JP2008288270A - Material for organic light-emitting element and organic light-emitting element using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic light-emitting element that can output a highly efficient and bright light and can be easily manufactured at a comparatively low cost. <P>SOLUTION: The organic light-emitting element is comprised of an anode and a cathode, and a layer made of an organic compound that is pinched between the anode and the cathode. Either of the anode and the cathode is transparent or semitransparent, and the layer made of the organic compound contains at least one kind of organic light-emitting element materials that are represented by a general formula (I). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an organic light emitting device material and an organic light emitting device using the same.

  An organic light emitting device is a device in which a thin film containing a fluorescent organic compound is sandwiched between an anode and a cathode. Further, by injecting holes and electrons from the anode and the cathode, respectively, excitons of the fluorescent compound are generated. When the excitons return to the ground state, the organic light emitting device emits light.

  Recent advances in organic light-emitting devices are remarkable, and their features include high brightness, a wide variety of emission wavelengths, high-speed response, and reduction in thickness and weight of light-emitting devices with a low applied voltage. From this, the organic light emitting element has suggested the possibility to a wide use.

  However, organic light emitting devices still have many problems in terms of durability, such as changes over time due to long-term use and deterioration due to atmospheric gas containing oxygen or moisture. When considering application to a full color display or the like, at present, it is necessary to emit blue, green, and red light with a longer life, high conversion efficiency, and high color purity.

  In order to solve these problems, a triarylamine derivative has been proposed as a constituent material of an organic light emitting device and applied to the organic light emitting device. As a specific example of the triarylamine derivative, N, N′-bis (3-methylphenyl) -N, N′-diphenyl [1,1′-biphenyl] -4,4′-diamine (TPD) is known. (See Non-Patent Document 1). In addition, a triarylamine derivative described in Patent Document 1 and a compound having a carboxyl group described in Patent Document 2 are disclosed.

  The triarylamine derivative of Patent Document 2 is particularly used as a modifier for the anode surface, and has an effect of increasing the affinity between the anode and a layer made of an organic compound, so that a good organic thin film can be formed. However, the luminous efficiency and durability life of the device itself were not sufficient in practice.

Japanese Patent Laid-Open No. 5-234681 JP-A-5-21165 Jpn. J. et al. Appl. Phys. , 27, L269 (1988)

  The present invention has been made to solve such problems of the prior art. An object of the present invention is to provide an organic light-emitting device that outputs light with high efficiency and high brightness, is easy to manufacture, and can be manufactured at a relatively low cost.

  As a result of intensive investigations to solve the above-mentioned problems, the present inventors have completed the present invention. That is, the organic light emitting device material of the present invention is characterized by being represented by the following general formula (I).

(In Formula (I), X ₁ is a substituted or unsubstituted arylene group. A ₁ and A ₂ are each a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic group. ₁ and A ₂ may be the same or different, and A ₁ and A ₂ may be bonded to each other to form a condensed ring, wherein R ₁ and R ₂ are each a hydrogen atom, A group selected from the group consisting of a halogen atom, a substituted or unsubstituted alkyl group and a substituted or unsubstituted aryl group, which may be the same or different, and n is an integer of 1 to 5. .)

  ADVANTAGE OF THE INVENTION According to this invention, the organic light emitting element which outputs highly efficient and high-intensity light, is easy to manufacture, and can be produced comparatively cheaply can be provided.

  Hereinafter, the present invention will be described in detail. 1st embodiment of the organic light emitting element material of this invention is a compound represented with the following general formula (I).

In the formula (I), X ₁ is a substituted or unsubstituted arylene group.

As the arylene group represented by X ₁ , 1,2-phenylene group, 1,2-biphenylene group, 2,3-biphenylene group, tetrafluorophenylene group, dimethylphenylene group, 1,2-naphthylene group, 2,3 -A naphthylene group, a phenanthrylene group, a pyrenylene group, a tetrasenylene group, a pentasenylene group, a peryleneylene group, etc. are mentioned, but of course, it is not limited to these. A 1,2-phenylene group is preferable.

  As the substituent that the arylene group may further have, a methyl group, ethyl group, n-propyl group, n-butyl group, pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n- Decyl group, isopropyl group, isobutyl group, sec-butyl group, tert-butyl group, isopentyl group, neopentyl group, tert-octyl group, benzyl group, 2-phenylethyl group and other alkyl groups, phenyl group, 4-methylphenyl Group, 4-ethylphenyl group, 3-chlorophenyl group, 3,5-dimethylphenyl group, triphenylamino group, biphenyl group, terphenyl group, naphthyl group, anthryl group, phenanthryl group, pyrenyl group and other aryl groups, pyridyl Group, bipyridyl group, methylpyridyl group, thienyl group, tertenyl group, propylthienyl group, Group, quinolyl group, carbazolyl group, heterocyclic group such as N-ethylcarbazolyl group, alkoxy group such as methoxy group, ethoxy group, propoxy group, benzyloxy group, aryloxy group such as phenoxy group, N-methyl Amino group, N-ethylamino group, N, N-dimethylamino group, N, N-diethylamino group, N-methyl-N-ethylamino group, N-benzylamino group, N-methyl-N-benzylamino group, N, N-dibenzylamino group, anilino group, N, N-diphenylamino group, N-phenyl-N-tolylamino group, N, N-ditolylamino group, N-methyl-N-phenylamino group, N, N- Amino groups such as dianisolylamino group, N-mesityl-N-phenylamino group, N, N-dimesitylamino group, and halogens such as fluorine, chlorine, bromine and iodine Child, a hydroxyl group, a cyano group, there may be mentioned a nitro group, but the present invention is of course not limited thereto.

In the formula (I), A ₁ and A ₂ are each a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic group.

As the aryl group represented by A ₁ and A ₂ , phenyl group, 4-methylphenyl group, 4-methoxyphenyl group, 4-ethylphenyl group, 4-fluorophenyl group, 4-trifluorophenyl group, 3,5 -Dimethylphenyl group, 2,6-diethylphenyl group, mesityl group, 4-tert-butylphenyl group, ditolylaminophenyl group, biphenyl group, terphenyl group, 1-naphthyl group, 2-naphthyl group, 1-anthryl Group, 2-anthryl group, 9-anthryl group, 2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group, 1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group, tetracenyl group, Examples include chrysenyl group, pentacenyl group, picenyl group, fluorenyl group, triphenylenyl group, perylenyl group, etc. Of course, it is not limited to these.

As the heterocyclic group represented by A ₁ and A ₂ , pyrrolyl group, pyridyl group, bipyridyl group, methylpyridyl group, terpyrrolyl group, thienyl group, 1-benzothienyl group, 2-benzothienyl group, terthienyl group, propylthienyl Group, furyl group, benzofuryl group, isobenzofuryl group, indolyl group, isoindolyl group, 1,10-phenanthroyl group, phenazinyl group, quinolyl group, isoquinolyl group, phenanthridinyl group, acridinyl group, carbazolyl group, oxazolyl group, An oxadiazolyl group, a thiazolyl group, a thiadiazolyl group, a pyrimidinyl group, a quinoxalyl group, a quinazolyl group and the like can be mentioned, but of course not limited thereto.

  Examples of the substituent that the aryl group and heterocyclic group may further have include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a pentyl group, an n-hexyl group, an n-heptyl group, and an n-octyl group. Group, n-decyl group, isopropyl group, isobutyl group, sec-butyl group, tert-butyl group, isopentyl group, neopentyl group, tert-octyl group, benzyl group, 2-phenylethyl group and other alkyl groups, phenyl group, 4-methylphenyl group, 4-ethylphenyl group, 3-chlorophenyl group, 3,5-dimethylphenyl group, triphenylamino group, biphenyl group, terphenyl group, naphthyl group, anthryl group, phenanthryl group, pyrenyl group, etc. Aryl group, pyridyl group, bipyridyl group, methylpyridyl group, thienyl group, tertenyl group, propylthienyl Group, furyl group, quinolyl group, carbazolyl group, heterocyclic group such as N-ethylcarbazolyl group, carbazolylphenyl group, halogen atom such as fluorine, chlorine, bromine, iodine, hydroxyl group, cyano group, nitro group Of course, it is not limited to these.

A ₁ and A ₂ may be the same or different from each other. A ₁ and A ₂ may be bonded to each other to form a condensed ring such as a carbazole ring.

In the formula (I), R ₁ and R ₂ are groups selected from the group consisting of a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group and a substituted or unsubstituted aryl group, respectively.

Examples of the halogen atom represented by R ₁ and R ₂ include fluorine, chlorine, bromine or iodine.

Examples of the alkyl group represented by R ₁ and R ₂ include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n -Decyl group, isopropyl group, isobutyl group, sec-butyl group, tert-butyl group, isopentyl group, neopentyl group, tert-octyl group, fluoromethyl group, difluoromethyl group, trifluoromethyl group, 2-fluoroethyl group, 2,2,2-trifluoroethyl group, perfluoroethyl group, 3-fluoropropyl group, perfluoropropyl group, 4-fluorobutyl group, perfluorobutyl group, 5-fluoropentyl group, 6-fluorohexyl group, Chloromethyl group, trichloromethyl group, 2-chloroethyl group, 2,2,2-trichloroethyl group, 4-chlorobutyl Tyl group, 5-chloropentyl group, 6-chlorohexyl group, bromomethyl group, 2-bromoethyl group, iodomethyl group, 2-iodoethyl group, hydroxymethyl group, hydroxyethyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl Group, cyclopentylmethyl group, cyclohexylmethyl group, cyclohexylethyl group, 4-fluorocyclohexyl group, norbornyl group, adamantyl group, and the like, but are not limited thereto.

As the aryl group represented by R ₁ and R ₂ , phenyl group, 4-methylphenyl group, 4-methoxyphenyl group, 4-ethylphenyl group, 4-fluorophenyl group, 4-trifluorophenyl group, 3,5 -Dimethylphenyl group, 2,6-diethylphenyl group, mesityl group, 4-tert-butylphenyl group, ditolylaminophenyl group, biphenyl group, terphenyl group, 1-naphthyl group, 2-naphthyl group, 1-anthryl Group, 2-anthryl group, 9-anthryl group, 2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group, 1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group, tetracenyl group, Examples include chrysenyl group, pentacenyl group, picenyl group, fluorenyl group, triphenylenyl group, perylenyl group, etc. Of course, it is not limited to these.

  Examples of the substituent that the alkyl group and aryl group may further have include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a pentyl group, an n-hexyl group, an n-heptyl group, and an n-octyl group. N-decyl group, isopropyl group, isobutyl group, sec-butyl group, tert-butyl group, isopentyl group, neopentyl group, tert-octyl group, alkyl group such as benzyl group, 2-phenylethyl group, phenyl group, 4 -Aryl such as methylphenyl group, 4-ethylphenyl group, 3-chlorophenyl group, 3,5-dimethylphenyl group, triphenylamino group, biphenyl group, terphenyl group, naphthyl group, anthryl group, phenanthryl group, pyrenyl group Group, pyridyl group, bipyridyl group, methylpyridyl group, thienyl group, tertenyl group, propylthiyl group Examples thereof include heterocyclic groups such as nyl group, furyl group, quinolyl group, carbazolyl group and N-ethylcarbazolyl group, halogen atoms such as fluorine, chlorine, bromine and iodine, hydroxyl group, cyano group and nitro group. It is not limited to these.

R ₁ and R ₂ may be the same or different from each other.

  In the formula (I), n is an integer of 1 to 5.

  In addition, all or some of the hydrogen atoms contained in the compound of formula (I) may be substituted with deuterium atoms.

  A second embodiment of the material for an organic light-emitting device of the present invention is a compound represented by the following general formula (II).

In formula _{(II), X 1, A} 1, R 1, R 2 and n are the same as _{X 1, A 1, R 1} , R 2 and n in formula (I).

In the formula (II), X ₂ is a substituted or unsubstituted arylene group.

Examples of the arylene group represented by X ₂ include a phenylene group, a biphenylene group, a tetrafluorophenylene group, a dimethylphenylene group, a fluorenylene group, a naphthylene group, an anthrylene group, a phenanthrylene group, a pyrenylene group, a tetrasenylene group, a pentasenylene group, and a peryleneylene group. Of course, it is not limited to these.

  As the substituent that the arylene group may further have, a methyl group, ethyl group, n-propyl group, n-butyl group, pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n- Decyl group, isopropyl group, isobutyl group, sec-butyl group, tert-butyl group, isopentyl group, neopentyl group, tert-octyl group, benzyl group, 2-phenylethyl group and other alkyl groups, phenyl group, 4-methylphenyl group 4-ethylphenyl group, 3-chlorophenyl group, 3,5-dimethylphenyl group, triphenylamino group, biphenyl group, terphenyl group, naphthyl group, anthryl group, phenanthryl group, pyrenyl group and other aryl groups, pyridyl group Bipyridyl group, methylpyridyl group, thienyl group, tertenyl group, propylthienyl group, Group, heterocyclic group such as quinolyl group, carbazolyl group and N-ethylcarbazolyl group, halogen atom such as fluorine, chlorine, bromine and iodine, hydroxyl group, cyano group and nitro group, but of course limited to these Is not to be done.

In the formula (II), A ₃ and A ₄ are each a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic group.

Specific examples of the aryl group and heterocyclic group represented by A ₃ and A ₄ are the same as the specific examples of A ₁ and A _{2 in} the formula (I).

  Examples of the substituent that the aryl group and heterocyclic group may further have include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a pentyl group, an n-hexyl group, an n-heptyl group, and an n-octyl group. Group, n-decyl group, isopropyl group, isobutyl group, sec-butyl group, tert-butyl group, isopentyl group, neopentyl group, tert-octyl group, benzyl group, 2-phenylethyl group and other alkyl groups, phenyl group, 4-methylphenyl group, 4-ethylphenyl group, 3-chlorophenyl group, 3,5-dimethylphenyl group, triphenylamino group, biphenyl group, terphenyl group, naphthyl group, anthryl group, phenanthryl group, pyrenyl group, etc. Aryl group, pyridyl group, bipyridyl group, methylpyridyl group, thienyl group, tertenyl group, propylthienyl , Furyl group, quinolyl group, carbazolyl group, N-ethylcarbazolyl group and other heterocyclic groups, hydroxymethyl group, 1-hydroxyethyl group, 1-hydroxypropyl group, 1-hydroxybutyl group, 1-hydroxy A hydroxyalkyl group such as a pentyl group, a halogen atom such as fluorine, chlorine, bromine and iodine, a hydroxyl group, a cyano group, a nitro group and the like can be mentioned, but of course not limited thereto.

Preferably, either A ₃ or A ₄ is a substituent represented by the following general formula (i).

  In formula (i), n is an integer of 1 to 5.

In formula (i), R ₄ and R ₅ are groups selected from the group consisting of a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group and a substituted or unsubstituted aryl group, respectively. Specific examples of the halogen atom, the alkyl group and the aryl group represented by R ₄ and R ₅ , and the substituent that the alkyl group and the aryl group may have are the same as those for R ₁ and R ₂ in formula (I). is there.

R ₄ and R ₅ may be the same or different.

In the formula (i), R _{6 to} R ₉ are each a group selected from the group consisting of a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, an aryl group, and an amino group.

Examples of the halogen atom represented by R _{6 to} R ₉ include fluorine, chlorine, bromine, and iodine.

Examples of the alkyl group represented by R _{6 to} R ₉ include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n -Decyl group, isopropyl group, isobutyl group, sec-butyl group, tert-butyl group, isopentyl group, neopentyl group, tert-octyl group, fluoromethyl group, difluoromethyl group, trifluoromethyl group, 2-fluoroethyl group, 2,2,2-trifluoroethyl group, perfluoroethyl group, 3-fluoropropyl group, perfluoropropyl group, 4-fluorobutyl group, perfluorobutyl group, 5-fluoropentyl group, 6-fluorohexyl group, Chloromethyl group, trichloromethyl group, 2-chloroethyl group, 2,2,2-trichloroethyl group, 4-chlorobutyl Tyl group, 5-chloropentyl group, 6-chlorohexyl group, bromomethyl group, 2-bromoethyl group, iodomethyl group, 2-iodoethyl group, hydroxymethyl group, hydroxyethyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl Group, cyclopentylmethyl group, cyclohexylmethyl group, cyclohexylethyl group, 4-fluorocyclohexyl group, norbornyl group, adamantyl group, and the like, but are not limited thereto.

As the aryl group represented by R _{6 to} R ₉ , phenyl group, 4-methylphenyl group, 4-methoxyphenyl group, 4-ethylphenyl group, 4-fluorophenyl group, 4-trifluorophenyl group, 3,5 -Dimethylphenyl group, 2,6-diethylphenyl group, mesityl group, 4-tert-butylphenyl group, ditolylaminophenyl group, biphenyl group, terphenyl group, 1-naphthyl group, 2-naphthyl group, 1-anthryl Group, 2-anthryl group, 9-anthryl group, 2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group, 1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group, tetracenyl group, Examples include chrysenyl group, pentacenyl group, picenyl group, fluorenyl group, triphenylenyl group, perylenyl group, etc. Of course, it is not limited to these.

Examples of the amino group represented by R _{6 to} R ₉ include N-methylamino group, N-ethylamino group, N, N-dimethylamino group, N, N-diethylamino group, N-methyl-N-ethylamino. Group, N, N-diphenylamino group, N-methyl-N-phenylamino group, N-phenyl-N-tolylamino group, N, N-ditolylamino group, N, N-dianisolylamino group, N-mesityl- N-phenylamino group, N, N-dimesitylamino group, N-phenyl-N- (4-tert-butylphenyl) amino group, N-phenyl-N- (4-trifluoromethylphenyl) amino group, N-naphthyl -N-phenylamino group, N-phenyl-N-phenanthrylamino group, N-phenyl-N-pyrenylamino group, N-fluorenyl-N-phenylamino group, N-phenyl Examples of the aryl-N-pyridylamino group, N, N-dinaphthylamino group, and N, N-difluorenylamino group include, but are not limited to these.

  Examples of the substituent that the alkyl group may further have include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, and an n- Decyl group, isopropyl group, isobutyl group, sec-butyl group, tert-butyl group, isopentyl group, neopentyl group, tert-octyl group, benzyl group, 2-phenylethyl group and other alkyl groups, phenyl group, 4-methylphenyl Group, 4-ethylphenyl group, 3-chlorophenyl group, 3,5-dimethylphenyl group, triphenylamino group, biphenyl group, terphenyl group, naphthyl group, anthryl group, phenanthryl group, pyrenyl group and other aryl groups, pyridyl Group, bipyridyl group, methylpyridyl group, thienyl group, tertenyl group, propylthienyl group, free Groups, quinolyl groups, carbazolyl groups, heterocyclic groups such as N-ethylcarbazolyl groups, halogen atoms such as fluorine, chlorine, bromine and iodine, hydroxyl groups, cyano groups, and nitro groups. It is not something.

R _{6 to} R ₉ may be the same or different from each other.

In addition, adjacent substituents of R _{6 to} R ₉ may be bonded to each other to form a ring.

A ₃ and A ₄ may be the same or different, and either X ₂ and A _{1 or} A ₃ and A ₄ may be bonded to each other to form a condensed ring such as a carbazole ring. .

  In addition, all or some of the hydrogen atoms contained in the compound of formula (II) may be substituted with deuterium atoms.

  3rd embodiment of the organic light emitting element material of this invention is a compound shown by the following general formula (III).

In formula _{(III), X 1, A} 1, R 1, R 2 and n are the same as _{X 1, A 1, R 1} , R 2 and n in formula (I).

In the formula (III), X ₃ represents a trivalent substituent derived from a substituted or unsubstituted aromatic ring.

Examples of the trivalent substituent represented by X ₃ include trivalent substituents derived from a benzene ring, biphenyl ring, fluorene ring, naphthalene ring, phenanthrene ring, pyrene ring, tetracene ring, pentacene ring, perylene ring and the like. Of course, it is not limited to these.

  Examples of the substituent that the trivalent arylene group may further include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a pentyl group, an n-hexyl group, an n-heptyl group, and an n-octyl group. N-decyl group, isopropyl group, isobutyl group, sec-butyl group, tert-butyl group, isopentyl group, neopentyl group, tert-octyl group, benzyl group, 2-phenylethyl group and other alkyl groups, phenyl group, 4- Aryl groups such as methylphenyl group, 4-ethylphenyl group, 3-chlorophenyl group, 3,5-dimethylphenyl group, triphenylamino group, biphenyl group, terphenyl group, naphthyl group, anthryl group, phenanthryl group, pyrenyl group , Pyridyl group, bipyridyl group, methylpyridyl group, thienyl group, tertenyl group, propylthienyl group , Furyl group, quinolyl group, carbazolyl group, heterocyclic group such as N-ethylcarbazolyl group, halogen atom such as fluorine, chlorine, bromine, iodine, hydroxyl group, cyano group, nitro group, of course, It is not limited.

In formula (III), A _{5 to} A ₈ are each a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic group.

Specific examples of the aryl group and heterocyclic group represented by A _{5 to} A ₈ and the substituents that the aryl group and heterocyclic group may further have include the specific examples of A ₂ and A ₃ in formula (II) It is the same.

The substituent represented by A _{5 to} A ₈ is preferably a substituent represented by the following formula (i).

A _{5 to} A ₈ may be the same or different, and any of A ₅ and A _{6 or} A ₇ and A ₈ may be bonded to each other to form a condensed ring such as a carbazole ring.

  In addition, all or part of the hydrogen atoms contained in the compound of formula (III) may be substituted with deuterium atoms.

  The organic light emitting device material of the present invention can be used as a constituent material of an organic light emitting device. Preferably, it can be used as a hole injection / transport material. In particular, when it is used as a material constituting the hole injection layer, the effect of improving the light emission efficiency and life of the device is increased.

  In the material for an organic light emitting device of the present invention, an intramolecular interaction occurs between a tertiary amine moiety and a hydroxyl group. Due to this intramolecular interaction, the organic light emitting device material of the present invention is superior in hole injecting and transporting properties and non-crystalline compared to amine compounds conventionally used as constituent materials of organic light emitting devices. Also excellent. Furthermore, the material for an organic light emitting device of the present invention has a hydroxyl group in the molecule. Since the hydroxyl group has low acidity, the protons of the substituent are less likely to be released than a substituent having strong acidity such as a carboxyl group, and the device does not deteriorate due to the free protons. For this reason, the lifetime of the organic light emitting device is improved.

  Next, typical examples of the organic light-emitting device material of the present invention will be given. However, it is not limited to these compounds.

  Next, the organic light emitting device of the present invention will be described in detail.

  The organic light-emitting device of the present invention includes an anode, a cathode, and a layer made of an organic compound that is sandwiched between the anode and the cathode. In the organic light-emitting device of the present invention, either the anode or the cathode is transparent or translucent.

  Hereinafter, the organic light emitting device of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view showing a first embodiment of the organic light-emitting device of the present invention. In the organic light emitting device 10 of FIG. 1, an anode 2, a light emitting layer 3, and a cathode 4 are sequentially provided on a substrate 1. The organic light emitting device 10 of FIG. 1 is useful when the light emitting layer 3 is composed of an organic compound having all of hole transporting ability, electron transporting ability, and light emitting performance. Moreover, it is useful also when the light emitting layer 3 is comprised by mixing the organic compound which has any of the characteristic of hole transport ability, electron transport ability, and luminous property.

  FIG. 2 is a cross-sectional view showing a second embodiment of the organic light emitting device of the present invention. In the organic light emitting device 20 of FIG. 2, an anode 2, a hole transport layer 5, an electron transport layer 6 and a cathode 4 are sequentially provided on a substrate 1. The organic light emitting device 20 of FIG. 2 is useful when a light emitting organic compound having either hole transporting property or electron transporting property and an organic compound having only electron transporting property or only hole transporting property are used in combination. . In the organic light emitting device 20, the hole transport layer 5 or the electron transport layer 6 also serves as the light emitting layer.

  FIG. 3 is a cross-sectional view showing a third embodiment of the organic light-emitting device of the present invention. An organic light emitting device 30 in FIG. 3 is obtained by inserting the light emitting layer 3 between the hole transport layer 5 and the electron transport layer 6 in the organic light emitting device 20 in FIG. The organic light emitting device 30 has functions of separating carrier transport and light emission, and an organic compound having hole transport property, electron transport property, and light emission property can be used in combination in a timely manner. For this reason, the degree of freedom of material selection is greatly increased, and various compounds having different emission wavelengths can be used, so that the emission hue can be diversified. Furthermore, it is possible to effectively confine each carrier or exciton in the central light emitting layer 3 to improve the light emission efficiency of the organic light emitting element 30.

  FIG. 4 is a cross-sectional view showing a fourth embodiment of the organic light emitting device of the present invention. An organic light emitting device 40 in FIG. 4 is obtained by inserting a hole injection layer 7 between the anode 2 and the hole transport layer 5 in the organic light emitting device 30 in FIG. 3. The organic light emitting device 40 is effective for lowering the voltage because the adhesion between the anode 2 and the hole transport layer 5 or the hole injection property is improved by inserting the hole injection layer 7.

  FIG. 5 is a cross-sectional view showing a fifth embodiment of the organic light-emitting device of the present invention. The organic light emitting device 50 in FIG. 5 is different from the organic light emitting device 30 in FIG. 3 in that a layer (hole / exciton blocking layer 8) that prevents holes or excitons (excitons) from passing to the cathode 4 side is It is inserted between the electron transport layer 6. By using a compound having a very high ionization potential as the hole / exciton blocking layer 8, the light emission efficiency of the organic light emitting device 50 is improved.

  However, FIGS. 1 to 5 are very basic element configurations, and the configuration of the organic light emitting element using the organic light emitting element material of the present invention is not limited thereto. For example, an insulating layer, an adhesive layer, or an interference layer may be provided at the interface between the electrode and the organic layer. The hole transport layer 5 may be composed of two layers having different ionization potentials.

  The organic light emitting device material of the present invention can be used in any of the forms shown in FIGS. In the organic light emitting device shown in FIGS. 1 to 5, at least one of the light emitting layer 3, the hole transport layer 5, the electron transport layer 6, the hole injection layer 7, and the hole / exciton blocking layer 8 is formed in the present invention. At least one organic light emitting device material is contained. The organic light emitting device material of the present invention may be contained in a plurality of layers. Moreover, the organic light emitting element material of the present invention may be contained in two or more types in one layer.

  The material for an organic light-emitting device of the present invention is preferably contained in the hole injection layer 7 or the hole transport layer 5, but if necessary, a low molecular weight or polymer based hole transport compound known so far, A luminescent compound or an electron transporting compound can also be used together.

  The hole injection / transport material preferably has excellent mobility for facilitating the injection of holes from the anode and transporting the injected holes to the light emitting layer. In addition to the organic light emitting device material of the present invention, the low molecular and high molecular materials having hole injection / transport performance include phenylenediamine derivatives, triazole derivatives, oxadiazole derivatives, imidazole derivatives, pyrazoline derivatives, pyrazolone derivatives, oxazoles. Derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, phthalocyanine derivatives, porphyrin derivatives, and poly (vinylcarbazole), poly (silylene), poly (thiophene), and other conductive polymers, of course, but are not limited to these It is not a thing.

  Examples of the light-emitting material include polycyclic condensed aromatic compounds (eg, naphthalene derivatives, phenanthrene derivatives, fluorene derivatives, pyrene derivatives, tetracene derivatives, coronene derivatives, chrysene derivatives, perylene derivatives, 9,10-diphenylanthracene derivatives, rubrene, etc.), Quinacridone derivatives, acridone derivatives, coumarin derivatives, pyran derivatives, Nile red, pyrazine derivatives, benzimidazole derivatives, benzothiazole derivatives, benzoxazole derivatives, stilbene derivatives, organometallic complexes (for example, organoaluminum such as tris (8-quinolinolato) aluminum Complexes, organic beryllium complexes) and poly (phenylene vinylene) derivatives, poly (fluorene) derivatives, poly (phenylene) derivatives, poly (thienylene vinylene) derivatives, Li (acetylene) polymer derivatives such as derivatives, but not of course not limited thereto.

  The electron injecting and transporting material can be arbitrarily selected from those having the function of facilitating the injection of electrons from the cathode and transporting the injected electrons to the light emitting layer, and the balance with the carrier mobility of the hole transporting material. It is selected in consideration of etc. Electron injection / transport materials include oxadiazole derivatives, oxazole derivatives, thiazole derivatives, thiadiazole derivatives, pyrazine derivatives, triazole derivatives, triazine derivatives, perylene derivatives, quinoline derivatives, quinoxaline derivatives, fluorenone derivatives, anthrone derivatives, phenanthroline derivatives, organic Although metal complexes etc. are mentioned, of course, it is not limited to these.

  As a material constituting 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, and tungsten, or alloys formed by combining these metals, tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO ), Metal oxides such as indium zinc oxide can be used. In addition, conductive polymers such as polyaniline, polypyrrole, polythiophene, and polyphenylene sulfide can also be used. These electrode materials may be used alone or in combination. 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. For example, simple metals such as lithium, sodium, potassium, calcium, magnesium, aluminum, indium, ruthenium, titanium, manganese, yttrium, silver, lead, tin, chromium, or alloys formed by combining these metals (for example, lithium- Indium, sodium-potassium, magnesium-silver, aluminum-lithium, aluminum-magnesium, magnesium-indium, 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. Moreover, the cathode may be composed of a single layer or a plurality of layers.

  Either the anode or the cathode is transparent or translucent.

  Although it does not specifically limit as a board | substrate used with the organic light emitting element of this invention, Transparent substrates, such as opaque board | substrates, such as a metal board | substrate and a ceramic board | substrate, glass, quartz, a plastic sheet, are used. It is also possible to control the color light by using a color filter film, a fluorescent color conversion filter film, a dielectric reflection film or the like on the substrate.

  Note that a protective layer or a sealing layer can be provided for the manufactured element in order to prevent contact with oxygen, moisture, or the like. Examples of protective layers include diamond thin films, inorganic material films such as metal oxides and metal nitrides, polymer films such as fluororesins, polyparaxylene, polyethylene, silicone resins, and polystyrene resins, and photocurable resins. Can be mentioned. Further, it is possible to cover glass, a gas impermeable film, a metal, etc., and to package the element itself with an appropriate sealing resin.

  The organic light emitting device of the present invention can also be produced by producing a thin film transistor (TFT) on a substrate and connecting it.

  Further, the method of extracting light from the element may be a bottom emission configuration (configuration of extracting light from the substrate side) or a top emission configuration (configuration of extracting light from the opposite side of the substrate).

  In particular, an organic layer using the organic light emitting device material of the present invention is useful as a light emitting layer, an electron transport layer or a hole injection layer, a hole transport layer, and a layer formed by a vacuum deposition method, a solution coating method, or the like. Crystallization is unlikely to occur and the stability over time is excellent.

  In the organic light emitting device of the present invention, the layer containing the material for the organic light emitting device of the present invention is generally a vacuum deposition method, an ionization deposition method, sputtering, a plasma deposition method or a solution prepared by dissolving in an appropriate solvent. A thin film is formed by a known coating method. Here, examples of the known coating method include spin coating, dipping, casting method, LB method, and inkjet method. In particular, when a film is formed by a coating method, the film can be formed in combination with an appropriate binder resin.

  The binder resin can be selected from a wide range of binder resins. For example, polyvinyl carbazole resin, polycarbonate resin, polyester resin, polyarylate resin, polystyrene resin, ABS resin, polybutadiene resin, polyurethane resin, acrylic resin, methacrylic resin, butyral resin, polyvinyl acetal resin, polyamide resin, polyimide resin, polyethylene resin, Examples include, but are not limited to, polyethersulfone resins, diallyl phthalate resins, phenol resins, epoxy resins, silicone resins, polysulfone resins, urea resins, and the like. These final resins may be used alone or as a copolymer polymer in which one kind or a mixture of two or more kinds is used. Furthermore, you may use together additives, such as a well-known plasticizer, antioxidant, and an ultraviolet absorber, as needed.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

<Example 1> [Exemplary Compound No. 1] Production method of 41]

(1) Synthesis of Intermediate [3] The following reagents and solvent were charged into a 100 ml eggplant flask and a condenser tube was attached.

Aromatic amine compound [1]: 5.00 g
4-iodotoluene [2]: 3.34 g
Potassium carbonate: 5.0g
Copper powder: 4.0g
Orthodichlorobenzene: 40 ml
Next, the reaction solution was stirred for 24 hours while refluxing. After completion of the reaction, the reaction solution was cooled and filtered, and the filtrate was concentrated under reduced pressure to distill away orthodichlorobenzene, and then toluene was added to precipitate crude crystals, which were collected by filtration. Next, the obtained crude crystals were purified using silica gel column chromatography (developing solvent: toluene / hexane mixed solvent) to obtain 2.81 g of intermediate [3] as white fine crystals.

(2) Synthesis of intermediate [5] Under a nitrogen stream, 420 mg (1.02 mmol) of intermediate [3] and 10 ml of degassed toluene were mixed, and intermediate [3] was dissolved in a toluene solvent. Next, 0.44 g of potassium phosphate and 10 mg of palladium acetate were sequentially added to the reaction solution. Next, 330 mg (1.60 mmol) of methyl 2-bromobenzoate [4] dissolved in 3 ml of toluene was dropped into the reaction solution while stirring the reaction solution on an oil bath heated to 50 ° C. Next, the reaction solution was stirred for about 8 hours while heating on an oil bath heated to 80 ° C. under a nitrogen stream. After completion of the reaction, the reaction solution was returned to room temperature, ethyl acetate and water were added, the organic layer was separated and dried over sodium sulfate, and then the solvent was distilled off under reduced pressure. Next, purification by silica gel column chromatography (toluene: heptane = 1: 3) yielded 320 mg of intermediate [5].

(3) Exemplified Compound No. Synthesis of 41 Under ice cooling, 5 mg of lithium aluminum hydride (LAH) was added to 2 ml of tetrahydrofuran (THF). Next, a solution in which 200 mg (0.37 mmol) of the intermediate [5] was dissolved in 2 ml of THF was added dropwise, and the reaction solution was stirred for about 1 hour under ice cooling. After completion of the reaction, methanol was added to the reaction solution, diluted hydrochloric acid was further added, and the organic layer was extracted with ethyl acetate. The extracted organic layer was dried with sodium sulfate. Next, the solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography (developing solvent: toluene / heptane = 1/3). 100 mg of 41 was obtained.

  In Example 1 (2), the reaction was carried out in the same manner as in Example 1 except that N, N-diphenylamine was used instead of the intermediate [3]. 1 is obtained.

  In Example 1 (2), the reaction was carried out in the same manner as in Example 1 except that N- (1-naphthyl) -N-phenylamine was used instead of the intermediate [3]. 3 is obtained.

  In Example 1 (2), the reaction was carried out in the same manner as in Example 1 except that N- (9-phenanthryl) -N-phenylamine was used instead of the intermediate [3]. 4 is obtained.

  In Example 1 (2), the reaction was carried out in the same manner as in Example 1 except that N- (1-pyrenyl) -N-phenylamine was used instead of the intermediate [3]. 5 is obtained.

  In Example 1 (2), the reaction was carried out in the same manner as in Example 1 except that 2-phenylamino-9,9-dimethylfluorene was used instead of the intermediate [3]. 6 is obtained.

  In Example 1 (2), the reaction was carried out in the same manner as in Example 1 except that carbazole was used instead of the intermediate [3]. 7 is obtained.

  In Example 1 (2), the reaction was carried out in the same manner as in Example 1 except that N, N-ditolylamine was used instead of the intermediate [3], whereby Exemplified Compound No. 8 is obtained.

  Example 1 (1) is the same as Example 1 except that N, N′-diphenylbenzene-1,4-diamine is used instead of N ′, N′-ditolyldiphenyl-4,4′-diamine. By carrying out the reaction, Exemplified Compound No. 22 is obtained.

  Example 1 (1) is the same as Example 1 except that N, N′-ditolylbenzene-1,4-diamine is used instead of N ′, N′-ditolyldiphenyl-4,4′-diamine. By carrying out the reaction in the same manner, Exemplified Compound No. 25 is obtained.

  Example 1 (1) is the same as Example 1 except that N, N′-dixylbenzene-1,4-diamine is used instead of N ′, N′-ditolyldiphenyl-4,4′-diamine. By carrying out the reaction in the same manner, Exemplified Compound No. 26 is obtained.

<Example 2> [Preparation of organic light-emitting device]
An organic light emitting device having the structure shown in FIG. 4 was produced by the method shown below.

  On the glass substrate (substrate 1), indium tin oxide (ITO) was deposited as an anode 2 with a film thickness of 120 nm by a sputtering method. Next, the substrate was successively subjected to ultrasonic cleaning with acetone and isopropyl alcohol (IPA), then boiled and cleaned with IPA, and then dried. Further, UV / ozone cleaning was performed. The substrate thus treated was used as a transparent conductive support substrate.

  Next, as a hole injection material, N, N′-bis (9,9-dimethyl-2-fluorenyl) N, N′-diphenyl-4,4′-biphenyldiamine and exemplary compound 41 are 95 in a weight ratio. : A chloroform solution of 5 was prepared.

  This solution was dropped on the ITO electrode, and a thin film was formed by spin coating first at a rotation of 500 RPM for 10 seconds and then at a rotation of 1000 RPM for 1 minute. Thereafter, the film was dried in a vacuum oven at 80 ° C. for 10 minutes to completely remove the solvent in the thin film. The film thickness of the formed hole injection layer 7 was 50 nm.

Next, N, N′-bis (9,9-dimethyl-2-fluorenyl) N, N′-diphenyl-4,4′-biphenyldiamine is vacuum deposited as a hole transport layer 5 on the hole injection layer 7. Thus, a thin film having a thickness of 10 nm was formed. At this time, the degree of vacuum during vapor deposition was set to 1.0 × 10 ⁻⁴ Pa, and the film formation rate was set to 0.2 nm / sec to 0.3 nm / sec.

Next, 1,1 ′-(9,9-dimethyl-2,7-fluorenyl) dipyrene was vacuum deposited on the hole transport layer 5 as the light emitting layer 3 to form a thin film having a thickness of 20 nm. At this time, the degree of vacuum during vapor deposition was set to 1.0 × 10 ⁻⁴ Pa, and the film formation rate was set to 0.2 nm / sec to 0.3 nm / sec.

Next, as the electron transport layer 6, 2,9-bis (9,9-dimethyl-2-fluorenyl) -1,10-phenanthroline was vacuum deposited on the light emitting layer 3 to form a thin film having a thickness of 40 nm. At this time, the degree of vacuum during vapor deposition was set to 1.0 × 10 ⁻⁴ Pa, and the film formation rate was set to 0.2 nm / sec to 0.3 nm / sec.

Next, an aluminum-lithium alloy (lithium concentration of 1 atomic%) was vacuum deposited on the electron transport layer 6 to form a metal layer film having a thickness of 10 nm. Further, aluminum was vacuum-deposited on the metal layer film to form a thin film having a thickness of 150 nm. When forming these two thin films, the degree of vacuum during vapor deposition was 1.0 × 10 ⁻⁴ Pa, and the film formation rate was 1.0 nm / sec to 1.2 nm / sec. The aluminum-lithium alloy film and the aluminum film function as an electron injection electrode (cathode 4).

  Next, a protective glass plate was placed in a dry air atmosphere and sealed with an acrylic resin adhesive so as not to cause element degradation due to moisture adsorption. As described above, an organic light emitting device was obtained.

  When the voltage was applied to the obtained device using the ITO electrode (anode 2) as the positive electrode and the Al-Li electrode (cathode 4) as the negative electrode, 1,1 '-(9,9-dimethyl-2,7-fluorenyl) Dipyrene-derived luminescence was confirmed. Further, when a voltage was applied to the device under a nitrogen atmosphere for 100 hours, good continuation of light emission was observed.

  As described above, the organic light-emitting device including the organic light-emitting device material of the present invention gave highly efficient light emission at a low applied voltage. Moreover, this organic light emitting device is also excellent in durability.

It is sectional drawing which shows 1st embodiment in the organic light emitting element of this invention. It is sectional drawing which shows 2nd embodiment in the organic light emitting element of this invention. It is sectional drawing which shows 3rd embodiment in the organic light emitting element of this invention. It is sectional drawing which shows 4th embodiment in the organic light emitting element of this invention. It is sectional drawing which shows 5th embodiment in the organic light emitting element of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Anode 3 Light emitting layer 4 Cathode 5 Hole transport layer 6 Electron transport layer 7 Hole injection layer 8 Hole / exciton blocking layer 10, 20, 30, 40, 50 Organic light emitting device

Claims (9)

A material for an organic light-emitting device, which is a compound represented by the following general formula (I):

(In Formula (I), X ₁ is a substituted or unsubstituted arylene group. A ₁ and A ₂ are each a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic group. ₁ and A ₂ may be the same or different, and A ₁ and A ₂ may be bonded to each other to form a condensed ring, wherein R ₁ and R ₂ are each a hydrogen atom, A group selected from the group consisting of a halogen atom, a substituted or unsubstituted alkyl group and a substituted or unsubstituted aryl group, which may be the same or different, and n is an integer of 1 to 5. .) A material for an organic light-emitting device, which is a compound represented by the following general formula (II):

(In Formula (II), X ₂ is a substituted or unsubstituted arylene group. A ₃ and A ₄ are a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic group. ₃ and A ₄ may be the same or different, and A ₃ and A ₄ may be bonded to each other to form a condensed ring. A material for an organic light-emitting device, which is a compound represented by the following general formula (III):

(In Formula (III), X ₃ is a trivalent substituent derived from a substituted or unsubstituted aromatic ring. A _{5 to} A ₈ are each a substituted or unsubstituted aryl group or substituted or unsubstituted. A _{5 to} A ₈ may be the same or different from each other, and either A ₅ and A _{6 or} A ₇ and A ₈ are bonded to each other to form a condensed ring. May be.) The material for an organic light-emitting element according to claim 1, wherein X ₁ is a substituted or unsubstituted 1,2-phenylene group. The organic light-emitting device material according to claim 2, wherein the A ₃ or the A ₄ is a substituent represented by the following general formula (i).

(In formula (i), n is an integer of 1 to 5. R ₄ and R ₅ are each a group consisting of a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group and a substituted or unsubstituted aryl group. R _{6 to} R ₉ are each a group selected from the group consisting of a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, an aryl group, and an amino group. The selected groups may be the same or different, and adjacent substituents of R _{6 to} R ₉ may be bonded to each other to form a ring. The organic light-emitting element material according to claim 3, wherein any one of the A _{5 to the} A ₈ is represented by the following general formula (i).

An anode and a cathode;
A layer composed of an organic compound sandwiched between the anode and the cathode,
Either the anode or the cathode is transparent or translucent,
An organic light emitting device, wherein the layer made of the organic compound contains at least one material for an organic light emitting device according to any one of claims 1 to 6.   8. The organic light emitting device according to claim 7, wherein the organic light emitting device material is contained in a hole injection layer.   The organic light emitting device according to claim 7, wherein the organic light emitting device material is contained in a hole transport layer.

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