KR101764810B1 - Composition for forming organic electroluminescence element, vapor deposition film, method for producing the vapor deposition film, and organic electroluminescence element - Google Patents

Abstract

The present invention relates to a composition for forming an organic electroluminescence element which can uniformly heat an organic compound to stabilize the organic compound for a long time, a vapor deposition film using the organic compound in the composition for forming an organic electroluminescence element, And an organic electroluminescent device having the evaporated film formed thereon.
A composition for forming an organic electroluminescent device includes a vaporizable organic compound having a molecular weight of 2,000 or less and a medium capable of dissolving or dispersing the organic compound, and the component of the medium is not vaporized at the vaporization temperature of the organic compound. Wherein the medium is at least one selected from organic compound salts and polymer compounds having a number average molecular weight of 10,000 or more.

Description

Technical Field [0001] The present invention relates to a composition for forming an organic electroluminescent device, a deposition film, a method of manufacturing the same, and an organic electroluminescent device,

The present invention relates to a composition for forming an organic electroluminescent device, a vapor deposition film using the organic compound in the composition for forming an organic electroluminescent device, a production method thereof, and an organic electroluminescent device (hereinafter referred to as " Device ", " organic EL device ").

A method of vacuum-depositing an organic compound, comprising the steps of: (i) placing the organic compound in a metal boat and energizing the metal boat to sublimate the organic compound to reach the substrate to solidify; (ii) A filament is disposed around the crucible to energize the organic compound to reach the substrate and solidify the organic compound.

In general, when the film formation of the organic compound is performed for a long period of time, the organic compound which is vaporized (vaporized) without melting does not have a deposition stability lower than that of the organic compound vaporized after melting once and the organic compound in the metal boat or the crucible collapses , And is locally heated by the low thermal conductivity of the metal boat or the crucible, and decomposition proceeds, and it is often difficult to stably deposit for a long time.

Particularly, in the case of mass production, it is necessary to carry out vapor deposition continuously for hundreds of hours, so that the amount of organic compounds to be charged into the metal boat or the crucible becomes large, and it becomes difficult to uniformly heat the organic compound which does not melt.

Therefore, until now, in order to uniformly apply heat to the organic compound, it has been necessary to stir a metal boat or a crucible, or introduce a mechanism for supplying a small amount of an organic compound.

In addition, conventionally, in order to promote charge injection into a light emitting layer, there is a method of forming a composition for forming a light emitting layer containing a light emitting material and a molten salt by application or vacuum deposition (for example, Patent Document 1) There is a problem that stable film formation can not be performed.

Further, a method of adding an additive in particulate form (for example, Thermoball (manufactured by Naga Gas Co., Ltd.)) having an electric conductivity equivalent to that of a metal and stable even at a high temperature is added to the organic compound in order to uniformly heat the organic compound However, there has been a problem that it is not possible to suppress the rapid rate deviation due to the collapse of the organic compound.

Japanese Patent Application Laid-Open No. 2007-204749

SUMMARY OF THE INVENTION The present invention has been made to solve all the above-mentioned conventional problems and to achieve the following objects. That is, the present invention relates to a composition for forming an organic electroluminescence element which can uniformly heat an organic compound to stabilize an organic compound for a long time, a vapor-deposited film of the organic compound in the composition for forming an organic electroluminescence element, And an organic electroluminescent device having the evaporated film formed thereon.

In order to solve the above problems, the inventors of the present invention have conducted intensive investigations, and as a result, have found that a vaporizable organic compound having a molecular weight of 2,000 or less and a medium capable of dissolving or dispersing the organic compound, It has been found that stable heating of the organic compound can be performed for a long period of time by heating the organic compound uniformly by heating the composition for forming an organic electroluminescent element which is not vaporized.

The present invention is based on the above knowledge by the present inventors, and means for solving the above problems are as follows. In other words,

≪ 1 > A vaporizable organic electroluminescent device comprising a vaporizable organic compound having a molecular weight of 2,000 or less and a medium capable of dissolving or dispersing the organic compound, wherein the component of the medium is not vaporized at a vaporization temperature of the organic compound .

(2) The composition for forming an organic electroluminescent device according to (1) above, wherein the decomposition temperature of the medium is 30 ° C or more higher than the vaporization temperature of the organic compound.

<3> The organic electroluminescent device according to <1> or <2>, wherein the medium is a liquid at a vaporization temperature of the organic compound under a pressure of 1 × 10 ^-2 Pa or less.

<4> The organic electroluminescent device according to any one of <1> to <3>, wherein the medium is at least one selected from the group consisting of an organic compound salt and a polymer compound having a number average molecular weight of 10,000 or more.

<5> The organic electroluminescent device according to <4>, wherein the cations of the organic compound salt include 1,3-dialkylimidazolium cations, N-alkylpyridinium cations, tetraalkylammonium cations, N, N-dialkylpyrrolidinium cations, Tetraalkylphosphonium cations and derivatives thereof, and the organic compound salt has at least one kind selected from the group consisting of a halogen anion, a borate-based anion, a phosphate-based anion, a sulfonate-based anion and an imide- Emitting layer.

<6> The organic electroluminescent device according to any one of <1> to <5>, wherein the organic compound is vaporizable by heating under a pressure of 1 × 10 ^-2 Pa or less.

<7> The organic electroluminescent device according to any one of <1> to <6>, wherein the organic compound comprises a carbazole skeleton.

<8> The organic electroluminescent device according to any one of <1> to <7>, wherein the organic compound comprises at least one of a platinum complex and an iridium complex.

<9> A process for producing an organic electroluminescence device, comprising the steps of: depositing an organic compound in the composition for forming an organic electroluminescence element described in any one of <1> to <8> Is formed on the substrate.

&Lt; 10 > A vapor-deposited film characterized by being produced by the method for producing a vapor-deposited film according to the above-mentioned < 9 >.

<11> The vapor-deposited film according to <10>, wherein the content of the medium is less than 0.001 mol% with respect to the organic compound.

<12> An organic electroluminescent device according to <10> or <11>, wherein at least one layer of a vapor deposition film is formed.

(Effects of the Invention)

According to the present invention, there is provided a composition for forming an organic electroluminescent element capable of solving all of the above problems in the prior art to achieve the above object, and capable of heating the organic compound uniformly to stabilize the organic compound for a long time, A vapor deposition film of an organic compound in a composition for forming an electroluminescent device, a manufacturing method thereof, and an organic electroluminescent device in which the vapor deposition film is formed.

1 is a schematic view showing an example of the layer structure of the organic electroluminescent device of the present invention.

(Composition for forming an organic electroluminescent device)

The composition for forming an organic electroluminescent device of the present invention contains at least an organic compound and a medium, and further contains other components as necessary.

<Organic compounds>

The organic compound is not particularly limited as long as it is a vaporizable organic compound having a molecular weight of 2,000 or less and can be appropriately selected in accordance with the purpose. However, the organic compound is preferably a material for an organic electroluminescence device, and an organic compound containing a carbazole skeleton, And an iridium complex are more preferable.

The material for the organic electroluminescence device is not particularly limited as long as it is an organic compound used in an organic electroluminescence device and can be appropriately selected in accordance with the purpose. For example, in a material used for an organic electroluminescence device described later, (A-1) to (A-10) and the like as vaporizable organic compounds having a molecular weight of not more than 2,000.

The organic compound containing the carbazole skeleton is not particularly limited and may be appropriately selected depending on the purpose, and includes the compounds represented by the following structural formulas (A-1) to (A-2).

The organic compound including the platinum complex is not particularly limited and can be appropriately selected depending on the purpose. Examples of the organic compound include compounds represented by the following structural formulas (A-5) to (A-7).

The organic compound containing the iridium complex is not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include compounds represented by the following structural formulas (A-8) to (A-10).

The molecular weight of the organic compound is not particularly limited as long as it is 2,000 or less. The molecular weight of the organic compound is suitably selected according to the purpose, but is preferably 100 to 2,000, more preferably 150 to 1,500, and particularly preferably 200 to 1,300.

If the molecular weight is more than 2,000, it may be decomposed by heating without vaporization. On the other hand, if the molecular weight is within a particularly preferable range, it is advantageous in that there are many materials which can be formed by vacuum deposition in a stable manner.

The molecular weights of the structural formulas (A-1) to (A-10) are respectively 408, 404, 4): 414, structural formula (A-5): 593, structural formula (A-6): 638, structural formula (A-7): 617, structural formula (A- The structural formula (A-10) is 1,198.

<Media>

As the medium is soluble or dispersing an organic compound, and this is not specially limited in the medium that is not vaporized components in the vaporization temperature of the organic compound, and can be suitably selected according to the purposes, 1 × 10 ^-2 of the organic compound Pa or less, and more preferably a medium having a melting point of lower than 100 占 폚.

The component of the medium includes not only the medium itself but also a decomposition product of the medium.

Further, since the medium can be handled as a nonvolatile liquid, it is easy to automate the supply of the organic compound if the medium and the organic compound are mixed in advance.

The decomposition temperature of the medium is not particularly limited and may be appropriately selected according to the purpose. It is preferably higher than the vaporization temperature of the organic compound by 30 ° C or more, more preferably 40 ° C or more, desirable.

If the difference between the decomposition temperature of the medium and the vaporization temperature of the organic compound is less than 30 캜, the medium itself may be vaporized, the medium may be decomposed, and the decomposition product may be vaporized. On the other hand, if the decomposition temperature of the medium is within a particularly preferable range, vaporization and decomposition of the thermal medium can be suppressed, which is advantageous in that no adverse influence is exerted on the thin film or element to be produced.

Further, when the organic compound is a mixture of two or more kinds of compounds, the vaporization temperature of the organic compound indicates the highest vaporization temperature of the two or more compounds.

Further, in the case where the medium is a mixture of two or more kinds of compounds, the decomposition temperature of the medium indicates the lowest decomposition temperature of the two or more kinds of compounds.

Specific examples of the medium are not particularly limited and can be appropriately selected according to the purpose. Examples thereof include organic compound salts (molten salt, ionic liquid), polymer compounds and the like.

- organic compound salt (molten salt, ionic liquid) -

The organic compound salt (molten salt, ionic liquid) is not particularly limited and may be appropriately selected according to the purpose. An organic compound salt which is a liquid at room temperature is preferable, a liquid having low viscosity at room temperature, , And an organic compound salt having high heat resistance and high thermal conductivity is more preferable. In addition, the organic compound salt (molten salt, ionic liquid) often has a property of dissolving the organic compound.

Specific examples of the organic compound salt (molten salt, ionic liquid) include 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate (the following structural formula (B-1)), N-methyl- 1-ethyl-3-methylimidazolium chloride (the following structural formula (B-3)), 1-ethyl-3-methylimidazolium chloride Butylpyridinium tetrafluoroborate (the following structural formula (B-6)), 1-butylpyridinium hexafluorophosphate (the following structural formula (B-8)), trihexyltetradecylphosphonium bistrifluoromethanesulfonyl (Organic compound salt of the following structural formula (B-10)), and the like.

The cation of the organic compound salt is not particularly limited and may be appropriately selected according to the purpose. Examples thereof include 1,3-dialkylimidazolium cation, N-alkylpyridinium cation, tetraalkylammonium cation, N, N - dialkylpyrrolidinium cation, tetraalkylphosphonium cation, derivatives thereof, and the like.

The anion of the organic compound salt is not particularly limited and may be appropriately selected depending on the purpose. Examples of the anion include a halogen anion, a borate anion, a phosphate anion, a sulfonate anion and an imide anion.

- Polymer compound -

The number average molecular weight of the polymer compound is not particularly limited and may be appropriately selected depending on the purpose. The number average molecular weight is preferably 10,000 or more, more preferably 13,000 or more, and particularly preferably 15,000 or more.

If the number average molecular weight of the polymer compound is less than 10,000, there is a possibility that the medium may be vaporized when used as a heat medium. On the other hand, if the number average molecular weight of the polymer compound is within a particularly preferable range, it is advantageous in that it is difficult to vaporize by heating.

Examples of such a polymer compound include natural polymers, synthetic resins, silicone resins, synthetic fibers and synthetic rubbers. Materials suitable for melting and decomposing points may be selected depending on the vaporization temperature of the organic material to be vaporized.

(Vapor Deposition Film and Manufacturing Method Thereof)

The method for producing a vapor-deposited film of the present invention includes at least a vapor-deposition film forming step and further includes other steps suitably selected as necessary.

&Lt; Vapor deposition process &

The deposition film formation process is a process for depositing an organic compound in the composition for forming an organic electroluminescence device of the present invention to form a vapor-deposited film of the organic compound in the above composition for forming an organic electroluminescence device on a substrate.

The pressure in the vapor deposition film formation step is not particularly limited and may be appropriately selected depending on the purpose. The pressure is preferably 1 10 ^-2 Pa or less, more preferably 1 10 ^-3 Pa or less, ^-4 Pa or less is particularly preferable.

If the pressure in the vapor deposition film formation step exceeds 1 10 ^-2 Pa, the average free step becomes short and the material may be difficult to reach the substrate. On the other hand, when the pressure in the deposition film formation step is within a particularly preferable range, it is advantageous in that deposition is easy to be performed, and the influence of the residual gas on the thin film and devices is reduced.

The temperature in the vapor deposition film formation step is not particularly limited and may be appropriately selected depending on the purpose. The temperature is preferably 50 to 500 ° C, more preferably 70 to 400 ° C, more preferably 100 to 300 ° C desirable.

If the temperature in the vapor deposition film formation step is less than 50 캜, the vaporized organic compound may not be a film, and if it exceeds 500 캜, the material may be decomposed. On the other hand, when the temperature in the vapor deposition film forming step is within a particularly preferable range, it is advantageous in that various crucibles and boats can be used.

- Vapor Deposition -

The vapor-deposited film is not particularly limited as long as it is a vapor-deposited film of an organic compound in the composition for forming an organic electroluminescent element of the present invention. The vapor-deposited film may be appropriately selected depending on the purpose. Examples thereof include organic thin films.

The thickness of the vapor deposition film is not particularly limited and can be suitably selected in accordance with the purpose.

Further, it is preferable that the vapor deposition film contains less than 0.001 mol% of the components of the medium with respect to the organic compound, i.e., substantially does not contain the components of the medium.

- Equipment -

The substrate is not particularly limited and may be appropriately selected depending on the purpose, and examples thereof include substrates described later. The term "substrate phase" means "in contact with the substrate surface" to "above the substrate".

(Organic electroluminescent device)

The organic electroluminescent device of the present invention has at least one organic layer including a light emitting layer between the anode and the cathode (electrode), and if necessary, has other layers. At least one of the layers of the organic electroluminescent device is a vapor deposition film of the present invention.

The organic layer may have at least the light emitting layer and may have an electron transporting layer, an electron injecting layer, and if necessary, a hole injecting layer, a hole transporting layer, a hole blocking layer, and an electronic blocking layer.

<Light Emitting Layer>

The light emitting layer is a layer that receives holes from an anode, a hole injecting layer, or a hole transporting layer when an electric field is applied, receives electrons from a cathode, an electron injecting layer, or an electron transporting layer, and provides a field for recombination of holes and electrons to emit light .

The light emitting layer may be composed solely of a light emitting material or may be a mixed layer of a host material and a luminescent dopant. The luminescent dopant may be a fluorescent light-emitting material, a phosphorescent light-emitting material, or two or more kinds. The host material is preferably a charge transporting material. The host material may be one kind or two kinds or more, and for example, a configuration in which a host material of electron transporting property and a host material of hole transporting property are mixed is listed. The light emitting layer may contain a material that does not have charge transportability and does not emit light.

The light-emitting layer may be a single layer or two or more layers, and each layer may emit light of a different color.

The light emitting layer is not particularly limited and may be formed by a known method. For example, the light emitting layer may be formed preferably by a dry film forming method such as a vapor deposition method, a sputtering method, a wet coating method, a transfer method, a printing method, .

The thickness of the light emitting layer is not particularly limited and may be appropriately selected according to the purpose. The thickness is preferably 2 nm to 500 nm, more preferably 3 nm to 200 nm, and further preferably 10 nm to 200 nm from the viewpoint of the light emitting efficiency. The light emitting layer may be a single layer or two or more layers.

As the luminescent dopant, phosphorescent luminescent material, fluorescent luminescent material and the like can all be used as a dopant (phosphorescent dopant, fluorescent luminescent dopant).

The light emitting layer may contain two or more kinds of luminescent dopants in order to improve the color purity or to extend the light emitting wavelength region.

The phosphorescent dopant is not particularly limited and may be appropriately selected in accordance with the object. Complexes containing a transition metal atom or a lanthanoid atom can be exemplified.

The transition metal atom is not particularly limited and may be appropriately selected depending on the purpose. Ruthenium, rhodium, palladium, tungsten, rhenium, osmium, iridium, gold, silver, copper and platinum are preferable, and rhenium, iridium and platinum More preferred are iridium and platinum.

The lanthanoid atom is not particularly limited and may be appropriately selected in accordance with the purpose. Examples of the lanthanoid atom include lanthanum, cerium, plazodym, neodymium, samarium, europium, gadolinium, terbium, dysprosium, , Thulium, ytterbium, and lutezium. Of these, neodymium, europium and gadolinium are preferable.

Examples of ligands for the complexes include G. Wilkinson et al., Comprehensive Coordination Chemistry, published by Pergamon Press, 1987, H. Yersin, Photochemistry and Photophysics of Coordination Compounds, Springer-Verlag, 1987, &Quot; Metallic Chemistry-Fundamentals and Applications &quot; issued to Shokabo Sha 1982, and the like.

Examples of the ligand include a halogen ligand (preferably a chlorine ligand), an aromatic carbocyclic ligand (e.g., cyclopentadienyl anion, benzene anion, naphthyl anion, etc.), preferably 5 to 30 carbon atoms, More preferably 6 to 20 carbon atoms and particularly preferably 6 to 12 carbon atoms), a nitrogen-containing heterocyclic ligand (e.g., phenyl pyridine, benzoquinoline, quinolinol, bipyridyl, phenanthrol (Preferably 6 to 30 carbon atoms, more preferably 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, and particularly preferably 6 to 12 carbon atoms), a diketone ligand (e.g., Acetyl acetone and the like), a carboxylic acid ligand (for example, an acetic acid ligand and the like are listed, preferably 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, and particularly preferably 2 to 16 carbon atoms) , Alcohol (For example, a phenolate ligand and the like are listed, preferably 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and more preferably 6 to 20 carbon atoms), a silyloxy ligand (for example, Trimethylsilyloxy ligand, dimethyl-tert-butylsilyloxy ligand, triphenylsilyloxy ligand, etc., preferably 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, and particularly preferably 3 to 20 carbon atoms) , A carbon monoxide ligand, an isonitrile ligand, a cyano ligand, a phosphorus ligand (for example, a triphenylphosphine ligand), preferably 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, (For example, a phenylthiolate ligand and the like are listed, preferably 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, more preferably 1 to 20 carbon atoms, more preferably 6 to 20 carbon atoms) And a phosphine oxide ligand (for example, a triphenylphosphine oxide ligand, etc.), preferably 3 to 30 carbon atoms, more preferably 8 to 30 carbon atoms, and more preferably 2 to 20 carbon atoms, More preferably 18 to 30 carbon atoms are particularly preferable), and a nitrogen-containing heterocyclic ligand is more preferable.

The complex may have one transition metal atom or two or more transition metal atoms in the compound. Or may contain two or more kinds of metal atoms at the same time.

Among these, as the luminescent dopant, for example, those described in US 6303238 B1, US 6097147, WO 00/57676, WO 00/70655, WO 01/08230, WO 01/39234 A2, WO 01/41512 A1, WO 02/02714 A2, WO 02/15645 A1, WO 02/44189 A1, WO 05/19373 A2, JP-A 2001-247859, JP-A 2002-302671, JP-A 2002-117978, JP-A 2003-133074, JP- Japanese Patent Application Laid-Open Nos. 235076, 2003-123982, 2002-170684, EP 1211257, 2002-226495, 2002-234894, 2001-247859, 2001-298470, 2002-173674, 2002-203678, 2002-203679, 2004-357791, 2006-256999, 2007-19462, 2007-84635, 2007 -96259 and the like, and the like. 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, , A Pt complex, and a Re complex are more preferable. Among them, an Ir complex, a Pt complex, and a Re complex that include at least one of a metal-carbon bond, a metal-nitrogen bond, a metal-oxygen bond, and a metal-sulfur bond are more preferable. From the viewpoints of light emission efficiency, driving durability, chromaticity and the like, an Ir complex, a Pt complex, and a Re complex including a three or more-dimensional position ligand are particularly preferable.

The fluorescent luminescent dopant is not particularly limited and may be appropriately selected according to the purpose. Examples of the fluorescent luminescent dopant include benzoxazole, benzimidazole, benzothiazole, styrylbenzene, polyphenyl, diphenylbutadiene, tetraphenylbutadiene , Naphthalimide, coumarin, pyran, perinone, oxadiazole, aldazine, pyrrolidine, cyclopentadiene, bisstyryl anthracene, quinacridone, pyrrolopyridine, thiadiazolopyridine, cyclopentadiene, A condensation polycyclic aromatic compound (anthracene, phenanthroline, pyrene, perylene, lubrene or pentacene), a metal complex of 8-quinolinol, a pyromethene complex or a rare earth complex , Polymer compounds such as polythiophene, polyphenylene, and polyphenylene vinylene, organic silanes, derivatives thereof, and the like.

Examples of the luminescent dopant include, but are not limited to, the following.

The luminescent dopant in the luminescent layer is contained in the luminescent layer generally in an amount of 0.1% by mass to 50% by mass with respect to the total mass of the compound forming the luminescent layer, but is preferably contained in an amount of 1% by mass to 50% by mass from the viewpoints of durability and external quantum efficiency, And more preferably 2% by mass to 40% by mass.

The thickness of the light-emitting layer is not particularly limited, but is usually preferably from 2 nm to 500 nm, more preferably from 3 nm to 200 nm, and particularly preferably from 5 nm to 100 nm, from the viewpoint of external quantum efficiency.

As the host material, a hole transporting host material (sometimes referred to as a hole transporting host) having excellent hole transportability and an electron transporting host compound having an excellent electron transporting property (sometimes referred to as an electron transporting host) may be used.

Examples of the hole transporting host in the light emitting layer include pyrrole, indole, carbazole, azaindole, azacarbazole, triazole, oxazole, oxadiazole, pyrazole, imidazole, thiophene, polyarylalkane, pyrazoline, The present invention relates to a process for producing a compound represented by the general formula (1), which comprises reacting a compound represented by the general formula , Conductive polymeric oligomers such as polysilane compounds, poly (N-vinylcarbazole), aniline-based copolymers, thiophene oligomers and polythiophene, organic silanes, carbon films and their derivatives.

Among them, an indole derivative, a carbazole derivative, an aromatic tertiary amine compound and a thiophene derivative are preferable, a compound having a carbazole group in a molecule is more preferable, and a compound having a t-butyl-substituted carbazole group is particularly preferable .

The electron-transporting host in the light-emitting layer preferably has an electron affinity (Ea) of 2.5 eV or more and 3.5 eV or less, more preferably 2.6 eV or more and 3.4 eV or less, or 2.8 eV or more and 3.3 eV or less Particularly preferred. The ionization potential Ip is preferably 5.7 eV or more and 7.5 eV or less, more preferably 5.8 eV or more and 7.0 eV or less, particularly preferably 5.9 eV or more and 6.5 eV or less, from the viewpoint of improvement of durability and lowering of drive voltage.

Specific examples of such electron transporting hosts include pyridine, pyrimidine, triazine, imidazole, pyrazole, triazole, oxazole, oxadiazole, fluorenone, anthraquinodimethane, Heterocyclic tetracarboxylic acid anhydrides such as quinone, thiopyran dioxide, carbodiimide, fluorenylidenemethane, distyrylpyrazine, fluorine-substituted aromatic compounds and naphthaleneperylene, phthalocyanines and derivatives thereof (other rings and condensed rings , Metal complexes of 8-quinolinol derivatives, metal phthalocyanines, various metal complexes represented by metal complexes having benzoxazole or benzothiazole as ligands, and the like.

As the electron transporting host, metal complexes, azole derivatives (benzimidazole derivatives, imidazopyridine derivatives and the like), and azine derivatives (pyridine derivatives, pyrimidine derivatives and triazine derivatives) are preferable. Among them, A complex compound is more preferable. The metal complex compound is more preferably a metal complex having a ligand having at least any one of a nitrogen atom, an oxygen atom and a sulfur atom coordinated to a metal.

The metal ion in the metal complex is not particularly limited and may be appropriately selected in accordance with the object. It is preferably at least one selected from beryllium ion, magnesium ion, aluminum ion, gallium ion, zinc ion, indium ion, tin ion, More preferably a beryllium ion, an aluminum ion, a gallium ion, a zinc ion, a platinum ion or a palladium ion, and particularly preferably an aluminum ion, a zinc ion or a palladium ion.

Examples of ligands contained in the metal complex include various known ligands. For example, &quot; Photochemistry and Photophysics of Coordination Compounds &quot;, Springer-Verlag, H. Yersin, , Shokabosa, Yamamoto Akio, published in 1982, and the like.

As the ligand, a nitrogen-containing heterocyclic ligand (preferably having 1 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, and particularly preferably 3 to 15 carbon atoms) is preferable. The ligand may be a single-seated ligand or a ligand of two or more positions, but it is preferably a ligand of two or more positions and six or less positions. It is also preferable that a ligand of two or more and six or less positions and a mixed ligand of a single position are also used.

Examples of the ligand include an azine ligand (for example, a pyridine ligand, a bipyridyl ligand, a terpyridine ligand and the like are listed), a hydroxyphenylzole ligand (for example, a hydroxyphenylbenzimidazole ligand, a hydroxy Hydroxyphenylimidazole ligands, hydroxyphenylimidazopyridine ligands, etc.), alkoxy ligands (for example, methoxy, ethoxy, butoxy, 2-ethylhexyloxy (Preferably 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and particularly preferably 1 to 10 carbon atoms), an aryloxy ligand (e.g., phenyloxy, 1-naphthyloxy, 2 Naphthyloxy, 2,4,6-trimethylphenyloxy, 4-biphenyloxy and the like, preferably 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, and particularly preferably 6 to 12 carbon atoms. ) Are listed.

A pyridyloxy group, a pyrimidyloxy group, a quinolyloxy group, etc., preferably 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and more preferably 1 to 12 carbon atoms. Preferably 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and particularly preferably 1 to 12 carbon atoms), alkylthio ligands (for example, methylthio, ethylthio and the like) , Arylthio ligands (for example, phenylthio and the like, preferably 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, and particularly preferably 6 to 12 carbon atoms), heteroarylthio ligands Benzothiazolylthio, 2-benzoxazolylthio, 2-benzothiazolylthio and the like, preferably 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and the number of carbon atoms 1 to 12 are particularly preferred), siloxy ligands (e.g., Triethoxysilyl group, triisopropylsilyl group, etc., preferably 1 to 30 carbon atoms, more preferably 3 to 25 carbon atoms, and particularly preferably 6 to 20 carbon atoms. An aromatic anion ligand (for example, phenyl anion, naphthyl anion and anthranyl anion are exemplified, preferably 6 to 30 carbon atoms, more preferably 6 to 25 carbon atoms, and particularly preferably 6 to 20 carbon atoms) , Aromatic heterocyclic anion ligands (e.g., pyrrole anion, pyrazole anion, pyrazole anion, triazole anion, oxazole anion, benzoxazole anion, thiazole anion, benzothiazole anion, thiophene anion, Anthraquinone, anthraquinone, anthraquinone, anthraquinone, anthraquinone, anthraquinone, anthraquinone, and the like; An aryloxy ligand, an aromatic hydrocarbon anion ligand, an aromatic hetero ring anion ligand, and the like are more preferable, and a nitrogen-containing heterocyclic ligand, an aryloxy ligand, a siloxy ligand, an aromatic hydrocarbon anion ligand, desirable.

Examples of the metal complex electron transporting host include, for example, Japanese Patent Application Laid-Open Nos. 2002-235076, 2004-214179, 2004-221062, 2004-221065, 2004-221068, 2004- 327313 and the like.

In the light emitting layer, the triplet minimum excitation level (T1) of the host material is preferably higher than T1 of the phosphorescent light emitting material in terms of color purity, luminous efficiency, and driving durability.

The content of the host compound is not particularly limited, but is preferably 15% by mass or more and 95% by mass or less with respect to the total mass of the compound forming the light-emitting layer from the viewpoint of light emission efficiency and drive voltage.

&Lt; 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 cathode side and transporting them to the anode side. The electron injecting material and electron transporting material used in these layers may be either a low molecular compound or a high molecular compound.

Specific examples thereof include pyridine derivatives, quinoline derivatives, pyrimidine derivatives, pyrazine derivatives, phthalazine derivatives, phenanthroline derivatives, triazine derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, , Anthraquinodimethane derivatives, anthrone derivatives, diphenylquinone derivatives, thiopyran oxide derivatives, carbodiimide derivatives, fluorenylidene methane derivatives, distyrylpyrazine derivatives, aromatic rings such as naphthalene and perylene, A metal complex of an 8-quinolinol derivative, a metal phthalocyanine, various metal complexes typified by a metal complex having benzoxazole or benzothiazole as a ligand, an organosilane derivative represented by a siloxane, etc. .

The electron injecting layer or the electron transporting layer of the organic electroluminescent device of the present invention may contain an electron donating dopant. The electron donor dopant to be introduced into the electron injecting layer or the electron transporting layer is not particularly limited as long as it has the property of reducing an organic compound as an electron donor and may be an alkali metal such as Li or an alkaline earth metal such as Mg or a transition metal containing a rare earth metal A reducing organic compound and the like are preferably used. Specifically, metals such as Li, Na, K, Be, Mg, Ca, Sr, Ba, Y, Cs, La, Sm, Gd and Yb can be preferably used as the metal do. Examples of the reducing organic compound include a nitrogen-containing compound, a sulfur-containing compound, and a phosphorus-containing compound.

Other materials described in JP-A-6-212153, JP-A-2000-196140, JP-A-2003-68468, JP-A-2003-229278 and JP-A-2004-342614 can be used.

These electron donating dopants may be used alone or in combination of two or more. The amount of the electron donating dopant varies depending on the kind of the material, but is preferably from 0.1% by mass to 99% by mass, more preferably from 1.0% by mass to 80% by mass, and still more preferably from 2.0% by mass to 70% Particularly preferred.

The thickness of the electron injection layer and electron transport layer is preferably 500 nm or less from the viewpoint of lowering the driving voltage.

The thickness of the electron transporting layer is preferably 1 nm to 500 nm, more preferably 5 nm to 200 nm, and particularly preferably 10 nm to 100 nm. The thickness of the electron injection layer is preferably 0.1 nm to 200 nm, more preferably 0.2 nm to 100 nm, and particularly preferably 0.5 nm to 50 nm.

The electron injection layer and the electron transporting layer may be a single layer structure composed of one or more of the above materials, or a multi-layer structure composed of plural layers of the same composition or different compositions.

<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 injecting layer and the hole transporting layer may have a single layer structure or a multilayer structure composed of plural layers of the same composition or different compositions.

The hole injecting material or the hole transporting material used in these layers may be a low molecular compound or a polymer compound.

The hole injecting material or the hole transporting material is not particularly limited and may be appropriately selected according to the purpose. Examples thereof include pyrrole derivatives, carbazole derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives , Polyarylalkane derivatives, pyrazoline derivatives, parazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino substituted chalcone derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, Tertiary amine compounds, styrylamine compounds, aromatic dimethylidine compounds, phthalocyanine compounds, porphyrin compounds, thiophene derivatives, organosilane derivatives, and carbon. These may be used singly or in combination of two or more kinds.

The hole-injecting layer and the hole-transporting layer may contain an electron-accepting dopant.

The electron-accepting dopant may be an inorganic compound or an organic compound, provided that the electron-accepting dopant has a property of electron-accepting and oxidizing the organic compound.

The inorganic compound is not particularly limited and may be appropriately selected depending on the purpose, and examples thereof include metal halides and metal oxides.

Examples of the metal halide include ferric chloride, aluminum chloride, gallium chloride, indium chloride, antimony pentachloride, and the like.

Examples of the metal oxide include vanadium pentoxide, molybdenum trioxide, and the like.

The organic compound is not particularly limited and may be appropriately selected depending on the purpose. For example, a compound having a nitro group, a halogen, a cyano group, a trifluoromethyl group or the like as a substituent; Quinone compounds, acid anhydride compounds, fullerene, and the like.

These electron-accepting dopants may be used singly or in combination of two or more.

The amount of the electron-accepting dopant to be used is not particularly limited and is preferably 0.01% by mass to 50% by mass, more preferably 0.05% by mass to 30% by mass, based on the material of the hole transporting layer or the hole injecting material, And more preferably 0.1% by mass to 30% by mass.

The hole injecting layer and the hole transporting layer are not particularly limited and may be formed according to a known method. For example, a dry film forming method such as a vapor deposition method, a sputtering method, a wet coating method, a transfer method, a printing method, Or the like.

The thickness of the hole injection layer and the hole transport layer is preferably from 1 nm to 500 nm, more preferably from 5 nm to 250 nm, and further preferably from 10 nm to 200 nm.

&Lt; Hole block layer, electronic block layer >

The hole blocking layer is a layer having a function of preventing the holes transported to the light emitting layer from escaping from the anode side to the cathode side, and is usually formed as an organic compound layer adjacent to the light emitting layer and 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 escaping to the anode side, and is usually formed as an organic compound layer adjacent to the light emitting layer and the anode side.

Examples of the compound constituting the hole blocking layer include aluminum complexes such as BAlq, triazole derivatives, phenanthroline derivatives such as BCP, and the like.

As the compound constituting the electron blocking layer, for example, those listed above as the hole transporting materials can be used.

The electron blocking layer and the hole blocking layer are not particularly limited and can be formed by a known method. For example, a dry film forming method such as a vapor deposition method, a sputtering method, a wet coating method, a transfer method, a printing 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. The hole blocking layer and the electron blocking layer may be a single layer structure composed of one or more of the above materials, or a multi-layer structure composed of plural layers of the same composition or different composition.

<Electrode>

The organic electroluminescent device of the present invention includes a pair of electrodes, that is, an anode and a cathode. It is preferable that at least one of the anode and the cathode is transparent in nature of the organic electroluminescent device. Normally, the anode may function as an electrode for supplying holes to the organic compound layer, and the anode may function as an electrode for injecting electrons into the organic compound layer.

The shape, structure, size, and the like of the electrode are not particularly limited, and may be appropriately selected from known electrode materials depending on the use and purpose of the organic electroluminescent device.

As the material constituting the electrode, for example, a metal, an alloy, a metal oxide, a conductive compound or a mixture thereof is preferably listed.

- Bipolar -

Examples of the material constituting the positive electrode include conductive materials such as tin oxide (ATO, FTO) doped with antimony, fluorine, etc., tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), zinc oxide indium Metal oxides; Metals such as gold, silver, chromium, and nickel; A mixture or laminate of a metal and a conductive metal oxide; Inorganic conductive substances such as copper iodide and copper sulfide; Organic conductive materials such as polyaniline, polythiophene, and polypyrrole; Or a laminate of these and ITO. Of 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 negative electrode include alkali metals (for example, Li, Na, K and Cs), alkaline earth metals (for example, Mg and Ca), gold, silver, lead, aluminum, sodium - potassium alloy, lithium-aluminum alloy, magnesium-silver alloy, rare earth metals such as indium and ytterbium, and the like. These may be used singly, but two or more of them may be preferably used in combination from the standpoint of achieving both stability and electron injection property.

Among them, an alkali metal or an alkaline earth metal is preferable from the viewpoint of electron injection property, and a material mainly composed of aluminum is preferable from the viewpoint of excellent storage stability.

The material mainly composed of aluminum includes aluminum alone, an alloy of aluminum and 0.01 to 10 mass% of an alkali metal or alkaline earth metal, or a mixture thereof (e.g., a lithium-aluminum alloy, a magnesium- .

The method for forming the electrode is not particularly limited and may be carried out by a known method, for example, a wet method such as a printing method or a coating method; Physical methods such as vacuum evaporation, sputtering and ion plating; Chemical methods such as CVD and plasma CVD, and the like. Of these, the electrode can be formed on the substrate in accordance with a method suitably selected in consideration of suitability with the material constituting the electrode. For example, when ITO is selected as the material of the anode, it can be formed by a direct current or high frequency sputtering method, a vacuum evaporation method, an ion plating method, or the like. When a metal or the like is selected as the material of the cathode, one or more of them may be formed simultaneously or sequentially in accordance with a sputtering method or the like.

In the case of patterning at the time of forming the electrode, the patterning may be performed by chemical etching by photolithography or the like, by physical etching with a laser or the like, or by vacuum vapor deposition, sputtering or the like over the mask , Or by a lift-off method or a printing method.

<Substrate>

The organic electroluminescent device of the present invention is preferably formed on a substrate. The organic electroluminescent device of the present invention may be formed in a form in which the electrode and the substrate are directly in contact with each other, or may be formed in the form of passing through the intermediate layer.

The material of the substrate is not particularly limited and can be appropriately selected according to the purpose. For example, inorganic materials such as yttria stabilized zirconia (YSZ), glass (alkali-free glass, soda lime glass, etc.) Polyesters such as polyethylene terephthalate, polybutylene phthalate and polyethylene naphthalate; And organic materials such as polystyrene, polycarbonate, polyethersulfone, polyarylate, polyimide, polycycloolefin, norbornene resin and poly (chlorotrifluoroethylene).

The shape, structure, size and the like of the substrate are not particularly limited and may be appropriately selected depending on the use, purpose, etc. of the light emitting device. 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, a single member, or two or more members. The substrate may be transparent or opaque, and may be colorless or transparent if it is transparent.

A moisture permeation preventive layer (gas barrier layer) may be provided on the front or rear surface of the substrate.

Examples of the material of the moisture permeation-preventing layer (gas barrier layer) include inorganic substances such as silicon nitride and silicon oxide.

The moisture barrier layer (gas barrier layer) can be formed by, for example, high-frequency sputtering.

<Other configurations>

The other structures are not particularly limited and can be appropriately selected in accordance with the purpose. For example, a protective layer, a sealed container, a resin sealing layer, a sealing adhesive, and the like can be listed.

The contents of the protective layer, the sealing container, the resin sealing layer, the sealing adhesive and the like are not particularly limited and can be appropriately selected in accordance with the purpose. For example, those disclosed in JP-A-2009-152572 Can be applied.

1 is a schematic view showing an example of the layer structure of the organic electroluminescent device of the present invention. The organic EL device 10 includes an anode 2 (for example, an ITO electrode) formed on a glass substrate 1, a hole injection layer 3, a hole transport layer 4, a light emitting layer 5, and an electron transport layer 6 ), An electron injection layer 7, and a 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 through a power source.

<Driving>

In the organic electroluminescent device of the present invention, light emission can be obtained by applying a DC voltage (usually 2 volts to 15 volts) or a direct current between a positive electrode and a negative electrode (which may include an AC component if necessary).

The organic electroluminescent device 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 and the like can be applied.

As the organic electroluminescent device of the present invention, for example, a thin film transistor described in International Publication Nos. 2005/088726, 2006-165529, and 2008/0237598 can be applied.

The organic electroluminescent device of the present invention is not particularly limited, and the light extraction efficiency can be improved by various known studies. For example, it is possible to control the refractive index of the substrate, the ITO layer, and the organic layer, to control the thickness of the substrate, the ITO layer, and the organic layer by processing the substrate surface shape (for example, forming a fine uneven pattern) It is possible to improve the extraction efficiency of light and improve the external quantum efficiency.

The light extraction method from the organic electroluminescence device of the present invention may be a top emission type or a bottom emission type.

The organic electroluminescent device of the present invention may have a resonator structure. For example, a multilayer film mirror composed of a plurality of laminated films having different refractive indexes, a transparent or semitransparent electrode, a light emitting layer, and a metal electrode are polymerized on a transparent substrate. The light generated in the light emitting layer is resonated by repeating reflection between the multilayer film mirror and the metal electrode as reflectors.

In another preferred embodiment, the transparent or semitransparent electrode and the metal electrode function as a reflection plate, respectively, on the transparent substrate, and the light generated in the light-emitting layer is resonated repeatedly between the reflection.

In order to form the resonance structure, the effective refractive index of the two reflectors, the refractive index of each layer between the reflectors, and the optical path length determined from the thickness are adjusted to be optimal values for obtaining a desired resonance wavelength. The calculation formula in the case of the first embodiment is described in Japanese Patent Application Laid-Open No. 9-180883. The calculation formula in the case of the second embodiment is described in Japanese Patent Application Laid-Open No. 2004-127795.

<Applications>

The organic electroluminescent device of the present invention is not particularly limited and may be appropriately selected according to the purpose. Examples of the organic electroluminescent device include a display device, a display, a backlight, an electrophotographic light source, a recording light source, an exposure light source, , Optical communication, and the like.

As a method of making the organic EL display a full-color type, the three primary colors (blue (B), green (G), and blue , Red (R)) are arranged on a substrate, white light emitted by an organic electroluminescent element for white light emission is divided into three primary colors by passing through a color filter A color conversion method in which blue light emitted by an organic electroluminescent element for white coloration and blue light emission is passed through a fluorescent dye layer and is converted to red (R) and green (G) is known.

(Example)

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these embodiments at all.

(Example 1)

First, 50 mass% of organic compound H-1 (vaporization temperature at 3 占^10-4 Pa: 190 占 폚, vaporization type: molten) of the following structural formula (A-1) 1 (melting point: 3 占 폚, decomposition temperature: 340 占 폚) were mixed to prepare a composition for forming an organic electroluminescent device.

The thus prepared composition for forming an organic electroluminescence element was placed in a tungsten filament (product name: BOC-1, manufactured by Furuuchi Chemical Corporation) in an alumina crucible (trade name: AL-203, manufactured by Furuuchi Chemical Corporation) The current value in the tungsten filament was manually controlled so that the deposition rate (target rate) was maintained at 0.20 nm / s for 60 minutes. Table 1 shows the deviation (maximum rate, minimum rate) of the obtained deposition rate, the content of the medium component in the vapor deposition film, and the number of times of boiling occurring during the film formation period. It is considered that the dolbid is defined as the number of times that a rate exceeding ± 20% of the target rate occurs and is caused by the disintegration of the powder of the organic compound. Further, the substrate was made of quartz.

The vaporization temperature of the organic compound, the vaporization type of the organic compound, the melting point of the medium, the decomposition temperature of the medium, the deposition rate, and the content of the medium component in the vapor deposition film were respectively measured or judged as follows.

&Lt; Method of measuring vaporization temperature of organic compound >

The deposition rate of the organic compound was monitored by a vibrator, and the temperature at which the rate reached 0.2 nm / s was measured by a thermocouple provided immediately below the crucible, and the temperature was referred to as the vaporization temperature.

&Lt; Determination of vaporization type of organic compound >

Thermogravimetric analysis and differential thermal analysis were carried out using a product of ULVAC-RIKO, Inc, VAP-9000, in which the temperature of the organic compound was raised from room temperature to 500 ° C at a rate of 2 ° C / min under a vacuum of 1 × 10 ^-3 Pa. A material in which the endotherm is observed before the weight reduction starts (the melting point is present) is determined to be a melting type, and a material in which endothermic reaction does not occur until weight reduction is determined to be a sublimation type. Further, it was judged that the material in which the weight reduction was completed (the initial weight was vaporized as a whole) was vacuum-depositable, and the material in which the weight reduction was not completed (the residue remained) was decomposed.

&Lt; Method of measuring melting point and decomposition temperature of medium >

Thermogravimetric analysis and differential thermal analysis were carried out using a product of ULVAC-RIKO, Inc, VAP-9000, in which the temperature of the organic compound was raised from room temperature to 500 ° C at a rate of 2 ° C / min under a vacuum of 1 × 10 ^-3 Pa. The initiation temperature of the endothermic reaction before the weight reduction occurred was called the melting point. The material in which weight reduction occurred and the material in which the reduction was not completed (the residue remained) was regarded as a material to be decomposed, and the weight reduction starting temperature was referred to as decomposition temperature.

&Lt; Method of measuring deposition rate >

The deposition rate of each material was monitored by a quartz oscillator (manufactured by ULVAC-RIKO, Inc), and the maximum deposition rate and the lowest deposition rate exhibited by the quartz crystal vibrator during the 60 minute deposition were recorded as the lowest rate.

<Content of Medium Component in Vapor Deposition>

Elemental analysis of the thin film was performed using XPS (ESCA-3400, manufactured by Shimadzu Corporation). The amount of mixed media components was calculated by detecting the characteristic element of the medium (for example, the amount of sulfur atoms in the medium X-1). The content of the characteristic element was analyzed by the same method, and a calibration curve of the value detected in the analysis and the actual content was prepared, and the actual content was calculated. In addition, the above-mentioned medium component includes, in addition to the medium itself, a decomposition product of the medium (for example, an anion of an organic compound salt).

(Example 2)

1) (melting point: 3 占 폚, decomposition temperature: 340 占 폚) was mixed with the organic compound H-1 (vaporization temperature at 3 占^10-4 Pa: 190 占 폚, vaporization type: (Vaporization temperature: 200 占 폚, vaporization type: sublimation at 3 占^10-4 Pa) of the following structural formula (A-2) and the organic compound H-2 Except that a composition for forming an organic electroluminescence device was prepared by mixing a medium X-2 (melting point: -75 캜, decomposition temperature: 340 캜) of the composition (B-2) Maximum rate, minimum rate), the content of the medium component in the deposited film, and the number of times of the rubbing were measured. The results are shown in Table 1.

(Example 3)

1) (melting point: 3 占 폚, decomposition temperature: 340 占 폚) was mixed with the organic compound H-1 (vaporization temperature at 3 占^10-4 Pa: 190 占 폚, vaporization type: (Vaporization temperature: 100 占 폚, vaporization type: sublimation at 3 占^10-4 Pa) of the following structural formula (A-3) and the organic compound P-1 Except that a composition for forming an organic electroluminescence device was prepared by mixing Medium X-3 (melting point: 78 캜 (pulverized since it was not a liquid at room temperature) into a powder form, decomposition temperature: 210 캜) (Maximum rate, minimum rate) of the deposition rate, the content of the medium component in the vapor deposition film, and the number of times of the rubbing were measured in the same manner as in Example 1. The results are shown in Table 1.

(Example 4)

1) (melting point: 3 占 폚, decomposition temperature: 340 占 폚) was mixed with the organic compound H-1 (vaporization temperature at 3 占^10-4 Pa: 190 占 폚, vaporization type: (Vaporization temperature: 120 占 폚, vaporization type: sublimation at 3 占^10-4 Pa) of the following structural formula (A-4) and medium X (Maximum rate and minimum rate) in the same manner as in Example 1, except that the composition for forming an organic electroluminescence device was prepared by mixing the above-mentioned composition for forming an organic electroluminescence element-1 (melting point: 3 캜, decomposition temperature: The content of the medium component and the number of times of the rubbing were measured. The results are shown in Table 1.

(Example 5)

1) (melting point: 3 占 폚, decomposition temperature: 340 占 폚) was mixed with the organic compound H-1 (vaporization temperature at 3 占^10-4 Pa: 190 占 폚, vaporization type: (Vaporization temperature at 3 占^10-4 Pa: 270 占 폚, vaporization type: sublimation) of the organic compound Pt-1 of the following structural formula (A-5) and medium X (Having a number average molecular weight of 15,000, a melting point of 260 deg. C (which is not a liquid at room temperature and is in a powder state) and a decomposition temperature of 350 deg. C), and a composition for forming an organic electroluminescent device (Maximum rate, minimum rate) of the deposition rate, the content of the medium component in the vapor deposition film, and the number of times of the rubbing were measured in the same manner as in Example 1, The results are shown in Table 1.

The number average molecular weight of the polymethyl methacrylate was measured by the following measuring method.

&Lt; Method for measuring number average molecular weight >

The average molecular weight was measured by liquid chromatography. TSK gel was used for the column, chloroform was used as eluent, and polystyrene having a molecular weight as a standard sample was used. The measurement temperature was 40 占 폚.

(Example 6)

1) (melting point: 3 占 폚, decomposition temperature: 340 占 폚) was mixed with the organic compound H-1 (vaporization temperature at 3 占^10-4 Pa: 190 占 폚, vaporization type: (Vaporization temperature at 3 占^10-4 Pa: 180 占 폚, vaporization type: sublimation) of the following structural formula (A-6) and the organic compound Pt- Except that the composition for forming an organic electroluminescence device was prepared by mixing the composition X-6 (melting point: 15 캜, decomposition temperature: 250 캜) of the composition (B-6) Rate, minimum rate), the content of the medium component in the vapor deposition film, and the number of times of the rubbing were measured. The results are shown in Table 1.

(Example 7)

1) (melting point: 3 占 폚, decomposition temperature: 340 占 폚) was mixed with the organic compound H-1 (vaporization temperature at 3 占^10-4 Pa: 190 占 폚, vaporization type: (Vaporization temperature: 230 占 폚, vaporization type: sublimation at 3 占^10-4 Pa) of the organic compound Pt-3 of the following structural formula (A-7) and medium X (Maximum rate and minimum rate) of the deposition rate in the same manner as in Example 1, except that the composition for forming an organic electroluminescence device was prepared by mixing the above-mentioned composition for forming an organic electroluminescence element-2 (melting point: -75 캜, decomposition temperature: The content of the medium component and the number of times of the rubbing were measured. The results are shown in Table 1.

(Example 8)

1) (melting point: 3 占 폚, decomposition temperature: 340 占 폚) was mixed with the organic compound H-1 (vaporization temperature at 3 占^10-4 Pa: 190 占 폚, vaporization type: (Vaporization temperature: 220 占 폚, vaporization type: sublimation at 3 占^10-4 Pa) of the following structural formula (A-8) and the organic compound Ir- Except that the composition for forming an organic electroluminescence device was prepared by mixing a medium X-8 (melting point: 76 캜, decomposition temperature: 250 캜) of the composition (B-8) Rate, minimum rate), the content of the medium component in the vapor deposition film, and the number of times of the rubbing were measured. The results are shown in Table 1.

(Example 9)

1) (melting point: 3 占 폚, decomposition temperature: 340 占 폚) was mixed with the organic compound H-1 (vaporization temperature at 3 占^10-4 Pa: 190 占 폚, vaporization type: (Vaporization temperature at 3 占^10-4 Pa: 250 占 폚, vaporization type: sublimation) of the organic compound Ir-2 of the following structural formula (A-9) and medium X (Maximum rate and minimum rate) of the deposition rate in the same manner as in Example 1, except that the composition for forming an organic electroluminescence device was prepared by mixing the above-mentioned composition for forming an organic electroluminescence element-2 (melting point: -75 캜, decomposition temperature: The content of the medium component and the number of times of the rubbing were measured. The results are shown in Table 1.

(Example 10)

1) (melting point: 3 占 폚, decomposition temperature: 340 占 폚) was mixed with the organic compound H-1 (vaporization temperature at 3 占^10-4 Pa: 190 占 폚, vaporization type: (Vaporization temperature: 260 占 폚, vaporization type: sublimation at 3 占^10-4 Pa) of the following structural formula (A-10) and the organic compound Ir- Except that a composition for forming an organic electroluminescent device was prepared by mixing a medium X-10 (melting point: -50 占 폚, decomposition temperature: 350 占 폚) of the composition (B-10) Maximum rate, minimum rate), the content of the medium component in the deposited film, and the number of times of the rubbing were measured. The results are shown in Table 1.

(Comparative Example 1)

(Melting point: 78 占 폚 (which was not liquid at room temperature and pulverized into a powder) instead of using medium X-1 (melting point: 3 占 폚, decomposition temperature: 340 占 폚) (Maximum rate and minimum rate) of the deposition rate, the content of the medium component in the vapor deposition film and the content of the organic component in the vapor deposition film were measured in the same manner as in Example 1, Dolby frequency was measured. The results are shown in Table 2.

(Comparative Example 2)

(Melting point: 78 占 폚 (which was not liquid at room temperature and was pulverized into powder form) instead of using medium X-2 (melting point: -75 占 폚, decomposition temperature: 340 占 폚) (Maximum rate and minimum rate) in the same manner as in Example 2 except that a composition for forming an organic electroluminescent device was prepared using the composition of the present invention And the number of Dolby times were measured. The results are shown in Table 2.

(Comparative Example 3)

The deviation (maximum rate, minimum rate) and the number of times of deposition were measured in the same manner as in Example 1 except that the composition for forming an organic electroluminescence device was prepared without mixing the medium X-1 in Example 1 . The results are shown in Table 3.

(Comparative Example 4)

(Maximum rate, minimum rate) and the number of times of the droplet rubbing were measured in the same manner as in Example 2 except that the composition for forming an organic electroluminescence device was prepared without mixing the medium X-2 in Example 2 . The results are shown in Table 3.

(Comparative Example 5)

The deviation (maximum rate, minimum rate) and the number of times of the droplet exposures were measured in the same manner as in Example 3, except that the composition for forming an organic electroluminescence element was formed without mixing the medium X-3 in Example 3 . The results are shown in Table 3.

(Comparative Example 6)

The deviation (maximum rate, minimum rate) and the number of times of deposition were measured in the same manner as in Example 4 except that the composition for forming an organic electroluminescence device was prepared without mixing the medium X-1 in Example 4 . The results are shown in Table 3.

(Comparative Example 7)

The deviation (maximum rate, minimum rate) and the number of times of deposition were measured in the same manner as in Example 5 except that the composition for forming an organic electroluminescence device was prepared without mixing the medium X-5 in Example 5 . The results are shown in Table 3.

(Comparative Example 8)

The deviation (maximum rate, minimum rate) and the number of times of deposition were measured in the same manner as in Example 6 except that the composition for forming an organic electroluminescent element was prepared without mixing the medium X-6 in Example 6 . The results are shown in Table 3.

(Comparative Example 9)

The deviation (maximum rate, minimum rate) and the number of times of deposition were measured in the same manner as in Example 7 except that the composition for forming an organic electroluminescence device was prepared without mixing the medium X-2 in Example 7 . The results are shown in Table 3.

(Comparative Example 10)

The deviation (maximum rate and minimum rate) of the deposition rate and the number of times of the droplet rubbing were measured in the same manner as in Example 8 except that the composition for forming an organic electroluminescent element was prepared without mixing the medium X-8 in Example 8 . The results are shown in Table 3.

(Comparative Example 11)

The deviation (maximum rate, minimum rate) and the number of times of the droplet deposition were measured in the same manner as in Example 9, except that the composition for forming an organic electroluminescent element was prepared without mixing the medium X-2 in Example 9 . The results are shown in Table 3.

(Comparative Example 12)

The deviation (maximum rate, minimum rate) and the number of times of deposition were measured in the same manner as in Example 10 except that the composition for forming an organic electroluminescence device was prepared without mixing the medium X-10 in Example 10 . The results are shown in Table 3.

(Example 11, Example 12, Comparative Example 13, Comparative Example 14)

The composition for forming an organic electroluminescence element used in Example 1, Example 2, Comparative Example 1, and Comparative Example 2 and the composition for forming an organic electroluminescence element used in Example 6 were placed in a vacuum (pressure: 3 x 10 ^-4 Pa) And each was heated to produce a co-evaporated film. The substrate was made of quartz, and the thickness of the vapor deposition film was set to 30 nm. The deposition rate was controlled so that the concentration of the organic compound Pt-2 was 15 mass%. The PL quantum yield of the obtained co-deposited film was measured by the following method. The results are shown in Table 4.

&Lt; Measurement method of PL quantum yield >

Hamamatsu Photonics K.K. The product was measured at an excitation wavelength of 350 nm using a thin film quantum yield measuring apparatus (C9920-02).

(Example 13, Example 14, Comparative Example 15, Comparative Example 16)

An organic EL device using the co-evaporated film prepared in Example 11, Example 12, Comparative Example 13, and Comparative Example 14 as a light emitting layer was produced as follows.

The device structure of the organic EL device was ITO (100 nm) / 2-TNATA (4,4 ', 4 "-tris (N- (2-naphthyl) -N- phenylamino) -triphenylamine + 0.3% F4TCNQ (120 nm) / NPD (bis [N- (1-naphthyl) -N-phenyl] benzidine (30 nm) / H-3 (3,6-di (N-carbazolyl) -N-phenylcarbazole) (3 nm) / light emitting layer (EML) Quinolinate) 4-phenylphenolate) aluminum) (30 nm) / LiF (1 nm) / Al (70 nm).

In the obtained organic EL device, blue light emission derived from the organic compound Pt-2 was observed.

Further, the front luminance (cd / m 2) and the luminance half-life (durability) (unit: hour) were measured. The results are shown in Table 5. The light emitting area was 4 mm 2. The emission layer (EML) was a co-evaporated film produced in the same manner as in Example 11, Example 12, Comparative Example 13, and Comparative Example 14.

&Lt; Fabrication of organic EL device >

A glass substrate on which ITO was formed with a thickness of 0.7 mm and a size of 2.5 cm x 2.5 cm was placed in a cleaning container and subjected to ultrasonic cleaning in 2-propanol, followed by shrinking under the conditions of an oxygen flow rate of 70 mL / min. , Ltd. Oxygen plasma treatment was carried out using an EXAM-type plasma cleaning apparatus.

Subsequently, 2-TNATA and F4TCNQ were co-deposited on the anode (ITO) at 0.5 nm / s and 0.0015 nm / s, respectively. The thickness was 120 nm.

Subsequently, α-NPD was deposited as a hole transporting layer at 0.1 nm / s and a thickness of 30 nm on the hole injection layer.

Subsequently, H-3 as a second hole transporting layer was deposited to a thickness of 3 nm at 0.1 nm / s on the hole transporting layer.

Subsequently, the organic compound H-2 (3,3'-di- (N-carbazole) -biphenyl) as the luminescent layer and the organic compound Pt-2 at 0.085 nm / s Respectively. And a thickness of 30 nm.

Subsequently, BAlq was deposited to a thickness of 30 nm at 0.1 nm / s as an electron transporting layer.

Then, LiF as an electron injecting layer was deposited to a thickness of 1 nm at 0.05 nm / s on the electron transporting layer.

Subsequently, a mask (mask having a light emitting region of 2 mm x 2 mm) patterned as a cathode was provided on the electron injecting layer, and metal aluminum was deposited to have a thickness of 70 nm at 0.3 nm / s.

The laminate thus prepared was placed in a glove box substituted with nitrogen gas, and sealed with a glass sealing substrate and an ultraviolet curable adhesive (XNR5516HV, manufactured by NAGASE & CO., LTD.).

<Measurement of front luminance (unit: cd / m 2)

A DC current of 0.5 mA was applied to each device using a Source Measure Unit 2400 manufactured by TOYO Corporation to emit light. The luminance was measured using a luminance system BM-8 manufactured by Topcon.

&Lt; Measurement of half-life of luminance (durability) (unit: hour) >

Each device was continuously energized with a constant current of 0.5 mA to measure the time until the luminance reached about half of the initial luminance.

(Example 15, Comparative Example 17 and Comparative Example 18)

The organic EL devices of Example 13 and Comparative Example 15 were fabricated ten times each, and the devices of Example 15 and Comparative Example 17 were used. Elements having the same constitution were fabricated 10 times in the same manner as in Example 15 except that no heating medium was used at all, thereby obtaining the element of Comparative Example 18. The maximum value and the minimum value deviation (= (maximum value-minimum value) / maximum value) among the ten organic EL elements were compared with the front luminance when 0.5 mA was passed through the device. Table 6 shows the results.

From Tables 1 to 3, the stability of the deposition rate was clearly improved in Examples 1 to 10 as compared with Comparative Examples 3 to 12 in which no medium was mixed. In Examples 1 to 10, since the film forming composition was not in the powder state but in the liquid state at the vaporization temperature of the organic compound, the powder did not collapse and no rapid increase in the deposition rate was found. The composition of the deposited vapor-deposited films was analyzed by XPS. As to the vapor-deposited films of Examples 1 to 10, it was confirmed that the content of the medium component in the vapor-deposited film was 0.001 mol% or less, and the vapor-deposited films of Comparative Examples 1 to 2 It was confirmed that the incorporation of the medium component into the vapor deposition film was about 0.01 mol%. In Comparative Examples 1 to 2, since the vaporization temperature of the organic compound and the decomposition temperature of the medium are close to each other, it is considered that the medium is vaporized or the decomposed medium component enters the vapor deposition film.

It can be seen from Table 3 that although the deposition time is as short as about 60 minutes in Comparative Examples 3 to 12, the deposition rate is greatly dispersed and the dolbid due to the collapse of the organic compound powder frequently occurs. Further, it was found from Table 3 that the Dolbid is particularly likely to occur in sublimation type organic compounds (Comparative Examples 4 to 12).

From Table 4, in Comparative Example 13 and Comparative Example 14, the quantum yield of PL greatly decreased. In Examples 11 and 12, the PL quantum yield was also high because the deposition rate was stable and the medium component was not mixed into the vapor deposition film.

From Table 5, high frontal luminance and high durability (long luminance half-life) were obtained in Examples 13 and 14 as compared with Comparative Example 15 and Comparative Example 16.

From Table 6, the organic EL device of Comparative Example 17 has a small variation in performance but a low frontal luminance. Further, the device of Comparative Example 18 had a high front luminance, but poor repeatability. On the other hand, it was found that the organic EL device of Example 15 had a high frontal luminance and improved deposition stability, resulting in improved repetitive reproducibility.

The organic electroluminescent device of the present invention is preferably used for display devices, displays, backlights, electrophotography, illumination light sources, recording light sources, exposure light sources, reading light sources, markers, signboards,

1 substrate 2 anode
3 hole injection layer 4 hole transport layer
5 luminescent layer 6 electron transport layer
7 electron injection layer 8 cathode
10 organic EL device

Claims (12)

A vaporizable organic compound having a molecular weight of 2,000 or less and a medium capable of dissolving or dispersing the organic compound, wherein the medium component is not vaporized at a vaporization temperature of the organic compound, and the medium has an organic compound salt and a number average molecular weight of 10,000 And at least one member selected from the group consisting of poly (methyl methacrylate) and poly (methyl methacrylate). The method according to claim 1,
Wherein the decomposition temperature of the medium is 30 DEG C or more higher than the vaporization temperature of the organic compound. The method according to claim 1,
Wherein the medium is a liquid at a vaporization temperature of the organic compound under a pressure of 1 x 10 &lt; ^-2 &gt; Pa or less. delete The method according to claim 1,
The cation of the organic compound salt may be selected from the group consisting of 1,3-dialkylimidazolium cation, N-alkylpyridinium cation, tetraalkylammonium cation, N, N-dialkylpyrrolidinium cation, tetraalkylphosphonium cation and derivatives thereof And the anion of the organic compound salt is at least one selected from the group consisting of a halogen anion, a borate anion, a phosphate anion, a sulfonate anion and an imide anion. The method according to claim 1,
Wherein the organic compound is vaporizable by heating under a pressure of 1 x 10 &lt; ^-2 &gt; Pa or less. The method according to claim 1,
Wherein the organic compound comprises a carbazole skeleton. The method according to claim 1,
Wherein the organic compound comprises at least one of a platinum complex and an iridium complex. A process for producing a vapor deposition film characterized by depositing an organic compound in the composition for forming an organic electroluminescence element described in claim 1 and forming a vapor deposition film of an organic compound in the composition for forming an organic electroluminescence element, Way. A vapor-deposited film produced by the method for producing a vapor-deposited film according to claim 9. 11. The method of claim 10,
Wherein the content of the medium is less than 0.001 mol% based on the organic compound. The organic electroluminescent device according to claim 10, wherein the vapor-deposited film is formed of one or more layers.

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