JP2001115154A - Organic thin-film luminescent element and phosphor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic red phosphor which has a red luminescent peak at a wavelength longer than that of the orange-colored luminescence of a conventional red luminescent element and to provide an organic thin-film luminescent element. SOLUTION: The luminescent element has an organic luminescent layer containing a compound represented by formula 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic thin-film light-emitting device having a diode characteristic and comprising a laminated film of an organic semiconductor thin film and a phosphor which can be used for a thin display or the like.

[0002]

2. Description of the Related Art Organic thin-film light-emitting devices are manufactured by Eastman Kodak Company. W. Japanese Unexamined Patent Publication No.
9-194393, JP-A-63-264692, JP-A-63-295695, Applied
Physics Letter Vol. 51, No. 12, page 913 (1
987), and Journal of Applied Physics, Vol. 65, No. 9, page 3610 (1989);
Applied Physics Letter Vol. 69, No. 15, page 2160 (1996); Applied Physics Letter Vol. 70, No. 2, page 152 (1997); Applied Physics Letter, Vol. 70, No. 13, No. 13 1
665 (1997) and JP-A-10-308281 of Eastman Kodak Company.

FIG. 1 shows a configuration example of an organic thin film light emitting device.
First, a composite oxide of indium and tin (hereinafter referred to as IT) is formed on a transparent insulating substrate (1) such as glass or resin film by vapor deposition, ion plating or sputtering.
O) is formed as a transparent conductive film anode (2). Next, a hole injection / transport layer (3) composed of an organic semiconductor thin film layer formed by stacking about two to three layers in the order of ionization potential is formed thereon.

For example, first, copper phthalocyanine (hereinafter, abbreviated as CuPc, ionization potential of 5.2 eV), which is highly stable against oxidation, is formed as a first hole injection / transport layer to a thickness of 10 nm by vacuum evaporation.

Further, pinholes which cause short-circuiting of the element are prevented, and N, N'-di (1-naphthyl) -N, N'- represented by high chemical transmittance (Chem. 3). Diphenyl-1,1'-biphenyl-4,4'-diamine (hereinafter N
Abbreviated as PD. A glass transition temperature of 96 ° C. and an ionization potential of 5.4 eV) are formed as a second hole injection / transport layer by a vapor deposition method or the like.

[0006]

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[0007]

Next, tris (8-quinolinolato) aluminum (hereinafter abbreviated as Alq) as an organic light emitting layer (7) on the hole injecting and transporting layer (3). Ionization potential 5.8e.
An organic phosphor such as a bisstyrylbiphenyl compound represented by V) or (Formula 4) is formed to a thickness of about 40 to 100 nm by a vapor deposition method or the like.

[0009]

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A fluorescent dye having a high fluorescence quantum yield, such as a coumarin-based, pyran-based, or dimethylquinacridone, is co-deposited with a light-emitting layer host material in the organic light-emitting layer or thermally diffused after forming a multilayer with the light-emitting layer host material. Doping by the method described above can increase the emission luminance or change the emission color.

In the case of a red light-emitting element, DCM represented by (Chemical Formula 5) or DC represented by (Chemical Formula 6) is contained in the Alq organic light-emitting layer.
M2, a pyran-based dye such as DCJTB shown in Chemical Formula 7 is doped by about 1%.

[0012]

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[0013]

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[0014]

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A driving voltage can be reduced by forming an electron transporting layer (8) having an excellent electron injecting and transporting ability on the organic light emitting layer (7) (see FIG. 2).

Next, Al or Al: Li is used as the cathode (10).
Low work function alloys such as alloys and rare earth alloys are deposited by co-evaporation to a thickness of about 200 to 1000 nm.

When Al is used for the cathode, in order to further increase the electron injection efficiency, an electron injection layer containing an alkali metal such as lithium fluoride or lithium oxide having a thickness of about 0.5 nm is formed on the organic light emitting layer (7) or the electron transport layer (7). Forming between 8) and cathode (10) is also performed.

In the device manufactured as described above, holes and electrons are injected into the light emitting layer by applying a DC low voltage of about 3 V or more using the transparent electrode side as an anode, and emit light by recombination.

In the light emitting device formed as described above, 12
A luminance of 1000 cd / m ² or more can be obtained by applying a DC voltage of about V.

However, DCM has a light emission peak wavelength of about 585 nm, and further has a longer light emission wavelength.
Even 2 and DCJTB had a problem that the emission peak wavelength was about 620 nm, and the emission spectrum contained a lot of components of 600 nm or less, so that it looked orange.

In addition, DCM and DCM2 have a problem in that, during synthesis, two molecules of an aldehyde component react with a methyl group as in (Chem. 8), resulting in an infrared-emitting, difficult-to-separate impurity that lowers luminous efficiency.

[0022]

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Therefore, a new red light-emitting element having high luminous efficiency, having a longer-wavelength emission spectrum peak, and free from quenching impurities which are difficult to separate during synthesis has been demanded.

[0024]

SUMMARY OF THE INVENTION The present invention relates to a conventional DC
The M-based red light-emitting material solves the problem of quenching impurities that are difficult to separate due to orange light emission. Also, a red organic phosphor having a longer wavelength red light emission peak and a red light emitting organic thin film light emitting element have been developed. It was made for the purpose of providing.

[0025]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has an organic thin-film light-emitting device comprising a phosphor represented by the general formula 1 in a light-emitting layer; This is a phosphor composed of the phosphor indicated by No. 2.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION As specific examples of the phosphor represented by the general formula 1, there can be mentioned the phosphors represented by the following formulas (9) to (15). Further, specific examples of the phosphor represented by the general formula 2 include compounds represented by the following formulas (10) to (15).

[0027]

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[0028]

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[0029]

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[0030]

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[0031]

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[0032]

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[0033]

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These phosphors extend the conjugation and increase the fluorescence wavelength.
Benzopyran ring introduced for longer wavelength
And Further, it is represented by (Chem. 10) to (Chem. 15).
Phosphors have sterically large aromatic groups so that they are difficult to crystallize.
Amine or R_Four~ R _FiveTo introduce an aromatic substituent into
ing.

These phosphors are 4-dicyanomethylidene
It can be easily synthesized by Knoevenagel condensation of 2-methyl-chromone with the corresponding monoaldehyde compound. Since 4-dicyanomethylidene-2-methyl-chromone has only one active methyl group, it reacts only with the monoaldehyde compound at a ratio of 1: 1 and does not generate quenching impurities which are difficult to separate during synthesis.

The phosphor compound represented by the general formula 2 can be dispersed in a transparent resin and used as a phosphor for a wavelength conversion filter, in addition to a phosphor for an organic EL.

These phosphors can be used as a material having a red emission peak wavelength, and can be used alone or in combination of two or more.

Hereinafter, the organic thin-film light emitting device of the present invention will be described with reference to FIGS. 1 to 3.

FIG. 1 shows an organic thin-film light-emitting device according to the present invention, in which an anode (2), a hole injection / transport layer (3), an organic light-emitting layer (7), a cathode (10), an insulating seal are provided on a substrate (1). This is an example of a case where the sealing layer (11) is formed in the order of the stop layer (11), and the sealing plate (13) is adhered and sealed with an adhesive material (12).

The hole injecting / transporting layer is usually composed of 1 to 3 layers. When the layer is composed of 3 layers, the value of the ionization potential of each layer is anode <first hole injecting / transporting layer <second hole injecting / transporting layer. By disposing the third hole injection / transport layer in the order of <organic light emitting layer, the efficiency of hole injection into the organic light emitting layer (7) is improved, and EL light emission can be obtained at a low voltage.

FIG. 2 further shows that between the organic light emitting layer (7) and the cathode (10), at the interface between the organic light emitting layer and the organic light emitting layer, the efficiency of electron injection into the light emitting layer is increased, or the flow of holes to the cathode is suppressed. This is a case where an electron transport layer (8) having an effect is provided.

FIG. 3 shows a case in which the light emitting layer has a multilayer structure. An anode (2), a hole injection / transport layer (3), a blue organic light emitting layer (17), and a green organic light emitting layer are formed on a substrate (1). Light-emitting layer (1
8), a red organic light emitting layer (19), an electron transport layer (8), a cathode (10), an insulating sealing layer (11), and a sealing plate (13) with an adhesive material (12). This is an example in which the structure is bonded and sealed, and a mixed emission of blue, red, and green can be obtained.

A similar structure can be formed on the substrate in the reverse order from the cathode.

Hereinafter, the method of manufacturing the material and the device will be described in more detail.

The substrate (1) uses a transparent insulating material such as a plastic film such as glass or polyethersulfone. The substrate (1) may be colored to improve contrast and resistance, or may be a circularly polarized light filter, a multilayer antireflection filter, an ultraviolet absorption filter, an RGB color filter,
A fluorescent wavelength conversion filter, a silica coating layer and the like may be provided on the inner and outer surfaces.

The anode (2) usually has a surface resistance of 1 to 50Ω.
/ □, using a transparent electrode having a visible light transmittance of 70% or more.

For example, in the case of ITO (work function 4.6 to 4.8)
eV) an amorphous or microcrystalline transparent conductive film of zinc aluminum oxide, or silver or copper, or an alloy layer of silver and copper, having a thickness of about 10 nm to reduce resistance, using ITO, indium-zinc composite oxide, A film having a structure sandwiched by an amorphous or microcrystalline transparent conductive film such as titanium or tin oxide is formed on a transparent insulating substrate (1) such as a glass or plastic film by a vacuum deposition or sputtering method to form a transparent electrode. It is desirable to use as.

When used in a simple matrix drive display, it is necessary to provide a metal bus line made of a low-resistance metal such as Cu or Al in contact with the line of the transparent electrode to further reduce the resistance.

In addition, a translucent electrode in which gold or platinum is thinly deposited or a translucent electrode in which polyaniline, polypyrrole, polythiophene or the like is coated with a low-resistance conductive polymer doped with a Lewis acid can be used.

However, in other cases, the anode (2) may be opaque. In this case, a metal plate such as gold, platinum, palladium, nickel or the like having a large work function for easily injecting holes into the organic light emitting layer (7) through the hole injecting and transporting layer (3) is provided on the anode (2). Using a semiconductor substrate of silicon, gallium phosphide, amorphous silicon carbide, copper oxide, or the like having a work function of 4.6 eV or more, or a substrate in which the metal or semiconductor is coated on an insulating substrate (1), and a cathode (10)
Is a transparent electrode or a translucent electrode. If the cathode (10) is also opaque, at least one end of the organic light emitting layer (7) needs to be transparent.

Next, a hole injection / transport layer (3) is formed on the anode (2). The hole injection transport layer (3) is made of NPD, CuP
and low-molecular-weight hole injection / transport materials such as metal phthalocyanines such as c and chlorinated copper phthalocyanine, metal-free phthalocyanines, N, N'-dimethylquinacridone, compounds represented by the following formulas (16) and (17), and poly ( It can be selected from polymeric hole transport materials such as para-phenylene vinylene) and polyaniline, other existing organic hole transport materials, and inorganic semiconductor films such as p-type silicon carbide film and p-type diamond film.

[0052]

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[0053]

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The hole injecting and transporting layer may be formed as a single layer or a multilayer by a dry method such as a vacuum evaporation method and a sublimation transfer method, a wet method such as a spin coating method, a dip coating method, a roll coating method and an ink jet method, and a CVD method. A film can be formed.

Next, an organic light emitting layer (7) is formed on the hole injection / transport layer (3).

The organic light emitting layer (4) is a layer containing one or more kinds of arbitrary phosphors having strong fluorescence in the visible region, and has a strong fluorescence in a solid state, can form a smooth film, and has good film formability. Can form the organic light emitting layer (7) only with a phosphor, but when the fluorescence is quenched in a solid state or when a smooth film cannot be formed, a smooth film can be formed as a guest compound and the film forming property can be improved. It can be used by dispersing it in an appropriate concentration in a host compound composed of a good hole injecting and transporting material or an electron injecting and transporting material or in an appropriate resin binder.

In the light emitting device of the present invention, the organic light emitting layer (7)
Among them, the phosphor compounds represented by the general formulas 1 and 2 can be used as a guest compound or a host compound.

When the compound represented by the general formula 1 is used as a guest compound or a host compound, examples of the phosphor that can be used as the host compound include 450 nm to 450 nm.
A phosphor film having a fluorescence peak wavelength at 600 nm can be used. Further, it is desired that the guest material has an oxidation potential equal to or higher than the oxidation potential of the guest material and a reduction potential equal to or higher than the absolute value of the reduction potential of the guest material. Examples of phosphors that can be used as a host material include Alq and Tris (8-
(Quinolinolate) scandium complex, bis (10-hydroxybenzo [h] quinolinolate) represented by (Formula 18)
Examples of the beryllium complex and other materials shown in (Chemical Formula 19) to (Chemical Formula 21) are given.

[0059]

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[0060]

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[0061]

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[0062]

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These organic light emitting layer materials can be formed by vacuum evaporation, cumulative film, sublimation transfer, ink jet, or by dispersing in a suitable resin binder and coating by a method such as spin coating. .

The thickness of the organic light emitting layer (7) is 100 nm or less, preferably 5 to 50 nm even when it is formed as a single layer or a laminate.

Further, the organic light emitting layer (7) can be formed in multiple layers. For example, on the hole injecting and transporting layer (3), a film containing 1% of the phosphor represented by the general formula 1 as a guest molecule (Chemical Formula 9) is formed on a 10 to 30 nm film (Chemical Formula 22) or (Chemical Formula 2).
A film made of the compound shown in 3) is formed in a thickness of 10 to 30 nm,
Further, when an Alq film is formed to a thickness of 10 to 30 nm to form an organic light emitting layer (7) composed of three layers, a white EL including red, blue, and green emission wavelengths can be obtained.

[0066]

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[0067]

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Next, when the electron transporting layer (8) is laminated on the organic light emitting layer (7), preferable conditions for the material of the electron transporting layer are good film forming properties, high electron mobility, and low LUMO state density. It is large, and the LUMO energy level is between the same level as the LUMO energy level (reduction potential) of the organic light emitting layer material and the Fermi level (work function) of the cathode material, and more desirably, the ionization potential (oxidation potential) is organic light emission. The hole blocking property is higher than that of the layer material.

Further, in an element in which the anode (2) is opaque and light is extracted from the transparent or translucent cathode (5), it must be substantially transparent at least in the fluorescent wavelength region of the organic light emitting layer material.

Examples of the electron transport layer include compounds represented by the following formula (18), triazole compounds described in JP-A-7-90260, compounds represented by the following formula (24), hexadecafluorocopper phthalocyanine, bathocuproine, Examples thereof include a charge transfer complex of an organic light emitting material that emits ultraviolet to blue light and an alkali metal, an alkaline earth metal, or a rare earth metal, inorganic semiconductors such as silicon carbide and amorphous silicon films, and photoconductive films.

[0071]

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When the light emitting layer is formed by doping the guest light emitting body into the host light emitting base material, the host light emitting base material can be used as the electron transport layer.

The electron transport layer (8) is formed by a method such as a vacuum evaporation method, a CVD method, a coating method such as a spin coating method, or a cumulative film method, and has a thickness of 1 nm to 1 μm. It is formed in layers or multilayers.

Next, as the cathode (10), a single metal such as Mg or Al, or in order to achieve both low work function and stability,
Li, Mg, Ca, Sr, La, C with low work function
An alloy system containing one or more metals such as e, Er, Eu, Sc, Y, and Yb is used.

When Al is used for the cathode, an electron injection layer of about 0.5 nm containing an alkali metal such as lithium fluoride, lithium oxide, an organic lithium salt, or a lithium-containing organic metal is used to increase the electron injection efficiency. It is also formed between the layer (7) or the electron transport layer (8) and the cathode (10).

Depending on the material, the cathode may be formed by a resistance heating evaporation method, an electron beam evaporation method, a reactive evaporation method, an ion plating method, or a sputtering method using an alloy target. A thickness of about 1000 nm is formed on the organic light emitting layer (7) or the electron transport layer (8).

When the cathode is formed in a stripe shape,
Cathode metal patterning is performed by a cathode partition separation method, a mask evaporation method, an ion beam etching method, a reactive etching method, or the like.

Next, in order to prevent oxidation of the organic layers and electrodes of the device,
Next, an insulating sealing layer (11) is formed on the element. Insulation sealing layer
(11) is formed immediately after the formation of the cathode (10). Absolute
Examples of the edge sealing layer material include SiO_Two, SiO, Ge
O, MgO, CaO, Al_TwoO _Three, B_TwoO_Three, Ti
O_TwoOxides such as ZnO, SnO, etc.
Stoichiometric ratio), MgF_Two, Li
F, BaF_Two, AlF_Three, FeF_ThreeEtc., Si,_Three
N_FourInorganic materials such as nitride, parylene and polyethylene
And other organic polymer materials.
However, the present invention is not limited to the above example. These can be used alone or
Is a composite or multi-layer deposition method, reactive deposition method, C
VD method, sputtering method, ion plating method, etc.
To form a film.

To further improve the water vapor barrier performance, a metal such as Al or In is laminated on the insulating sealing layer (11).

In order to prevent corrosion of the cathode, Li was formed on the cathode, in the sealing layer, or on the surface in contact with the sealing layer as a sacrificial anticorrosion layer.
Such as alkali metals and alkaline earth metals such as Ca and Mg,
A layer of a rare earth metal such as Yb may be provided, or a mixed layer of a sealing inorganic compound and those metals may be provided.

Further, in order to prevent moisture from penetrating, the substrate of the light emitting element is sealed in a vacuum with a hermetic seal, or a commercially available low moisture-absorbing photo-curable adhesive, epoxy-based adhesive, silicone-based adhesive, Using an adhesive resin such as an ethylene-vinyl acetate copolymer adhesive sheet or an adhesive material (12) such as low-melting glass, the periphery of a sealing plate (13) such as a metal plate or a glass plate is adhered and sealed. In addition to a glass plate, a metal plate or the like can be used if a laminate material of a metal foil and a plastic film or an adhesive containing insulating spacer beads is used. A layer or sheet of a desiccant such as calcia or barium oxide or a getter material made of an alkali metal, an alkaline earth metal, a rare earth, zirconia, or the like may be placed on the sealing layer or inside the sealing plate (13).

The organic thin-film light-emitting device constructed as described above emits light when the positive hole injection transport layer (3) is connected to the power supply (14) via the lead wire (15) and a DC voltage is applied. Even when an AC voltage is applied, light is emitted while the electrode on the hole injection / transport layer (3) side is positively applied with a voltage.

By arranging the organic thin film light emitting devices according to the present invention two-dimensionally on a substrate, a thin display capable of displaying characters and images can be obtained.

A three-color light-emitting element can be arranged two-dimensionally in combination with blue and green light-emitting elements, or a color display can be realized by using a white light-emitting element and a color filter.

[0085]

EXAMPLES <Example 1> The synthesis of Chemical formula 10 is shown below. 2-
After dissolving 22.40 g (140 mmol) of methylchromone and 9.44 g (143 mmol) of malononitrile in 200 ml of acetic anhydride, the mixture was reacted under reflux for 3 hours while stirring under nitrogen.
After distilling off acetic acid and acetic anhydride, 300 ml of hot water was added.
After cooling to room temperature, 26.58 g of a black solid was obtained by filtration. Ethyl acetate / hexane (1: 3) was used as eluent to obtain 8.74 g (42 mmol) of 4-dicyanomethylidene-2-methyl-chromone by silica gel column chromatography. 30% isolated yield.

1.25 g (6 mmol) of 4-dicyanomethylidene-2-methyl-chromone and 1.79 g (6.54 mmol) of 4-diphenylaminobenzaldehyde were dissolved in 130 ml of toluene, and 2.8 ml of piperidine and 1.4 ml of acetic acid were dissolved. After the addition, the reaction was carried out under reflux for 8 hours while distilling off generated water using a Dean-Stark trap under stirring under nitrogen. After cooling the reaction mixture to room temperature, a brown solid was removed by filtration, and the filtrate was concentrated to dryness. Piperidine-acetate was sublimated and removed with a vacuum dryer. In addition, ethyl acetate / hexane (3:
Silica gel column chromatography was performed using 7) as an eluent to obtain 0.97 g of a dark brown compound of the formula (10). Isolation yield 35 mol%. 233.5-235.4 ° C. It was identified by mass spectrum and NMR. FIG. 4 shows the proton NMR spectrum of this compound. The ionization potential measured with a surface analyzer AC-1 manufactured by Riken Keiki Co., Ltd. was 5.6 eV,
Absorption edge wavelength is 622nm (2.0eV), glass transition temperature 88 ℃
Met.

<Example 2> The deposition rate of Alq was 0.2 nm /
The vapor deposition rate of the compound represented by Chemical Formula 9 was set to about 1% of the vapor deposition rate of Alq, and co-deposition was performed to a thickness of about 40 nm. FIG. 5 shows the fluorescence spectrum of the obtained film.

Example 3 The deposition rate of Alq was 0.2 nm /
sec, and the deposition rate of the compound represented by the formula (10) is Alq
Was co-deposited to a thickness of about 40 nm while changing the deposition rate to about 2%. The fluorescence spectrum of the obtained film is shown by the solid line in FIG.
The dashed line indicates the fluorescence spectrum of a single film of the compound represented by Chemical Formula 10 at about 44 nm. The fluorescence peak wavelength can be increased to about 690 nm by increasing the ratio of (Formula 10) in Alq.

Example 4 As a transparent insulating substrate (1), a 1.1 mm-thick blue glass plate was used.
Anode (2) was formed by coating ITO of 0 nm by a sputtering method. This transparent conductive substrate was sufficiently washed with water and plasma before use.

The hole injecting and transporting layer was first made of Aldrich CuPc to a thickness of 10 nm as the first hole injecting and transporting layer (4).
Vacuum deposited to form a second hole injection / transport layer (5)
The hole transporting material shown in 6) was vacuum deposited to a thickness of 30 nm. Further, NPD was used as a third hole injection / transport layer (6).
Vacuum deposited with a thickness of 0 nm.

Next, Alq and the compound represented by the formula (9) were deposited as an organic light emitting layer (7) at a deposition rate ratio of 100: 1.5 to a thickness of 40 nm, and 10 nm of Alq was deposited as an organic electron transporting layer (8).
m was deposited.

On the upper surface, LiF was formed as an electron injection layer (9).
Was deposited to a thickness of 0.5 nm, and Al was added as a cathode (10) to a thickness of 200 nm.
nm.

Next, germanium oxide was deposited in a thickness of 1 μm under Ar plasma as an insulating sealing film (11), and Al was deposited in a thickness of 200 nm as a pinhole prevention film (20).

Finally, a cover glass (13) washed with plasma under dry nitrogen was attached with a photosensitive adhesive (12).

This element has a peak wavelength of about 655 at a voltage of 4 V or more when a voltage is applied by connecting the anode and the cathode to a DC power supply.
It emitted red light of 15 nm and obtained a maximum luminance of 3000 cd / m ² or more at 15 V.

<Example 5> A light emitting device was manufactured in the same manner as in Example 4, except that (Formula 10) was used instead of (Formula 9). 15V
And emitted red light in the same manner.

<Example 6> As a transparent insulating substrate (1), a blue glass plate having a thickness of 1.1 mm was used.
Anode (2) was formed by coating ITO of 0 nm by a sputtering method. This transparent conductive substrate was sufficiently washed with water and plasma before use.

The hole injecting / transporting layer was first made of Aldrich CuPc of 14 nm as the first hole injecting / transporting layer (4).
Vacuum deposited to form a second hole injection / transport layer (5)
The hole transport material shown in 7) was spin-coated with a thickness of 48 nm.

Next, Alq and the compound represented by the formula (11) were used as the organic light emitting layer (7) at a deposition rate ratio of 100: 2 to 50 nm.
Evaporated.

On the top surface, LiF was added as an electron injection layer to a thickness of 0.1 μm.
5 nm was deposited, and 200 nm of Al was deposited as a cathode (10).

Next, germanium oxide was deposited to a thickness of 1 μm under Ar plasma as an insulating sealing film (11), and Al was deposited to a thickness of 200 nm as a pinhole prevention film.

Finally, the cover glass which has been plasma-cleaned under dry nitrogen is used as a sealing plate (13) as a photosensitive adhesive (12).
Pasted in.

This device has a peak wavelength of about 650 at a voltage of 4 V or more when a voltage is applied by connecting the anode and the cathode to a DC power supply.
It emitted red light of 15 nm and obtained a maximum luminance of 726 cd / m ^{2 at} 15 V.

<Examples 7 to 10> When a light emitting device was manufactured using (Chemical Formulas 12) to (Chemical Formula 15) in place of (Chemical Formula 9) in Example 4, red light emission was similarly obtained.

[0105]

The phosphor according to the present invention can obtain a red emission peak having a longer wavelength than the conventional DCM phosphor.
A red organic thin-film light-emitting element having high luminance and good color purity can be provided.

[0106]

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one embodiment of an organic thin film light emitting device of the present invention.

FIG. 2 is an explanatory view showing another embodiment of the organic thin film light emitting device of the present invention.

FIG. 3 is an explanatory view showing another embodiment of the organic thin film light emitting device of the present invention.

FIG. 4 is an explanatory diagram showing a proton NMR spectrum of Chemical Formula 10.

FIG. 5 is an explanatory diagram showing a fluorescence spectrum of Chemical formula 9.

FIG. 6 is an explanatory diagram showing a fluorescence spectrum of a co-deposited film of Chemical Formula 10 and Alq.

[Explanation of symbols]

 (1) substrate (2) anode (3) hole injection / transport layer (7) organic light emitting layer (8) electron transport layer (10) cathode (11) insulating sealing layer (12) Adhesive material layer (13) Sealing plate (14) Power supply (17) Blue organic light emitting layer (18) Green organic light emitting layer (19) Red organic light emitting layer

Continuation of the front page (72) Kan Yoshida, Inventor F-term (reference), 1-5-1, Taito, Taito-ku, Tokyo 3K007 AB02 AB04 BB01 CA01 CB01 DA01 DB03 EB00

Claims (2)

[Claims] 1. An organic thin-film light-emitting device comprising at least one organic thin-film layer including at least an organic light-emitting layer between electrodes opposed to each other, wherein a phosphor having a structure represented by the following general formula 1 is used. An organic thin-film light-emitting element, which is contained in a thin-film layer. Embedded image (Where R ₁ and R ₂ are each independently an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, an isopropyl group, a tertiary butyl group, or an aryl group such as a phenyl group, a tolyl group, a naphthyl group, Or a carbocyclic or heterocyclic system or a biphenylene group to which R ₁ and R ₂ are bonded;
₁ and R ₂ form a carbazole ring containing a bonded nitrogen atom. R ₃ and R ₄ are each independently hydrogen, a phenyl group, a biphenyl group or a naphthyl group. R ₅ and R ₆ are each independently hydrogen, a phenyl group, or a biphenyl group. ) 2. It has a structure represented by the general formula 2.
Phosphor to be featured. Embedded image(Where R₁, R_TwoIs phenyl, tolyl, naphthyl
Aryl group such as phenyl group, or carbocyclic or heterocyclic system
Or R₁, R_TwoIs a bonded biphenylene group, and R
₁, R_TwoForms a carbazole ring containing a nitrogen atom
To achieve. R_Three, R _FourAre independently hydrogen or phenyl,
It is a phenyl group or a naphthyl group. R_Five, R₆Is independent
Represents hydrogen, a phenyl group, or a biphenyl group. )