JP2011035172A - Method of manufacturing organic electroluminescent element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic electroluminescent element which has superior durability, high light emission efficiency, and superior operation stability, and to provide a method of designing the same. <P>SOLUTION: The organic electroluminescent element is characterized by comprising a light-emitting layer in which a Raman shift has a Raman peak within the range of 800 to 1,200 cm<SP>-1</SP>. The organic electroluminescent element is also characterized in that the wavenumber difference between the maximum Raman peak of the light-emitting layer as determined in the form of a layer and the Raman peak of the material that forms the light-emitting layer as determined in the form of a crystal is 2 cm<SP>-1</SP>at the maximum. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an organic electroluminescent device and a method for manufacturing the organic electroluminescent device.

  Organic electroluminescence devices have features such as self-emission and high-speed response, and are expected to be applied to flat panel displays. In particular, organic thin films (hole transport layer) that have a hole transport property and organic materials that have an electron transport property. Since a two-layer type (laminated type) in which a thin film (electron transport layer) is laminated is reported, it has attracted attention as a large-area light-emitting element that emits light at a low voltage of 10 V or less.

In such an organic EL element, it is considered that there are problems in light emission efficiency, durability, and operation stability for full-scale practical use, and various studies have been made (for example, see Patent Documents 1 to 3). .
However, from the existing viewpoints including selection of the light emitting material and improvement of the manufacturing method, no radical means for solving the above-mentioned problems has been found.

JP 2008-130646 A JP 2001-167890 A JP 2009-103523 A

  An object of the present invention is to solve the conventional problems and achieve the following objects. That is, an object of the present invention is to provide an organic electroluminescent device having excellent durability and high luminous efficiency and excellent operational stability, and a method for producing the organic electroluminescent device.

As a result of intensive studies to solve the above problems, the present inventors have obtained the following knowledge. That is, the Raman shift of the light emitting layer has a Raman peak in the range of 800 cm ^{−1 to} 1,200 cm ⁻¹ , and the wave number difference from the Raman peak measured in the crystalline state is 2 cm ^{− It} was found that the organic electroluminescent device having ¹ or less has the effects of improving the thermal stability, improving the efficiency, and reducing the voltage of the organic electroluminescent device. The fact that the wave number difference from the Raman peak is 2 cm ^-1 or less at most is that the molecular arrangement of the light emitting layer has regularity close to the crystalline state, that is, the LUMO level and HOMO level dispersion in the light emitting layer. , Which means that the position dependency is small. It was discovered that by suppressing the dispersion and position dependency of the LUMO level and the HOMO level, it is possible to achieve the effects of improved thermal stability, reduced drive voltage due to increased carrier mobility, and improved efficiency.

The present invention is based on the above findings of the present inventors, and means for solving the above problems are as follows. That is,
<1> The Raman peak has a Raman peak in the range of 800 cm ^{−1 to} 1,200 cm ⁻¹ , the Raman peak measured in the state of the layer, and the Raman peak measured in the crystalline state of the material forming the layer An organic electroluminescent element comprising a light emitting layer having a peak wave number difference of 2 cm ⁻¹ at most.
<2> The organic electroluminescent element according to <1>, wherein the light emitting layer contains a carbazole compound represented by the following general formula (1) as a host material.
(In the general formula (1), R ₁ is hydrogen, an alkyl group, an alkenyl group, a substituted or unsubstituted aromatic, .R ₂ to R ₉ represent either a substituted or unsubstituted heterocyclic compound Represents any one of hydrogen, deuterium, a halogen atom, a substituted or unsubstituted aromatic, and a substituted or unsubstituted heterocyclic group.)
<3> The organic electroluminescent element according to <2>, wherein the light emitting layer contains a platinum complex as a guest material.
<4> The organic electroluminescent element according to <2>, wherein the light emitting layer contains an iridium complex as a guest material.
<5> The Raman peak has a Raman peak in the range of 800 cm ^{−1 to} 1,200 cm ⁻¹ , the Raman peak measured in the state of the layer, and the Raman peak measured in the crystalline state of the material forming the layer Organic electroluminescence, wherein the difference between the maximum temperature and the minimum temperature of the host vapor deposition source, guest vapor deposition source, and substrate during vapor deposition is 2 ° C. or less so that the peak wave number difference of 2 cm ⁻¹ is at most It is a manufacturing method of an element.
<6> The Raman peak has a Raman peak in the range of 800 cm ^{−1 to} 1,200 cm ⁻¹ , the Raman peak measured in the state of the layer, and the Raman peak measured in the crystalline state of the material forming the layer even greater difference in peak wavenumber host deposition source during vapor deposition such that the 2 cm ^-1, the difference between the maximum and minimum temperatures of the guest evaporation sources and the substrate 2 ℃ or less, and the deposition source, the guest evaporation source and the substrate It is a method for producing an organic electroluminescent device, characterized in that vapor deposition is performed at a temperature change rate of 0.2 ° C./s or less.

  ADVANTAGE OF THE INVENTION According to this invention, the said conventional problems can be solved, the said objective can be achieved, it is excellent in durability, and it is the organic electroluminescent element and organic electric field which were excellent in luminous efficiency and excellent in operation stability. A method for manufacturing a light-emitting element can be provided.

It is sectional drawing which shows the structural example of the organic electroluminescent element of this invention.

(Organic electroluminescence device)
The organic electroluminescent element of the present invention is not particularly limited and can be appropriately selected according to the purpose. For example, the organic electroluminescent element has at least one organic layer including a light emitting layer between an anode and a cathode, Furthermore, it has another structure as needed.

<Light emitting layer>
The light emitting layer has a Raman peak in the range of 800 cm ^{−1 to} 1,200 cm ⁻¹ , and the Raman peak measured in the layer state and the Raman forming material measured in the crystalline state The peak wave number difference from the peak is at most 2 cm ⁻¹ .

  There is no restriction | limiting in particular as thickness of the said light emitting layer, According to the objective, it can select suitably, 2 nm-500 nm are preferable, 3 nm-200 nm are more preferable from a viewpoint of luminous efficiency, and 10 nm-100 nm are still more preferable. The light emitting layer may be a single layer or two or more layers.

The light emitting layer is not particularly limited as long as it is a material having a Raman peak in the range of 800 cm ^{−1 to} 1,200 cm ⁻¹ of the light emitting layer to be formed, and is appropriately selected according to the purpose. For example, it is preferable to include at least a host material and a guest material.

-Host material-
There is no restriction | limiting in particular as said host material, Although it can select suitably according to the objective, It is preferable that the carbazole compound shown by following General formula (1) is included.
(In the general formula (1), R ₁ represents any _one of hydrogen, an alkyl group, an alkenyl group, a substituted or unsubstituted aromatic, a substituted or unsubstituted heterocyclic compound, and R _{2 to} R _9. Represents any one of hydrogen, deuterium, a halogen atom, a substituted or unsubstituted aromatic, and a substituted or unsubstituted heterocyclic group.)

Is not particularly limited, examples of the substituent represented by R ¹ to R ^8, for example, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an amino group, an alkoxy group, an aryloxy group, a heterocyclic oxy group , Acyl group, alkoxycarbonyl group, aryloxycarbonyl group, acyloxy group, acylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfonylamino group, sulfamoyl group, carbamoyl group, alkylthio group, arylthio group, heterocyclic thio group Sulfonyl group, sulfinyl group, ureido group, phosphoric acid amide group, hydroxy group, mercapto group, halogen group, cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, hetero A ring group, Lil group, silyloxy group, such as a hydrogen atom. These substituents may be further substituted with other substituents, and these substituents may be bonded to each other to form a ring.

  Here, as an alkyl group, Preferably it is C1-C30, More preferably, it is C1-C20, Most preferably, it is C1-C10, for example, methyl, ethyl, n-propyl, iso-propyl, n -Butyl, tert-butyl, n-octyl, n-nonyl, n-decyl, n-dodecyl, n-octadecyl, n-hexadecyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl, 1-adamantyl, trifluoromethyl Etc.

  Moreover, as an alkenyl group, Preferably it is C2-C30, More preferably, it is C2-C20, Most preferably, it is C2-C10, for example, vinyl, allyl, 1-propenyl, 1-isopropenyl, -Butenyl, 2-butenyl, 3-pentenyl and the like can be mentioned.

  The alkynyl group preferably has 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, and particularly preferably 2 to 10 carbon atoms. Examples thereof include ethynyl, propargyl, 1-propynyl, and 3-pentynyl. It is done.

  Moreover, as an aryl group, Preferably it is C6-C30, More preferably, it is C6-C20, Most preferably, it is C6-C12, for example, phenyl, o-methylphenyl, m-methylphenyl, p- Examples include methylphenyl, 2,6-xylyl, p-cumenyl, mesityl, naphthyl, anthranyl, and the like.

  Further, the heteroaryl group preferably has 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, and examples of the hetero atom include a nitrogen atom, an oxygen atom, and a sulfur atom, specifically, for example, imidazolyl and pyrazolyl. , Pyridyl, pyrazyl, pyrimidyl, triazinyl, quinolyl, isoquinolinyl, pyrrolyl, indolyl, furyl, thienyl, benzoxazolyl, benzimidazolyl, benzthiazolyl, carbazolyl, azepinyl and the like.

  The amino group preferably has 0 to 30 carbon atoms, more preferably 0 to 20 carbon atoms, and particularly preferably 0 to 10 carbon atoms. For example, amino, methylamino, dimethylamino, diethylamino, dibenzylamino, Examples include diphenylamino and ditolylamino.

  Moreover, as an alkoxy group, Preferably it is C1-C30, More preferably, it is C1-C20, Most preferably, it is C1-C10, for example, methoxy, an ethoxy, butoxy, 2-ethylhexyloxy etc. are mentioned. It is done.

  Moreover, as an aryloxy group, Preferably it is C6-C30, More preferably, it is C6-C20, Most preferably, it is C6-C12, for example, phenyloxy, 1-naphthyloxy, 2-naphthyloxy, etc. Is mentioned.

  Moreover, as a heterocyclic oxy group, Preferably it is C1-C30, More preferably, it is C1-C20, Most preferably, it is C1-C12, for example, pyridyloxy, pyrazyloxy, pyrimidyloxy, quinolyloxy etc. are mentioned. .

  The acyl group preferably has 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and particularly preferably 1 to 12 carbon atoms, and examples thereof include acetyl, benzoyl, formyl, and pivaloyl.

  Moreover, as an alkoxycarbonyl group, Preferably it is C2-C30, More preferably, it is C2-C20, Most preferably, it is C2-C12, for example, methoxycarbonyl, ethoxycarbonyl, etc. are mentioned.

  The aryloxycarbonyl group preferably has 7 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, and particularly preferably 7 to 12 carbon atoms, and examples thereof include phenyloxycarbonyl.

  Moreover, as an acyloxy group, Preferably it is C2-C30, More preferably, it is C2-C20, Most preferably, it is C2-C10, for example, acetoxy, benzoyloxy, etc. are mentioned.

  The acylamino group preferably has 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, and particularly preferably 2 to 10 carbon atoms, and examples thereof include acetylamino and benzoylamino.

  Moreover, as an alkoxycarbonylamino group, Preferably it is C2-C30, More preferably, it is C2-C20, Most preferably, it is C2-C12, for example, methoxycarbonylamino etc. are mentioned.

  The aryloxycarbonylamino group preferably has 7 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, and particularly preferably 7 to 12 carbon atoms, and examples thereof include phenyloxycarbonylamino.

  Moreover, as a sulfonylamino group, Preferably it is C1-C30, More preferably, it is C1-C20, Most preferably, it is C1-C12, for example, methanesulfonylamino, benzenesulfonylamino, etc. are mentioned.

  The sulfamoyl group preferably has 0 to 30 carbon atoms, more preferably 0 to 20 carbon atoms, and particularly preferably 0 to 12 carbon atoms. For example, sulfamoyl, methylsulfamoyl, dimethylsulfamoyl, phenylsulfamo Famoyl etc. are mentioned.

  The carbamoyl group preferably has 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and particularly preferably 1 to 12 carbon atoms. Examples thereof include carbamoyl, methylcarbamoyl, diethylcarbamoyl, and phenylcarbamoyl. .

  Moreover, as an alkylthio group, Preferably it is C1-C30, More preferably, it is C1-C20, Most preferably, it is C1-C12, for example, methylthio, ethylthio, etc. are mentioned.

  Moreover, as an arylthio group, Preferably it is C6-C30, More preferably, it is C6-C20, Most preferably, it is C6-C12, for example, phenylthio etc. are mentioned.

  The heterocyclic thio group preferably has 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and particularly preferably 1 to 12 carbon atoms. For example, pyridylthio, 2-benzimidazolylthio, 2-benzoxa Examples include zolylthio and 2-benzthiazolylthio.

  Moreover, as a sulfonyl group, Preferably it is C1-C30, More preferably, it is C1-C20, Most preferably, it is C1-C12, for example, mesyl, tosyl, trifluoromethanesulfonyl etc. are mentioned.

  Moreover, as a sulfinyl group, Preferably it is C1-C30, More preferably, it is C1-C20, Most preferably, it is C1-C12, for example, methanesulfinyl, benzenesulfinyl, etc. are mentioned.

  Moreover, as a ureido group, Preferably it is C1-C30, More preferably, it is C1-C20, Most preferably, it is C1-C12, for example, ureido, methylureido, phenylureido etc. are mentioned.

  Moreover, as a phosphoric acid amide group, Preferably it is C1-C30, More preferably, it is C1-C20, Most preferably, it is C1-C12, for example, diethyl phosphoric acid amide, phenylphosphoric acid amide etc. are mentioned. It is done.

  Moreover, as a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned, for example.

  Moreover, as a heterocyclic group, Preferably it is C1-C30, More preferably, it is C1-C12, As a hetero atom, it is a nitrogen atom, an oxygen atom, a sulfur atom, specifically, for example, piperidyl, Examples thereof include morpholino and pyrrolidyl.

  The silyl group preferably has 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, and particularly preferably 3 to 24 carbon atoms. For example, trimethylsilyl, triethylsilyl, triisopropylsilyl, dimethyl-tert-butylsilyl , Dimethylphenylsilyl, diphenyl-tert-butylsilyl, triphenylsilyl, tri-1-naphthylsilyl, tri-2-naphthylsilyl and the like.

  Moreover, as a silyloxy group, Preferably it is C3-C40, More preferably, it is C3-C30, Most preferably, it is C3-C24, for example, trimethylsilyloxy, triphenylsilyloxy, etc. are mentioned.

The substituent for R ^{1 to} R ⁸ is preferably a hydrogen atom, an alkyl group, an aryl group, a heteroaryl group, a halogen group, a cyano group, or a silyl group, and more preferably a deuterium atom, an alkyl group, a heteroaryl group, or a halogen. Group, cyano group and silyl group, particularly preferably a deuterium atom, an alkyl group, a heteroaryl group and a silyl group. These substituents may be further substituted with other substituents, and these substituents may be bonded to each other to form a ring.

The alkyl group for R ^{1 to} R ⁸ is preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, n-octyl, cyclopropyl, cyclopentyl,
Cyclohexyl, 1-adamantyl, trifluoromethyl, more preferably methyl, isopropyl, tert-butyl, n-octyl, cyclopentyl, cyclohexyl, 1-adamantyl, trifluoromethyl, particularly preferably tert-butyl, cyclohexyl, 1-adamantyl, trifluoromethyl. These substituents may be further substituted with other substituents, and these substituents may be bonded to each other to form a ring.

The heteroaryl group of R ^{1 to} R ⁸ is preferably imidazolyl, pyrazolyl, pyridyl, quinolyl, isoquinolinyl, pyrrolyl, indolyl, furyl, thienyl, benzoxazolyl, benzimidazolyl, benzthiazolyl, carbazolyl, azepinyl, more preferably imidazolyl. , Pyrazolyl, quinolyl, indolyl, furyl, thienyl, benzimidazolyl, carbazolyl and azepinyl, particularly preferably indolyl, furyl, thienyl, benzimidazolyl, carbazolyl and azepinyl. These substituents may be further substituted with other substituents, may form a condensed ring structure, or these substituents may be bonded to each other to form a ring.

The silyl group for R ^{1 to} R ⁸ is preferably trimethylsilyl, triethylsilyl, triisopropylsilyl, methyldiphenylsilyl, dimethyl-tert-butylsilyl, dimethylphenylsilyl, diphenyl-tert-butylsilyl, triphenylsilyl, more preferably trimethylsilyl. , Triisopropylsilyl, dimethyl-tert-butylsilyl, diphenyl-tert-butylsilyl, and triphenylsilyl, particularly preferably trimethylsilyl, dimethyl-tert-butylsilyl, and triphenylsilyl. These substituents may be further substituted with other substituents, and these substituents may be bonded to each other to form a ring.

Particularly preferred as substituents for R ² and R ⁷ are an alkyl group, an aryl group, a silyl group and a hydrogen atom, more preferred are an alkyl group, a silyl group and a deuterium atom, and particularly preferred are a tert-butyl group, an adamantyl group, a trimethylsilyl group, a triphenylsilyl group, and a deuterium atom;

Particularly preferred as substituents for R ³ and R ⁶ are an alkyl group, an aryl group, a silyl group, and a deuterium atom, and more preferred are an alkyl group, a silyl group, and a deuterium atom, and particularly preferred are , Tert-butyl group, adamantyl group, trimethylsilyl group, triphenylsilyl group, deuterium atom.

Specific examples of combinations of substituents consisting of R ¹ to R ⁸ are illustrated below, but the invention is not limited to these compounds.

However, in the compounds represented by h-21 and h-22, m and n represent a molar ratio, m is an integer from 1 to 100, and n is an integer from 0 to 99.

  As content of the said host material, it is preferable that it is 10 mass%-99 mass% with respect to the total compound mass which forms the said light emitting layer, 20 mass%-95 mass% are more preferable, 50 mass%- 90 mass% is still more preferable.

The phosphorescent dopant is not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include a complex containing a transition metal atom or a lanthanoid atom.
The transition metal atom is not particularly limited and may be appropriately selected depending on the intended purpose. Ruthenium, rhodium, palladium, tungsten, rhenium, osmium, iridium, gold, silver, copper, and platinum are preferable, and rhenium. , Iridium, and platinum are more preferable, and iridium and platinum are particularly preferable.
The lanthanoid atom is not particularly limited and may be appropriately selected depending on the purpose.For example, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and Lutesium. Among these, neodymium, europium, and gadolinium are preferable.

Examples of the ligand of the complex include G.I. Wilkinson et al., Comprehensive Coordination Chemistry, Pergamon Press, 1987, H.C. Examples include ligands described in Yersin's "Photochemistry and Photophysics of Coordination Compounds" published by Springer-Verlag 1987, Akio Yamamoto "Organic Metal Chemistry-Fundamentals and Applications-" .
Examples of the ligand include a halogen ligand (preferably a chlorine ligand), an aromatic carbocyclic ligand (for example, a cyclopentadienyl anion, a benzene anion, a naphthyl anion, etc.). Preferably 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, still more preferably 6 to 12 carbon atoms), a nitrogen-containing heterocyclic ligand (for example, phenylpyridine, benzoquinoline, quinolinol, Bipyridyl, phenanthroline, etc. are mentioned, C5-C30 is preferable, C6-C30 is more preferable, C6-C20 is further more preferable, C6-C12 is especially preferable, Diketone ligand (for example, , Acetylacetone and the like), carboxylic acid ligands (for example, acetic acid ligands and the like, preferably having 2 to 30 carbon atoms) C2-C20 is more preferable, C2-C16 is especially preferable), an alcoholate ligand (For example, phenolate ligand etc. are mentioned, C1-C30 is preferable and C1-C20 is more. Preferably, the number of carbon atoms is more preferably 6 to 20, and a silyloxy ligand (for example, trimethylsilyloxy ligand, dimethyl-tert-butylsilyloxy ligand, triphenylsilyloxy ligand, etc.). 3 to 40 are preferable, 3 to 30 carbon atoms are more preferable, and 3 to 20 carbon atoms are particularly preferable), a carbon monoxide ligand, an isonitrile ligand, a cyano ligand, a phosphorus ligand (e.g. A phenylphosphine ligand, and the like, preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, still more preferably 3 to 20 carbon atoms, and 6 to 6 carbon atoms. 0 is particularly preferred), thiolato ligands (for example, phenylthiolato ligands, etc. are mentioned, preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and further preferably 6 to 20 carbon atoms). Phosphine oxide ligands (for example, triphenylphosphine oxide ligands, etc., preferably having 3 to 30 carbon atoms, more preferably 8 to 30 carbon atoms, and particularly preferably 18 to 30 carbon atoms) Are preferred, and nitrogen-containing heterocyclic ligands are more preferred.
The complex may have one transition metal atom in the compound, or may be a so-called binuclear complex having two or more. Different metal atoms may be contained simultaneously.

  Among these, as the luminescent dopant, for example, US6303238B1, US6097147, WO00 / 57676, WO00 / 70655, WO01 / 08230, WO01 / 39234A2, WO01 / 41512A1, WO02 / 02714A2, WO02 / 15645A1, WO02 / 44189A1, WO05 / 19373A2, JP2001-247859, JP2002-302671, JP2002-117978, JP JP 2003-133074 A, JP 2002-235076 A, JP 2003-123982 A, JP 2002-170684 A, EP 12111257 A, JP 2002-226 A. No. 95, JP-A No. 2002-234894, JP-A No. 2001-247859, JP-A No. 2001-298470, JP-A No. 2002-173684, JP-A No. 2002-203678, JP-A No. 2002-203679 Phosphorescence emission described in patent documents such as Japanese Patent Laid-Open Nos. 2004-357791, 2006-256999, 2007-194462, 2007-84635, and 2007-96259 Compound etc. are mentioned. Among them, Ir complex, Pt complex, Cu complex, Re complex, W complex, Rh complex, Ru complex, Pd complex, Os complex, Eu complex, Tb complex, Gd complex, Dy complex, and Ce complex are preferable, and Ir complex, Pt More preferred are complexes and Re complexes. Of these, Ir complexes, Pt complexes, and Re complexes containing at least one coordination mode of metal-carbon bond, metal-nitrogen bond, metal-oxygen bond, and metal-sulfur bond are even more preferable. Furthermore, from the viewpoints of luminous efficiency, driving durability, chromaticity, etc., an Ir complex, a Pt complex, and a Re complex containing a tridentate or higher multidentate ligand are particularly preferable.

  The fluorescent light-emitting dopant is not particularly limited and may be appropriately selected depending on the purpose. Benzoxazole, benzimidazole, benzothiazole, styrylbenzene, polyphenyl, diphenylbutadiene, tetraphenylbutadiene, naphthalimide, coumarin , Pyran, perinone, oxadiazole, aldazine, pyralidine, cyclopentadiene, bisstyrylanthracene, quinacridone, pyrrolopyridine, thiadiazolopyridine, cyclopentadiene, styrylamine, aromatic dimethylidin compound, condensed polycyclic aromatic compound (anthracene, Phenanthroline, pyrene, perylene, rubrene, or pentacene), metal complexes of 8-quinolinol, various metal complexes represented by pyromethene complexes and rare earth complexes, polythio E down, polyphenylene, polyphenylene vinylene polymer compounds such as organosilanes, and derivatives thereof.

The content of the guest material is preferably 0.5% by mass to 30% by mass, and preferably 0.5% by mass to 25% by mass with respect to the total compound mass generally forming the light emitting layer in the light emitting layer. % Is more preferable, and 5% by mass to 20% by mass is still more preferable.
If the content is less than 0.5% by mass, the luminous efficiency may be reduced, and if it exceeds 30% by mass, the luminous efficiency may be reduced due to association of the guest material itself.

<< Iridium Complex >>
There is no restriction | limiting in particular as said iridium complex, Although it can select suitably according to the objective, As a preferable iridium complex, WO2007 / 095118 gazette, WO2006 / 121811 gazette, WO2008 / 109824 gazette, US7279232 gazette, The iridium complexes described in WO2006 / 014599, WO2008 / 117889, JP-A-2001-345183, and WO2003 / 033617 are exemplified, but the invention is not limited thereto.

<< Platinum complex >>
There is no restriction | limiting in particular as said platinum complex, Although it can select suitably according to the objective, As a preferable platinum complex, WO2005 / 042550, WO2005 / 042444, Unexamined-Japanese-Patent No. 2005-310733, Unexamined-Japanese-Patent No. Examples include, but are not limited to, platinum complexes described in Japanese Patent Application Publication No. 2006-093542.

There is no restriction | limiting in particular as a formation method of the said light emitting layer, Although it can select suitably according to the objective, It is preferable to form by a vapor deposition method.
The deposition method is not particularly limited, but based on the deposition conditions of T _substrate , ΔT _host , ΔT _guest , ΔT _substrate , dT _host / dt, dT _guest / dt, and dT _substrate / dt, the host material, It is preferable to form the guest material by vapor deposition.
Here, the T _substrate , the ΔT _host , the ΔT _guest , the ΔT _substrate , the dT _host / dt, the dT _guest / dt, and the dT _substrate / dt have the following contents, respectively.
T _substrate : Set substrate temperature during vapor deposition (℃)
ΔT _host : Difference between the maximum temperature and the minimum temperature of the host evaporation source during evaporation (℃)
ΔT _guest : Difference between the maximum temperature and the minimum temperature of the guest deposition source during deposition (℃)
ΔT _substrate : Difference between the maximum and minimum substrate temperatures during vapor deposition (℃)
dT _host / dt: Maximum value of host temperature change rate during vapor deposition (° C./s)
dT _guest / dt: Maximum rate of change in guest temperature during vapor deposition (° C./s)
dT _substrate / dt: Maximum value of temperature change rate of substrate during vapor deposition (° C./s)

There is no restriction | limiting in particular as said T _board | _substrate , Although it can select suitably according to material, It is higher than (Tg) -50 degreeC or more and (Tg) -20 degrees C or less with respect to glass transition temperature (Tg). Preferably there is.
Although there is no restriction | limiting in particular as said (DELTA) T _host , 2 degrees C or less is preferable, 1 degrees C or less is more preferable, and 0.5 degrees C or less is especially preferable.
Although there is no restriction | limiting in particular as said (DELTA) T _guest , 2 degrees C or less is preferable, 1 degree C or less is more preferable, and 0.5 degree C or less is especially preferable.
Although there is no restriction | limiting in particular as said (DELTA) T _board | _substrate , 2 degrees C or less is preferable, 1 degrees C or less is more preferable, and 0.5 degrees C or less is especially preferable.
Although there is no restriction | limiting in particular as said dT _host / dt, 0.2 degrees C / s or less is preferable, 0.1 degrees C / s or less is more preferable, 0.05 degrees C / s or less is especially preferable.
Although there is no restriction | limiting in particular as said dT _guest / dt, 0.2 degrees C / s or less is preferable, 0.1 degrees C / s or less is more preferable, 0.05 degrees C / s or less is especially preferable.
The dT _substrate / dt is not particularly limited, but is preferably 0.2 ° C./s or less, more preferably 0.1 ° C./s or less, and particularly preferably 0.05 ° C./s or less.
When the T _substrate , the ΔT _host , the ΔT _guest , the ΔT _substrate , the dT _host / dt, the dT _guest / dt, and the dT _substrate / dt are within the preferable numerical ranges, the durability of the device, light emission Efficiency and operational stability can be significantly improved.

  Examples of the other layers include an electron transport layer, an electron injection layer, and, if necessary, a hole injection layer, a hole transport layer, a hole block layer, and an electron block layer.

<Hole injection layer, hole transport layer>
The hole injection layer and the hole transport layer are layers having a function of receiving holes from the anode or the anode side and transporting them to the cathode side. The hole injection layer and the hole transport layer may have a single layer structure or a multilayer structure composed of a plurality of layers having the same composition or different compositions.
The hole injection material or hole transport material used for these layers may be a low molecular compound or a high molecular compound.
The hole injection material or hole transport material is not particularly limited and may be appropriately selected depending on the purpose. For example, a pyrrole derivative, a carbazole derivative, a triazole derivative, an oxazole derivative, an oxadiazole derivative, an imidazole derivative, Polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic tertiary amine compounds, styrylamine Examples thereof include compounds, aromatic dimethylidin compounds, phthalocyanine compounds, porphyrin compounds, thiophene derivatives, organosilane derivatives, and carbon. These may be used individually by 1 type and may use 2 or more types together.

The hole injection layer and the hole transport layer may contain an electron accepting dopant.
As the electron-accepting dopant, an inorganic compound or an organic compound can be used as long as it has an electron-accepting property and oxidizes an organic compound.
The inorganic compound is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include metal halides such as ferric chloride, aluminum chloride, gallium chloride, indium chloride, and antimony pentachloride; vanadium pentoxide, And metal oxides such as molybdenum trioxide.
The organic compound is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a compound having a nitro group, a halogen, a cyano group, a trifluoromethyl group or the like as a substituent; a quinone compound, an acid anhydride Compounds, fullerenes, and the like.
These electron-accepting dopants may be used alone or in combination of two or more.
The amount of the electron-accepting dopant used is not particularly limited and varies depending on the type of material, but is preferably 0.01% by mass to 50% by mass with respect to the hole transport layer material or the hole injection material, 0.05 The mass% to 30 mass% is more preferable, and 0.1 mass% to 30 mass% is still more preferable.

The hole injection layer and the hole transport layer are not particularly limited and can be formed according to a known method. For example, a dry film forming method such as a vapor deposition method and a sputtering method, a wet coating method, a transfer method, and a printing method. It can be suitably formed by a method, an ink jet method, or the like.
The thickness of the hole injection layer and the hole transport layer is preferably 1 nm to 500 nm, more preferably 5 nm to 250 nm, and still more preferably 10 nm to 200 nm.

<Electron injection layer, electron transport layer>
The electron injection layer and the electron transport layer are layers having a function of receiving electrons from the cathode or the cathode side and transporting them to the anode side. The electron injection material and the electron transport material used for these layers may be a low molecular compound or a high molecular compound.
Specifically, pyridine derivatives, quinoline derivatives, pyrimidine derivatives, pyrazine derivatives, phthalazine derivatives, phenanthroline derivatives, triazine derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, fluorenone derivatives, anthraquinodimethane derivatives, anthrone Derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimide derivatives, fluorenylidenemethane derivatives, distyrylpyrazine derivatives, naphthalene, perylene and other aromatic ring tetracarboxylic acid anhydrides, phthalocyanine derivatives, 8-quinolinol derivative metal complexes, Metal phthalocyanines, various metal complexes represented by metal complexes with benzoxazole and benzothiazole as ligands, organosilane derivatives represented by siloles Body, or the like is preferably a layer containing.

The electron injection layer or the electron transport layer may contain an electron donating dopant. The electron-donating dopant introduced into the electron-injecting layer or the electron-transporting layer only needs to have an electron-donating property and have a property of reducing an organic compound. Alkali metals such as Li and alkaline earths such as Mg Metals, transition metals including rare earth metals, reducing organic compounds, and the like are preferably used. As the metal, a metal having a work function of 4.2 eV or less can be preferably used. Specifically, Li, Na, K, Be, Mg, Ca, Sr, Ba, Y, Cs, La, Sm, Gd , And Yb. Examples of the reducing organic compound include nitrogen-containing compounds, sulfur-containing compounds, and phosphorus-containing compounds.
In addition, the materials described in JP-A-6-212153, JP-A-2000-196140, JP-A-2003-68468, JP-A-2003-229278, JP-A-2004-342614, and the like are used. Can be used.

  The electron donating dopant may be used alone or in combination of two or more. The amount of the electron donating dopant varies depending on the type of material, but is preferably 0.1% by mass to 99% by mass, and 1.0% by mass to 80% by mass with respect to the electron transport layer material. Is more preferable, and 2.0 mass% to 70 mass% is particularly preferable.

The thicknesses of the electron injection layer and the electron transport layer are each preferably 500 nm or less from the viewpoint of lowering the driving voltage.
The thickness of the electron transport layer is preferably 1 nm to 500 nm, more preferably 5 nm to 200 nm, and even more preferably 10 nm to 100 nm. In addition, the thickness of the electron injection layer is preferably 0.1 nm to 200 nm, more preferably 0.2 nm to 100 nm, and further preferably 0.5 nm to 50 nm.
The electron injection layer and the electron transport layer may have a single layer structure composed of one or more of the above-described materials, or may have a multilayer structure composed of a plurality of layers having the same composition or different compositions.

<Hole blocking layer, electron blocking layer>
The hole blocking layer is a layer having a function of preventing holes transported from the anode side to the light emitting layer from passing through to the cathode side, and is usually provided as an organic compound layer adjacent to the light emitting layer on the cathode side. .
The electron blocking layer is a layer having a function of preventing electrons transported from the cathode side to the light emitting layer from passing through to the anode side, and is usually provided as an organic compound layer adjacent to the light emitting layer on the anode side.
Examples of the compound constituting the hole blocking layer include aluminum complexes such as BAlq, triazole derivatives, and phenanthroline derivatives such as BCP.
As a compound which comprises the said electronic block layer, what was mentioned, for example as the above-mentioned hole transport material can be utilized.

The electron block layer and the hole block layer are not particularly limited and can be formed according to a known method, for example, a dry film forming method such as a vapor deposition method and a sputtering method, a wet coating method, a transfer method, and a printing method. It can be suitably formed by an inkjet method or the like.
The thickness of the hole blocking layer and the electron blocking layer is preferably 1 nm to 200 nm, more preferably 1 nm to 50 nm, and still more preferably 3 nm to 10 nm. In addition, the hole blocking layer and the electron blocking layer may have a single-layer structure made of one or more of the materials described above, or may have a multilayer structure made up of a plurality of layers having the same composition or different compositions. Good.

<Electrode>
The organic electroluminescent element of the present invention includes a pair of electrodes, that is, an anode and a cathode. In view of the nature of the organic electroluminescence device, at least one of the anode and the cathode is preferably transparent. Usually, the anode only needs to have a function as an electrode for supplying holes to the organic compound layer, and the cathode only needs to have a function as an electrode for injecting electrons into the organic compound layer.
There is no restriction | limiting in particular about the shape, a structure, a magnitude | size, etc. as said electrode, According to the use and objective of an organic electroluminescent element, it can select suitably from well-known electrode materials.
As a material which comprises the said electrode, a metal, an alloy, a metal oxide, a conductive compound, or a mixture thereof etc. are mentioned suitably, for example.

-Anode-
Examples of the material constituting the anode include tin oxide doped with antimony and fluorine (ATO, FTO), tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO). Conductive metal oxides; metals such as gold, silver, chromium and nickel; mixtures or laminates of these metals and conductive metal oxides; inorganic conductive materials such as copper iodide and copper sulfide; polyaniline, polythiophene, Examples thereof include organic conductive materials such as polypyrrole, and laminates of these with ITO. Among these, conductive metal oxides are preferable, and ITO is particularly preferable in terms of productivity, high conductivity, transparency, and the like.

-Cathode-
Examples of the material constituting the cathode include alkali metals (eg, Li, Na, K, Cs, etc.), alkaline earth metals (eg, Mg, Ca, etc.), gold, silver, lead, aluminum, sodium-potassium alloys, Examples thereof include lithium-aluminum alloys, magnesium-silver alloys, rare earth metals such as indium and ytterbium. These may be used alone, but two or more can be suitably used in combination from the viewpoint of achieving both stability and electron injection.
Among these, alkali metals and alkaline earth metals are preferable from the viewpoint of electron injection properties, and materials mainly composed of aluminum are preferable from the viewpoint of excellent storage stability.
The material mainly composed of aluminum is aluminum alone, an alloy of aluminum and 0.01% by mass to 10% by mass of alkali metal or alkaline earth metal, or a mixture thereof (for example, lithium-aluminum alloy, magnesium-aluminum). Alloy).

  The method for forming the electrode is not particularly limited and can be performed according to a known method. For example, a wet method such as a printing method or a coating method; a physical method such as a vacuum deposition method, a sputtering method, or an ion plating method; Examples include chemical methods such as CVD and plasma CVD. Among these, it can be formed on the substrate in accordance with an appropriately selected method in consideration of suitability with the material constituting the electrode. For example, when ITO is selected as the anode material, it can be formed according to a direct current or high frequency sputtering method, a vacuum deposition method, an ion plating method, or the like. When a metal or the like is selected as the cathode material, one or more of them can be formed simultaneously or sequentially according to a sputtering method or the like.

  In addition, when patterning is performed when forming the electrode, it may be performed by chemical etching such as photolithography, or may be performed by physical etching using a laser or the like. It may be performed by sputtering or the like, or may be performed by a lift-off method or a printing method.

<Board>
The organic electroluminescent element of the present invention is preferably provided on a substrate, and may be provided in such a manner that the electrode and the substrate are in direct contact with each other, or may be provided in an intermediate layer. .
The material for the substrate is not particularly limited and may be appropriately selected depending on the intended purpose. For example, inorganic materials such as yttria-stabilized zirconia (YSZ) and glass (such as alkali-free glass and soda lime glass); polyethylene terephthalate And polyesters such as polybutylene phthalate and polyethylene naphthalate; organic materials such as polystyrene, polycarbonate, polyethersulfone, polyarylate, polyimide, polycycloolefin, norbornene resin, and poly (chlorotrifluoroethylene).

  There is no restriction | limiting in particular about the shape of the said board | substrate, a structure, a magnitude | size, It can select suitably according to the use, purpose, etc. of a light emitting element. In general, the shape of the substrate is preferably a plate shape. The structure of the substrate may be a single layer structure, a laminated structure, may be formed of a single member, or may be formed of two or more members. The substrate may be transparent or opaque, and if transparent, it may be colorless and transparent or colored and transparent.

The substrate may be provided with a moisture permeation preventing layer (gas barrier layer) on the front surface or the back surface.
Examples of the material of the moisture permeation preventive layer (gas barrier layer) include inorganic substances such as silicon nitride and silicon oxide.
The moisture permeation preventing layer (gas barrier layer) can be formed by, for example, a high frequency sputtering method.

-Other configurations-
There is no restriction | limiting in particular as said other structure, According to the objective, it can select suitably, For example, a protective layer, a sealing container, a resin sealing layer, a sealing adhesive etc. can be mentioned.
There is no restriction | limiting in particular as contents, such as the said protective layer, the said sealing container, the said resin sealing layer, and the said sealing adhesive agent, According to the objective, it can select suitably, for example, Unexamined-Japanese-Patent No. 2009-152572. The matters described in the gazette can be applied.

  FIG. 1 is a schematic view showing an example of the layer structure of the organic electroluminescent element of the present invention. The organic EL element 10 includes an anode 2 (for example, ITO electrode) formed on a glass substrate 1, a hole injection layer 3, a hole transport layer 4, a light emitting layer 5, an electron transport layer 6, and an electron injection. The layer structure is formed by laminating the layer 7 and the cathode 8 (for example, an Al—Li electrode) in this order. The anode 2 (for example, ITO electrode) and the cathode 8 (for example, Al-Li electrode) are connected to each other via a power source.

-Drive-
The organic electroluminescence device of the present invention emits light by applying a direct current (which may include an alternating current component as necessary) voltage (usually 2 to 15 volts) or a direct current between the anode and the cathode. Obtainable.
The organic electroluminescent element of the present invention can be applied to an active matrix by a thin film transistor (TFT). As the active layer of the thin film transistor, amorphous silicon, high temperature polysilicon, low temperature polysilicon, microcrystalline silicon, oxide semiconductor, organic semiconductor, carbon nanotube, or the like can be used.
The organic electroluminescent element of the present invention can be applied with the thin film transistor described in, for example, International Publication No. 2005/088726 pamphlet, Japanese Patent Application Laid-Open No. 2006-165529, US Patent Application Publication No. 2008/0237598.

There is no restriction | limiting in particular in the organic electroluminescent element of this invention, Light extraction efficiency can be improved by various well-known devices. For example, by processing the substrate surface shape (for example, forming a fine concavo-convex pattern), controlling the refractive index of the substrate, ITO layer, organic layer, controlling the thickness of the substrate, ITO layer, organic layer, etc. It is possible to improve the external quantum efficiency.
The light extraction method from the organic electroluminescence device of the present invention may be a top emission method or a bottom emission method.

The organic electroluminescent element of the present invention may have a resonator structure. For example, a multilayer mirror made of a plurality of laminated films having different refractive indexes, a transparent or translucent electrode, a light emitting layer, and a metal electrode are superimposed on a transparent substrate. The light generated in the light emitting layer resonates repeatedly with the multilayer mirror and the metal electrode as a reflection plate.
In another preferred embodiment, a transparent or translucent electrode and a metal electrode each function as a reflecting plate on a transparent substrate, and light generated in the light emitting layer repeats reflection and resonates between them.
In order to form a resonant structure, the optical path length determined from the effective refractive index of the two reflectors and the refractive index and thickness of each layer between the reflectors is adjusted to the optimum value to obtain the desired resonant wavelength. Is done. The calculation formula in the case of the first aspect is described in JP-A-9-180883. The calculation formula in the case of the second aspect is described in Japanese Patent Application Laid-Open No. 2004-127795.

-Application-
The organic electroluminescent element of the present invention is not particularly limited and may be appropriately selected depending on the intended purpose. However, the display element, display, backlight, electrophotography, illumination light source, recording light source, exposure light source, reading light source, label It can be suitably used for signboards, interiors, optical communications, and the like.
As a method for making the organic EL display of a full color type, as described in, for example, “Monthly Display”, September 2000, pages 33 to 37, the three primary colors (blue (B), green (G), red light (R)), a three-color light emitting method in which organic EL elements that respectively emit light corresponding to red (R) are arranged on a substrate, and white light emission by an organic electroluminescent element for white light emission is divided into three primary colors through a color filter. A white method, a color conversion method for converting blue light emission by a blue light emitting organic electroluminescent element into red (R) and green (G) through a fluorescent dye layer, and the like are known.

(Method for manufacturing organic electroluminescent device)
In the method for producing an organic electroluminescent element of the present invention, the Raman shift has a Raman peak in the range of 800 cm ^{−1 to} 1,200 cm ⁻¹ , and the Raman peak measured in the state of the layer and the material for forming the layer are used. Vapor deposition when the difference between the maximum temperature and the minimum temperature of the host vapor deposition source, guest vapor deposition source, and substrate during vapor deposition is 2 ° C. or less so that the peak wave number difference from the Raman peak measured in the crystalline state is at most 2 cm ^−1. To do.
In the method for producing an organic electroluminescent element of the present invention, the Raman shift has a Raman peak in the range of 800 cm ^{−1 to} 1,200 cm ⁻¹ , and the Raman peak measured in the state of the layer and the material for forming the layer are used. The difference between the maximum temperature and the minimum temperature of the host vapor deposition source, the guest vapor deposition source and the substrate during vapor deposition is 2 ° C. or less so that the peak wave number difference from the Raman peak measured in the crystalline state is at most 2 cm ^−1. The temperature change rate of the evaporation source, the guest evaporation source and the substrate is 0.2 ° C./s or less.
Thermal stability test: The organic electroluminescent device is placed in a thermostatic layer where the temperature can be controlled. The cycle of raising the temperature of the constant temperature layer from 40 ° C. to 100 ° C. at a rate of 2 ° C./min and then lowering to 40 ° C. at a rate of 2 ° C./min is performed as 10 cycles, The ΔV and ΔL when a current of 0.5 mA is applied before and after 10 cycles are measured.
The matters described in the description of the organic electroluminescent element of the present invention can be applied to a specific manufacturing method of the organic electroluminescent element.

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

[Production Example 1]
On a glass substrate having a thickness of 0.5 mm and a square of 2.5 cm, ITO (Indium Tin Oxide) was provided as an anode by a sputtering method so as to have a thickness of 100 nm. Next, this ITO-attached glass substrate was put into a cleaning container, subjected to ultrasonic cleaning in 2-propanol, and then subjected to UV-ozone treatment for 30 minutes.
Next, on the anode (ITO), 2-TNATA (4,4 ′, 4 ″ -Tris (N- (2-naphthyl) -N-phenyl-amino) -triphenylamine) is formed to a thickness of 120 nm as a hole injection layer. Vapor deposited.
Next, on the glass substrate with ITO, α-NPD (Bis [N- (1-naphthyl) -N-phenyl] benzidine)) was formed to a thickness of 7 nm as a hole transport layer by a vacuum deposition method. Next, an amine compound 1 represented by the following structural formula was deposited as a second hole transport layer on the hole transport layer to a thickness of 3 nm.

Next, on the second hole transport layer, a light emitting layer was formed with a thickness of 100 nm to 500 nm by vapor-depositing a host material and a guest material according to the conditions of Examples and Comparative Examples shown in Table 1-1.
The light emitting layer is formed under the vapor deposition conditions of T _substrate , ΔT _host , ΔT _guest , ΔT _substrate , dT _host / dt, dT _guest / dt, and dT _substrate / dt shown in Table 1. The deposition conditions were finely adjusted from the set conditions.

Here, T _substrate , ΔT _host , ΔT _guest , ΔT _substrate , dT _host / dt, dT _guest / dt, and dT _substrate / dt have the following contents, respectively.
T _substrate : Setting substrate (glass substrate) temperature during vapor deposition (℃)
ΔT _host : Difference between the maximum temperature and the minimum temperature of the host evaporation source during evaporation (℃)
ΔT _guest : Difference between the maximum temperature and the minimum temperature of the guest deposition source during deposition (℃)
ΔT _substrate : Difference between the maximum and minimum substrate temperatures during vapor deposition (℃)
dT _host / dt: Maximum value of host temperature change rate during vapor deposition (° C./s)
dT _guest / dt: Maximum rate of change in guest temperature during vapor deposition (° C./s)
dT _substrate / dt: Maximum value of temperature change rate of substrate during vapor deposition (° C./s)
The T _substrate , T _host (temperature of the host vapor deposition source during vapor deposition), and T _guest (temperature of the guest vapor deposition source during vapor deposition) during deposition are constantly monitored using a thermocouple thermometer, and ΔT _host and ΔT _{guest are} monitored. , ΔT _substrate , dT _host / dt, dT _guest / dt, and dT _substrate / dt were calculated based on the measured data.

Next, a mask patterned as a cathode (a mask having a light emitting region of 2 mm × 2 mm) was placed on the light emitting layer, and metal aluminum (Al) was deposited to a thickness of 100 nm.
By the above, the organic electroluminescent element in the comparative example 1 and Examples 1-1 to 1-3 was manufactured.

However, the host material H-1 and guest material G-1 in Table 1-1 represent compounds represented by the following structural formulas.
-Host material H-1-

-Guest material G-1-

(Measurement method and evaluation method)
-Measurement method of Raman peak and peak wavelength difference-
Using a Raman apparatus (a spectroscope manufactured by Tokyo Instruments, Nanofinder 30), the excitation light is a He-Ne laser (wavelength 632.8 nm), the diffraction grating is a grating frequency of 1,800 lines / mm, the center wavelength is 675 nm, and the Raman peak The peak wavelength difference was measured. The wave number interval of the measurement data was 0.5 cm ⁻¹ , and the Raman peak was read by fitting the measured peak to a Gaussian function using spectrum analysis software and interpolating the point interval to 0.03 cm ⁻¹ .
The crystal state of the host material used for forming the light emitting layer was confirmed with a commercially available powder X-ray diffractometer (RINT 2500, manufactured by Rigaku Corporation). When a clear X-ray diffraction peak was observed in the powder state before vapor deposition, the powder state was regarded as a crystalline state, and when no X-ray diffraction peak was observed in the powder, a polycrystal was separately prepared. The maximum Raman peak of the crystal is measured using the Raman apparatus with the spot of excitation laser light irradiated on the crystal being reduced to about 1 μm in diameter.
In addition, the Raman peak measurement in an organic electroluminescent element is 100 nm-500 nm in thickness by vapor-depositing the said host material and the said guest material on the said glass substrate with ITO separately from the Example and comparative example which are shown to a table | surface. The light emitting layer was formed as a single layer as an organic layer, and the Al was deposited on the light emitting layer. The results are shown in Table 1-2 below.

(Measurement method of luminous efficiency)
A direct voltage was applied to each element to emit light using an organic electroluminescence display device (source measure unit type 2400 manufactured by KEITHLEY). The brightness was measured using a luminance meter BM-8 manufactured by Topcon Corporation. The emission spectrum and emission wavelength were measured using a spectrum analyzer PMA-11 manufactured by Hamamatsu Photonics. Based on these numerical values, the light emission efficiency at a current density of ^2.5 mA / cm ² was calculated as the external quantum efficiency by a luminance conversion method. Based on the calculated values, the external quantum efficiencies of the organic electroluminescent elements in the examples when the external quantum efficiency of the comparative example was set to 100 were relatively evaluated. The results are shown in Table 1-2 below.

-Operational stability measurement method-
In order to evaluate the operational stability (driving voltage stability, luminance stability) of the organic electroluminescence device, a heat shock test was conducted as follows.
The heat shock test for the organic electroluminescent device was conducted by placing the organic electroluminescent device in a temperature-controllable constant temperature layer and increasing the temperature of the constant temperature layer from 40 ° C. to 100 ° C. at a rate of 2 ° C./min. The cycle immediately descending to 40 ° C. at a rate of 2 ° C./min is assumed to be one cycle, and the cycle is performed 10 times. The voltage change (ΔV) and luminance change (0.5 V current when the current is 0.5 mA before and after the execution of 10 cycles) ΔL) was measured. The results are shown in Table 1-2 below.

(Production Example 2)
Organic electroluminescent elements in Comparative Example 2 and Example 2 were produced in the same manner as in Production Example 1 except that the conditions for forming the light emitting layer were the conditions shown in Table 2-1 below.

However, the guest material G-2 in Table 2-1 represents a compound represented by the following structural formula.
-Guest material G-2-

  Various characteristics of the organic electroluminescent elements in Comparative Example 2 and Example 2 were measured and evaluated by the measurement method and the evaluation method shown in Production Example 1. The results are shown in Table 2-2 below.

(Production Example 3)
Organic electroluminescent elements in Comparative Example 3 and Example 3 were produced in the same manner as in Production Example 1 except that the conditions for forming the light emitting layer were the conditions shown in Table 3-1 below.

However, the guest material G-3 in Table 3-1 represents a compound represented by the following structural formula.
-Guest material G-3-

  Various characteristics of the organic electroluminescence elements in Comparative Example 3 and Example 3 were measured and evaluated by the measurement method and the evaluation method shown in Production Example 1. The results are shown in Table 3-2 below.

(Production Example 4)
Organic electroluminescent elements in Comparative Example 4 and Example 4 were produced in the same manner as in Production Example 1 except that the conditions for forming the light emitting layer were the conditions shown in Table 4-1 below.

However, the guest material G-4 in Table 4-1 represents a compound represented by the following structural formula.
-Guest material G-4-

  Various characteristics of the organic electroluminescence elements in Comparative Example 4 and Example 4 were measured and evaluated by the measurement method and evaluation method shown in Production Example 1. The results are shown in Table 4-2 below.

(Production Example 5)
Organic electroluminescent elements in Comparative Example 5 and Example 5 were produced in the same manner as in Production Example 1 except that the formation conditions of the light emitting layer were changed to the conditions shown in Table 5-1 below.

However, the host material H-2 in Table 5-1 represents a compound represented by the following structural formula.
-Host material H-2-

  Various characteristics of the organic electroluminescent elements in Comparative Example 5 and Example 5 were measured and evaluated by the measurement method and the evaluation method shown in Production Example 1. The results are shown in Table 5-2 below.

(Production Example 6)
Organic electroluminescent elements in Comparative Example 6 and Example 6 were produced in the same manner as in Production Example 1 except that the conditions for forming the light emitting layer were the conditions shown in Table 6-1 below.

However, the guest material G-5 in Table 6-1 represents a compound represented by the following structural formula.
-Guest material G-5

  Various characteristics of the organic electroluminescent elements in Comparative Example 6 and Example 6 were measured and evaluated by the measurement method and the evaluation method shown in Production Example 1. The results are shown in Table 6-2 below.

(Production Example 7)
Organic electroluminescent elements in Comparative Example 7 and Example 7 were produced in the same manner as in Production Example 1 except that the formation conditions of the light emitting layer were changed to the conditions shown in Table 7-1 below.

However, the guest material G-6 in Table 7-1 represents a compound represented by the following structural formula.
-Guest material G-6

  Various characteristics of the organic electroluminescent elements in Comparative Example 7 and Example 7 were measured and evaluated by the measurement method and evaluation method shown in Production Example 1. The results are shown in Table 7-2 below.

(Production Example 8)
Organic electroluminescent elements in Comparative Example 8 and Example 8 were produced in the same manner as in Production Example 1 except that the conditions for forming the light emitting layer were the conditions shown in Table 8-1 below.

However, guest material G-7 in Table 8-1 represents a compound represented by the following structural formula.
-Guest material G-7-

  Various characteristics of the organic electroluminescent elements in Comparative Example 8 and Example 8 were measured and evaluated by the measurement method and the evaluation method shown in Production Example 1. The results are shown in Table 8-2 below.

(Production Example 9)
Organic electroluminescent elements in Comparative Example 9 and Example 9 were produced in the same manner as in Production Example 1 except that the conditions for forming the light emitting layer were the conditions shown in Table 9-1 below.

However, the guest material G-8 in Table 9-1 represents a compound represented by the following structural formula.
-Guest material G-8-

  Various characteristics of the organic electroluminescent elements in Comparative Example 9 and Example 9 were measured and evaluated by the measurement method and the evaluation method shown in Production Example 1. The results are shown in Table 9-2 below.

(Production Example 10)
Organic electroluminescent elements in Comparative Example 10 and Example 10 were produced in the same manner as in Production Example 1 except that the conditions for forming the light emitting layer were the conditions shown in Table 10-1.

However, the host material H-3 in Table 10-1 represents a compound represented by the following structural formula.
-Host material H-3-

  Various characteristics of the organic electroluminescent elements in Comparative Example 10 and Example 10 were measured and evaluated by the measurement method and the evaluation method shown in Production Example 1. The results are shown in Table 10-2 below.

(Production Example 11)
Organic electroluminescent elements in Comparative Example 11 and Example 11 were produced in the same manner as in Production Example 1 except that the conditions for forming the light emitting layer were the conditions shown in Table 11-1.

However, guest material G-9 in Table 11-1 represents a compound represented by the following structural formula.
-Guest material G-9-

  By the measurement method and the evaluation method shown in Production Example 1, various characteristics of the organic electroluminescent elements in Comparative Example 11 and Example 11 were measured and evaluated. The results are shown in Table 11-2 below.

  The organic electroluminescent device of the present invention is excellent in durability and has high luminous efficiency and excellent operational stability. For example, a display device, display, backlight, electrophotography, illumination light source, recording light source, exposure light source, reading light source It is suitably used for signs, signs, interiors, optical communications, and the like.

DESCRIPTION OF SYMBOLS 1 Board | substrate 2 Anode 3 Hole injection layer 4 Hole transport layer 5 Light emitting layer 6 Electron transport layer 7 Electron injection layer 8 Cathode 10 Organic electroluminescent element

Is not particularly limited, examples of the substituent represented by R ² to R ^9, for example, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, an amino group, an alkoxy group, an aryloxy group, a heterocyclic oxy group , Acyl group, alkoxycarbonyl group, aryloxycarbonyl group, acyloxy group, acylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfonylamino group, sulfamoyl group, carbamoyl group, alkylthio group, arylthio group, heterocyclic thio group Sulfonyl group, sulfinyl group, ureido group, phosphoric acid amide group, hydroxy group, mercapto group, halogen group, cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, hetero A ring group, Lil group, silyloxy group, such as a hydrogen atom. These substituents may be further substituted with other substituents, and these substituents may be bonded to each other to form a ring.

The substituent for R ^{2 to} R ⁹ is preferably a hydrogen atom, an alkyl group, an aryl group, a heteroaryl group, a halogen group, a cyano group, or a silyl group, more preferably a deuterium atom, an alkyl group, a heteroaryl group, or a halogen. Group, cyano group and silyl group, particularly preferably a deuterium atom, an alkyl group, a heteroaryl group and a silyl group. These substituents may be further substituted with other substituents, and these substituents may be bonded to each other to form a ring.

The alkyl group for R ^{2 to} R ⁹ is preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, n-octyl, cyclopropyl, cyclopentyl, cyclohexyl, 1-adamantyl, trifluoromethyl, More preferred are methyl, isopropyl, tert-butyl, n-octyl, cyclopentyl, cyclohexyl, 1-adamantyl and trifluoromethyl, and particularly preferred are tert-butyl, cyclohexyl, 1-adamantyl and trifluoromethyl. These substituents may be further substituted with other substituents, and these substituents may be bonded to each other to form a ring.

The heteroaryl group of R ^{2 to} R ⁹ is preferably imidazolyl, pyrazolyl, pyridyl, quinolyl, isoquinolinyl, pyrrolyl, indolyl, furyl, thienyl, benzoxazolyl, benzimidazolyl, benzthiazolyl, carbazolyl, azepinyl, more preferably imidazolyl. , Pyrazolyl, quinolyl, indolyl, furyl, thienyl, benzimidazolyl, carbazolyl and azepinyl, particularly preferably indolyl, furyl, thienyl, benzimidazolyl, carbazolyl and azepinyl. These substituents may be further substituted with other substituents, may form a condensed ring structure, or these substituents may be bonded to each other to form a ring.

The silyl group of R ^{2 to} R ⁹ is preferably trimethylsilyl, triethylsilyl, triisopropylsilyl, methyldiphenylsilyl, dimethyl-tert-butylsilyl, dimethylphenylsilyl, diphenyl-tert-butylsilyl, triphenylsilyl, more preferably trimethylsilyl. , Triisopropylsilyl, dimethyl-tert-butylsilyl, diphenyl-tert-butylsilyl, and triphenylsilyl, particularly preferably trimethylsilyl, dimethyl-tert-butylsilyl, and triphenylsilyl. These substituents may be further substituted with other substituents, and these substituents may be bonded to each other to form a ring.

Specific examples of combinations of substituents consisting of R ^{2 to} R ⁹ are listed below, but the present invention is not limited to these compounds.

However, in the compounds represented by h-21 and h-22, m and n represent a molar ratio, m is an integer from 1 to 100, and n is an integer from 0 to 99.

(Production Example 4)
Organic electroluminescent elements in Comparative Example 4 and Reference Example 4 were produced in the same manner as in Production Example 1 except that the formation conditions of the light emitting layer were changed to those shown in Table 4-1 below.

Various characteristics of the organic electroluminescent elements in Comparative Example 4 and Reference Example 4 were measured and evaluated by the measurement method and evaluation method shown in Production Example 1. The results are shown in Table 4-2 below.

(Production Example 6)
Organic electroluminescent elements in Comparative Example 6 and Reference Example 6 were produced in the same manner as in Production Example 1 except that the formation conditions of the light emitting layer were changed to the conditions shown in Table 6-1 below.

However, the guest material G-5 in Table 6-1 represents a compound represented by the following structural formula.
-Guest material G-5

Various characteristics of the organic electroluminescent elements in Comparative Example 6 and Reference Example 6 were measured and evaluated by the measurement method and evaluation method shown in Production Example 1. The results are shown in Table 6-2 below.

(Production Example 7)
Organic electroluminescent elements in Comparative Example 7 and Reference Example 7 were produced in the same manner as in Production Example 1 except that the conditions for forming the light emitting layer were the conditions shown in Table 7-1 below.

However, the guest material G-6 in Table 7-1 represents a compound represented by the following structural formula.
-Guest material G-6

Various characteristics of the organic electroluminescent elements in Comparative Example 7 and Reference Example 7 were measured and evaluated by the measurement method and evaluation method shown in Production Example 1. The results are shown in Table 7-2 below.

(Production Example 8)
Organic electroluminescent elements in Comparative Example 8 and Reference Example 8 were produced in the same manner as in Production Example 1 except that the conditions for forming the light emitting layer were changed to the conditions shown in Table 8-1 below.

However, guest material G-7 in Table 8-1 represents a compound represented by the following structural formula.
-Guest material G-7-

Various characteristics of the organic electroluminescent elements in Comparative Example 8 and Reference Example 8 were measured and evaluated by the measurement method and evaluation method shown in Production Example 1. The results are shown in Table 8-2 below.

(Production Example 9)
Organic electroluminescent elements in Comparative Example 9 and Reference Example 9 were produced in the same manner as in Production Example 1 except that the formation conditions of the light emitting layer were changed to those shown in Table 9-1 below.

Various characteristics of the organic electroluminescent elements in Comparative Example 9 and Reference Example 9 were measured and evaluated by the measurement method and evaluation method shown in Production Example 1. The results are shown in Table 9-2 below.

(Production Example 11)
Organic electroluminescent elements in Comparative Example 11 and Reference Example 11 were produced in the same manner as in Production Example 1 except that the formation conditions of the light emitting layer were changed to those shown in Table 11-1.

However, guest material G-9 in Table 11-1 represents a compound represented by the following structural formula.
-Guest material G-9-

Various characteristics of the organic electroluminescent elements in Comparative Example 11 and Reference Example 11 were measured and evaluated by the measurement method and evaluation method shown in Production Example 1. The results are shown in Table 11-2 below.

(Production Example 4)
Except that a condition indicating a formation condition of the light-emitting layer in the following Table 4-1, in the same manner as in Production Example 1 to produce an organic electroluminescence device in Comparative Example 4 and Example 4.

The measurement methods and evaluation methods shown in Production Example 1 was measured and evaluation of properties of the organic electroluminescent device of Comparative Example 4 and Example 4. The results are shown in Table 4-2 below.

(Production Example 7)
Except that a condition indicating a formation condition of the light-emitting layer in the following Table 7-1, in the same manner as in Production Example 1 to produce an organic electroluminescence device in Comparative Example 7 and Example 7.

However, the guest material G-6 in Table 7-1 represents a compound represented by the following structural formula.
-Guest material G-6

The measurement methods and evaluation methods shown in Production Example 1 was measured and evaluation of properties of the organic electroluminescent device of Comparative Example 7 and Example 7. The results are shown in Table 7-2 below.

(Production Example 9)
Except that a condition indicating a formation condition of the light-emitting layer in the following Table 9-1, in the same manner as in Production Example 1 to produce an organic electroluminescence device in Comparative Example 9 and Example 9.

The measurement methods and evaluation methods shown in Production Example 1 was measured and evaluation of properties of the organic electroluminescent device of Comparative Example 9 and Example 9. The results are shown in Table 9-2 below.

(Production Example 11)
Except that a condition indicating a formation condition of the light-emitting layer in the following Table 11-1, in the same manner as in Production Example 1 to produce an organic electroluminescence device in Comparative Example 11 and Example 11.

However, guest material G-9 in Table 11-1 represents a compound represented by the following structural formula.
-Guest material G-9-

The measurement methods and evaluation methods shown in Production Example 1 was measured and evaluation of properties of the organic electroluminescent device of Comparative Example 11 and Example 11. The results are shown in Table 11-2 below.

Claims (6)

The peak wave number of the Raman peak having a Raman peak in the range of 800 cm ^{−1 to} 1,200 cm ⁻¹ , measured in the state of the layer, and the Raman peak measured in the crystalline state of the material forming the layer. An organic electroluminescent element comprising a light emitting layer having a difference of at most 2 cm ⁻¹ . The organic electroluminescent element of Claim 1 in which a light emitting layer contains the carbazole compound shown by following General formula (1) as a host material.
(In the general formula (1), R ₁ is hydrogen, an alkyl group, an alkenyl group, a substituted or unsubstituted aromatic, .R ₂ to R ₉ represent either a substituted or unsubstituted heterocyclic compound Represents any one of hydrogen, deuterium, a halogen atom, a substituted or unsubstituted aromatic, and a substituted or unsubstituted heterocyclic group.)   The organic electroluminescent element according to claim 2, wherein the light emitting layer contains a platinum complex as a guest material.   The organic electroluminescent element according to claim 2, wherein the light emitting layer contains an iridium complex as a guest material. The peak wave number of the Raman peak having a Raman peak in the range of 800 cm ^{−1 to} 1,200 cm ⁻¹ , measured in the state of the layer, and the Raman peak measured in the crystalline state of the material forming the layer. Manufacturing of an organic electroluminescent device characterized in that the difference between the maximum temperature and the minimum temperature of the host vapor deposition source, guest vapor deposition source and substrate during vapor deposition is 2 ° C. or less so that the difference is at most 2 cm ^−1. Method. The peak wave number of the Raman peak having a Raman peak in the range of 800 cm ^{−1 to} 1,200 cm ⁻¹ , measured in the state of the layer, and the Raman peak measured in the crystalline state of the material forming the layer. The difference between the maximum temperature and the minimum temperature of the host vapor deposition source, guest vapor deposition source and substrate during vapor deposition is 2 ° C. or less, and the temperature change of the vapor deposition source, guest vapor deposition source and substrate so that the difference is at most 2 cm ^−1. Vapor deposition is performed at a rate of 0.2 ° C./s or less.