JP5577700B2 - ORGANIC ELECTROLUMINESCENT MATERIAL, ORGANIC ELECTROLUMINESCENT ELEMENT, DISPLAY DEVICE AND LIGHTING DEVICE - Google Patents

Description

  The present invention relates to a new compound, an organic electroluminescence element containing the compound, a display device using the same, and an illumination device.

  Conventionally, as a light-emitting electronic display device, there is an electroluminescence display (hereinafter referred to as ELD). Examples of constituent elements of ELD include inorganic electroluminescent elements and organic electroluminescent elements (hereinafter referred to as organic EL elements). Inorganic electroluminescent elements have been used as planar light sources, but an alternating high voltage is required to drive the light emitting elements. An organic EL device has a structure in which a light emitting layer containing a compound that emits light is sandwiched between a cathode and an anode, injects electrons and holes into the light emitting layer, and recombines them to generate excitons (exciton). It is an element that emits light by using light emission (fluorescence / phosphorescence) when this exciton is deactivated, and can emit light at a voltage of about several volts to several tens of volts, and it is self-luminous. In addition, it is attracting attention from the viewpoints of space saving, portability and the like because it is a thin film type complete solid element with a wide viewing angle and high visibility.

  However, in organic EL elements for practical use in the future, development of organic EL elements that emit light efficiently and with high luminance with lower power consumption is desired.

  In Japanese Patent No. 3093796, a small amount of a phosphor is doped into a stilbene derivative, a distyrylarylene derivative or a tristyrylarylene derivative to achieve an improvement in light emission luminance and a longer device lifetime. Further, an element having an organic light-emitting layer in which an 8-hydroxyquinoline aluminum complex is used as a host compound and a small amount of phosphor is doped thereto (for example, JP-A 63-264692), and an 8-hydroxyquinoline aluminum complex is used as a host compound. For example, an element having an organic light emitting layer doped with a quinacridone dye (for example, JP-A-3-255190) is known.

  As described above, when light emission from excited singlet is used, the generation ratio of singlet excitons and triplet excitons is 1: 3, and thus the generation probability of luminescent excited species is 25%. Since the efficiency is about 20%, the limit of the external extraction quantum efficiency (η) is set to 5%.

  However, since Princeton University reported on an organic EL device using phosphorescence emission from an excited triplet (MA Baldo et al., Nature, 395, 151-154 (1998)), Research on materials that exhibit phosphorescence has become active.

  For example, M.M. A. Baldo et al. , Nature, 403, 17, 750-753 (2000), US Pat. No. 6,097,147, and the like.

  When the excited triplet is used, the upper limit of the internal quantum efficiency is 100%. In principle, the luminous efficiency is four times that of the excited singlet. Therefore, it is attracting attention as a lighting application.

  For example, S.M. Lamansky et al. , J .; Am. Chem. Soc. , 123, 4304 (2001), etc., many compounds are being studied for synthesis centering on heavy metal complexes such as iridium complexes.

  In addition, the aforementioned M.I. A. Baldo et al. , Nature, 403, 17, 750-753 (2000), studies have been made using tris (2-phenylpyridine) iridium as a dopant.

In addition, M.M. E. Thompson et al. In The 10th International Works on Inorganic and Organic Electroluminescence (EL'00, Hamamatsu) used L ₂ Ir (acac), for example, (ppy) ₂ Ir (acac), e 0 g, Tetsuo Tsutsui, etc., again The 10th International Workshop on Inorganic and Organic Electroluminescence (EL'00, Hamamatsu), the dopant as tris (2-(p-tolyl) pyridine) iridium (Ir _{(ptpy) 3),} tris ( Studies using benzo [h] quinoline) iridium (Ir (bzq) ₃ ) and the like are being conducted (note that these metal complexes are generally called ortho-metalated iridium complexes).

  In addition, the S. Lamansky et al. , J .; Am. Chem. Soc. , 123, 4304 (2001), Patent Document 4 and the like, attempts have been made to form devices using various iridium complexes.

  In order to obtain high luminous efficiency, in the 10th International Works on Inorganic and Organic Electroluminescence (EL'00, Hamamatsu), Ikai et al. Uses a hole transporting compound as a host of a phosphorescent compound. In addition, M.M. E. Thompson et al. Use various electron transporting materials as a host of phosphorescent compounds, doped with a novel iridium complex.

  For example, JP 2002-332291 A, 2002-332292, 2002-338588, 2002-226495, 2002-234894, Inorganic Chemistry, Vol. 41, No. 12, 3055. ˜3066 (2002), etc. are also drawing attention to orthometalated complexes in which the central metal is platinum instead of iridium. With respect to this type of complex, many examples are known in which ligands are characterized.

  In either case, the light emission brightness and light emission efficiency of the light emitting device are greatly improved compared to conventional devices because the emitted light is derived from phosphorescence. There was a problem that it was lower than the conventional element. As described above, it is difficult for phosphorescent highly efficient light-emitting materials to shorten the light emission wavelength and improve the light emission lifetime of the device, and the performance that can withstand practical use cannot be sufficiently achieved.

  Also, International Publication No. 02/15645 pamphlet, Japanese Patent Application Laid-Open No. 2003-123982, Japanese Patent Publication No. 2002-117978, Japanese Patent Publication No. 2003-146996, International Publication No. 04/016711 pamphlet, Inorganic Chemistry, Vol. 41, No. 12, 3055-3066 (2002), Applied Physics Letters, 79, 2082 (2001), Applied Physics Letters, 83, 3818 (2003), New Journal of Chemistry, 26. 1171 (2002), regarding the shortening of the wavelength, an electron withdrawing group such as a fluorine atom, a trifluoromethyl group, a cyano group or the like has been introduced into phenylpyridine as a substituent. It is known that picolinic acid and pyrazabole-based ligands are introduced as ligands. However, with these ligands, the emission wavelength of the luminescent material is shortened to achieve blue, and a highly efficient device is achieved. On the other hand, since the light emission lifetime of the device is greatly deteriorated, improvement of the trade-off has been demanded.

  A phosphorescent high-efficiency light-emitting material is difficult to shorten the emission wavelength and improve the light-emission lifetime of the device, and has not been able to achieve sufficient performance for practical use.

  As a means for improving the lifetime of the organic EL material, development focusing on the structure of the luminescent dopant has been promoted, and as a result, a structure that can withstand practical use is being found. However, small changes in structure, such as introduction of substituents into dopants, have a significant effect on lifetime, and there remains a problem to be solved.

  For example, metal complexes having phenylpyrazole as a ligand are known (see, for example, Patent Documents 1 and 2). However, although the phenyl radical substitution mode disclosed herein improves the light emitting device lifetime, it is still not sufficient, and there is still room for improvement from the viewpoint of light emission efficiency.

  Until now, there have been many approaches to control the wavelength and improve the lifetime by introducing a substituent into the basic skeleton of the dopant, but it cannot be said to have been successful. Therefore, paying attention to the structure of the host material used in the light-emitting layer together with the dopant compound, and introducing a structure similar to the partial structure of the host compound as the partial structure of the dopant, there is a tendency that the lifetime is improved in some structures. It was. In particular, it has been found that the tendency is remarkable by introducing a condensed ring containing a nitrogen-containing heterocycle as a partial structure of the dopant.

  This tendency is thought to be due to a good interaction with the host compound by introducing a specific condensed ring into the partial structure of the dopant, particularly a condensed ring containing a nitrogen-containing heterocycle, It is considered that the introduction of an indole ring derivative or a carbazole ring derivative makes a good interaction with the host remarkable.

Up to now, examples of introducing a carbazole ring derivative as a partial structure of a dopant compound have been disclosed in Patent Document 3, Patent Document 4 and the like, but specific description about the introduction position and specific description of the introduction effect The originality of the present invention is not impaired. In addition, the knowledge regarding the formula weight of the condensed ring including the nitrogen-containing heterocycle and the element lifetime when considered as a substituent has never been suggested so far, and is a completely new knowledge.
International Publication No. 04/085450 Pamphlet JP 2005-53912 A International Publication No. 2006/121811 Pamphlet International Publication No. 2006/046980 Pamphlet

  An object of the present invention is to provide a novel compound, an organic EL element, an illumination device, and a display device that contain the novel compound, have high external extraction quantum efficiency, and have a long lifetime.

The above object of the present invention is achieved by the following configurations 1 to 21. Specifically, according to the present invention, in the following configuration 3, the linking group is a phenylene group, a dibenzofurylene group, a carbazolylene group, or these There is provided an organic electroluminescent device material which is a divalent group in which a plurality of groups are bonded .

  1. An organic electroluminescent material comprising at least one compound containing a partial structure represented by the general formula (1).

(Wherein R ^{1 to} R ⁴ represent a hydrogen atom or a substituent, and at least one of R ¹ or R ² has a condensed ring containing at least one nitrogen atom as a partial structure and has a formula weight of 100 or more. And the sum of the formula weights of the substituents represented by R ^{1 to} R ⁴ is 1000 to 10000. n1 represents an integer of 0 to 4, and Q is necessary to form an aromatic hydrocarbon ring. Represents an atomic group, and M represents a transition metal.)
2. 2. The organic electroluminescent material according to 1 above, wherein the compound containing the partial structure represented by the general formula (1) is represented by the following general formula (1a).

(Wherein R ^{1 to} R ⁴ represent a hydrogen atom or a substituent , and at least one of R ¹ or R ² has a condensed ring containing at least one nitrogen atom as a partial structure and has a formula weight of 100 or more. And the sum of the formula weights of the substituents represented by R ^{1 to} R ⁴ is 1000 to 10000. n1 represents an integer of 0 to 4, and Q is necessary to form an aromatic hydrocarbon ring. Represents an atomic group, and M represents a transition metal.)
3. 2. The organic electroluminescent material according to 1 above, wherein the compound containing the partial structure represented by the general formula (1) is represented by the following general formula (1b).

(Wherein R ¹ represents a hydrogen atom, a 3-carbazolyl group or an N-carbazolyl group linked via a linking group, but at least one N-carbazolyl group linked via a linking group or a N-carbazolyl group) Represents a carbazolyl group, and the linking group is a divalent group derived from a phenyl group or a dibenzofuryl group, R ² represents an alkyl group or a substituent represented by the following general formula (2): R ³ And R ⁴ represents a hydrogen atom, n1 represents an integer of 0 to 4, Q represents a benzene ring, and M represents iridium.)
(Wherein, ^{R 5} is, .N2 represents a hydrogen atom or an alkyl group is an integer of 0-5.)
4). 2. The organic electroluminescent material according to 1 above, wherein the compound containing the partial structure represented by the general formula (1) is represented by the following general formula (1c).
(Wherein R ¹ , R ³ and R ⁴ represent a hydrogen atom. R ² represents a substituent represented by the following general formula (3). N1 represents an integer of 0 to 4, and Q represents Represents a benzene ring, and M represents iridium.)
(Wherein R ⁶ represents a hydrogen atom or a carbazolyl group or indolyl group linked via two or more linking groups, at least one being a carbazolyl group or indolyl linked via two or more linking groups) And the linking group represents a divalent group derived from a phenyl group, a carbazolyl group, or a dibenzofuryl group, and n3 represents an integer of 0 to 3.)

5 . In one general formula ^(1), an organic electroluminescent material according to the 1 the sum of the formula weight of the substituent represented by R 1 to R ⁴ is characterized in that it is a 1500 to 5000.

6 . Substituents represented by R ¹ to R ⁴ in one general formula (1), was or, substituents represented by R ^6, at least one indole ring derivatives as a partial structure in one general formula (3) 4. The organic electroluminescent material according to 1 or 3, which is contained .

7 . Substituents represented by R ¹ to R ⁴ in one general formula (1), was or, substituents represented by R ^6, at least one carbazole ring derivatives as a partial structure in one general formula (3) 4. The organic electroluminescent material according to 1 or 3, which is contained .

8 . In one general formula (1), an organic electroluminescent material according to the 1 aromatic hydrocarbon ring formed by Q is characterized in that it is a benzene ring.

9 . In one general formula (1), an organic electroluminescent material according to above, wherein the substituent represented by R ³ and R ⁴ are hydrogen atoms.

10 . The organic electroluminescent material according to the 1 substituent represented by R ¹ is characterized by containing at least two fused rings in one general formula (1).

11 . In one general formula (3), an organic electroluminescent material according to the 3, wherein the substituent represented by R ⁶ contains an indole ring derivative as a partial structure.

12 . In one general formula (3), an organic electroluminescent material according to the 3, wherein the substituent represented by R ⁶ contains a carbazole ring derivative as a partial structure.

13 . In one general formula (3), an organic electroluminescent material according to the 3, wherein the substituent represented by R ⁶ contains at least three carbazole ring derivative.

14 . In one general formula (3), an organic electroluminescent material according to the 3 wherein the amount of substituents represented by ^{R 6} is characterized in that 500 to 2,000.

15. The substituent represented by R ¹ is composed of a linking group and a condensed ring containing at least one nitrogen atom, and the linking group is bonded to an aromatic hydrocarbon ring formed by Q. The organic electroluminescent material according to any one of 1 , 2 and 5 to 14.

16. The substituent represented by R ¹ represents a condensed ring containing at least one nitrogen atom, and the carbon atom on the condensed ring is bonded to the aromatic hydrocarbon ring formed by Q. The organic electroluminescent material according to any one of 1 , 2, and 5 to 14.

  17. The organic electroluminescent element characterized by containing the organic electroluminescent material of any one of said 1-16.

  18. The organic electroluminescent material of any one of said 1-16 is contained in a light emitting layer, The organic electroluminescent element characterized by the above-mentioned.

  19. 17. An organic electroluminescence device, wherein an organic layer containing the organic electroluminescence material according to any one of 1 to 16 is formed by a wet process.

  20. 20. A display device comprising the organic electroluminescence element according to any one of 17 to 19 above.

  21. 20. An illumination device comprising the organic electroluminescence element according to any one of 17 to 19 above.

  According to the present invention, it was possible to provide a novel compound, an organic EL element, an illumination device, and a display device that include the novel compound, have a high external extraction quantum efficiency, and have a long lifetime.

It is the schematic diagram which showed an example of the display apparatus comprised from an organic EL element. It is a schematic diagram of a display part. It is the schematic of an illuminating device. It is sectional drawing of an illuminating device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Display 3 Pixel 5 Scanning line 6 Data line A Display part B Control part 107 Glass substrate with a transparent electrode 106 Organic EL layer 105 Cathode 102 Glass cover 108 Nitrogen gas 109 Water catching agent

In the compound of this invention, it has succeeded in obtaining the compound (it is also called a metal complex) effective in formation of an organic electroluminescent element by having the structure of any one of Claims 1-16 , Using the compound, it was possible to obtain an organic electroluminescence device (organic EL device) having high external extraction quantum efficiency and long device lifetime (improving robustness). Moreover, it succeeded also in obtaining the display apparatus and the illuminating device which comprised the said organic EL element.

  Hereinafter, details of each component according to the present invention will be sequentially described.

<< Compound Containing Partial Structure Represented by General Formula (1) >>
The compound containing the partial structure represented by the general formula (1) of the present invention will be described.

In the general formula (1), R ^{1 to} R ⁴ each represents a hydrogen atom or a substituent, and at least one of R ^{1 and} R ² has a condensed ring containing at least one nitrogen atom as a partial structure and has a formula weight of 100 or more. N represents an integer of 0 to 4, Q represents an atomic group necessary for forming an aromatic hydrocarbon ring, and M represents a transition metal.

In the general formula (1), examples of the substituent represented by R ^{1 to} R ⁴ include an alkyl group (for example, methyl group, ethyl group, propyl group, isopropyl group, tert-butyl group, pentyl group, hexyl group, octyl group). Group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, etc.), cycloalkyl group (for example, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (for example, vinyl group, allyl group, 1-propenyl group, 2-butenyl group) 1,3-butadienyl group, 2-pentenyl group, isopropenyl group, etc.), alkynyl group (for example, ethynyl group, propargyl group, etc.), aromatic hydrocarbon group (aromatic carbocyclic group, aryl group, etc.), For example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, Renyl group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group, etc.), aromatic heterocyclic group (for example, furyl group, thienyl group, pyridyl group, pyridazinyl group, pyrimidinyl group, pyrazinyl group, triazinyl group) A group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, a quinazolinyl group, a carbazolyl group, a carbolinyl group, a diazacarbazolyl group (in which one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom ), Phthalazinyl group, etc.), heterocyclic group (eg, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.), alkoxy group (eg, methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group) , Octyloxy group Dodecyloxy group etc.), cycloalkoxy group (eg cyclopentyloxy group, cyclohexyloxy group etc.), aryloxy group (eg phenoxy group, naphthyloxy group etc.), alkylthio group (eg methylthio group, ethylthio group, propylthio group) , Pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio group (eg, cyclopentylthio group, cyclohexylthio group etc.), arylthio group (eg, phenylthio group, naphthylthio group etc.), alkoxycarbonyl group (eg, Methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl group (for example, phenyloxycarbonyl group) Group, naphthyloxycarbonyl group, etc.), sulfamoyl group (for example, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecyl) Aminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), acyl group (for example, acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc.), acyloxy group (for example, Cetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), amide group (for example, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, Propylcarbonylamino group, pentylcarbonylamino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbonylamino group, octylcarbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group (for example, amino Carbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexyl Aminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), ureido group (for example, methylureido group, ethylureido) Group, pentylureido group, cyclohexylureido group, octylureido group, dodecylureido group, phenylureido group, naphthylureido group, 2-pyridylaminoureido group, etc.), sulfinyl group (for example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, Cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group, phenylsulfinyl group, naphthylsulfinyl group, 2-pyridylsulfi Nyl group, etc.), alkylsulfonyl group (eg, methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group, etc.), arylsulfonyl group or heteroarylsulfonyl group (eg, Phenylsulfonyl group, naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.), amino group (for example, amino group, ethylamino group, dimethylamino group, butylamino group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, Anilino group, naphthylamino group, 2-pyridylamino group, etc.), halogen atom (eg, fluorine atom, chlorine atom, bromine atom etc.), fluorinated hydrocarbon group (eg, fluoromethyl group, trifluoromethyl group, pentafluoro) Til group, pentafluorophenyl group, etc.), cyano group, nitro group, hydroxy group, mercapto group, silyl group (for example, trimethylsilyl group, triisopropylsilyl group, triphenylsilyl group, phenyldiethylsilyl group, etc.), phosphono group, etc. Is mentioned.

  These substituents may be further substituted with the above substituents. In addition, a plurality of these substituents may be bonded to each other to form a ring.

In the general formula (1), among the substituents represented by R _{1 to} R ₄ , at least one of R _{1 and} R ₂ has a formula weight of 100 having a condensed ring containing at least one nitrogen atom as a partial structure. Examples of the condensed ring containing the above substituents and containing at least one nitrogen atom include indole ring, carbazole ring, carboline ring, diazacarbazole ring, etc., preferably carbazole ring, carboline And a diazacarbazole ring (in which one of carbon atoms constituting the carboline ring of the carboline ring is replaced by a nitrogen atom), and a carbazole ring is most preferable.

  Q represents an atomic group necessary for forming an aromatic hydrocarbon ring, and is also referred to as an aromatic hydrocarbon ring group (also referred to as an aromatic carbocyclic group, an aryl group, etc., for example, a phenyl group, a p-chlorophenyl group, Mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group, metaterphenylyl group, etc., preferably A phenyl group (benzene ring), a biphenylyl group (biphenyl ring), a metaterphenylyl group, etc., each having a substituent.

  In addition, examples of the substituent include alkyl groups (for example, methyl group, ethyl group, propyl group, isopropyl group, tert-butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group). Group) and alkoxy groups (for example, methoxy group, ethoxy group, propyloxy group, isopropyloxy group, tert-butyloxy group, pentyloxy group, hexyloxy group, octyloxy group, dodecyloxy group, etc.) are preferable. Is preferably a branched alkyl group (for example, isopropyl group, tert-butyl group and the like) or a branched alkoxy group (for example, isopropyloxy group, tert-butyloxy group and the like).

  Examples of the transition metal represented by M include ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and gold. More preferred are iridium and platinum.

In the general formula (1), the substituent represented by R ² is preferably represented by the following general formula (2) or general formula (3).

In the formula, the substituent represented by R ⁵ represents a hydrogen atom or a substituent, and n2 represents an integer of 0 to 5. Here, the substituent represented by R ⁵ has the same definition as that described for R ^{1 to} R ⁴ in the general formula (1).

In the formula, the substituent represented by R ⁶ similarly represents a hydrogen atom or a substituent, and n3 represents an integer of 0 to 3.

Further, in the general formula ^(1), preferably formula weight of the sum of the substituents represented by R 1 to R ⁴ is 1,000 to 10,000, ^more, substituents represented by R 1 to R ⁴ The total sum of the formula weights is preferably 1500 to 5000.

The substituent represented by R ^{1 to} R ⁴ in the general formula (1), the substituent represented by R ⁵ in the general formula (2), or R ⁶ in the general formula (3) At least one of the substituted groups preferably contains an indole ring derivative as a partial structure. Here, the indole ring derivative includes those having a substituted indole ring having an indole skeleton and those having an indole ring as a part of the condensed ring.

Also, the substituent represented by R ^{1 to} R ⁴ in the general formula (1), the substituent represented by R ⁵ in the general formula (2), or R ⁶ in the general formula (3) At least one of the represented substituents preferably contains a carbazole ring derivative as a partial structure. Here, the carbazole ring derivative includes those having a substituted carbazole ring having a carbazole skeleton and those having a carbazole ring as part of a condensed ring.

  In the general formula (1), the aromatic hydrocarbon ring formed by Q is preferably a benzene ring.

In the general formula (1), the substituent represented by R ³ and R ⁴ is preferably a hydrogen atom.

In the general formula (1), the substituent represented by R ¹ preferably contains at least two condensed rings. The condensed ring here is a condensed ring comprising a carbon ring such as naphthalene ring, anthracene ring, benzofuran ring, dibenzofuran ring, benzothiophene ring, dibenzothiophene ring in addition to the condensed ring containing at least one nitrogen atom. And a condensed ring containing a hetero atom other than nitrogen. Among them, it is preferable that the substituent represented by R ^{1 includes a} dibenzofuran ring or the like in addition to the condensed ring containing at least one nitrogen atom.

In the general formula (3), which is a preferable substituent represented by R ² in the general formula (1), the substituent represented by R ⁶ preferably contains an indole ring derivative as a partial structure. . Here, the indole ring derivative includes those having a substituted indole ring having an indole skeleton and those having an indole ring as a part of the condensed ring.

In the general formula (3), which is a preferred substituent represented by R ² in the general formula (1), the substituent represented by R ⁶ preferably contains a carbazole ring derivative as a partial structure. Furthermore, the substituent represented by R ⁶ preferably contains at least three carbazole ring derivatives. Here, the carbazole ring derivative includes those having a substituted carbazole ring having a carbazole skeleton and those having a carbazole ring as part of a condensed ring.

Further, in the general formula (3), the formula weight of the substituent represented by ^{R 6} is preferably 500 to 2,000.

In one embodiment, the substituent represented by R ¹ in the general formula (1) is composed of a condensed ring containing a linking group and at least one nitrogen atom, and the linking group is formed by Q. It is also preferred that it is bonded to an aromatic hydrocarbon ring.

  Here, the linking group is not particularly limited as long as it is a divalent linking group, but is preferably an alkylene group, an arylene group, or a heteroarylene group, for example, an alkylene group having up to 8 carbon atoms, such as a phenylene group, a p-chlorophenyl group, Xylylene group, naphthylene group, etc., biphenylene group, and also include, for example, thienylene group, pyridyl group, pyridazinyl group, pyrimidinyl group, pyrazinyl group, triazinylene group, preferably phenylene group, biphenylene group each having a substituent Etc.

In addition, when the substituent represented by R ¹ in the general formula (1) represents a condensed ring containing at least one nitrogen atom, the aromatic hydrocarbon formed by Q as the carbon atom on the condensed ring It is also a preferred embodiment that it is bonded to a ring.

  Hereinafter, although the specific example of the compound containing the partial structure represented by General formula (1) based on this invention is shown, this invention is not limited to these.

  These compounds can be synthesized by known methods. For example, International Publication No. 04/085450, Japanese Patent Application Laid-Open No. 2005-53912, International Publication No. 2006/121811, International Publication No. 2006/046980, and the like. Can be produced by the method described in 1. above.

<< Constituent layers of organic EL elements >>
The constituent layers of the organic EL element of the present invention will be described. In this invention, although the preferable specific example of the layer structure of an organic EL element is shown below, this invention is not limited to these.
(I) Anode / light emitting layer / electron transport layer / cathode (ii) Anode / hole transport layer / light emitting layer / electron transport layer / cathode (iii) Anode / hole transport layer / light emitting layer / hole blocking layer / electron Transport layer / cathode (iv) anode / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / cathode (v) anode / anode buffer layer / hole transport layer / light emitting layer / hole Blocking layer / electron transport layer / cathode buffer layer / cathode In the organic EL device of the present invention, the blue light emitting layer preferably has a light emission maximum wavelength of 430 nm to 480 nm, and the green light emitting layer has a light emission maximum wavelength of 510 nm to 550 nm, The red light emitting layer is preferably a monochromatic light emitting layer having a light emission maximum wavelength in the range of 600 nm to 640 nm, and is preferably a display device using these. Alternatively, a white light emitting layer may be formed by laminating at least three light emitting layers. Further, a non-light emitting intermediate layer may be provided between the light emitting layers. The organic EL element of the present invention is preferably a white light emitting layer, and is preferably a lighting device using these.

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

<Light emitting layer>
The light emitting layer according to the present invention is a layer that emits light by recombination of electrons and holes injected from the electrode, the electron transport layer, or the hole transport layer, and the light emitting portion is in the layer of the light emitting layer. May be the interface between the light emitting layer and the adjacent layer.

  The total film thickness of the light emitting layer is not particularly limited, but from the viewpoint of improving the uniformity of the film, preventing unnecessary application of high voltage during light emission, and improving the stability of the emission color with respect to the drive current. It is preferable to adjust in the range of 2 nm to 5 μm, more preferably in the range of 2 nm to 200 nm, and particularly preferably in the range of 10 nm to 20 nm.

  For the production of the light-emitting layer, a light-emitting dopant or a host compound, which will be described later, is formed and formed by a known thinning method such as a vacuum deposition method, a spin coating method, a casting method, an LB method, or an ink-jet method. it can.

  The light emitting layer of the organic EL device of the present invention preferably contains a light emitting host compound and at least one kind of light emitting dopant (such as a phosphorescent dopant (also referred to as a phosphorescent dopant) or a fluorescent dopant).

(Host compound (also called luminescent host))
The light-emitting host compound used in the present invention is not particularly limited in terms of structure, but typically, a carbazole derivative, a triarylamine derivative, an aromatic borane derivative, a nitrogen-containing heterocyclic compound, a thiophene derivative, a furan derivative, Those having a basic skeleton such as an oligoarylene compound, or a carboline derivative or a diazacarbazole derivative (here, a diazacarbazole derivative is a compound in which at least one carbon atom of a hydrocarbon ring constituting a carboline ring of a carboline derivative is nitrogen Represents an atom substituted with an atom.) And the like.

  In the present invention, the host compound has a mass ratio of 20% or more among the compounds contained in the light emitting layer, and a phosphorescence quantum yield of phosphorescence emission at a room temperature (25 ° C.) of 0. Defined as less than 1 compound. The phosphorescence quantum yield is preferably less than 0.01. Moreover, it is preferable that the mass ratio in the layer is 20% or more among the compounds contained in a light emitting layer.

  As the host compound, the above host compounds may be used alone or in combination of two or more. By using a plurality of types of host compounds, it is possible to adjust the movement of charges, and the organic EL element can be made highly efficient. Moreover, it becomes possible to mix different light emission by using multiple types of the compound containing the partial structure represented by the said General formula (1), and the light emission dopant mentioned later, and can obtain arbitrary luminescent colors by this. it can.

  The light emitting host used in the present invention may be a conventionally known low molecular compound or a high molecular compound having a repeating unit, and a low molecular compound having a polymerizable group such as a vinyl group or an epoxy group (deposition polymerization property). Light emitting host).

  As a known host compound that may be used in combination, a compound that has a hole transporting ability and an electron transporting ability, prevents the emission of light from being increased in wavelength, and has a high Tg (glass transition temperature) is preferable.

  Specific examples of known host compounds include compounds described in the following documents.

  JP-A-2001-257076, 2002-308855, 2001-313179, 2002-319491, 2001-357777, 2002-334786, 2002-8860, 2002-334787, 2002-15871, 2002-334788, 2002-43056, 2002-334789, 2002-75645, 2002-338579, 2002-105445 gazette, 2002-343568 gazette, 2002-141173 gazette, 2002-352957 gazette, 2002-203683 gazette, 2002-363227 gazette, 2002-231453 gazette, No. 003-3165, No. 2002-234888, No. 2003-27048, No. 2002-255934, No. 2002-286061, No. 2002-280183, No. 2002-299060, No. 2002. -302516, 2002-305083, 2002-305084, 2002-308837, and the like.

(Luminescent dopant)
The luminescent dopant will be described.

  As the light-emitting dopant, a fluorescent dopant (also referred to as a fluorescent compound) or a phosphorescent dopant (also referred to as a phosphorescent emitter, a phosphorescent compound, a phosphorescent compound, or the like) can be used, but the emission efficiency is higher. From the viewpoint of obtaining an organic EL element, the light emitting dopant (sometimes referred to simply as a light emitting material) used in the light emitting layer or light emitting unit of the organic EL element of the present invention is represented by the general formula (1). A compound containing a partial structure is contained as a phosphorescent dopant.

(Phosphorescent dopant)
The phosphorescent dopant according to the present invention will be described.

  The phosphorescent dopant according to the present invention is a compound in which light emission from an excited triplet is observed. Specifically, the phosphorescent dopant is a compound that emits phosphorescence at room temperature (25 ° C.) and has a phosphorescence quantum yield of 25. Although it is defined as a compound of 0.01 or more at ° C., a preferable phosphorescence quantum yield is 0.1 or more.

  The phosphorescence quantum yield can be measured by the method described in Spectroscopic II, page 398 (1992 edition, Maruzen) of Experimental Chemistry Course 4 of the 4th edition. Although the phosphorescence quantum yield in a solution can be measured using various solvents, the phosphorescence dopant according to the present invention achieves the phosphorescence quantum yield (0.01 or more) in any solvent. That's fine.

  There are two types of light emission of phosphorescent dopants in principle. One is the recombination of carriers on the host compound to which carriers are transported to generate an excited state of the host compound, and this energy is transferred to the phosphorescent dopant. The energy transfer type that obtains light emission from the phosphorescent dopant, and the other is that the phosphorescent dopant becomes a carrier trap, carrier recombination occurs on the phosphorescent dopant, and light emission from the phosphorescent dopant is obtained. Although it is a trap type, in any case, the excited state energy of the phosphorescent dopant is required to be lower than the excited state energy of the host compound.

  The phosphorescent dopant according to the present invention is preferably a complex compound containing a group 8-10 metal in the periodic table, more preferably an iridium compound, an osmium compound, or a platinum compound (platinum complex compound). Rare earth complexes, most preferably iridium compounds.

  In the present invention, the phosphorescent dopant can be appropriately selected from those selected from compounds containing the partial structure represented by the general formula (1).

  Further, in the present invention, in addition to those selected from the compound containing the partial structure represented by the general formula (1), a known phosphorescent dopant used for the light emitting layer of the organic EL element may be used. it can.

  Although the specific example of the well-known compound used as a phosphorescence dopant below is shown, this invention is not limited to these. These compounds are described, for example, in Inorg. Chem. 40, 1704-1711, and the like.

(Fluorescent dopant (also called fluorescent compound))
Fluorescent dopants (fluorescent compounds) include coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, pyrylium dyes, perylene dyes Examples thereof include dyes, stilbene dyes, polythiophene dyes, and rare earth complex phosphors.

  Next, an injection layer, a blocking layer, an electron transport layer, and the like used as a constituent layer of the organic EL element of the present invention will be described.

<< Injection layer: electron injection layer, hole injection layer >>
The injection layer is provided as necessary, and there are an electron injection layer and a hole injection layer, and as described above, it exists between the anode and the light emitting layer or the hole transport layer and between the cathode and the light emitting layer or the electron transport layer. May be.

  An injection layer is a layer provided between an electrode and an organic layer in order to reduce drive voltage and improve light emission luminance. “Organic EL element and its forefront of industrialization (issued by NTT Corporation on November 30, 1998) 2), Chapter 2, “Electrode Materials” (pages 123 to 166) in detail, and includes a hole injection layer (anode buffer layer) and an electron injection layer (cathode buffer layer).

  The details of the anode buffer layer (hole injection layer) are described in JP-A-9-45479, JP-A-9-260062, JP-A-8-288069 and the like. As a specific example, copper phthalocyanine is used. Examples thereof include a phthalocyanine buffer layer represented by an oxide, an oxide buffer layer represented by vanadium oxide, an amorphous carbon buffer layer, and a polymer buffer layer using a conductive polymer such as polyaniline (emeraldine) or polythiophene.

  The details of the cathode buffer layer (electron injection layer) are described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like. Specifically, strontium, aluminum, etc. Metal buffer layer typified by lithium, alkali metal compound buffer layer typified by lithium fluoride, alkaline earth metal compound buffer layer typified by magnesium fluoride, oxide buffer layer typified by aluminum oxide, etc. . The buffer layer (injection layer) is preferably a very thin film, and the film thickness is preferably in the range of 0.1 nm to 5 μm although it depends on the material.

<Blocking layer: hole blocking layer, electron blocking layer>
The blocking layer is provided as necessary in addition to the basic constituent layer of the organic compound thin film as described above. For example, it is described in JP-A Nos. 11-204258, 11-204359, and “Organic EL elements and their forefront of industrialization” (issued by NTT, Inc. on November 30, 1998). There is a hole blocking (hole blocking) layer.

  The hole blocking layer has a function of an electron transport layer in a broad sense, and is made of a hole blocking material that has a function of transporting electrons and has a remarkably small ability to transport holes. The probability of recombination of electrons and holes can be improved by blocking. Moreover, the structure of the electron carrying layer mentioned later can be used as a hole-blocking layer concerning this invention as needed.

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

  The hole blocking layer preferably contains the carbazole derivative, carboline derivative or diazacarbazole derivative mentioned as the host compound.

  In the present invention, when a plurality of light emitting layers having different light emission colors are provided, the light emitting layer having the shortest wavelength of light emission is preferably closest to the anode among all the light emitting layers. In this case, it is preferable to additionally provide a hole blocking layer between the shortest wave layer and the light emitting layer next to the anode next to the anode. Furthermore, it is preferable that 50% by mass or more of the compound contained in the hole blocking layer provided at the position has an ionization potential of 0.3 eV or more larger than the host compound of the shortest wave emitting layer.

  The ionization potential is defined by the energy required to emit an electron at the HOMO (highest occupied molecular orbital) level of the compound to the vacuum level, and can be obtained by the following method, for example.

  (1) Using Gaussian 98 (Gaussian 98, Revision A.11.4, MJ Frisch, et al, Gaussian, Inc., Pittsburgh PA, 2002.), a molecular orbital calculation software manufactured by Gaussian, USA The ionization potential can be obtained as a value obtained by rounding off the second decimal place of the value (eV unit converted value) calculated by performing structural optimization using B3LYP / 6-31G *. This calculation value is effective because the correlation between the calculation value obtained by this method and the experimental value is high.

  (2) The ionization potential can also be obtained by a method of directly measuring by photoelectron spectroscopy. For example, a method known as ultraviolet photoelectron spectroscopy can be suitably used by using a low energy electron spectrometer “Model AC-1” manufactured by Riken Keiki Co., Ltd.

  On the other hand, the electron blocking layer has a function of a hole transport layer in a broad sense, and is made of a material that has a function of transporting holes and has an extremely small ability to transport electrons, and transports electrons while transporting holes. By blocking, the recombination probability of electrons and holes can be improved. Moreover, the structure of the positive hole transport layer mentioned later can be used as an electron blocking layer as needed. The film thickness of the hole blocking layer and the electron transport layer according to the present invention is preferably 3 nm to 100 nm, and more preferably 5 nm to 30 nm.

《Hole transport layer》
The hole transport layer is made of a hole transport material having a function of transporting holes, and in a broad sense, a hole injection layer and an electron blocking layer are also included in the hole transport layer. The hole transport layer can be provided as a single layer or a plurality of layers.

  The hole transport material has any one of hole injection or transport and electron barrier properties, and may be either organic or inorganic. For example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, Examples thereof include stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers, particularly thiophene oligomers.

  The above-mentioned materials can be used as the hole transport material, but it is preferable to use a porphyrin compound, an aromatic tertiary amine compound and a styrylamine compound, particularly an aromatic tertiary amine compound.

  Representative examples of aromatic tertiary amine compounds and styrylamine compounds include N, N, N ', N'-tetraphenyl-4,4'-diaminophenyl; N, N'-diphenyl-N, N'- Bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine (TPD); 2,2-bis (4-di-p-tolylaminophenyl) propane; 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane; N, N, N ′, N′-tetra-p-tolyl-4,4′-diaminobiphenyl; 1,1-bis (4-di-p-tolyl) Aminophenyl) -4-phenylcyclohexane; bis (4-dimethylamino-2-methylphenyl) phenylmethane; bis (4-di-p-tolylaminophenyl) phenylmethane; N, N'-diphenyl-N, N ' − (4-methoxyphenyl) -4,4'-diaminobiphenyl; N, N, N ', N'-tetraphenyl-4,4'-diaminodiphenyl ether; 4,4'-bis (diphenylamino) quadriphenyl; N, N, N-tri (p-tolyl) amine; 4- (di-p-tolylamino) -4 '-[4- (di-p-tolylamino) styryl] stilbene; 4-N, N-diphenylamino- (2-diphenylvinyl) benzene; 3-methoxy-4'-N, N-diphenylaminostilbenzene; N-phenylcarbazole, as well as two of those described in US Pat. No. 5,061,569 Having a condensed aromatic ring in the molecule, for example, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-308 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in Japanese Patent No. 88 are linked in a starburst type ( MTDATA) and the like.

  Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used. In addition, inorganic compounds such as p-type-Si and p-type-SiC can also be used as the hole injection material and the hole transport material.

  JP-A-11-251067, J. Org. Huang et. al. A so-called p-type hole transport material as described in a book (Applied Physics Letters 80 (2002), p. 139) can also be used. In the present invention, these materials are preferably used because a light-emitting element with higher efficiency can be obtained.

  The hole transport layer can be formed by thinning the hole transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. it can. Although there is no restriction | limiting in particular about the film thickness of a positive hole transport layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5 nm-200 nm. The hole transport layer may have a single layer structure composed of one or more of the above materials.

  Alternatively, a hole transport layer having a high p property doped with impurities can be used. Examples thereof include JP-A-4-297076, JP-A-2000-196140, JP-A-2001-102175, J. Pat. Appl. Phys. 95, 5773 (2004), and the like.

  In the present invention, it is preferable to use a hole transport layer having such a high p property because a device with lower power consumption can be produced.

《Electron transport layer》
The electron transport layer is made of a material having a function of transporting electrons, and in a broad sense, an electron injection layer and a hole blocking layer are also included in the electron transport layer. The electron transport layer can be provided as a single layer or a plurality of layers.

  Conventionally, in the case of a single electron transport layer and a plurality of layers, an electron transport material (also serving as a hole blocking material) used for an electron transport layer adjacent to the light emitting layer on the cathode side is injected from the cathode. As long as it has a function of transferring electrons to the light-emitting layer, any material can be selected and used from among conventionally known compounds. For example, nitro-substituted fluorene derivatives, diphenylquinone derivatives Thiopyrandioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives and the like. Furthermore, in the above oxadiazole derivative, a thiadiazole derivative in which an oxygen atom of the oxadiazole ring is substituted with a sulfur atom, or a quinoxaline derivative having a quinoxaline ring known as an electron withdrawing group can also be used as an electron transport material. Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.

  Also, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) aluminum, Tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), etc., and the central metals of these metal complexes are In, Mg, Cu , Ca, Sn, Ga, or Pb can also be used as an electron transport material. In addition, metal-free or metal phthalocyanine, or those having terminal ends substituted with an alkyl group or a sulfonic acid group can be preferably used as the electron transporting material. In addition, the distyrylpyrazine derivative exemplified as the material of the light emitting layer can also be used as an electron transport material, and an inorganic semiconductor such as n-type-Si, n-type-SiC, etc. as in the case of the hole injection layer and the hole transport layer. Can also be used as an electron transporting material.

  The electron transport layer can be formed by thinning the electron transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. Although there is no restriction | limiting in particular about the film thickness of an electron carrying layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5 nm-200 nm. The electron transport layer may have a single layer structure composed of one or more of the above materials.

  Further, an electron transport layer having a high n property doped with impurities can also be used. Examples thereof include JP-A-4-297076, JP-A-10-270172, JP-A-2000-196140, 2001-102175, J.A. Appl. Phys. 95, 5773 (2004), and the like.

  In the present invention, it is preferable to use an electron transport layer having such a high n property because an element with lower power consumption can be manufactured.

"anode"
As the anode in the organic EL element, an electrode material made of a metal, an alloy, an electrically conductive compound, or a mixture thereof having a high work function (4 eV or more) is preferably used. Specific examples of such electrode materials include metals such as Au, and conductive transparent materials such as CuI, indium tin oxide (ITO), SnO2, and ZnO. Alternatively, an amorphous material such as IDIXO (In2O3-ZnO) that can form a transparent conductive film may be used. For the anode, these electrode materials may be formed into a thin film by a method such as vapor deposition or sputtering, and a pattern having a desired shape may be formed by a photolithography method, or when pattern accuracy is not so high (about 100 μm or more) A pattern may be formed through a mask having a desired shape at the time of vapor deposition or sputtering of the electrode material. Or when using the substance which can be apply | coated like an organic electroconductivity compound, wet film forming methods, such as a printing system and a coating system, can also be used. When light emission is extracted from the anode, it is desirable that the transmittance be greater than 10%, and the sheet resistance as the anode is preferably several hundred Ω / □ or less. Further, although the film thickness depends on the material, it is usually in the range of 10 nm to 1000 nm, preferably in the range of 10 nm to 200 nm.

"cathode"
On the other hand, as the cathode, a material having a low work function (4 eV or less) metal (referred to as an electron injecting metal), an alloy, an electrically conductive compound, and a mixture thereof as an electrode material is used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al2O3) mixture. , Indium, lithium / aluminum mixtures, rare earth metals and the like. Among these, from the point of durability against electron injection and oxidation, etc., a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function than this, for example, a magnesium / silver mixture, Magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al2O3) mixtures, lithium / aluminum mixtures, aluminum and the like are preferred. The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. The sheet resistance as a cathode is preferably several hundred Ω / □ or less, and the film thickness is usually selected in the range of 10 nm to 5 μm, preferably 50 nm to 200 nm. In order to transmit the emitted light, if either one of the anode or the cathode of the organic EL element is transparent or translucent, the light emission luminance is improved, which is convenient.

  Moreover, after producing the said metal by the film thickness of 1 nm-20 nm to a cathode, the transparent or semi-transparent cathode can be produced by producing the electroconductive transparent material quoted by description of the anode on it, By applying this, an element in which both the anode and the cathode are transmissive can be manufactured.

《Support substrate》
As a support substrate (hereinafter also referred to as a substrate, substrate, substrate, support, etc.) that can be used in the organic EL device of the present invention, there is no particular limitation on the type of glass, plastic, etc. May be opaque. When extracting light from the support substrate side, the support substrate is preferably transparent. Examples of the transparent support substrate preferably used include glass, quartz, and a transparent resin film. A particularly preferable support substrate is a resin film capable of giving flexibility to the organic EL element.

  Examples of the resin film include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, cellulose acetate propionate (CAP), Cellulose esters such as cellulose acetate phthalate (TAC) and cellulose nitrate or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide , Polyethersulfone (PES), polyphenylene sulfide, polysulfones Cycloolefin resins such as polyetherimide, polyetherketoneimide, polyamide, fluororesin, nylon, polymethylmethacrylate, acrylic or polyarylate, Arton (trade name, manufactured by JSR) or Appel (trade name, manufactured by Mitsui Chemicals) Can be mentioned.

On the surface of the resin film, an inorganic film, an organic film, or a hybrid film of both may be formed. Water vapor permeability (25 ± 0.5 ° C.) measured by a method according to JIS K 7129-1992. , Relative humidity (90 ± 2)% RH) is preferably 0.01 g / (m ² · 24 h) or less, and further, oxygen measured by a method according to JIS K 7126-1987. A high barrier film having a permeability of 10 ⁻³ cm ³ / (m ² · 24 h · atm) or less and a water vapor permeability of 10 ⁻³ g / (m ² · 24 h) or less is preferable. More preferably, the transmittance is 10 ⁻⁵ g / (m ² · 24 h) or less.

  As a material for forming the barrier film, any material may be used as long as it has a function of suppressing entry of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like can be used. Further, in order to improve the brittleness of the film, it is more preferable to have a laminated structure of these inorganic layers and layers made of organic materials. Although there is no restriction | limiting in particular about the lamination | stacking order of an inorganic layer and an organic layer, It is preferable to laminate | stack both alternately several times.

  The method for forming the barrier film is not particularly limited. For example, the vacuum deposition method, sputtering method, reactive sputtering method, molecular beam epitaxy method, cluster ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma weight A combination method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, and the like can be used, but an atmospheric pressure plasma polymerization method as described in JP-A-2004-68143 is particularly preferable.

  Examples of the opaque support substrate include metal plates such as aluminum and stainless steel, films, opaque resin substrates, and ceramic substrates.

  The external extraction efficiency at room temperature of light emission of the organic EL device of the present invention is preferably 1% or more, more preferably 5% or more. Here, the external extraction quantum efficiency (%) = the number of photons emitted to the outside of the organic EL element / the number of electrons sent to the organic EL element × 100.

  In addition, a hue improvement filter such as a color filter may be used in combination, or a color conversion filter that converts the emission color from the organic EL element into multiple colors using a phosphor may be used in combination. In the case of using a color conversion filter, the λmax of light emission of the organic EL element is preferably 480 nm or less.

<Sealing>
As a sealing means used for this invention, the method of adhere | attaching a sealing member, an electrode, and a support substrate with an adhesive agent can be mentioned, for example.

  As a sealing member, it should just be arrange | positioned so that the display area | region of an organic EL element may be covered, and concave plate shape or flat plate shape may be sufficient. Further, transparency and electrical insulation are not particularly limited.

  Specific examples include a glass plate, a polymer plate / film, and a metal plate / film. Examples of the glass plate include soda-lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz. Examples of the polymer plate include polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, and polysulfone. Examples of the metal plate include those made of one or more metals or alloys selected from the group consisting of stainless steel, iron, copper, aluminum, magnesium, nickel, zinc, chromium, titanium, molybdenum, silicon, germanium, and tantalum.

In the present invention, a polymer film and a metal film can be preferably used because the element can be thinned. Furthermore, the polymer film has an oxygen permeability measured by a method according to JIS K 7126-1987 of 1 × 10 ⁻³ cm ³ / (m ² · 24 h · atm) or less, and conforms to JIS K 7129-1992. The water vapor permeability (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) measured by the above method is preferably 1 × 10 ⁻³ g / (m ² · 24 h) or less.

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

  Specific examples of the adhesive include photocuring and thermosetting adhesives having reactive vinyl groups such as acrylic acid oligomers and methacrylic acid oligomers, and moisture curing adhesives such as 2-cyanoacrylates. be able to. Moreover, heat | fever and chemical curing types (two-component mixing), such as an epoxy type, can be mentioned. Moreover, hot-melt type polyamide, polyester, and polyolefin can be mentioned. Moreover, a cationic curing type ultraviolet curing epoxy resin adhesive can be mentioned.

  In addition, since an organic EL element may deteriorate by heat processing, what can be adhesive-hardened from room temperature to 80 degreeC is preferable. A desiccant may be dispersed in the adhesive. Application | coating of the adhesive agent to a sealing part may use commercially available dispenser, and may print like screen printing.

  In addition, it is also preferable that the electrode and the organic layer are coated on the outside of the electrode facing the support substrate with the organic layer interposed therebetween, and an inorganic or organic layer is formed in contact with the support substrate to form a sealing film. . In this case, the material for forming the film may be any material that has a function of suppressing intrusion of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like may be used. it can. Further, in order to improve the brittleness of the film, it is preferable to have a laminated structure of these inorganic layers and layers made of organic materials. The method for forming these films is not particularly limited. For example, vacuum deposition, sputtering, reactive sputtering, molecular beam epitaxy, cluster-ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma A polymerization method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used.

  In the gap between the sealing member and the display area of the organic EL element, an inert gas such as nitrogen or argon, or an inert liquid such as fluorinated hydrocarbon or silicon oil can be injected in the gas phase and liquid phase. preferable. A vacuum is also possible. Moreover, a hygroscopic compound can also be enclosed inside.

  Examples of the hygroscopic compound include metal oxides (for example, sodium oxide, potassium oxide, calcium oxide, barium oxide, magnesium oxide, aluminum oxide) and sulfates (for example, sodium sulfate, calcium sulfate, magnesium sulfate, cobalt sulfate). Etc.), metal halides (eg calcium chloride, magnesium chloride, cesium fluoride, tantalum fluoride, cerium bromide, magnesium bromide, barium iodide, magnesium iodide etc.), perchloric acids (eg perchloric acid) Barium, magnesium perchlorate, and the like), and anhydrous salts are preferably used in sulfates, metal halides, and perchloric acids.

《Protective film, protective plate》
In order to increase the mechanical strength of the element, a protective film or a protective plate may be provided on the outer side of the sealing film on the side facing the support substrate with the organic layer interposed therebetween or on the sealing film. In particular, when the sealing is performed by the sealing film, the mechanical strength is not necessarily high, and thus it is preferable to provide such a protective film and a protective plate. As a material that can be used for this, the same glass plate, polymer plate / film, metal plate / film, and the like used for the sealing can be used, but the polymer film is light and thin. Is preferably used.

《Light extraction》
The organic EL element emits light inside a layer having a refractive index higher than that of air (refractive index is about 1.7 to 2.1) and can extract only about 15% to 20% of the light generated in the light emitting layer. It is generally said. This is because light incident on the interface (interface between the transparent substrate and air) at an angle θ greater than the critical angle causes total reflection and cannot be taken out of the device, or between the transparent electrode or light emitting layer and the transparent substrate. This is because the light is totally reflected between the light and the light is guided through the transparent electrode or the light emitting layer, and as a result, the light escapes in the direction of the element side surface.

  As a method for improving the light extraction efficiency, for example, a method of forming irregularities on the surface of the transparent substrate to prevent total reflection at the interface between the transparent substrate and the air (US Pat. No. 4,774,435), A method for improving the efficiency by providing the substrate with a light condensing property (Japanese Patent Laid-Open No. Sho 63-314795), a method for forming a reflective surface on the side surface of the element (Japanese Patent Laid-Open No. 1-220394), a substrate and a light emitter A method of forming an antireflection film by introducing a flat layer having an intermediate refractive index between them (Japanese Patent Laid-Open No. 62-172691), a flat layer having a lower refractive index than the substrate between the substrate and the light emitter Of introducing a diffraction grating (Japanese Patent Laid-Open No. 2001-202827), a method of forming a diffraction grating between any one of a substrate, a transparent electrode layer and a light emitting layer (including between the substrate and the outside) (Japanese Patent Laid-Open No. 11-283951) ) Etc.

  In the present invention, these methods can be used in combination with the organic EL device of the present invention. However, a method of introducing a flat layer having a lower refractive index than the substrate between the substrate and the light emitter, or a substrate, transparent A method of forming a diffraction grating between any layers of the electrode layer and the light emitting layer (including between the substrate and the outside) can be suitably used.

  In the present invention, by combining these means, it is possible to obtain an element having higher luminance or durability.

  When a medium having a low refractive index is formed between the transparent electrode and the transparent substrate with a thickness longer than the wavelength of light, the light extracted from the transparent electrode has a higher extraction efficiency to the outside as the refractive index of the medium is lower.

  Examples of the low refractive index layer include aerogel, porous silica, magnesium fluoride, and a fluorine-based polymer. Since the refractive index of the transparent substrate is generally about 1.5 to 1.7, the low refractive index layer preferably has a refractive index of about 1.5 or less. Further, it is preferably 1.35 or less.

  The thickness of the low refractive index medium is preferably at least twice the wavelength in the medium. This is because the effect of the low refractive index layer is diminished when the thickness of the low refractive index medium is about the wavelength of light and the electromagnetic wave that has exuded by evanescent enters the substrate.

  The method of introducing a diffraction grating into an interface or any medium that causes total reflection is characterized by a high effect of improving light extraction efficiency. This method uses the property that the diffraction grating can change the direction of light to a specific direction different from refraction by so-called Bragg diffraction such as first-order diffraction and second-order diffraction. Light that cannot be emitted due to total internal reflection between layers is diffracted by introducing a diffraction grating in any layer or medium (in a transparent substrate or transparent electrode), and the light is removed. I want to take it out.

  It is desirable that the diffraction grating to be introduced has a two-dimensional periodic refractive index. This is because light emitted from the light emitting layer is randomly generated in all directions, so in a general one-dimensional diffraction grating having a periodic refractive index distribution only in a certain direction, only light traveling in a specific direction is diffracted. The light extraction efficiency does not increase so much. However, by making the refractive index distribution a two-dimensional distribution, light traveling in all directions is diffracted, and light extraction efficiency is increased.

  As described above, the position where the diffraction grating is introduced may be in any of the layers or in the medium (in the transparent substrate or in the transparent electrode), but is preferably in the vicinity of the organic light emitting layer where light is generated.

  At this time, the period of the diffraction grating is preferably about 1/2 to 3 times the wavelength of light in the medium.

  The arrangement of the diffraction grating is preferably two-dimensionally repeated such as a square lattice, a triangular lattice, or a honeycomb lattice.

<Condenser sheet>
The organic EL device of the present invention is processed on the light extraction side of the substrate so as to provide, for example, a microlens array structure, or combined with a so-called condensing sheet, for example, with respect to a specific direction, for example, the device light emitting surface. By condensing in the front direction, the luminance in a specific direction can be increased.

  As an example of the microlens array, quadrangular pyramids having a side of 30 μm and an apex angle of 90 degrees are arranged two-dimensionally on the light extraction side of the substrate. One side is preferably 10 μm to 100 μm. If it becomes smaller than this, the effect of diffraction will generate | occur | produce and color, and if too large, thickness will become thick and is not preferable.

  As the condensing sheet, for example, a sheet that is put into practical use in an LED backlight of a liquid crystal display device can be used. As such a sheet, for example, a brightness enhancement film (BEF) manufactured by Sumitomo 3M Limited can be used. As the shape of the prism sheet, for example, the base material may be formed by forming a △ -shaped stripe having a vertex angle of 90 degrees and a pitch of 50 μm, or the vertex angle is rounded and the pitch is changed randomly. Other shapes may be used.

  Moreover, in order to control the light emission angle from a light emitting element, you may use together a light diffusing plate and a film with a condensing sheet. For example, a diffusion film (light-up) manufactured by Kimoto Co., Ltd. can be used.

<< Method for producing organic EL element >>
As an example of the method for producing the organic EL device of the present invention, a method for producing an organic EL device comprising an anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode will be described.

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

  Next, an organic compound thin film of a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and a hole blocking layer, which are organic EL element materials, is formed thereon.

  As a method for forming each of these layers, there are a vapor deposition method, a wet process (spin coating method, casting method, ink jet method, printing method) and the like as described above, but it is easy to obtain a homogeneous film and it is difficult to generate pinholes. In view of the above, in the present invention, film formation by a coating method such as a spin coating method, an ink jet method, or a printing method is preferable.

  Examples of the liquid medium for dissolving or dispersing the organic EL material according to the present invention include ketones such as methyl ethyl ketone and cyclohexanone, fatty acid esters such as ethyl acetate, halogenated hydrocarbons such as dichlorobenzene, toluene, xylene, and mesitylene. Aromatic hydrocarbons such as cyclohexylbenzene, aliphatic hydrocarbons such as cyclohexane, decalin, and dodecane, and organic solvents such as DMF and DMSO can be used. Moreover, as a dispersion method, it can disperse | distribute by dispersion methods, such as an ultrasonic wave, high shear force dispersion | distribution, and media dispersion | distribution.

  After these layers are formed, a thin film made of a cathode material is formed thereon by 1 μm or less, preferably by a method such as vapor deposition or sputtering so that the film thickness is in the range of 50 nm to 200 nm. By providing, a desired organic EL element can be obtained.

  In addition, it is also possible to reverse the production order and produce the cathode, the electron injection layer, the electron transport layer, the light emitting layer, the hole transport layer, the hole injection layer, and the anode in this order. When a DC voltage is applied to the multicolor display device thus obtained, light emission can be observed by applying a voltage of about 2 to 40 V with the positive polarity of the anode and the negative polarity of the cathode. An alternating voltage may be applied. The alternating current waveform to be applied may be arbitrary.

<Application>
The organic EL element of the present invention can be used as a display device, a display, and various light emission sources. For example, lighting devices (home lighting, interior lighting), clock and liquid crystal backlights, billboard advertisements, traffic lights, light sources of optical storage media, light sources of electrophotographic copying machines, light sources of optical communication processors, light Although the light source of a sensor etc. are mentioned, It is not limited to this, Especially, it can use effectively for the use as a backlight of a liquid crystal display device, and a light source for illumination.

  In the organic EL device of the present invention, patterning may be performed by a metal mask, an ink jet printing method, or the like at the time of film formation, if necessary. In the case of patterning, only the electrode may be patterned, the electrode and the light emitting layer may be patterned, or the entire layer of the element may be patterned. In the fabrication of the element, a conventionally known method is used. Can do.

  The light emission color of the organic EL device of the present invention and the compound according to the present invention is shown in FIG. 4.16 on page 108 of “New Color Science Handbook” (edited by the Japan Color Society, University of Tokyo Press, 1985). It is determined by the color when the result measured with the total CS-1000 (manufactured by Konica Minolta Sensing) is applied to the CIE chromaticity coordinates.

When the organic EL element of the present invention is a white element, white means that the chromaticity in the CIE1931 color system at 1000 cd / m ² is X when the 2 ° viewing angle front luminance is measured by the above method. = 0.33 ± 0.07 and Y = 0.33 ± 0.1.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these. In addition, although the display of "%" is used in an Example, unless otherwise indicated, "mass%" is represented.

Example 1
<< Production of Organic EL Element 1-1 >>
After patterning on a substrate (made by NH Techno Glass Co., Ltd .: NA-45) having a 150 nm ITO film formed on glass as an anode, the transparent support substrate provided with this ITO transparent electrode was ultrasonically cleaned with iso-propyl alcohol. Then, it was dried with dry nitrogen gas, and UV ozone cleaning was performed for 5 minutes. The transparent support substrate is fixed to a substrate holder of a commercially available vacuum deposition apparatus, while α-NPD, CBP, Ir-12, BCP, and Alq ₃ are placed in five tantalum resistance heating boats, respectively. (Vacuum chamber).

  Further, lithium fluoride was placed in a resistance heating boat made of tantalum, and aluminum was placed in a resistance heating boat made of tungsten, and attached to the second vacuum tank of the vacuum evaporation apparatus.

First, after reducing the pressure of the first vacuum tank to 4 × 10 ⁻⁴ Pa, the heating boat containing α-NPD was energized and heated, and the transparent support substrate was deposited at a deposition rate of 0.1 to 0.2 nm / sec. The film was deposited to a thickness of 20 nm, and a hole injection / transport layer was provided.

  Further, the heating boat containing CBP and the boat containing Ir-12 are energized independently to adjust the deposition rate of CBP as the light emitting host and Ir-12 as the light emitting dopant to 100: 6. And it vapor-deposited so that it might become a film thickness of 30 nm, and provided the light emitting layer.

Subsequently, the said heating boat containing BCP was heated by supplying electricity, and a 10-nm-thick hole blocking layer was provided at a deposition rate of 0.1-0.2 nm / second. Furthermore, the heating boat containing Alq ₃ was heated by energizing to provide an electron transport layer having a film thickness of 20 nm at a deposition rate of 0.1 to 0.2 nm / second.

  Next, after the element deposited up to the electron transport layer was transferred to the second vacuum chamber while being vacuumed, it was remotely controlled from the outside of the apparatus so that a stainless steel rectangular perforated mask was placed on the electron transport layer. Installed.

After depressurizing the second vacuum tank to 2 × 10 ⁻⁴ Pa, a cathode buffer layer having a film thickness of 0.5 nm was provided at a deposition rate of 0.01 to 0.02 nm / second by energizing a boat containing lithium fluoride. Next, a boat containing aluminum was energized, a cathode having a film thickness of 150 nm was attached at a deposition rate of 1 to 2 nm / second, and an organic EL device 1-1 was produced.

<< Production of Organic EL Elements 1-2 to 1-6 >>
In the production of the organic EL element 1-1, the organic EL elements 1-2 to 1-6 were produced in the same manner except that the luminescent dopant Ir-12 was changed as shown in Table 1.

<< Evaluation of organic EL elements >>
When evaluating the obtained organic EL elements 1-2 to 1-6, the non-light-emitting surface of each organic EL element after production is covered with a glass case, and a glass substrate having a thickness of 300 μm is used as a sealing substrate. An epoxy-based photo-curing adhesive (Lux Track LC0629B manufactured by Toagosei Co., Ltd.) is applied as a sealing material in the periphery, and this is placed on the cathode to be in close contact with the transparent support substrate and irradiated with UV light from the glass substrate side. Then, it was cured and sealed, and an illumination device as shown in FIGS. 3 and 4 was formed and evaluated.

  FIG. 3 is a schematic diagram of the lighting device, and the organic EL element 101 is covered with a glass cover 102 (in addition, the sealing operation with the glass cover is performed in a nitrogen atmosphere without bringing the organic EL element 101 into contact with the atmosphere. (In a high purity nitrogen gas atmosphere with a purity of 99.999% or more). 4 shows a cross-sectional view of the lighting device. In FIG. 4, reference numeral 105 denotes a cathode, 106 denotes an organic EL layer, and 107 denotes a glass substrate with a transparent electrode. The glass cover 102 is filled with nitrogen gas 108 and a water catching agent 109 is provided.

(External quantum efficiency)
By lighting the organic EL element under a constant current condition of room temperature (about 23 to 25 ° C.) and ^2.5 mA / cm ² , and measuring the light emission luminance (L) [cd / m ² ] immediately after the start of lighting, The external extraction quantum efficiency (η) was calculated. Here, CS-1000 (manufactured by Konica Minolta Sensing) was used for measurement of light emission luminance. The external extraction quantum efficiency was expressed as a relative value with the organic EL element 1-1 as 100.

(Luminescent life)
The organic EL element was continuously lit at a constant current of ^2.5 mA / cm ² at room temperature, and the time (τ ^1/2 ) required to reach half the initial luminance was measured. The light emission lifetime was expressed as a relative value at which the organic EL element 1-1 was set to 100.

(Luminescent color)
The organic EL device was visually evaluated for the luminescent color when the organic EL device was continuously lit under a constant current condition of ^2.5 mA / cm ² at room temperature.

  The obtained results are shown in Table 1.

  From Table 1, the organic EL device produced by using the metal complex according to the present invention has a high emission efficiency and a long emission life while having a short blue light emission of pure blue to blue green as compared with the organic EL device of the comparative example. It is clear that crystallization can be achieved.

Example 2
<< Preparation of Organic EL Element 2-1 >>
An anode of indium tin oxide (ITO, indium / tin = 95/5 molar ratio) was formed on a glass support substrate of 25 mm × 25 mm × 0.5 mm by a sputtering method using a direct current power (thickness: 200 nm). The surface resistance of this anode was 10Ω / □. Polyvinylcarbazole (hole transporting binder polymer) / Ir-12 (blue light-emitting orthometalated complex) / 2- (4-biphenylyl) -5- (4-t-butylphenyl) -1,3,4 -Oxadiazole (electron transport material) = A dichloroethane solution in which a mass ratio of 200/2/50 was dissolved was applied by a spin coater to obtain a light-emitting layer having a thickness of 100 nm. A patterned mask (a mask with a light emission area of 5 mm × 5 mm) is placed on the organic compound layer, and lithium fluoride 0.5 nm is deposited as a cathode buffer layer and aluminum 150 nm is deposited as a cathode in a deposition apparatus to form a cathode. A blue light-emitting organic EL device 2-1 was prepared.

<< Production of Organic EL Elements 2-2 to 2-6 >>
In the production of the organic EL element 2-1, organic EL elements 2-2 to 2-6 were produced in the same manner except that the emission dopant Ir-12 was changed as shown in Table 2.

<< Evaluation of organic EL elements >>
When evaluating the obtained organic EL elements 2-1 to 2-6, as in Example 1, the non-light-emitting surface of each organic EL element after production was covered with a glass case, and a glass substrate having a thickness of 300 μm was sealed. An epoxy-based photo-curing adhesive (Lux Track LC0629B manufactured by Toagosei Co., Ltd.) is applied as a sealing material around the substrate, and this is overlaid on the cathode and brought into close contact with the transparent support substrate. UV light was irradiated from the side, cured and sealed, and an illumination device as shown in FIGS. 1 and 2 was formed and evaluated.

  Subsequently, the luminance and luminous efficiency were measured as follows.

(Luminance, luminous efficiency)
Using a source measure unit 2400 type manufactured by Toyo Technica, a direct current voltage is applied to an organic EL element to emit light, and a light emission luminance (cd / m ² ) and ^2.5 mA / cm ² when a direct current voltage of 10 V is applied. Luminous efficiency (lm / W) when passing current was measured. The obtained results are shown in Table 2. It represents with the relative value which sets the organic EL element 2-1 to 100.

(Luminescent life)
The organic EL element was continuously lit at a constant current of ^2.5 mA / cm ² at room temperature, and the time (τ ^1/2 ) required to reach half the initial luminance was measured. The light emission lifetime is represented by a relative value at which the organic EL element 2-1 is set to 100.

  From Table 2, the organic EL element produced using the metal complex according to the present invention can achieve high luminous efficiency and high luminance while having short-wave emission of pure blue to blue green compared with the organic EL element of the comparative example. Is clear.

Example 3
<Production of full-color display device>
(Production of blue light emitting element)
The organic EL element 1-4 of Example 1 was used as a blue light emitting element.

(Production of green light emitting element)
A green light emitting device was produced in the same manner as in the organic EL device 1-1 of Example 1 except that Ir-12 was changed to Ir-1, and this was used as a green light emitting device.

(Production of red light emitting element)
A red light emitting device was produced in the same manner as in the organic EL device 1-1 of Example 1 except that Ir-12 was changed to Ir-9, and this was used as a red light emitting device.

  The red, green, and blue light-emitting organic EL elements produced above were juxtaposed on the same substrate to produce an active matrix type full-color display device having a configuration as shown in FIG. In FIG. 2, only the schematic diagram of the display part A of the produced display device is shown. That is, a plurality of pixels 3 (light emission color is a red region pixel, a green region pixel, a blue region pixel, etc.) juxtaposed with a wiring portion including a plurality of scanning lines 5 and data lines 6 on the same substrate. The scanning lines 5 and the plurality of data lines 6 in the wiring portion are each made of a conductive material, and the scanning lines 5 and the data lines 6 are orthogonal to each other in a lattice shape and are connected to the pixels 3 at the orthogonal positions (for details, see FIG. Not shown). The plurality of pixels 3 are driven by an active matrix system provided with an organic EL element corresponding to each emission color, a switching transistor as an active element, and a driving transistor, and a scanning signal is applied from a scanning line 5. The image data signal is received from the data line 6 and light is emitted according to the received image data. In this way, a full color display device was manufactured by appropriately juxtaposing red, green, and blue pixels.

  It has been found that when this full-color display device is driven, high brightness, high durability, and a clear full-color moving image display can be obtained.

Example 4
<< Preparation of White Light Emitting Element and White Lighting Device-1 >>
The electrode of the transparent electrode substrate of Example 1 is patterned to 20 mm × 20 mm, and α-NPD is formed as a hole injection / transport layer with a thickness of 25 nm thereon as in Example 1, and further contains CBP. The heated boat, the boat containing Exemplified Compound (1-9) and the boat containing Ir-9 were energized independently, and CBP as a luminescent host and Exemplified Compound (1-9) as a luminescent dopant and The vapor deposition rate of Ir-9 was adjusted to 100: 5: 0.6, vapor deposition was performed to a thickness of 30 nm, and a light emitting layer was provided.

Next, BCP was deposited to a thickness of 10 nm to provide a hole blocking layer. Further, Alq ₃ was formed at 40 nm to provide an electron transport layer.

  Next, as in Example 1, a square perforated mask having the same shape as the transparent electrode made of stainless steel was placed on the electron injection layer, and lithium fluoride 0.5 nm was used as the cathode buffer layer and aluminum 150 nm was used as the cathode. Evaporated film was formed.

  This element was provided with a sealing can having the same method and the same structure as in Example 1, and a flat lamp as shown in FIGS. 3 and 4 was produced. When this flat lamp was energized, almost white light was obtained, and it was found that it could be used as a lighting device. It turned out that white light emission is obtained similarly even if it replaces with the other compound of illustration.

Example 5
<< Production of White Light Emitting Element and White Lighting Device-2 >>
After patterning on a substrate (NA-45 manufactured by NH Techno Glass Co., Ltd.) formed by depositing 100 nm of ITO (indium tin oxide) on a 100 mm × 100 mm × 1.1 mm glass substrate as an anode, this ITO transparent electrode was provided. The transparent support substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes.

  On this transparent support substrate, a solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, Bayer, Baytron P Al 4083) to 70% with pure water at 3000 rpm for 30 seconds. After the film formation by spin coating, the film was dried at 200 ° C. for 1 hour to provide a first hole transport layer having a thickness of 30 nm.

  This substrate was transferred to a nitrogen atmosphere, and a solution of 50 mg of compound A dissolved in 10 ml of toluene was formed on the first hole transport layer by spin coating at 1000 rpm for 30 seconds. After irradiating with ultraviolet light for 180 seconds to carry out photopolymerization / crosslinking, vacuum drying was performed at 60 ° C. for 1 hour to form a second hole transport layer.

  Next, using a solution prepared by dissolving Compound B (60 mg), Compound Ir-9 (3.0 mg), and Exemplified Compound (1-6) (3.0 mg) in 6 ml of toluene, spin was performed at 1000 rpm for 30 seconds. A film was formed by a coating method. Irradiated with ultraviolet light for 15 seconds to cause photopolymerization / crosslinking, and further heated in vacuum at 150 ° C. for 1 hour to obtain a light emitting layer.

  Furthermore, a film in which Compound C (20 mg) was dissolved in 6 ml of toluene was used to form a film by spin coating under conditions of 1000 rpm and 30 seconds. Ultraviolet light was irradiated for 15 seconds, photopolymerization / crosslinking was performed, and further heating was performed in vacuum at 80 ° C. for 1 hour to form a hole blocking layer.

Subsequently, this substrate was fixed to a substrate holder of a vacuum vapor deposition apparatus, and 200 mg of Alq ₃ was put into a molybdenum resistance heating boat and attached to the vacuum vapor deposition apparatus. After reducing the vacuum chamber to 4 × 10 ⁻⁴ Pa, the heating boat containing Alq ₃ was heated by heating, and deposited on the electron transport layer at a deposition rate of 0.1 nm / second to further form a film. An electron transport layer having a thickness of 40 nm was provided.

  In addition, the substrate temperature at the time of vapor deposition was room temperature.

  Then, 0.5 nm of lithium fluoride and 110 nm of aluminum were vapor-deposited, the cathode was formed, and the white light emitting organic EL element was produced.

  When this element was energized, it was found that substantially white light was obtained and it could be used as a lighting device.

Claims (6)

The organic electroluminescent material characterized by containing at least one of the general formula (1b) in represented Ru of compounds.
(Wherein R ¹ represents a hydrogen atom, a 3-carbazolyl group or an N-carbazolyl group linked via a linking group, but at least one N-carbazolyl group or a linking group linked via a linking group is N- Represents a carbazolyl group, and the linking group is a phenylene group, a dibenzofurylene group, a carbazolylene group, or a divalent group in which a plurality of these groups are bonded, and R ² is an alkyl group or a group represented by the following general formula (2). R ³ and R ⁴ each represent a hydrogen atom, and the sum of the formula weights of the substituents represented by R ^{1 to} R ⁴ is 1000 to 10000. n1 represents an integer of 0 to 4. Q represents a benzene ring, and M represents iridium.
(Wherein, ^{R 5} is, .N2 represents a hydrogen atom or an alkyl group is an integer of 0-5.) An organic electroluminescent element comprising the organic electroluminescent material according to claim 1 . An organic electroluminescent element comprising the organic electroluminescent material according to claim 1 in a light emitting layer. An organic electroluminescence device, wherein an organic layer containing the organic electroluminescence material according to claim 1 is formed by a wet process. Display apparatus comprising the organic electroluminescent element of any one of claims 2-4. An illuminating device comprising the organic electroluminescence element according to any one of claims 2 to 4 .