JP2006019543A - Organic electroluminescence element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic electroluminescence element by which durable light emission is possible. <P>SOLUTION: The organic electroluminescence element comprises at least one layer of an organic compound layer containing a light emission layer having light-emitting material between a pair of electrodes. At least one layer of the organic compound layer contains a compound which has at least one kind of atoms selected from Si, Ge, Sn and Pb and which does not emit light substantially. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a light emitting device capable of emitting light by converting electric energy into light, and more particularly to an organic electroluminescent device.

  An organic electroluminescence (EL) element has attracted attention as a promising display element because it can emit light with high luminance at a low voltage. An important characteristic value of this organic electroluminescence device is external quantum efficiency. The external quantum efficiency is calculated by “external quantum efficiency φ = number of photons emitted from the device / number of electrons injected into the device”, and it can be said that the larger this value, the more advantageous the device in terms of power consumption.

  The external quantum efficiency of the organic electroluminescence device is determined by “external quantum efficiency φ = internal quantum efficiency × light extraction efficiency. In an organic EL device using fluorescence emission from an organic compound, the limit value of the internal quantum efficiency is 25%. Since the light extraction efficiency is about 20%, the limit value of the external quantum efficiency is about 5%.

An element using a triplet light emitting material (phosphorescent material) has been reported as a method for improving the external quantum efficiency of the element by improving the internal quantum efficiency of the organic electroluminescent element (Patent Document 1). This device can improve the external quantum efficiency as compared with a conventional device using fluorescent light emission (singlet light emitting device), and the maximum value of the external quantum efficiency is 8% (external quantum at 100 cd / m ^2). The efficiency has reached 7.5%), but improvement has been desired in terms of durability.
International Publication No. 00/070655 Pamphlet

  An object of the present invention is to provide a light-emitting element with good durability.

The object of the present invention has been achieved by the following means.
<1> An organic electroluminescent device having a light emitting layer containing at least one layer of a host material and a light emitting material between a pair of electrodes, wherein Si, Ge, Sn, and Pb are used as the host material in the light emitting layer. An organic electroluminescent device comprising a metal complex having at least one selected atom and having a bidentate or more ligand.

<2> An organic electroluminescent device having at least one light emitting layer between a pair of electrodes, wherein at least one atom selected from Si, Ge, Sn, and Pb is interposed between the light emitting layer and the cathode. And an organic electroluminescent device comprising a layer containing a metal complex having a bidentate or more ligand.

<3> An organic electroluminescent device having at least one light emitting layer between a pair of electrodes, wherein at least one atom selected from Si, Ge, Sn, and Pb is interposed between the light emitting layer and the anode. And an organic electroluminescent device comprising a layer containing a metal complex having a bidentate or more ligand.

<4> The metal complex of the above metal complex is at least one metal selected from Group 3 to Group 12 metals and Group 13 to Group 6 metals in the Periodic Table <1> > The organic electroluminescent element as described in any one of <3>.

<5> The organic electroluminescent element according to the above <4>, wherein the metal of the metal complex is at least one metal selected from aluminum, gallium, indium, and thallium.

<6> The metal complex having at least one atom selected from Si, Ge, Sn, and Pb and having a bidentate or higher ligand is a compound represented by the following general formula (1). The organic electroluminescent element according to any one of <1> to <5>, wherein:

(Wherein R ^{11 to} R ¹⁴ represent a hydrogen atom or a substituent. At least one group of R ^{11 to} R ¹⁴ is coordinated to a metal atom.)

<7> The metal complex having at least one atom selected from Si, Ge, Sn, and Pb and having a bidentate or higher ligand is a silicon-containing heterocyclic compound having a Si atom in the ring. The organic electroluminescent element as described in <6> above, wherein

<8> The organic electroluminescent element as described in <6> above, wherein the general formula (1) is a compound represented by the following general formula (2).

(In General Formula (2), Q ²¹ represents an atomic group that forms a ring structure, and Q ²² represents an atomic group that forms a nitrogen-containing heterocycle. Z ²¹ and Z ²² are each independently a carbon atom, or Represents a nitrogen atom, M ²¹ represents a metal ion, L ²¹ represents a ligand, silicon is contained in Q ²¹ or Q ²² , or a substituent thereof, m ²¹ represents an integer of 1 to 4, m ²² represents an integer of 0 to 6.)

<9> The organic electroluminescence device according to <6>, wherein the general formula (1) is a compound represented by the following general formula (3).

(In General Formula (3), Q ³¹ represents an atomic group that forms a ring structure, and Q ³² represents an atomic group that forms a nitrogen-containing heterocycle. Z ³¹ and Z ³² are each independently a carbon atom, or Represents a nitrogen atom, M ³¹ represents a metal ion, L ³¹ represents a ligand, X ³¹ represents an oxygen atom, a sulfur atom, or a substituted nitrogen atom, and silicon represents Q ³¹ or Q ³² , or a substitution thereof. (M ³¹ represents an integer of 1 to 4, and m ³² represents an integer of 0 to 6.)

<10> The organic electroluminescent element as described in <6> above, wherein the general formula (1) is a compound represented by the following general formula (4).

(In the general formula (4), Q ⁴¹ and Q ⁴² each represent an atomic group forming a nitrogen-containing heterocycle. Z ⁴¹ and Z ⁴² each independently represent a carbon atom or a nitrogen atom, and M ⁴¹ represents a metal. L ⁴¹ represents a ligand, silicon is contained in Q ⁴¹ or Q ⁴² , or a substituent thereof, m ⁴¹ represents an integer of 1 to 4, and m ⁴² represents an integer of 0 to 6. To express.)

<11> The organic electroluminescence device according to <6>, wherein the general formula (1) is a compound represented by the following general formula (5).

(In the general formula (5), Q ⁵¹ represents an atomic group forming a silicon-containing heterocycle, and R ⁵¹ and R ⁵² represent a substituent. At least one group of Q ⁵¹ , R ⁵¹ and R ⁵² represents , Coordinated to a metal atom.)

<12> The organic electroluminescent element as described in <6> above, wherein the general formula (1) is a compound represented by the following general formula (6).

(In General Formula (6), R ⁶¹ and R ⁶² each represent a substituent, and L ⁶¹ and L ⁶² each represent a group that coordinates to a metal ion.)

<13> The organic electroluminescent element as described in <6> above, wherein the general formula (1) is a compound represented by the following general formula (7).

(In the general formula (7), Q ⁷¹ represents an atomic group forming a nitrogen-containing heterocycle. Z ⁷¹ represents a carbon atom or a nitrogen atom, M ⁷¹ represents a metal ion, and L ⁷¹ represents a ligand. X ⁷¹ represents an oxygen atom, a sulfur atom, or a substituted nitrogen atom, m ⁷¹ represents an integer of 1 to 4, and m ⁷² represents an integer of 0 to 6.)

<14> M ⁷¹ of the compound represented by the general formula (7), aluminum, organic electroluminescent according to the <13>, wherein the at least one metal selected gallium, indium, and thallium Light emitting element.

  ADVANTAGE OF THE INVENTION According to this invention, the light emitting element which can perform highly durable light emission can be provided.

In the first aspect of the present invention, the organic electroluminescent element is an organic electroluminescent element having a light emitting layer containing at least one layer of a host material and a light emitting material between a pair of electrodes (hereinafter referred to as “the element of the present invention”). (Also referred to as “light-emitting element” or “EL element”), which has at least one atom selected from Si, Ge, Sn, and Pb as a host material in the light-emitting layer. It contains a metal complex having a ligand (hereinafter also referred to as “metal complex in the present invention”).
In the organic electroluminescence device of the present invention, the light emitting layer contains a metal complex having at least one atom selected from Si, Ge, Sn, and Pb and having a bidentate or more ligand. Can provide a light-emitting element with good resistance.

In the first aspect of the present invention, the metal complex in the present invention is a compound that acts as a host material and does not substantially emit light in the light emitting element, and is a compound mainly responsible for charge injection and transport in the light emitting layer. The compound itself does not substantially emit light in the light emitting element.
In the present invention, “substantially no light emission” means that the light emission amount from the compound that does not substantially emit light is preferably 5% or less, more preferably 3% or less of the total light emission amount of the entire device. Yes, more preferably 1% or less.
The amount of light emission can be obtained by separating the EL spectrum of the device from the single PL spectrum of the compound and the light emitting material that do not substantially emit light, and comparing the respective areas.

  1st aspect of this invention WHEREIN: It is preferable that content of the metal complex in this invention is 50 to 99.5 mass% with respect to the total mass of this content layer, and is 70 to 99 mass%. % Or less, more preferably 80% by mass or more and 95% by mass or less. By setting it as the said range, it becomes the tendency for luminous efficiency to improve.

The second aspect of the present invention is an organic electroluminescent device having at least one light emitting layer between a pair of electrodes, and is selected from Si, Ge, Sn, and Pb between the light emitting layer and the cathode. It is an organic electroluminescent element characterized by having a layer containing a metal complex having at least one kind of atom and having a bidentate or more ligand.

A third aspect of the present invention is an organic electroluminescent device having at least one light emitting layer between a pair of electrodes, and is selected from Si, Ge, Sn, and Pb between the light emitting layer and the anode. It is an organic electroluminescent element characterized by having a layer containing a metal complex having at least one kind of atom and having a bidentate or more ligand.

  2nd and 3rd aspect of this invention WHEREIN: It is preferable that content of the metal complex in this invention is 50 to 100 mass% with respect to the total mass of this content layer, and is 80 to 100 mass%. More preferably, it is 90 mass% or less, More preferably, it is 90 mass% or more and 100 mass% or less. By setting it as the said range, it becomes the tendency for luminous efficiency to improve.

  As the Si, Ge, Sn, and Pb in the present invention, a silicon atom and a germanium atom are more preferable, a silicon atom is more preferable, and the number of at least one atom selected from Si, Ge, Sn, and Pb is particularly limited. However, it is preferably 1 to 10 in the molecule, more preferably 1 to 6, and still more preferably 1 to 3. By setting it as the above range, the durability of the EL element tends to be improved.

  Hereinafter, among the metal complexes in the present invention, a metal complex having a silicon atom will be described as an example. However, for the compound having a germanium atom, a tin atom, and a lead atom that does not substantially emit light, the silicon atom is replaced with a germanium atom. , Tin atoms, and those replaced with lead atoms can be explained in the same manner, and the preferred ranges are also the same.

The silicon-containing metal complex is a multidentate metal complex having a bidentate or more ligand.
Multidentate coordination means that the ligand is coordinated to the metal at two or more sites (atoms).

  The polydentate ligand having a silicon atom is not particularly limited as long as it has a silicon atom and coordinates in a multidentate manner. However, alkylsilane (methylsilane, isopropylsilane, t-butylsilane, etc.), alkenylsilane ( Vinyl silane), alkynyl silane (ethynyl silane, propargyl silane, etc.), aryl silane (phenyl silane, phenanthryl silane, triphenylenyl silane, etc.), heteroaryl silane (pyridyl silane, pyrazyl silane, imidazolyl silane, thienyl silane, etc.), Alkoxysilanes (methoxysilane, isopropoxysilane, etc.), aryloxysilanes (phenoxysilane, naphthyloxysilane, etc.), heterocyclic oxysilanes (pyridyloxysilane, pyrazolyloxysilane, tetrahydrofuran) Oxysilane etc.), aminosilanes (dimethylamino silane, diphenylamino silane), silicon-containing heterocycle (silole, etc. Azashiroru), such as hydroxyethyl silane (and pyridyl hydroxy silane) and the like.

  Metal complexes having a silicon atom include group 3 to group 12 transition metal complexes of the periodic table (based on IUPAC, 1985 atomic weight table) and group 13 typical metals (Al, Ga, In, Tl) complex, preferably iridium complex, platinum complex, rhenium complex, osmium complex, copper complex, palladium complex, rhodium complex, ruthenium complex, tungsten complex, rare earth complex, zinc complex, aluminum complex, gallium More preferred are complexes, indium complexes, and thallium complexes. Among metal complexes having a carbon-metal bond, iridium complexes, platinum complexes, rhodium complexes, and palladium complexes are more preferred, and iridium complexes and platinum complexes are particularly preferred. Among metal complexes having an oxygen-metal bond, zinc complexes, aluminum complexes, and gallium complexes are more preferable, and aluminum complexes, gallium complexes, indium complexes, and thallium complexes are particularly preferable.

  The metal complex having a silicon atom is preferably a compound represented by the general formula (1), and more preferably a compound represented by the general formulas (2) to (7). By using these metal complexes, the effects of the present invention are more remarkably exhibited.

The general formula (1) will be described.
R ^{11 to} R ¹⁴ represent a hydrogen atom or a substituent. R ¹¹ and R ¹² , and R ¹³ and R ¹⁴ may combine to form a silicon-containing heterocycle (such as a silole ring).

Examples of the substituent represented by R ^{11 to} R ¹⁴ include an alkyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and particularly preferably 1 to 10 carbon atoms such as methyl, And ethyl, iso-propyl, tert-butyl, n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, etc.), an alkenyl group (preferably having 2 to 30 carbon atoms, more preferably carbon 2 to 20, particularly preferably 2 to 10 carbon atoms such as vinyl, allyl, 2-butenyl, 3-pentenyl, etc.), alkynyl group (preferably having 2 to 30 carbon atoms, more preferably carbon 2-20, particularly preferably 2-10 carbon atoms, such as propargyl, 3-pentynyl, etc.), aryl A group (preferably having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenyl, p-methylphenyl, naphthyl, anthranyl, etc.), an amino group (Preferably having 0 to 30 carbon atoms, more preferably 0 to 20 carbon atoms, and particularly preferably 0 to 10 carbon atoms. For example, amino, methylamino, dimethylamino, diethylamino, dibenzylamino, diphenylamino, ditolylamino, etc. And an alkoxy group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 10 carbon atoms, such as methoxy, ethoxy, butoxy, 2-ethylhexyloxy and the like. An aryloxy group (preferably having 6 to 30 carbon atoms, more preferably 6 to 2 carbon atoms). Particularly preferably, it has 6 to 12 carbon atoms, and examples thereof include phenyloxy, 1-naphthyloxy, 2-naphthyloxy and the like, and a heterocyclic oxy group (preferably having 1 to 30 carbon atoms, more preferably carbon numbers). 1 to 20, particularly preferably 1 to 12 carbon atoms, such as pyridyloxy, pyrazyloxy, pyrimidyloxy, quinolyloxy, etc.), acyl groups (preferably 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms). Particularly preferably, it has 1 to 12 carbon atoms, and examples thereof include acetyl, benzoyl, formyl, pivaloyl, etc.), an alkoxycarbonyl group (preferably 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably Has 2 to 12 carbon atoms, for example, methoxycarbonyl, ethoxycarbonyl, etc. It is. ), An aryloxycarbonyl group (preferably having a carbon number of 7 to 30, more preferably a carbon number of 7 to 20, particularly preferably a carbon number of 7 to 12, such as phenyloxycarbonyl), an acyloxy group (preferably Has 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, and examples thereof include acetoxy and benzoyloxy.), An acylamino group (preferably 2 to 30 carbon atoms, More preferably, it has 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, and examples thereof include acetylamino, benzoylamino and the like, and an alkoxycarbonylamino group (preferably 2 to 30 carbon atoms, more preferably carbon atoms). 2 to 20, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonylamino An aryloxycarbonylamino group (preferably having 7 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, and particularly preferably 7 to 12 carbon atoms, such as phenyloxycarbonylamino). A sulfonylamino group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methanesulfonylamino and benzenesulfonylamino), a sulfamoyl group (Preferably having 0 to 30 carbon atoms, more preferably 0 to 20 carbon atoms, and particularly preferably 0 to 12 carbon atoms. Examples thereof include sulfamoyl, methylsulfamoyl, dimethylsulfamoyl, and phenylsulfamoyl. ), A carbamoyl group (preferably having 1 to 30 carbon atoms, more preferably A prime number of 1-20, particularly preferably a carbon number of 1-12, such as carbamoyl, methylcarbamoyl, diethylcarbamoyl, phenylcarbamoyl, etc., an alkylthio group (preferably having a carbon number of 1-30, more preferably a carbon number). 1 to 20, particularly preferably 1 to 12 carbon atoms, for example, methylthio, ethylthio, etc.), arylthio groups (preferably 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably carbon atoms). And a heterocyclic thio group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and particularly preferably 1 to 12 carbon atoms. Pyridylthio, 2-benzimidazolylthio, 2-benzoxazolylthio, 2-benzthiazolylthio Etc. ), A sulfonyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms such as mesyl and tosyl), a sulfinyl group (preferably carbon). 1 to 30, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methanesulfinyl, benzenesulfinyl, etc.), ureido group (preferably 1 to 30 carbon atoms, more Preferably it is C1-C20, Most preferably, it is C1-C12, for example, ureido, methylureido, phenylureido etc. are mentioned), phosphoric acid amide group (preferably C1-C30, more preferably It has 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms. Examples thereof include diethyl phosphoric acid amide and phenyl phosphoric acid amide. Hydroxy group, mercapto group, halogen atom (eg fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group Group, heterocyclic group (preferably having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, and examples of the hetero atom include a nitrogen atom, an oxygen atom and a sulfur atom, specifically, for example, imidazolyl, pyridyl and quinolyl. , Furyl, thienyl, piperidyl, morpholino, benzoxazolyl, benzimidazolyl, benzthiazolyl, carbazolyl group, azepinyl group, etc.), silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms). Particularly preferably having 3 to 24 carbon atoms, such as trimethylsilyl, And silyloxy groups (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, and particularly preferably 3 to 24 carbon atoms. For example, trimethylsilyloxy, triphenylsilyloxy, etc. And the like. These substituents may be further substituted.

R ^{11 to} R ¹⁴ are an alkyl group, an aryl group, a heteroaryl group, an alkenyl group, an alkoxy group, an aryloxy group, an alkylamino group, an arylamino group, a heterocyclic amino group, or a group that is bonded to form a silicon-containing heterocyclic ring. , A hydroxy group and a mercapto group are preferable, and an alkyl group, an aryl group, a heteroaryl group, an alkoxy group, an aryloxy group, and a group which is bonded to form a silicon-containing heterocycle are more preferable, an alkyl group, an aryl group and a heteroaryl group More preferably a group which forms a silicon-containing heterocycle by bonding, a hydroxy group or a mercapto group.

Sites coordinated to metals be contained all in one group of R ¹¹ to R ^14, be contained respectively in two or more groups of R ¹¹ to R ^14, it may be either. Although the atom to coordinate is not specifically limited, A carbon atom, a nitrogen atom, an oxygen atom, and a sulfur atom are preferable, and a carbon atom, an oxygen atom, and a nitrogen atom are more preferable.

The general formula (2) will be described.
Q ²¹ represents an atomic group that forms a ring structure, and Q ²² represents an atomic group that forms a nitrogen-containing heterocycle. Z ²¹ and Z ²² represent a carbon atom or a nitrogen atom, M ²¹ represents a metal ion, and L ²¹ represents a ligand. Silicon is included in Q ²¹ or Q ²² or in these substituents. m ²¹ represents an integer of 1 to 4, and m ²² represents an integer of 0 to 6.

The ring structure formed by Q ²¹ includes a benzene ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, a pyrrole ring, a pyrazole ring, an imidazole ring, a thiophene ring, a thiazole ring, an oxazole ring, a phosphinine ring, and a silole ring. A benzene ring, a pyridine ring, a pyrrole ring, a pyrazole ring, an imidazole ring, an oxazole ring, and a silole ring are more preferable, and a benzene ring, a pyridine ring, a pyrazole ring, an imidazole ring, and a silole ring are more preferable.

The substituent on Q ²¹ is not particularly limited, but is preferably a fluorine atom, a silyl group, or a fluorine-substituted alkyl group, more preferably a fluorine atom or a silyl group, and even more preferably a silyl group.

Q ²² represents an atomic group forming a nitrogen-containing heterocycle. The ring structure to be formed is not particularly limited, and examples thereof include a 5-membered or 6-membered nitrogen-containing aromatic ring. For example, a pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, pyrrole ring, pyrazole ring, imidazole ring, triazole Ring, thiazole ring, oxazole ring, oxadiazole ring, thiadiazole ring, azaphosphinine ring, condensed rings thereof, and tautomers thereof (for example, benzimidazole ring, indolenine ring, quinoline ring, etc.) .

The nitrogen-containing heterocycle formed by Q ²² includes a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, a pyrrole ring, a pyrazole ring, an imidazole ring, a triazole ring, a thiazole ring, an oxazole ring, an oxadiazole ring, a thiadiazole ring, Azaphosphinine ring is preferable, pyridine ring, pyrrole ring, pyrazole ring and imidazole ring are more preferable, and pyridine ring, pyrazole ring and imidazole ring are further preferable.

The substituent on Q ²² is not particularly limited, but is preferably an alkyl group, an aryl group, a dialkylamino group, a diarylamino group, an alkoxy group, an aryloxy group, or a silyl group, an alkyl group, a dialkylamino group, a diarylamino group, An alkoxy group is more preferable, and an alkyl group and a dialkylamino group are more preferable.

Z ²¹ represents a carbon atom or a nitrogen atom, preferably a carbon atom. Z ²² represents a carbon atom or a nitrogen atom, preferably a nitrogen atom.

M ²¹ represents a metal ion, preferably iridium ion, platinum ion, rhenium ion, osmium ion, copper ion, palladium ion, rhodium ion, ruthenium ion, tungsten ion, rare earth ion, zinc ion, aluminum ion or gallium ion.

L ²¹ represents a ligand. Examples of the ligand include “Photochemistry and Photophysics of Coordination Compounds” by Springer-Verlag H. Published in 1987 by Yersin, “Organometallic Chemistry-Fundamentals and Applications-” The ligands described in “Hanabobo, Akio Yamamoto, published in 1982” and the like, preferably halogen ligands (preferably chlorine coordination) Element, fluorine ligand), nitrogen-containing heterocyclic ligand (eg bipyridyl, phenanthroline, phenylpyridine, pyrazolylpyridine, benzimidazolylpyridine), diketone ligand, nitrile ligand, CO ligand, isonitrile coordination Ligands, phosphorus ligands (eg, phosphine derivatives, phosphite ester derivatives, phosphinin derivatives, etc.), carboxylic acid ligands (eg, acetic acid ligands, etc.), more preferably bidentate nitrogen-containing heterocycles Ligands such as bipyridyl, phenanthroline, phenylpyridine, pyrazolylpyridine, benzimidazolylpyridine, Nirupirazoru, or the like).

m ²¹ represents an integer of 1 to 4, and m ²² represents an integer of 0 to 6. The combination of m ²¹ and m ²² is preferably a combination in which the compound represented by the general formula (3) becomes a neutral complex. m ²¹ is preferably 1 to 3, and more preferably 2, 3. m ²² is preferably 0 to 2, 0, 1 are more preferred.

The general formula (3) will be described.
Q ³¹ , Q ³² , Z ³¹ , Z ³² , M ³¹ , L ³¹ , m ³¹ , and m ³² are Q ²¹ , Q ²² , Z ²¹ , Z ²² , M ²¹ , L ²¹ , m ²¹ , and m ²² , respectively. It is synonymous and the preferable range is also the same. X ³¹ represents an oxygen atom, a sulfur atom, or a substituted nitrogen atom (the substituent is an alkyl group, an aryl group, a heterocyclic group, an acyl group, a sulfonyl group, a phosphonyl group, etc.), preferably an oxygen atom or a substituted nitrogen atom, An oxygen atom is more preferable.

The general formula (4) will be described.
Q ⁴¹ represents an atomic group forming a nitrogen-containing heterocycle. Pyrrole ring nitrogen-containing heterocycle formed by Q ^41, a pyrazole ring, an imidazole ring, a triazole ring are preferred, a pyrrole ring, a pyrazole ring, an imidazole ring is more preferably a pyrazole ring, an imidazole ring are more preferred.

The substituent on Q ⁴¹ is not particularly limited, but is preferably a fluorine atom, a silyl group, or a fluorine-substituted alkyl group, more preferably a fluorine atom or a silyl group, and even more preferably a silyl group.

Q ⁴² , Z ⁴¹ , Z ⁴² , M ⁴¹ , L ⁴¹ , m ⁴¹ , and m ⁴² are synonymous with Q ²² , Z ²¹ , Z ²² , M ²¹ , L ²¹ , m ²¹ , and m ²² , respectively. Is the same.

The general formula (5) will be described.
Q ⁵¹ represents a group forming a silicon-containing heterocycle. The silicon-containing heterocyclic compound is not particularly limited as long as it is a silicon-containing heterocyclic ring having a silicon atom in the ring, but a 5-membered or 6-membered silicon-containing heterocyclic compound is preferable, and a 5-membered silicon-containing heterocyclic ring is preferable. Compounds are more preferred, siloles, silazoles and siladiazoles are more preferred, and siloles are particularly preferred.

The substituent on Q ⁵¹ is not particularly limited, but is preferably a fluorine atom, a silyl group, or a fluorine-substituted alkyl group, more preferably a fluorine atom or a fluorine-substituted alkyl group, and even more preferably a fluorine atom.

R ⁵¹ and R ⁵² each represent a substituent. Examples of the substituent include the group described for R ¹¹ , and the preferred range is also the same.

At least one of the atomic group represented by Q ⁵¹ and the group represented by R ⁵¹ and R ⁵² is coordinated to a metal atom. Although the atom to coordinate is not specifically limited, A carbon atom, a nitrogen atom, an oxygen atom, and a sulfur atom are preferable, and a carbon atom, an oxygen atom, and a nitrogen atom are more preferable.

The general formula (6) will be described.
R ⁶¹ and R ⁶² each represent a substituent. Examples of the substituent include the group described for R ¹¹ , and the preferred range is also the same.

L ⁶¹ and L ⁶² each represent a group that coordinates to a metal ion. The atom coordinated to the metal ion in L ⁶¹ and L ⁶² is not particularly limited, but is preferably a carbon atom, a nitrogen atom, an oxygen atom, or a sulfur atom, and more preferably a carbon atom, an oxygen atom, or a nitrogen atom.

  Examples of groups coordinated to metal ions include aryl groups coordinated with carbon atoms (such as phenyl and triphenylenyl groups), alkenyl groups coordinated with carbon atoms (such as vinyl groups), and heteroaryl groups coordinated with carbon atoms. (Pyridyl group, pyrazyl group, pyrimidyl group, pyrazolyl group, imidazolyl group, etc.), heteroaryl group coordinated by nitrogen atom (pyridyl group, pyrazyl group, pyrimidyl group, pyrazolyl group, imidazolyl group, etc.), oxy group (acyloxy group) Aryloxy group, etc.), substituted amino group (acylamino group, sulfonylamino group, alkylamino group, arylamino group, heteroarylamino group etc.), substituted imino group, group coordinated by phosphorus atom (alkylphosphino group, Arylphosphino group, alkoxyphosphino group, aryloxyphosphino group, Heterocyclic oxy phosphino group, a phosphinine group, etc. phosphole group).

L ⁶¹ is preferably an aryl group coordinated with a carbon atom, a heteroaryl group coordinated with a carbon atom, a heteroaryl group coordinated with a nitrogen atom, an oxy group, or a substituted amino group, and an aryl group coordinated with a carbon atom, A heteroaryl group coordinated with a carbon atom and a heteroaryl group coordinated with a nitrogen atom are more preferred, and an aryl group coordinated with a carbon atom is more preferred.

L ⁶² is preferably a heteroaryl group coordinated with a nitrogen atom, a substituted imino group, or a group coordinated with a phosphorus atom, more preferably a heteroaryl group coordinated with a nitrogen atom or a group coordinated with a phosphorus atom, A heteroaryl group coordinated with is more preferred.

The general formula (7) will be described.
R ⁷¹ and R ⁷² each represent a substituent. Examples of the substituent include the group described for R ¹¹ , and the preferred range is also the same.

Q ⁷¹ , Z ⁷¹ , X ⁷¹ , M ⁷¹ , L ⁷¹ , m ⁷¹ , and m ⁷² are the same as Q ³¹ , Z ³¹ , X ³¹ , M ³¹ , L ³¹ , m ³¹ , and m ³² , respectively. Is the same.

  The metal complex having a silicon atom in the present invention preferably has a silicon-metal bond, and more preferably has a silicon-transition metal bond.

  The substituent on the silicon atom constituting the silicon-metal bond is preferably an alkyl group, an aryl group, an amino group, an alkoxy group or a heterocyclic group, more preferably an alkyl group, an aryl group or a heterocyclic group, an alkyl group or an aryl group. A group is further preferred, and an alkyl group is particularly preferred.

  The metal ion constituting the silicon-metal bond may further have another ligand, such as an aryl group coordinated with a carbon atom (phenyl group, triphenylenyl group, etc.), an alkenyl group coordinated with a carbon atom. (Vinyl group, etc.), heteroaryl groups coordinated by carbon atoms (pyridyl group, pyrazyl group, pyrimidyl group, pyrazolyl group, imidazolyl group, etc.), heteroaryl groups coordinated by nitrogen atom (pyridyl group, pyrazyl group, pyrimidyl group) Group, pyrazolyl group, imidazolyl group, etc.), oxy group (acyloxy group, aryloxy group, etc.), substituted amino group (acylamino group, sulfonylamino group, alkylamino group, arylamino group, heteroarylamino group, etc.), substituted imino group Group coordinated by phosphorus atom (alkyl phosphino group, aryl phosphino group, alkoxy group) Phosphino group, aryloxyphosphino group, heterocyclic oxyphosphino group, phosphinin group, phosphole group, etc.), and heteroaryl groups coordinated with nitrogen atoms, substituted imino groups, and groups coordinated with phosphorus atoms Preferably, a heteroaryl group coordinated with a nitrogen atom or a group coordinated with a phosphorus atom is more preferable, and a heteroaryl group coordinated with a nitrogen atom is more preferable.

The T ₁ level (the energy level of the lowest triplet excited state) of the metal complex having a silicon atom is preferably 60 Kcal / mol or more (251.4 KJ / mol or more), 90 Kcal / mol or less (377.1 KJ / mol or less), 62 Kcal / mol or more (259.78 KJ / mol or more), 85 Kcal / mol or less (356.15 KJ / mol or less) is more preferable, 65 Kcal / mol or more (272.35 KJ / mol or more), 80 Kcal / mol or less (335.2 KJ) / Mol or less) is more preferable.

The external quantum efficiency of the light emitting device of the present invention is preferably 5% or more, more preferably 10% or more, and further preferably 13% or more. The value of the external quantum efficiency should be the maximum value of the external quantum efficiency when the device is driven at 20 ° C. or the value of the external quantum efficiency near 100 to 300 cd / m ² when the device is driven at 20 ° C. Can do. The external quantum efficiency in the present invention indicates a value at 300 cd / m ² when the device is driven at 20 ° C.

  The internal quantum efficiency of the light emitting device of the present invention is preferably 30% or more, more preferably 50% or more, and further preferably 70% or more. The internal quantum efficiency of the device is calculated by “internal quantum efficiency = external quantum efficiency / light extraction efficiency”. In a normal organic EL element, the light extraction efficiency is about 20%. However, the shape of the substrate, the shape of the electrode, the thickness of the organic layer, the thickness of the inorganic layer, the refractive index of the organic layer, the refractive index of the inorganic layer, etc. By devising it, it is possible to increase the light extraction efficiency to 20% or more.

  The glass transition point of the metal complex, the host material, the electron transport material, and the hole transport material in the present invention contained in the light emitting layer in the present invention is preferably 90 ° C. or higher and 400 ° C. or lower, and 100 ° C. or higher and 380 ° C. or lower. More preferably, it is more preferably 120 ° C. or more and 370 ° C. or less, and particularly preferably 140 ° C. or more and 360 ° C. or less.

The light emitting material used in the present invention will be described.
A light-emitting material is a compound that has a function of substantially emitting light in a light-emitting layer (hereinafter also referred to as a “light-emitting compound”), and emits both of fluorescence and phosphorescence. However, a compound that substantially emits phosphorescence in the light emitting layer is preferable.
Here, the compound having the function of substantially emitting light means that the light emission amount from the light-emitting compound is 95% or more, preferably 99% or more, more preferably 99% of the total light emission amount of the entire device. 0.5% or more, more preferably 100%.
The organic electroluminescent element of the present invention is more preferably an element in which the light emitting layer does not contain a fluorescent light emitting compound and the phosphorescent light emitting compound substantially emits light.

  The concentration of the light-emitting material in the light-emitting layer is not particularly limited, but is preferably the same amount or less than that of the main component that does not emit light. More preferably, it is 0.2 mass% or more, More preferably, it is 0.2 mass% or more and 30 mass% or less, It is especially preferable that it is 0.3 mass% or more and 20 mass% or less, 0.5 mass% or more 10 mass% or less is the most preferable.

  The phosphorescent light emitting compound is not particularly limited, but a transition metal complex is preferable. Among them, from the viewpoint of light emission efficiency, an iridium complex, a platinum complex, a rhenium complex, a ruthenium complex, a palladium complex, a rhodium complex, or a rare earth complex is more preferable. More preferred are iridium complexes and platinum complexes. Further, ortho-metalated iridium complexes having a difluorophenylpyridine ligand described in JP-A Nos. 2002-235076, 2002-170684, 2001-239281, and 2001-248165 are preferable.

  In addition, US6303238 B1, US6097147, WO 00/57676, WO 00/70655, WO 01/08230, WO 01/39234 A2, WO 01/41512 A1, WO 02/02714 A2, WO 02/15645 A1, JP 2001-151650 A No. 247859, Japanese Patent Application No. 2000-33561, Japanese Patent Application No. 2002-117978, Japanese Patent Application No. 2001-248165, Japanese Patent Application No. 2002-233501, Japanese Patent Application No. 2001-239281, Japanese Patent Application Laid-Open No. 2002-170684, Japanese Patent Application Laid-Open No. 2002-26495, Japanese Patent Application Laid-Open No. 2002-26495. -234894, JP-A-2001-247659, JP-A-2001-298470, JP-A-2002-173675, JP-A-2002-173684, JP-A-2002-203678, JP-A-2002-203 Phosphorescent compounds described in patent documents such as 79 can also be suitably used.

  The phosphorescence lifetime (room temperature) of the phosphorescent compound used in the present invention is not particularly limited, but is preferably 1 ms or less, and in particular, 100 μs from the viewpoint of luminous efficiency and durability in a high luminance region. Is more preferably 10 μs.

The T ₁ level (energy level in the lowest triplet excited state) of the phosphorescent compound in the present invention is preferably 60 Kcal / mol or more (251.4 KJ / mol or more), 90 Kcal / mol or less (377.1 KJ / mol or less). Among these, from the viewpoint of emission wavelength, 62 Kcal / mol or more (259.78 KJ / mol or more) and 85 Kcal / mol or less (356.15 KJ / mol or less) are more preferable, and 65 Kcal / mol or more (272.35 KJ / mol or more). ), 80 Kcal / mol or less (335.2 KJ / mol or less).

The layer adjacent to the light emitting layer (hole transport layer, electron transport layer, hole block layer, exciton block layer, etc.) has a T ₁ level (lowest triplet excited state energy level) of 60 Kcal / mol or more (251.4 KJ / mol or more), 90 Kcal / mol or less (377.1 KJ / mol or less) is preferable, 62 Kcal / mol or more (259.78 KJ / mol or more), 85 Kcal / mol or less (356.15 KJ / mol or less) is more preferable, 65 More preferably, Kcal / mol or more (272.35 KJ / mol or more), 80 Kcal / mol or less (335.2 KJ / mol or less).

  In the present invention, the metal complex having a silicon atom may be a low molecular compound, and an oligomer compound or a polymer compound having a phosphorescent material in the main chain or side chain (weight average molecular weight (polystyrene conversion) is preferred. May be 1000 to 5000000, more preferably 2000 to 1000000, and still more preferably 3000 to 100,000. However, the metal complex is preferably a low molecular compound.

  Next, although the example of the said metal complex in this invention is shown, this invention is not limited to this.

Next, the organic electroluminescent element of the present invention will be described.
The organic electroluminescent element of the present invention is not particularly limited, such as a system, a driving method, and a usage form. An organic EL (electroluminescence) element can be mentioned as a typical organic electroluminescent element.

  The light-emitting element of the present invention can improve the light extraction efficiency by various known devices. For example, by processing the substrate surface shape (for example, forming a fine concavo-convex pattern), controlling the refractive index of the substrate / ITO layer / organic layer, controlling the film thickness of the substrate / ITO layer / organic layer, etc. It is possible to improve light extraction efficiency and external quantum efficiency.

  The light-emitting element of the present invention may be a so-called top emission method (described in Japanese Patent Application Laid-Open Nos. 2003-208109, 2003-248441, 2003-257651, 2003-282261, etc.) in which light emission is extracted from the anode side.

  The substrate used in the light-emitting device of the present invention is not particularly limited, but inorganic materials such as zirconia-stabilized yttrium and glass, polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyethylene, polycarbonate, and polyethersulfone. , Polymer materials such as polyarylate, allyl diglycol carbonate, polyimide, polycycloolefin, norbornene resin, poly (chlorotrifluoroethylene), Teflon (R), polytetrafluoroethylene-polyethylene copolymer, etc. .

  The organic electroluminescent device of the present invention may contain a blue fluorescent light emitting compound in the light emitting layer, or a multicolor light emitting device using the blue light emitting device containing the blue fluorescent compound and the light emitting device of the present invention at the same time. Devices and full-color light emitting devices may be manufactured.

  The light emitting layer of the organic electroluminescent element of the present invention may have at least one laminated structure. The number of stacked layers is preferably 2 or more and 50 or less, more preferably 4 or more and 30 or less, and still more preferably 6 or more and 20 or less.

  The thickness of each layer constituting the stack is not particularly limited, but is preferably 0.2 nm or more and 20 nm or less, more preferably 0.4 nm or more and 15 nm or less, further preferably 0.5 nm or more and 10 nm or less, and more preferably 1 nm or more and 5 nm or less. Especially preferred

The light emitting layer of the organic electroluminescent element of the present invention may have a plurality of domain structures. The light emitting layer may have another domain structure. For example, the light emitting layer, and about 1 nm ³ of a region consisting of a mixture of metal complex A and the light emitting material B of the present invention, it consists of about 1 nm ³ of a region consisting of a mixture of a metal complex C and luminescent material D in the present invention May be. The diameter of each domain is preferably from 0.2 nm to 10 nm, more preferably from 0.3 nm to 5 nm, still more preferably from 0.5 nm to 3 nm, and particularly preferably from 0.7 nm to 2 nm.

  The method for forming the organic layer of the element of the present invention is not particularly limited, but resistance heating vapor deposition, electron beam, sputtering, molecular lamination method, coating method (spray coating method, dip coating method, impregnation method, roll coating) Method, gravure coating method, reverse coating method, roll brush method, air knife coating method, curtain coating method, spin coating method, flow coating method, bar coating method, micro gravure coating method, air doctor coating, blade coating method, squeeze coating Method, transfer roll coat method, kiss coat method, cast coat method, extrusion coat method, wire bar coat method, screen coat method, etc.), ink jet method, printing method, transfer method, etc. Resistant heating vapor deposition, coating method and transfer method are preferred Arbitrariness.

  The light-emitting device of the present invention is a device in which a light-emitting layer or at least one organic layer (organic compound film) including a light-emitting layer is formed between a pair of electrodes of an anode and a cathode. A hole transport layer, an electron injection layer, an electron transport layer, a protective layer, and the like may be provided, and each of these layers may have other functions. Various materials can be used for forming each layer.

  The anode supplies holes to a hole injection layer, a hole transport layer, a light emitting layer, and the like, and a metal, an alloy, a metal oxide, an electrically conductive compound, or a mixture thereof can be used. Is a material having a work function of 4 eV or more. Specific examples include conductive metal oxides such as tin oxide, zinc oxide, indium oxide and indium tin oxide (ITO), metals such as gold, silver, chromium and nickel, and these metals and conductive metal oxides. Inorganic conductive materials such as copper iodide and copper sulfide, organic conductive materials such as polyaniline, polythiophene, and polypyrrole, and laminates of these with ITO, preferably conductive metals It is an oxide, and ITO is particularly preferable from the viewpoint of productivity, high conductivity, transparency, and the like. Although the film thickness of the anode can be appropriately selected depending on the material, it is usually preferably in the range of 10 nm to 5 μm, more preferably 50 nm to 1 μm, still more preferably 100 nm to 500 nm.

As the anode, a layer formed on a soda-lime glass, non-alkali glass, a transparent resin substrate or the like is usually used. When glass is used, it is preferable to use non-alkali glass as the material in order to reduce ions eluted from the glass. Moreover, when using soda-lime glass, it is preferable to use what gave barrier coatings, such as a silica. The thickness of the substrate is not particularly limited as long as it is sufficient to maintain the mechanical strength, but when glass is used, a thickness of 0.2 mm or more, preferably 0.7 mm or more is usually used.
Various methods are used for producing the anode depending on the material. For example, in the case of ITO, an electron beam method, a sputtering method, a resistance heating vapor deposition method, a chemical reaction method (sol-gel method, etc.), a coating of a dispersion of indium tin oxide, etc. A film is formed by this method.
The anode can be subjected to cleaning or other treatments to lower the drive voltage of the element or increase the light emission efficiency. For example, in the case of ITO, UV-ozone treatment, plasma treatment, etc. are effective.

The cathode supplies electrons to the electron injection layer, the electron transport layer, the light emitting layer, etc., and the adhesion, ionization potential, stability, etc., between the negative electrode and the adjacent layer such as the electron injection layer, electron transport layer, light emitting layer, etc. Selected in consideration of As a material for the cathode, a metal, an alloy, a metal halide, a metal oxide, an electrically conductive compound, or a mixture thereof can be used. Specific examples include an alkali metal (for example, Li, Na, K, etc.) and its fluoride. Or oxides, alkaline earth metals (eg Mg, Ca, etc.) and fluorides or oxides thereof, gold, silver, lead, aluminum, sodium-potassium alloys or their mixed metals, lithium-aluminum alloys or their mixtures Examples thereof include metals, magnesium-silver alloys or mixed metals thereof, rare earth metals such as indium and ytterbium, preferably materials having a work function of 4 eV or less, more preferably aluminum, lithium-aluminum alloys or mixed metals thereof. , Magnesium-silver alloys or mixed metals thereof. The cathode can take not only a single layer structure of the compound and the mixture but also a laminated structure including the compound and the mixture. For example, a laminated structure of aluminum / lithium fluoride and aluminum / lithium oxide is preferable. The film thickness of the cathode can be appropriately selected depending on the material, but is usually preferably in the range of 10 nm to 5 μm, more preferably 50 nm to 1 μm, still more preferably 100 nm to 1 μm.
For production of the cathode, methods such as an electron beam method, a sputtering method, a resistance heating vapor deposition method, a coating method, and a transfer method are used, and a metal can be vapor-deposited alone or two or more components can be vapor-deposited simultaneously. Furthermore, a plurality of metals can be vapor-deposited simultaneously to form an alloy electrode, or a previously prepared alloy may be vapor-deposited.
The sheet resistance of the anode and the cathode is preferably low, and is preferably several hundred Ω / □ or less.

The host material in the light-emitting layer can inject holes from the anode or hole injection layer and hole transport layer when an electric field is applied, and can inject electrons from the cathode or electron injection layer and electron transport layer. Alternatively, any layer can be used as long as it can form a layer having a function of moving injected charges and a function of emitting light by providing a recombination field of holes and electrons.
In addition to the metal complex in the present invention, for example, benzoxazole, benzimidazole, benzothiazole, styrylbenzene, polyphenyl, diphenylbutadiene, tetraphenylbutadiene, naphthalimide, coumarin, perylene, perinone, oxadiazole, aldazine, pyralidine, cyclohexane Pentadiene, bisstyrylanthracene, quinacridone, pyrrolopyridine, thiadiazolopyridine, cyclopentadiene, styrylamine, aromatic dimethylidin compounds, various metal complexes represented by 8-quinolinol metal complexes and rare earth complexes, polythiophene, polyphenylene, polyphenylene vinylene Polymer compounds such as organic silanes, iridium trisphenylpyridine complexes, and transition metal complexes represented by platinum porphyrin complexes, Beauty, derivatives thereof. Although the film thickness of a light emitting layer is not specifically limited, Usually, the thing of the range of 1 nm-5 micrometers is preferable, More preferably, it is 5 nm-1 micrometer, More preferably, it is 10 nm-500 nm.
The method for forming the light emitting layer is not particularly limited, and methods such as resistance heating vapor deposition, electron beam, sputtering, molecular lamination method, coating method, ink jet method, printing method, LB method, and transfer method are used. Of these, resistance heating vapor deposition and coating are preferred.

The light emitting layer may be composed of a single compound of a light emitting material, or may be formed of a plurality of compounds.
There may be one or a plurality of light emitting layers, and each layer may emit light with a different emission color, for example, white light. White light may be emitted from a single light emitting layer.

The material of the hole injection layer and the hole transport layer may be any one having a function of injecting holes from the anode, a function of transporting holes, or a function of blocking electrons injected from the cathode. Good.
Specific examples thereof include the carbazole, triazole, oxazole, oxadiazole, imidazole, polyarylalkane, pyrazoline, pyrazolone, phenylenediamine, arylamine, amino-substituted chalcone, styrylanthracene, and fluorenone in addition to the above-mentioned compounds that do not substantially emit light. Hydrazone, stilbene, silazane, aromatic tertiary amine compound, styrylamine compound, aromatic dimethylidin compound, porphyrin compound, polysilane compound, poly (N-vinylcarbazole), aniline copolymer, thiophene oligomer, Examples thereof include conductive polymer oligomers such as polythiophene, organic silanes, carbon films, and derivatives thereof.
The film thicknesses of the hole injection layer and the hole transport layer are not particularly limited, but are usually preferably in the range of 1 nm to 5 μm, more preferably 5 nm to 1 μm, and still more preferably 10 nm to 500 nm. . The hole injection layer and the hole transport layer may have a single-layer structure composed of one or more of the materials described above, or may have a multilayer structure composed of a plurality of layers having the same composition or different compositions.
As a method for forming the hole injection layer and the hole transport layer, a vacuum deposition method, an LB method, a method in which the hole injection transport material is dissolved or dispersed in a solvent, a coating method, an ink jet method, a printing method, or a transfer method is used. It is done. In the case of the coating method, it can be dissolved or dispersed together with the resin component. Examples of the resin component include polyvinyl chloride, polycarbonate, polystyrene, polymethyl methacrylate, polybutyl methacrylate, polyester, polysulfone, polyphenylene oxide, polybutadiene, and poly (N -Vinyl carbazole), hydrocarbon resin, ketone resin, phenoxy resin, polyamide, ethyl cellulose, vinyl acetate, ABS resin, polyurethane, melamine resin, unsaturated polyester resin, alkyd resin, epoxy resin, silicone resin, and the like.

The material for the electron injection layer and the electron transport layer may be any material having any one of a function of injecting electrons from the cathode, a function of transporting electrons, and a function of blocking holes injected from the anode. Specific examples thereof include the metal complex in the present invention, triazole, oxazole, oxadiazole, imidazole, fluorenone, anthraquinodimethane, anthrone, diphenylquinone, thiopyran dioxide, carbodiimide, fluorenylidenemethane, distyryl. Various metal complexes such as pyrazine, naphthalene, perylene and other aromatic ring tetracarboxylic anhydrides, metal complexes of phthalocyanine, 8-quinolinol, metal phthalocyanine, metal complexes having benzoxazole and benzothiazole as ligands, organic silanes And derivatives thereof.
Although the film thickness of an electron injection layer and an electron carrying layer is not specifically limited, The thing of the range of 1 nm-5 micrometers is preferable normally, More preferably, it is 5 nm-1 micrometer, More preferably, it is 10 nm-500 nm. The electron injection layer and the electron transport layer may have a single layer structure composed of one or more of the above-described materials, or may have a multilayer structure composed of a plurality of layers having the same composition or different compositions.
As a method for forming the electron injection layer and the electron transport layer, a vacuum vapor deposition method, an LB method, a method in which the electron injection transport material is dissolved or dispersed in a solvent, a coating method, an ink jet method, a printing method, a transfer method, and the like are used. In the case of the coating method, it can be dissolved or dispersed together with the resin component. As the resin component, for example, those exemplified in the case of the hole injection transport layer can be applied.

As a material for the protective layer, any material may be used as long as it has a function of preventing substances that promote device deterioration such as moisture and oxygen from entering the device. Specific examples thereof include metals such as In, Sn, Pb, Au, Cu, Ag, Al, Ti, and Ni, MgO, SiO, SiO ₂ , Al ₂ O ₃ , GeO, NiO, CaO, BaO, and Fe ₂ O. ₃ , metal oxides such as Y ₂ O ₃ and TiO ₂ , metal fluorides such as MgF ₂ , LiF, AlF ₃ , and CaF ₂ , SiN _x , SiO _x N _y Such as nitride, polyethylene, polypropylene, polymethyl methacrylate, polyimide, polyurea, polytetrafluoroethylene, polychlorotrifluoroethylene, polydichlorodifluoroethylene, copolymer of chlorotrifluoroethylene and dichlorodifluoroethylene, tetrafluoroethylene And a copolymer obtained by copolymerizing a monomer mixture containing at least one comonomer, a fluorine-containing copolymer having a cyclic structure in the copolymer main chain, a water-absorbing substance having a water absorption of 1% or more, a water absorption of 0 .1% or less of moisture-proof substances and the like.
There is no particular limitation on the method for forming the protective layer. For example, vacuum deposition, sputtering, reactive sputtering, MBE (molecular beam epitaxy), cluster ion beam, ion plating, plasma polymerization (high frequency excitation ions) Plating method), plasma CVD method, laser CVD method, thermal CVD method, gas source CVD method, coating method, printing method, and transfer method can be applied.

  The use of the light emitting device of the present invention is not particularly limited, but is suitable for the fields of display device, display, backlight, electrophotography, illumination light source, recording light source, exposure light source, reading light source, sign, signboard, interior, optical communication, etc. Can be used.

  Hereinafter, the present invention will be specifically described, but the present invention is not limited thereto.

[Example 1]
The cleaned ITO substrate was put into a vapor deposition apparatus, and NPD (N, N′-di-α-naphthyl-N, N′-diphenyl) -benzidine) was vapor-deposited to 40 nm. On top of this, Ir (piq) ₃ and the compound (1-1) were deposited in a ratio of 6:94 (mass ratio) by 30 nm. Further, 6 nm of BAlq was vapor-deposited thereon, and Alq (tris (8-hydroxyquinoline) aluminum complex) was vapor-deposited thereon by 20 nm. On top of this, magnesium and silver were co-evaporated at a ratio of 10: 1 (molar ratio) to 100 nm to produce an EL device.
DC constant voltage (10V) using Toyo Technica source measure unit type 2400
Was applied to the EL element to emit light, red light emission was obtained.
When the driving durability of the device was performed at an initial luminance of 100 cd / m ² , the luminance half time was about twice that of the device of the comparative example.

[Comparative Example] (WO 00/70655 element described in Example 1)
The cleaned ITO substrate was put in a vapor deposition apparatus, and NPD was vapor-deposited by 40 nm. On top of this, Ir (ppy) ₃ and CBP were vapor-deposited at a ratio of 6:94 (mass ratio) of 30 nm, and BCP (2,9-dimethyl-4,7-diphenyl-phenanthroline) was vapor-deposited thereon at 6 nm. On top of this, 20 nm of Alq was deposited. On top of this, magnesium and silver were co-evaporated at a ratio of 10: 1 (molar ratio) to 100 nm to produce an EL device.
As a result of applying a constant DC voltage (10V) to the EL element to emit light using a source measure unit 2400 type manufactured by Toyo Technica,
Green emission was obtained.

  Similar effects can be obtained with other elements using a metal complex having a silicon atom and coordinating in a multidentate manner. Moreover, the same effect can be obtained also in an element using the compound of the present invention for an electron transport layer, a hole block layer, a hole transport layer and the like.

Claims (8)

An organic electroluminescent element having a light emitting layer containing at least one layer of a host material and a light emitting material between a pair of electrodes, wherein the light emitting layer has at least selected from Si, Ge, Sn, and Pb as a host material An organic electroluminescent device comprising a metal complex having a kind of atom and having a bidentate or more ligand. An organic electroluminescent device having at least one light emitting layer between a pair of electrodes, and having at least one atom selected from Si, Ge, Sn, and Pb between the light emitting layer and the cathode, An organic electroluminescence device comprising a layer containing a metal complex having a bidentate or more ligand. An organic electroluminescent device having at least one light emitting layer between a pair of electrodes, and having at least one atom selected from Si, Ge, Sn, and Pb between the light emitting layer and the anode, An organic electroluminescence device comprising a layer containing a metal complex having a bidentate or more ligand. The metal of the metal complex is at least one metal selected from metals in Groups 3 to 12 of the periodic table and metals in Group 13 of Periods 3 to 6. The organic electroluminescent element as described in any one. The organic electroluminescent element according to claim 4, wherein the metal of the metal complex is at least one metal selected from aluminum, gallium, indium, and thallium. The metal complex having at least one atom selected from Si, Ge, Sn, and Pb and having a bidentate or higher ligand is a compound represented by the following general formula (1): The organic electroluminescent element according to claim 1.

(Wherein R ^{11 to} R ¹⁴ represent a hydrogen atom or a substituent. At least one group of R ^{11 to} R ¹⁴ is coordinated to a metal atom.) The organic electroluminescence device according to claim 6, wherein the general formula (1) is a compound represented by the following general formula (7).

(In the general formula (7), Q ⁷¹ represents an atomic group forming a nitrogen-containing heterocycle. Z ⁷¹ represents a carbon atom or a nitrogen atom, M ⁷¹ represents a metal ion, and L ⁷¹ represents a ligand. X ⁷¹ represents an oxygen atom, a sulfur atom, or a substituted nitrogen atom, m ⁷¹ represents an integer of 1 to 4, and m ⁷² represents an integer of 0 to 6.) The organic electroluminescent device of claim 7, M ⁷¹ of the compound represented by the general formula (7), wherein aluminum, gallium, indium, and is at least one metal selected from thallium.