Bisanthracene Derivatives Having Solubilizing Substituent, and Organic Electroluminescence Device Using Same

Abstract

The present invention is to provide a light emitting material, for an organic EL device, exhibiting higher light emitting efficiency, and particularly, to provide a blue light emitting material, wherein the light emitting material comprises a compound of the following General Formula (1):

##STR00001## X is an aryl group including a tertiary amine structure, and Y is a phenyl group having an alkyl or aryl substituent at one ortho position.

Claims

1. A compound of the following General Formula (1): ##STR00019## in General Formula (1), X and Y represent substituents, X and Y are not the same as each other, X is an aryl group comprising a tertiary amine structure, and Y is a phenyl group having an alkyl or aryl substituent at one ortho position.

2. The compound of claim 1, wherein X is a substituent of the following General Formula (2): ##STR00020## in General Formula (2), Ra and Rb, comprising the positions of R2 to R5, independently represent a substituent optionally independently mono-, di-, tri-, tetra-, or penta-substituted fora ring to which Ra and Rb are each bound, or independently are not present Rc, including the positions of R1 and R6, exhibits a substituent optionally mono-, di-, tri-, or tetra-substituted for a ring to which Rc is bound, or is not present, and the substituent is independently a group selected from an alkyl group and an aryl group; provided that in the formula, in carbon atoms to which R1 and R2, R3 and R4, and R5 and R6 are each bonded, one or more pairs are optionally each independently directly bonded through a single bond, or bonded through an alkylene, an arylene, —O—, —S—, silylene (SiR11R12), —NR—, or —BR—; R11 and R12 each independently represent an alkyl or aryl group, and R represents a hydrogen atom, an alkyl group, or an aryl group; and * in the formula represents a position which is bonded to an anthracene ring on the left side of General Formula (1), and is any one of the ortho, meta, or para positions with respect to a nitrogen atom of triphenylamine derivative of General Formula (2).

3. The compound of claim 1, wherein Y is an o-biphenyl group.

4. A light emitting material for an organic electroluminescence device, comprising the compound of claim 1.

5. An organic electroluminescence device comprising the compound of claim 1.

6. An organic electroluminescence device having a light emitting layer comprising the compound of claim 1.

7. The organic electroluminescence device of claim 6, wherein the device comprises the compound as an emitter in the light emitting layer.

8. The organic electroluminescence device of claim 7, wherein the device further comprises an anthracene derivative compound, which is an aromatic hydrocarbon having no amino group, as a host material in the light emitting layer.

9. The compound of claim 1, wherein the compound of General Formula (1) includes any one of the compounds of the chemical formulae shown below: ##STR00021## ##STR00022## ##STR00023## ##STR00024##

Description

BRIEF DESCRIPTION OF DRAWINGS

[0032] FIG. 1 is a view schematically illustrating a typical structure of an organic EL device.

[0033] FIG. 2 is a view illustrating an absorption (UV-vis) spectrum (left) and a light emitting (PL) spectrum (right) of a toluene solution (10.sup.−5 M) of PAPAP-1 and PAPAP-0.

[0034] FIG. 3 is a view illustrating an absorption (UV-vis) spectrum (left) and a light emitting (PL) spectrum (right) of a toluene solution (10.sup.−5 M) of PAPAP-1 and PAPAP-12.

EXPLANATION OF REFERENCE NUMERALS AND SYMBOLS

[0035] 1 . . . Substrate [0036] 2 . . . Anode [0037] 3 . . . Hole injection layer [0038] 4 . . . Hole transport layer [0039] 5 . . . Organic light emitting layer [0040] 6 . . . Electron transport layer [0041] 7 . . . Cathode

BEST MODE

[0042] Hereinafter, exemplary embodiments of the present invention will be described in more detail.

[0043] The organic EL device of the present invention includes a cathode, an anode, and an organic layer disposed between the cathode and the anode, and is characterized in that the organic layer, particularly, a light emitting layer includes a compound of the following General Formula (1) described above.

##STR00008##

[0044] The compound of General Formula (1) is particularly useful as a light emitting material.

[0045] [Organic Electroluminescence Device]

[0046] An organic electroluminescence device of the present invention, that is, an organic EL device includes an organic layer containing the compound of General Formula (1). The organic layer is a light emitting layer, and it is preferred to use the compound of General Formula (1) as a light emitting material in the light emitting layer.

[0047] An organic EL device generally includes a first electrode, a second electrode, and one or more organic material layers disposed therebetween, and at least one of the first electrode and the second electrode is a light transmissive electrode. When holes are injected from an anode and electrons are injected from a cathode by applying a voltage between these two electrodes, the holes and the electrons are recombined in the organic material layer, and a light emitting material (emitter) included in the organic material layer emits light using the energy of excitons generated by the recombination. The organic EL device has a structure in which light is emitted from the organic material layer thereof and light is extracted from the side of the light transmissive electrode. The device structure of the organic EL device is not limited to any one, and various device structures have been proposed. As for the light emitting method, a top emission type, a bottom emission type, a double emission (double light emitting) type, and the like are known. The organic material layer of the organic EL device of the present invention may have a single layer structure consisting of one layer or a multi-layer structure having two or more layers, including a light emitting layer. When the organic material layer of the organic EL device of the present invention has a multi-layer structure, the organic material layer may have, for example, a structure in which a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and the like are stacked. Further, it is known that characteristics of an organic EL device may be improved by providing various layers such as a planarization layer for planarizing the surface of an electrode, a hole blocking layer, an electron blocking layer, and/or an exciton blocking layer, and these layers may also be applied to the organic EL device of the present invention. The compound of General Formula (1) of the present invention may be used in organic EL devices of all light emitting methods and structures. Therefore, the method of light emission and the device structure of the organic EL device including the compound of General Formula (1) of the present invention are not limited to specific ones.

[0048] A typical structure of the organic EL device is illustrated in FIG. 1. In FIG. 1, 1 denotes a substrate, 2 denotes an anode, 3 denotes a hole injection layer, 4 denotes a hole transport layer, 5 denotes an organic light emitting layer, 6 denotes an electron transport layer, and 7 denotes a cathode. Typically, an organic EL device having the structure illustrated as FIG. 1 is called an organic EL device having a forward structure. The organic EL device of the present invention may have the forward structure, but is not limited to this structure, and may be an organic EL device having a reverse structure, that is, a structure in which a substrate, a cathode, an electron transport layer, an organic light emitting layer, a hole transport layer, a hole injection layer, and a positive electrode are sequentially stacked. Furthermore, several of the plurality of organic layers may be omitted. Further, the organic EL device of the present invention is not limited to the above-described device structure, and may have any publicly-known device structure as the structure of the organic EL device.

[0049] The compound of General Formula (1) of the present invention may be used as a light emitting material for an organic EL device, particularly a blue light emitting material.

[0050] The organic EL device according to the present invention may be manufactured using methods for manufacturing an organic EL device and materials used for the organic EL device, which are publicly known, except that the use of the compound of General Formula (1) as a light emitting material, particularly a blue light emitting material is employed as a condition. For example, the organic EL device according to the present invention may be manufactured by depositing a metal, an alloy, or a metal oxide having conductivity, or a combination thereof on a substrate to form an anode, forming an organic material layer including one or more layers selected from a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and the like thereon, and then depositing a material, which may be used as a cathode, thereon, by using a physical vapor deposition (PVD) method such as sputtering or e-beam deposition. In addition to the method, as described above, an organic EL device may be made by sequentially depositing a cathode material, an organic material layer, and an anode material on a substrate in order to manufacture the organic EL device having a reverse structure. Further, several of the above-described organic layers may be omitted, and organic layers other than those described above may be added.

[0051] As a method of forming the organic material layer, it is possible to use a solution method, for example, a method such as spin coating, dip coating, doctor blade coating, screen printing, inkjet printing, or a thermal transfer method. In addition, a combination of solution and deposition methods may be used for different organic layers.

[0052] As a material for an anode, typically, it is preferred to use materials having a high work function so as to facilitate the injection of holes into an organic material layer. Specific examples of the anode material used in the present invention include: a metal such as vanadium, chromium, copper, zinc, and gold, or an alloy thereof; a metal oxide such as zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO); a combination of a metal and an oxide, such as ZnO:Al or Sn02:Sb; a conductive polymer such as poly(3-methylthiophene), poly[3,4-(ethylene-1,2-dioxy)thiophene] (PEDOT), polypyrrole, and polyaniline; and the like, but are not limited thereto.

[0053] As a material for a cathode, typically, it is preferred to use materials having a low work function so as to facilitate the injection of electrons into an organic material layer. Specific examples of the cathode material include: a metal such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, and lead, or an alloy thereof; a multi-layer structured material, such as LiF/Al or LiO.sub.2/Al, but are not limited thereto.

[0054] A publicly-known hole injection material may be used in the material for the hole injection layer of the organic EL device of the present invention. A hole injection material is a material that can smoothly receive the injection of holes from the anode at a low voltage, and it is preferred that the highest occupied molecular orbital (HOMO) of the hole injection material is between a work function of the anode material and the HOMO of the organic material layer opposite to the anode adjacent to the hole injection layer. Specific examples of the hole injection material include metal porphyrin, oligothiophene, arylamine-based organic materials, hexanitrile hexaazatriphenylene-based organic materials, quinacridone-based organic materials, perylene-based organic materials, anthraquinone and polyaniline, polythiophene-based conductive polymers and the like, but are not limited thereto.

[0055] As the material for the hole transport layer, a publicly-known hole transport material may be used. The material of the hole transport layer is a material that can receive the transport of holes from the anode or the hole injection layer to move the holes to the light emitting layer, and a material having high hole mobility is suitable. Specific examples thereof include: arylamine-based compounds; carbazole-based compounds; anthracene-based compounds; pyrene-based compounds; conductive polymers, and block copolymers having both conjugated portions and non-conjugated portions, and the like, but are not limited thereto.

[0056] In the organic EL device of the present invention, as a light emitting material for the light emitting layer, the bisanthracene derivative of General Formula (1) is used. As shown in the following examples, the compound of General Formula (1) of the present invention may be used as a light emitting material for an organic EL device, particularly a blue light emitting material.

[0057] When the bisanthracene derivative of General Formula (1) of the present invention is used as a light emitting material for an organic EL device, the bisanthracene derivative may be used alone for the light emitting layer, but it is particularly preferred to use the bisanthrasene derivative as a dopant, that is, a guest material, in combination with a host material. A compound that may be suitably used as a host material is a compound having a larger bandgap than the bisanthrasene derivative of General Formula (1) and also having a charge transport property, and any compound may be selected from the compounds and used as the host material. In the light emitting layer of the organic EL device, a method of using a light emitting material as a guest in combination with a host material is a well-known technique. Many compounds that can be used as host materials for the light emitting layer of the organic EL device are known in the art. Examples of the host material are not limited to those described below, but include, for example, 4,4′-bis(9H-carbazol-9-yl)biphenyl, 4,4′-bis(2,2-diphenylvinyl)biphenyl, 9,9′-bianthracene, 4,4′-bis(9H-carbazol-9-yl)biphenyl, 2,6-bis[3-(9H-carbazol-9-yl)phenyl]pyridine, bis[2-(2-pyridinyl)phenolate]beryllium (II), 4,4′-bis(9H-carbazol-9-yl)-2,2′-dimethylbiphenyl, 2,8-bis(9H-carbazol-9-yl)dibenzothiophene, 2,6-bis(9H-carbazol-9-yl)pyridine, 2,2″-bi-9,9′-spirobi[9H-fluorene], 9,9-bis[4-(1-pyrenyl)phenyl]fluorene, 9,10-bis(4-methoxyphenyl)anthracene, 4,4′-bis(2,2-diphenylvinyl)biphenyl, bis[2-[(oxo)diphenylphosphino]phenyl]ether, 9,10-diphenylanthracene, 9,10-di(1-naphthyl)anthracene, 1,3-di-9-carbazolylbenzene, 9,10-di(2-naphthyl)anthracene, 9-(naphthalen-1-yl)-10-(naphthalen-2-yl)anthracene (α,β-ADN), 3,3′-di(9H-carbazol-9-yl)-1,1′-biphenyl, 9,9′-diphenyl-9H,9′H-3,3′-bicarbazole, 3,3″-di(9H-carbazol-9-yl)-1,1′:3′,1″-terphenyl, 9-[3-(dibenzofuran-2-yl)phenyl]-9H-carbazole, diphenyl[9,9′-spirobi[9H-fluoren]-2-yl]phosphine oxide, 1,4-di(1-phenyl)benzene, 2,7-di(1-pyrenyl)-9,9′-spirobi[9H-fluorene], 2-methyl-9,10-di(2-naphthyl)anthracene, 2-methyl-9,10-di(1-naphthyl)anthracene, poly(N-vinylcarbazole), 9-phenyl-3,6-bis[4-(1-phenylbenzoimidazol-2-yl)phenyl]carbazole, 2-(9,9′-spirobi[fluoren]-2-yl)-4,6-diphenyl-1,3,5-triazine, tris(8-quinolinolato)aluminum, 1,3,5-tri(9H-carbazol-9-yl)benzene, tris(8-quinolinolato)aluminum, 4,4′,4″-tri-9-carbazolyltriphenylamine, 1,3,5-tri(1-naphthyl)benzene, 9,9′,10,10′-tetraphenyl-2,2′-bianthracene, and 2,2″:7″, 2″″-ter-9,9′-spirobi[9H-fluorene].

[0058] As a host material to be used in combination with the compound of General Formula (1) of the present invention, it is preferred to use, particularly, an anthracene derivative compound which is an aromatic hydrocarbon having no amino group in the molecule.

[0059] Among them, examples of the particularly preferred compound include 9,10-diphenylanthracene, 9,10-di(1-naphthyl)anthracene, 9,10-di(2-naphthyl)anthracene, 9,10-diphenylanthracene, 9-(naphthalen-1-yl)-10-(naphthalen-2-yl)anthracene (α,β-ADN), 2-methyl-9,10-di(2-naphthyl)anthracene, 2-methyl-9,10-di(1-naphthyl)anthracene, and 2-methyl-9-(naphthalen-1-yl)-10-(naphthalen-2-yl)anthracene.

[0060] In the organic EL device of the present invention, it is preferred that the compound of General Formula (1) is used in a combination with a host material so as to be included in the light emitting layer in an amount of 0.1 to 10 mass % based on the mass of the light emitting layer.

[0061] The organic EL device of the present invention may have an electron transport layer. An electron transport material for forming an electron transport layer is a material that can smoothly receive the injection of electrons from the cathode to move the electrons to the light emitting layer, and it is preferred to use a material having high electron mobility. Specific examples of the electron transport material include Al complexes of 8-hydroxyquinoline; complexes including Alq.sub.3; organic radical compounds; hydroxyflavone-metal complexes; anthracene-based compounds; pyrene-based compounds; benzoxazole-based, benzthiazole-based, and benzimidazole-based compounds; pyridyl-based compounds; phenanthroline-based compounds; quinoline-based compounds; quinazoline-based compounds, and the like, but are not limited thereto. In addition, an electron transport layer may be formed by doping these compounds with a metal or metal compound.

[0062] In addition to the above-described respective layers, a planarization layer for planarizing the surface of an electrode; and a layer selected from a hole blocking layer, an electron blocking layer, and an exciton blocking layer for confining holes, electrons, and/or excitons in a target organic layer may be used in the organic EL device, if necessary, and such a technology is a publicly-known technology. In addition, the publicly-known technology for the organic EL device may be applied to an organic EL device including the compound of General Formula (1) of the present invention.

[0063] Furthermore, since the compound of General Formula (1) of the present invention is dissolved in an organic solvent, an organic layer of an organic EL device, particularly, a light emitting layer may be formed by an application method using a solution including the compound of the present invention.

MODE FOR INVENTION

[0064] Hereinafter, the results of the Comparative Examples and the preferred Examples will be provided for helping the understanding of the present invention, and the present invention is not limited to the following Examples.

EXAMPLES

Synthesis Example

[0065] The compound PAPAP-0 used in the following Comparative Example is a compound having the following chemical formula.

##STR00009##

[0066] PAPAP-0 may be prepared by a publicly known method set forth, for example, in Adv. Funct. Mater. 24, p. 2064-2071, 2014. In this case, PAPAP-0 was synthesized by the following synthesis method.

##STR00010##

[0067] That is, 9-bromoanthracene and 4-benzonitrile boronic acid were put into a four-necked flask, the resulting mixture was refluxed under heating under nitrogen in a mixed solution consisting of an aqueous potassium carbonate solution, ethanol, toluene, and tetrakistriphenylphosphine palladium, and then the resulting product was purified to obtain a yellowish white solid An-Ph-CN at a yield of 95%. Next, a mixed solution consisting of An-Ph-CN, N-bromosuccinimide, and chloroform was refluxed under heating under nitrogen in a four-necked flask, and then the resulting product was purified to obtain a yellowish white solid Br-AP-CN at a yield of 95%. Next, Br-AP-CN and 4-chlorophenylboronic acid were put into a four-necked flask, the resulting mixture was refluxed under heating under nitrogen in a mixed solution consisting of an aqueous potassium carbonate solution, ethanol, toluene, and tetrakistriphenylphosphine palladium, and then ON-PAP-Cl was obtained. Next, a mixed solution consisting of CN-PAP-Cl, bis(pinacolato)diboron, S-Phos, 1,4-dioxane, potassium acetate, and palladium acetate was refluxed under heating under nitrogen in a four-necked flask, and then the resulting product was purified to obtain a yellow solid CN-PAP-Bpin at a yield of 96%. Next, CN-PAP-Bpin and MeO-PA-Br were put into a four-necked flask, the resulting mixture was refluxed under heating under nitrogen in a mixed solution consisting of an aqueous potassium carbonate solution, ethanol, toluene, and tetrakistriphenylphosphine palladium, and then the resulting product was purified to obtain an orange color solid PAPAP-0 at a yield of 86%.

[0068] PAPAP-1 is represented by the following structural formula, and may be prepared by a method shown below in accordance with the synthesis method of PAPAP-0.

##STR00011##

[0069] That is, 9-bromoanthracene and 4-chlorophenyl boronic acid were put into a four-necked flask, the resulting mixture was refluxed under heating under nitrogen in a mixed solution consisting of an aqueous potassium carbonate solution, ethanol, toluene, and tetrakistriphenylphosphine palladium, and then the resulting product was purified to obtain a yellowish white solid An-Ph-C1 at a yield of 87.7%. Next, a mixed solution consisting of An-Ph-Cl, bis(pinacolato)diboron, S-Phos, 1,4-dioxane, potassium acetate, and palladium acetate was refluxed under heating under nitrogen in a four-necked flask, and then the resulting product was purified to obtain a yellow solid An-Ph-Bpin at a yield of 57%. Next, 9-bromo-10-([1,1′-biphenyl]-2-yl)anthracene and An-Ph-Bpin were put into a four-necked flask, the resulting mixture was refluxed under heating under nitrogen in a mixed solution consisting of an aqueous potassium carbonate solution, ethanol, toluene, and tetrakistriphenylphosphine palladium, and then the resulting product was purified to obtain a yellowish white solid APA-2-biphenyl at a yield of 72.5%. Next, a mixed solution consisting of APA-2-biphenyl, N-bromosuccinimide, and chloroform was refluxed under heating under nitrogen in a four-necked flask, and then the resulting product was purified to obtain a yellowish white solid Br-APA-2-biphenyl at a yield of 92%. Next, Br-APA-2-biphenyl and 4-(diphenylamino)phenyl boronic acid were put into a four-necked flask, the resulting mixture was refluxed under heating under nitrogen in a mixed solution consisting of an aqueous potassium carbonate solution, ethanol, toluene, and tetrakistriphenylphosphine palladium, and then the resulting product was purified to obtain a yellowish white solid PAPAP-1 at a yield of 91%.

[0070] PAPAP-12 is represented by the following structural formula, and may be prepared by a method shown below in accordance with the synthesis method of PAPAP-0.

##STR00012## ##STR00013##

[0071] That is, 9-bromoanthracene and 4-chlorophenyl boronic acid were put into a four-necked flask, the resulting mixture was refluxed under heating under nitrogen in a mixed solution consisting of an aqueous potassium carbonate solution, ethanol, toluene, and tetrakistriphenylphosphine palladium, and then the resulting product was purified to obtain a yellowish white solid An-Ph-Cl at a yield of 87.7%. Next, a mixed solution consisting of An-Ph-Cl, bis(pinacolato)diboron, S-Phos, 1,4-dioxane, potassium acetate, and palladium acetate was refluxed under heating under nitrogen in a four-necked flask, and then the resulting product was purified to obtain a yellow solid An-Ph-Bpin at a yield of 57%. Next, 9-bromo-10-([1,1′-biphenyl]-2-yl)anthracene and An-Ph-Bpin were put into a four-necked flask, the resulting mixture was refluxed under heating under nitrogen in a mixed solution consisting of ethanol, toluene, an aqueous potassium carbonate solution, and tetrakistriphenylphosphine palladium, and then the resulting product was purified to obtain a yellowish white solid APA-2-biphenyl at a yield of 72.5%. Next, a mixed solution consisting of APA-2-biphenyl, N-bromosuccinimide, and chloroform was refluxed under heating under nitrogen in a four-necked flask, and then the resulting product was purified to obtain a yellowish white solid Br-APA-2-biphenyl at a yield of 92%. Next, Br-APA-2-biphenyl and 3-(diphenylamino)phenyl boronic acid were put into a four-necked flask, the resulting mixture was refluxed under heating under nitrogen in a mixed solution consisting of an aqueous potassium carbonate solution, ethanol, toluene, and tetrakistriphenylphosphine palladium, and then the resulting product was purified to obtain a yellowish white solid PAPAP-12 at a yield of 26%.

[Example 1] Solubility Test of PAPAP Derivative

[0072] Solubility tests were performed on PAPAP-1 and PAPAP-0 obtained from the Synthetic Example using cyclohexanone as a solvent. 10 mg of each of PAPAP-1 and PAPAP-0 was measured, 1 mL of cyclohexanone was added thereto, and thermal stirring was performed at a temperature of about 100° C.

[0073] By performing a solubility test with thermal stirring, it was confirmed that PAPAP-1 was soluble and PAPAP-0 was insoluble in cyclohexanone.

[0074] [Evaluation of Optical Characteristics]

[0075] The apparatus and measurement conditions used to evaluate the optical characteristics of the test sample are as follows.

[0076] (1) Ultraviolet Visible (UV-Vis) Spectrophotometer

[0077] Shimadzu Corporation UV-2600

[0078] Measurement conditions; Scan speed medium speed, measurement range 200 to 800 nm

[0079] Sampling pitch 0.5 nm, slit width 0.5 nm

[0080] (2) Fluorescence Spectrophotometer

[0081] HORIBA, Ltd. FluoroMax 2

[0082] Light source: Xenon lamp Integration Time: 5.0 sec

[0083] Exicit Mono Slits: 0.300 mm, Emiss Mono Slits: 0.300

[0084] (3) Measurement of Light Emitting Quantum Yield

[0085] Hamamatsu Photonics K.K. Integrating sphere, excitation light irradiation device L10092+A10079

[0086] Excitation light: 300 to 400 nm

Example 2

[0087] The absorption (UV-vis)emission (PL) spectra were measured by preparing a toluene solution (10.sup.−5 M) of PAPAP-1. The results are shown in FIG. 2. From the results of the UV-vis absorption spectrum, it was observed that the absorption edge of PAPAP-1 had a longer wavelength than PAPAP-0 (left side of FIG. 2). Further, it was also observed from the PL spectrum (right side of FIG. 2) that the light emitting wavelength was lengthened.

Example 3

[0088] The light emitting quantum yield was measured by preparing a toluene solution (10.sup.−5 M) of PAPAP-1. The measurement results are shown in the following Table 1.

Comparative Example 1

[0089] By performing the same processes as those described in Examples 2 and 3 using PAPAP-0 instead of PAPAP-1 as Comparative Example 1, the absorption (UV-vis)emission (PL) spectra and the light emitting quantum yield were measured.

[0090] [Evaluation Results]

[0091] The evaluation results of Examples 2 and 3 and Comparative Example 1 are shown in Table 1.

TABLE-US-00001 TABLE 1 Light Full width emitting at half Light emitting wavelength maximum quantum yield Compound (nm) (nm) (%) PAPAP-1 454 68 61 PAPAP-0 424 54 69

Example 4

[0092] First, a glass substrate on which a pre-patterned indium tin oxide (ITO) was thin-film-deposited to a thickness of 100 nm was placed in distilled water in which a detergent was dissolved, and washed with ultrasonic waves. In this case, a product manufactured by Fisher Co., was used as the detergent, and distilled water, which had been filtered twice with a filter manufactured by Millipore Co., was used as the distilled water. After the ITO was washed for 30 minutes, ultrasonic washing was conducted twice repeatedly using distilled water for 10 minutes. After the washing with distilled water was completed, the surface was ultrasonically washed sequentially with acetone, distilled water, and an isopropyl alcohol solvent, dried, and then surface-treated with UV-ozone (O.sub.3). Thereafter, in order to form an organic layer, a hole injection layer, a hole transport layer (HTL), and a light emitting layer were sequentially film-formed by spin coating. After film formation by spin coating, a substrate on which each of the above-described layers was deposited was put into a vapor deposition apparatus, and each one layer of a hole blocking layer, an electron transport layer, an electron injection layer and a negative electrode was sequentially deposited on the light emitting layer at a vacuum degree of about 10.sup.−4 to about 10.sup.−5 Pa.

[0093] More specifically, a toluene solution of a mixture of the following Compound A and the following Compound B mixed at a weight ratio of 8:2 (concentration of the mixture 1 mass %) was applied onto the ITO transparent electrode by a spin coating method and cured in a nitrogen atmosphere on a hot plate under conditions of 220° C. and 30 minutes to form a hole injection layer having a film thickness of 40 nm.

##STR00014##

[0094] A composition prepared by dissolving the following compound C at a weight ratio of 1% with respect to toluene was applied onto the hole injection layer by a spin coating method, and heat-treated on a hot plate under conditions of 200° C. and 30 minutes to form a hole transport layer having a film thickness of 20 nm.

##STR00015##

[0095] For the light emitting layer, 9-(naphthalen-1-yl)-10-(naphthalen-2-yl)anthracene (α,β-ADN) was used as a light emitting host material, and PAPAP-1 was used as a dopant material. A light emitting layer was formed by applying a solution including these components to a base material and removing the solvent. The concentration of the solution was adjusted to 2 mg/ml using cyclohexanone as the solvent to form a layer having a film thickness of about 20 nm by a spin coating method. The doping amount of the dopant material was 10 mass % based on the total amount of the host material.

[0096] Next, in order to sequentially form a hole blocking layer, an electron transport layer, and a metal layer on the light emitting layer, the substrate was transferred to a deposition apparatus, and the hole blocking layer was formed as a layer having a thickness of about 5 nm using 2-(3-(dibenzothiophen-4-yl)-[1,1-biphenyl]-3-yl)-4,6-diphenyl-1,3,5-triazine (DBT-TRZ). The electron transport layer was formed as a layer having a thickness of about 30 nm using 1,4-di(1,10-phenanthrolin-2-yl)benzene (DPB) as a host material and 8-hydroxyquinolinolato-lithium (Liq) as a guest material. The doping amount of the dopant material was 20 mass % based on the total amount of the host material. The electron injection layer was formed as a layer having a thickness of about 1 nm using 8-hydroxyquinolinolato-lithium (Liq), and a second electrode was formed as a layer having a thickness of about 75 nm using aluminum (Al). An organic EL device was manufactured according to the above-described method.

[0097] [Manufacture and Evaluation Results of Organic EL Device]

[0098] The light emitting characteristics of the organic EL device manufactured in accordance with the above-described method were measured using PHOTONIC MULTI-CHANNEL ANALYZER PMA-11 of Hamamatsu Photonics K.K. The measurement results are shown in the following table.

[0099] A non-doped type organic EL device of PAPAP-1 was manufactured using only PAPAP-1 without using a light emitting host material when the light emitting layer was formed. The measurement results of the light emitting characteristics are shown in the following Table 2.

TABLE-US-00002 TABLE 2 V.sub.100/η.sub.p.100/ V.sub.1000/η.sub.p.1000/ η.sub.c.100/ η.sub.c.1000/ Light η.sub.ext.100.sup.b) η.sub.ext.1000.sup.c) emitting V.sub.on.sup.a) (V/1 m W.sup.−1/ (V/1 m W.sup.−1/ CIE100 .sup.d) layer (V) cd A.sup.−1/%) cd A.sup.−1/%) (x, y) single 2.77 3.44/2.98/ 4.84/2.15/ (0.14, 0.20) film 3.27/2.30 3.32/2.17 .sup.a)Light emission initiation voltage (V) (@ 1 cd m.sup.−2) .sup.b)Voltage (V), Power efficiency (η.sub.p), Current efficiency (η.sub.c), External quantum efficiency (η.sub.ext.) (@ 100 cd m.sup.−2) .sup.c)Voltage (V), Power efficiency (η.sub.p), Current efficiency (η.sub.c), External quantum yield (η.sub.ext.) (@ 1000 cd m.sup.−2) .sup.d) Plane coordinates x and y of the Commission International de I' Eclairage (CIE) (@ 100 cd m.sup.−2) chromaticity diagram.

[0100] The measurement results of the light emitting characteristics of the doped type organic EL device of PAPAP-1 manufactured as Example 4 are shown in the following Table 3.

TABLE-US-00003 TABLE 3 V.sub.100/η.sub.p.100/ V.sub.1000/η.sub.p.1000/ Light η.sub.c.100/η.sub.ext.100.sup.b) η.sub.c.1000/η.sub.ext.1000.sup.c) emitting V.sub.on.sup.a) (V/1 m W.sup.−1/ (V/1 m W.sup.−1/ CIE100 .sup.d) layer (V) cd A.sup.−1/%) cd A.sup.−1/%) (x, y) Doped 2.79 3.54/4.16/ 4.91/3.20/ (0.14, film 4.68/3.65 4.99/3.90 0.18) .sup.a)Light emission initiation voltage (V) (@ 1 cd m.sup.−2) .sup.b)Voltage (V), Power efficiency (η.sub.p), Current efficiency (η.sub.c), External quantum efficiency (η.sub.ext.) (@ 100 cd m.sup.−2) .sup.c)Voltage (V), Power efficiency (η.sub.p), Current efficiency (η.sub.c), External quantum yield (η.sub.ext.) (@ 1000 cd m.sup.−2) .sup.d) Plane coordinates x and y of the Commission International de I′ Eclairage (CIE) (@ 100 cd m.sup.−2) chromaticity diagram.

[0101] From the results shown in Table 2, it can be seen that by using Compound PAPAP-1 which is an aspect of the present invention as a material for a light emitting layer (EML), a doped type organic EL device, which is difficult to manufacture when a technique in the related art PAPAP-0 is used, is successfully manufactured. Further, from the results shown in Table 3, it can be seen that the light emitting efficiency of the organic EL device is improved by changing the light emitting layer from a layer made of only a light emitting material to a doped film in which the light emitting layer is doped with a host material.

[0102] The compounds PAPAP-1 and PAPAP-12 used in the following test are compounds having the following chemical formulae.

##STR00016##

[Example 5] Comparative Test of Solubility of PAPAP Derivative

[0103] The solubilities of PAPAP-12 and PAPAP-1 were tested using cyclohexanone as a solvent. 10 mg of each of PAPAP-12 and PAPAP-1 was measured, 1 mL of cyclohexanone was added thereto, and thermal stirring was performed at a temperature of about 100° C.

[0104] By performing a solubility test under thermal stirring conditions, it was confirmed that both PAPAP-1 and PAPAP-12 were soluble in cyclohexanone.

[0105] [Evaluation of Optical Characteristics]

[0106] The apparatus and measurement conditions used to evaluate the following optical characteristics are as follows.

[0107] (1) Ultraviolet Visible (UV-Vis) Spectrophotometer

[0108] Shimadzu Corporation UV-2600

[0109] Measurement conditions; Scan speed medium speed, measurement range 200 to 800 nm [0110] Sampling pitch 0.5 nm, slit width 0.5 nm

[0111] (2) Fluorescence Spectrophotometer

[0112] HORIBA, Ltd. FluoroMax 2

[0113] Light source: Xenon lamp Integration Time: 5.0 sec

[0114] Exicit Mono Slits: 0.300 mm, Emiss Mono Slits: 0.300

[0115] (3) Measurement of Light Emitting Quantum Yield

[0116] Hamamatsu Photonics K.K. Integrating sphere, excitation light irradiation device L10092+A10079

[0117] Excitation light: 300 to 400 nm

Example 6

[0118] The absorption (UV-vis)emission (PL) spectra were measured by preparing a toluene solution (10.sup.−5 M) of PAPAP-12. The results are shown in FIG. 3. From the results of the UV-vis absorption spectrum, it was observed that the absorption edge of PAPAP-12 had a shorter wavelength than PAPAP-1. Further, it was also observed from the PL spectrum that the light emitting wavelength was shortened.

Example 7

[0119] The light emitting quantum yield was measured by preparing a toluene solution (10.sup.−5 M) of PAPAP-12. The measurement results are shown in the following Table 4.

[0120] By performing substantially the same processes as those described in Examples 2 and 3 using PAPAP-1 instead of PAPAP-12, the absorption (UV-vis)emission (PL) spectra and the light emitting quantum yield were measured.

[0121] [Evaluation Results]

[0122] The evaluation results of Examples 6 and 7 are shown in Table 4.

TABLE-US-00004 TABLE 4 Light Full width emitting at half Light emitting wavelength maximum quantum yield Compound (nm) (nm) (%) PAPAP-12 421 65 69 PAPAP-1 454 68 61

[0123] It can be seen that PAPAP-12 has a shorter light emitting wavelength, a narrower full width at half maximum, and a higher light emitting quantum yield than PAPAP-1.

Example 8

[0124] First, a pattern was formed in advance, and a washed ITO-glass substrate was surface-treated using UV-ozone (03). The thickness of the ITO layer (first electrode) of the ITO-glass substrate was about 100 nm. After the surface treatment, in order to form an organic layer, a hole injection layer, a hole transport layer (HTL), and a light emitting layer were sequentially film-formed by spin coating. After film formation by spin coating, a substrate on which each of the above-described layers was deposited was put into a vapor deposition apparatus, and each one layer of a hole blocking layer, an electron transport layer, an electron injection layer and a negative electrode was sequentially deposited on the light emitting layer at a vacuum degree of about 10.sup.−4 to about 10.sup.−5 Pa.

[0125] More specifically, a toluene solution of a mixture of the following Compound A and the following Compound B mixed at a weight ratio of 8:2 (concentration of the mixture 1 mass %) was applied onto the ITO transparent electrode by a spin coating method and cured in a nitrogen atmosphere on a hot plate under conditions of 220° C. and 30 minutes to form a hole injection layer having a film thickness of 40 nm.

##STR00017##

[0126] A composition prepared by dissolving the following compound C at a weight ratio of 1% with respect to toluene was applied onto the hole injection layer by a spin coating method, and heat-treated on a hot plate under conditions of 200° C. and 30 minutes to form a hole transport layer having a film thickness of 20 nm.

##STR00018##

[0127] For the light emitting layer, 9-(naphthalen-1-yl)-10-(naphthalen-2-yl)anthracene (α,β-ADN) was used as a light emitting host material, and PAPAP-12 was used as a dopant material. A light emitting layer was formed by applying a solution including these components to a base material and removing the solvent. The concentration of the solvent was adjusted to 2 mg/ml using cyclohexanone in the solvent to form a layer having a film thickness of about 20 nm by a spin coating method. The doping amount of the dopant material was 10 mass % based on the total amount of the host material.

[0128] Next, in order to sequentially form a hole blocking layer, an electron transport layer, and a metal layer on the light emitting layer, the substrate was transferred to a deposition apparatus, and the hole blocking layer was formed as a layer having a thickness of about 5 nm using 2-(3-(dibenzothiophen-4-yl)-[1,1-biphenyl]-3-yl)-4,6-diphenyl-1,3,5-triazine (DBT-TRZ). The electron transport layer was formed as a layer having a thickness of about 30 nm using 1,4-di(1,10-phenanthrolin-2-yl)benzene (DPB) as a host material and 8-hydroxyquinolinolato-lithium (Liq) as a guest material. The doping amount of the dopant material was 20 mass % based on the total amount of the host material. The electron injection layer was formed as a layer having a thickness of about 1 nm using 8-hydroxyquinolinolato-lithium (Liq), and a second electrode was formed as a layer having a thickness of about 75 nm using aluminum (Al). An organic EL device was manufactured by above-described method.

[0129] [Manufacture and Evaluation Results of Organic EL Device]

[0130] The light emitting characteristics of the organic EL device manufactured in accordance with the above-described method were measured using PHOTONIC MULTI-CHANNEL ANALYZER PMA-11 of Hamamatsu Photonics K.K. The measurement results are shown in the following table.

[0131] A non-doped type organic EL device of PAPAP-12 was manufactured using only PAPAP-12 without using a light emitting host material when the light emitting layer was formed. The measurement results of the light emitting characteristics are shown in the following Table 5.

TABLE-US-00005 TABLE 5 V.sub.100/η.sub.p.100/ V.sub.1000/η.sub.p.1000/ Light η.sub.c.100/η.sub.ext.100.sup.b) η.sub.c.1000/η.sub.ext.1000.sup.c) emitting V.sub.on.sup.a) (V/1 m W.sup.−1/ (V/1 m W.sup.−1/ CIE100 .sup.d) layer (V) cd A.sup.−1/%) cd A.sup.−1/%) (x, y) Single 3.18 4.38/0.77/ 6.85/0.45/ (0.17, film 1.08/0.96 0.99/0.87 0.15) .sup.a)Light emission initiation voltage (V), Power efficiency (η.sub.p), Current efficiency (η.sub.c), External quantum efficiency (η.sub.ext.) (@ 1 cd m.sup.−2) .sup.b)Voltage (V), Power efficiency (η.sub.p), Current efficiency (η.sub.c), External quantum efficiency (η.sub.ext.) (@ 100 cd m.sup.−2) .sup.c)Voltage (V), Power efficiency (η.sub.p), Current efficiency (η.sub.c), External quantum yield (η.sub.ext.) (@ 1000 cd m.sup.−2) .sup.d) Plane coordinates x and y of the Commission International de I′ Eclairage (CIE) (@ 100 cd m−2) chromaticity diagram.

[0132] A doped type organic EL device of PAPAP-12 was manufactured using the light emitting host material as described above when the light emitting layer was formed. The measurement results of the light emitting characteristics are shown in the following Table 6.

TABLE-US-00006 TABLE 6 V.sub.100/η.sub.p.100/ V.sub.1000/η.sub.p.1000/ Light η.sub.c.100/η.sub.ext.100.sup.b) η.sub.c.1000/η.sub.ext.1000.sup.c) emitting V.sub.on.sup.a) (V/1 m W.sup.−1/ (V/1 m W.sup.−1/ CIE100 .sup.d) layer (V) cd A.sup.−1/%) cd A.sup.−1/%) (x, y) Doped 2.81 3.46/1.56/ 5.10/0.98/ (0.15, film 1.72/1.83 1.59/1.72 0.10) .sup.a)Light emission initiation voltage (V), Power efficiency (η.sub.p), Current efficiency (η.sub.c), External quantum efficiency (η.sub.ext.) (@ 1 cd m.sup.−2) .sup.b)Voltage (V), Power efficiency (η.sub.p), Current efficiency (η.sub.c), External quantum efficiency (η.sub.ext.) (@ 100 cd m.sup.−2) .sup.c)Voltage (V), Power efficiency (η.sub.p), Current efficiency (η.sub.c), External quantum yield (η.sub.ext.) (@ 1000 cd m.sup.−2) .sup.d) Plane coordinates x and y of the Commission International de I′ Eclairage (CIE) (@ 100 cd m−2) chromaticity diagram.

[0133] From the results shown in Table 5, for an organic EL device having a light emitting layer (EML) formed using PAPAP-12 which is an aspect of the present invention as a light emitting material, the light emitting wavelength became shorter than the case where PAPAP-1 was used as a light emitting material. Furthermore, from the results shown in Tables 5 and 6, it can be seen that the light emitting efficiency is improved by changing the light emitting layer from the non-doped film to the doped film.

INDUSTRIAL APPLICABILITY

[0134] The compound of the present invention can be used as a material for an organic electroluminescence device, particularly, as a blue light emitting material.