, the opposing electrode area was 3 mm ² .
Hole transport layer (50 nm) HTL-2
Light emitting layer (30 nm) Host material: Exemplified Compound No. 117,
Guest material: Ir-8 (4 vol%),
Assist material: Ir (ppy) ₃ (16 vol%)
Hole blocking layer (10 nm) HBL-2
Electron transport layer (50 nm) ETL-1
Metal electrode layer 1 (0.5 nm) LiF
Metal electrode layer 2 (100 nm) Al

  Next, the organic light emitting device was covered with a protective glass plate in a dry air atmosphere and sealed with an acrylic resin adhesive so that the device did not deteriorate due to moisture adsorption. An organic light emitting device was obtained as described above.

With respect to the obtained organic light emitting device, when an applied voltage of 4.8 V was applied with the IZO electrode as the positive electrode and the Al electrode as the negative electrode, red light emission with a luminous efficiency of 12.8 cd / A and a luminance of 1000 cd / m ² was obtained. Observed. In this device, the CIE chromaticity coordinates were (x, y) = (0.68, 0.31). Further, in this light-emitting element, the luminance half life at a constant current density of 100 mA / cm ² was 470 hours.

<Examples 16 and 17, Comparative Examples 4 and 5>
A device was prepared in the same manner as in Example 15 except that the compounds used in the light emitting layer were changed to the compounds shown in Table 6, and the same evaluation was performed. The results obtained are shown in Table 6.

  As described above, the benzoindolocarbazole compound according to the present invention has high chemical stability, low S1 energy, and a shallow HOMO level. Therefore, the phosphorescent light emitting device having the light emitting assist material in the light emitting layer is similarly driven. An element with low voltage, high luminous efficiency, and long life can be obtained.

<Example 18>
In this example, an organic light emitting device having a structure in which an anode / hole transport layer / electron blocking layer / light emitting layer / hole blocking layer / electron transport layer / cathode were sequentially provided on a substrate was produced by the following method. .

On the IZO substrate produced by the same method as in Example 9, the following organic compound layer and electrode layer were continuously formed by vacuum evaporation by resistance heating in a 10 ⁻⁵ Pa vacuum chamber. At this time, the opposing electrode area was 3 mm ² .
Hole transport layer (40 nm) HTL-2
Electron blocking layer (10 nm) EBL-1
Light emitting layer (30 nm) Host material: Exemplified Compound No. 131,
Guest material: GD-1 (1 vol%),
Assist material: GA-1 (40 vol%)
Hole blocking layer (10 nm) HBL-3
Electron transport layer (30 nm) ETL-1
Metal electrode layer 1 (0.5 nm) LiF
Metal electrode layer 2 (100 nm) Al

  Next, the organic light emitting device was covered with a protective glass plate in a dry air atmosphere and sealed with an acrylic resin adhesive so that the device did not deteriorate due to moisture adsorption. An organic light emitting device was obtained as described above.

With respect to the obtained organic light emitting device, when an applied voltage of 4.1 V was applied with the IZO electrode as the positive electrode and the Al electrode as the negative electrode, the emission efficiency was 22.4 cd / A, and green light emission with a luminance of 2000 cd / m ² was emitted. Observed. In this device, the CIE chromaticity coordinates were (x, y) = (0.20, 0.69). Further, in this light-emitting element, the luminance half life at a constant current density of 100 mA / cm ² was 2450 hours.

<Example 19, Comparative Examples 6 and 7>
A device was produced in the same manner as in Example 18 except that the compounds used in the light emitting layer were changed to the compounds shown in Table 7, and the same evaluation was performed. The results obtained are shown in Table 7.

  As described above, the benzoindolocarbazole compound according to the present invention can be used as a light emitting layer host in the case where a fluorescent light emitting material is used for the light emitting layer guest. I understand that

<Example 20, comparative example 8>
A device was produced in the same manner as in Example 9 except that the compounds used in the hole transport layer, the electron blocking layer, and the light emitting layer were changed to the compounds shown in Table 8, and the same evaluation was performed. Table 8 shows the obtained results.

  As described above, it can be seen that the benzoindolocarbazole compound according to the present invention can provide an organic light-emitting device having a low driving voltage, a high light emission efficiency, and a long life even when used as a hole transport layer.

  As described above, the benzoindolocarbazole compound according to the present invention is a compound having the characteristics that the S1 energy is low, the HOMO level is shallow, and the chemical stability is high. Therefore, the organic light-emitting device having the benzoindolocarbazole compound according to the present invention as the host material of the light-emitting layer, in particular, the host material of the light-emitting layer of the red phosphorescent light-emitting device has a low driving voltage, high light emission efficiency, and long life. . Furthermore, among the benzoindolocarbazole compounds according to the present invention, a compound having an arylamino substituent and a particularly shallow HOMO level can be suitably used for a hole transport layer of an organic light emitting device.

DESCRIPTION OF SYMBOLS 1 Anode 2 Hole injection layer 3 Hole transport layer 4 Blue light emitting layer 5 Green light emitting layer 6 Red light emitting layer 7 Electron transport layer 8 Electron injection layer 9 Cathode 30 Display device 31 Substrate 38 TFT element 40 Organic light emitting element

Claims (21)

A benzoindolocarbazole compound represented by the following formula [1].

[In the formula [1], R _{1 to} R ₄ are each independently selected from a hydrogen atom, an alkyl group, and a group represented by the following formula [2]. However, at least one of R _{1 to} R ₄ is a group represented by the following formula [2]. ]

[In the formula [2], Ar ₁ represents a divalent hydrocarbon aromatic group having a substituent, an unsubstituted divalent hydrocarbon aromatic group, a divalent heteroaromatic group having a substituent, and Ar ₂ is selected from a substituted divalent heteroaromatic group, and Ar ₂ is a monovalent hydrocarbon aromatic group having a substituent, an unsubstituted monovalent hydrocarbon aromatic group, or a monovalent complex having a substituent. It is selected from an aromatic group and an unsubstituted monovalent heteroaromatic group. a is an integer of 0 to 2. When a is 2, two Ar ₁ may be the same or different. ] The benzoindolocarbazole compound according to claim 1, wherein R ₁ is a group represented by the formula [2].   In the formula [2], the divalent hydrocarbon aromatic group and the monovalent hydrocarbon aromatic group each have 6 to 22 carbon atoms, and the divalent heteroaromatic group. The benzoindolocarbazole compound according to claim 1 or 2, wherein the number of carbon atoms contained in each of the group and the monovalent heteroaromatic group is 4 or more and 22 or less. The benzoindolocarbazole compound according to any one of claims 1 to 3, wherein R _{2 to} R ₄ are each independently selected from the hydrogen atom and the alkyl group. The benzoindolocarbazole compound according to claim 4, wherein each of R _{2 to} R ₄ is the hydrogen atom. The a is 0 or 1, the Ar ₁ is a divalent hydrocarbon aromatic group having the substituent or the unsubstituted divalent hydrocarbon aromatic group, and the formula Ar ₂ is the substituent 6. The benzoindolocarbazole compound according to claim 1, wherein the benzoindolocarbazole compound is a monovalent hydrocarbon aromatic group having the above or the unsubstituted monovalent hydrocarbon aromatic group. Ar ₁ is a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthalenediyl group, a substituted or unsubstituted fluorenediyl group, a substituted or unsubstituted phene group. Nancelendiyl group, substituted or unsubstituted chrysenediyl group, substituted or unsubstituted triphenylenediyl group, substituted or unsubstituted biphenylene group, substituted or unsubstituted terphenylene group Ar ₂ is substituted or unsubstituted phenyl group, substituted or unsubstituted naphthyl group, substituted or unsubstituted fluorenyl group, substituted or unsubstituted Phenanthryl group, substituted or unsubstituted chrysenyl group, substituted Or a substituted triphenylenyl group, a substituted or unsubstituted biphenylenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted terphenyl group, The benzoindolocarbazole compound according to claim 6. Ar ₂ is a substituted or unsubstituted pyrenyl group, a substituted or unsubstituted anthracenyl group, a substituted or unsubstituted perylenyl group, a substituted or unsubstituted fluoranthenyl group The benzoindolocarbazole compound according to claim 6, which is selected from a substituted or unsubstituted benzofluoranthenyl group. The a is 0 or 1, and the Ar ₂ is the substituted or unsubstituted monovalent heteroaromatic group according to any one of claims 1 to 5, Benzindolocarbazole compounds. Ar ₂ has a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted quinolyl group, a substituted or unsubstituted group Isoquinolyl group, substituted or unsubstituted phenanthrolinyl group, substituted or unsubstituted bipyridyl group, substituted or unsubstituted carbazolyl group, substituted or unsubstituted indolo [3 , 2,1-kl] phenoxazinyl group, substituted or unsubstituted anthraquinolyl group, substituted or unsubstituted xanthone-yl group, substituted or unsubstituted anthronyl group, The benzoindolocarbazole compound according to claim 9. The benzoindolocarbazole compound according to claim 1, wherein Ar ₂ has an arylamino group as a substituent.   12. The organic light-emitting device having a pair of electrodes and an organic compound layer present between the pair of electrodes, wherein the organic compound layer has the benzoindolocarbazole compound according to claim 1. An organic light emitting device characterized by the above.   The organic compound layer is a light emitting layer having a host material and a guest material, and the host material is the benzoindolocarbazole compound according to any one of claims 1 to 11. 12. The organic light-emitting device according to 12.   The organic light-emitting element according to claim 13, wherein the guest material is a phosphorescent material.   The organic light-emitting device according to claim 14, wherein the phosphorescent material is an iridium complex.   16. The organic light emitting device according to claim 12, which emits red light.   16. The organic light emitting device according to claim 12, which emits white light.   It has a some pixel, At least 1 of these pixels has the organic light emitting element as described in any one of Claims 12 thru | or 17, and the active element connected to the said organic light emitting element. A display device characterized by that. An input unit for inputting image information and a display unit for displaying an image;
An image information processing apparatus, wherein the display unit is the display apparatus according to claim 18.   18. An illuminating device comprising: the organic light-emitting element according to claim 12; and an AD converter circuit for supplying a driving voltage to the organic light-emitting element.   An image forming apparatus comprising: a photosensitive member; a charging unit that charges the surface of the photosensitive member; an exposure unit that exposes the photosensitive member; and a developing unit that develops an electrostatic latent image formed on the surface of the photosensitive member. An image forming apparatus, wherein the exposure unit includes the organic light emitting element according to any one of claims 12 to 17.