JPH08288064A - Manufacture of organic electroluminescent element - Google Patents

Abstract

PURPOSE: To easily manufacture a multi-color organic electroluminescent element, of which light emitting efficiency is remarkably improved, by manufacturing an organic electroluminescent layer, which is interposed between a positive electrode and a negative electrode, with a lift-off method using a dry film resist. CONSTITUTION: A positive electrode 2, positive hole transporting layers 3, 3', 3'' as an organic light emitting layer, an electron transporting layer 4, and a negative electrode 5 are laminated in this order on a substrate 1 such as glass. The positive electrode 2 is made of indium oxide or the like, and performs positive hole billing in the organic light emitting layer. The positive hole transporting layer 3 is made of the aromatic diamine compound such as 1,1-bis(4- di-p-tolylaminophenyl)cyclohexane having a large mobility of positive hole. The electron transporting layer 4 is made of the aromatic group compound such as tetraphenyl buthadiene with high efficiency of electron filling from the negative electrode 5. The negative electrode 5 is made of metal such as beryllium having a low work function. In the case of changing color in the electron transporting layer 4, the lift-off method using the dry film resist is used for manufacturing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescence device, and more particularly, to a thin film type device which emits light by applying an electric field to a light emitting layer made of an organic compound.

[0002]

2. Description of the Related Art Conventionally, as a thin film type electroluminescent (EL) element, Z which is a II-VI group compound semiconductor of an inorganic material has been used.
In general, nS, CaS, SrS, etc. are doped with Mn or a rare earth element (Eu, Ce, Tb, Sm, etc.), which is the emission center, but EL elements made from the above inorganic materials are 1). AC drive is required (50 to 1000 Hz), 2) high drive voltage (up to 200 V), 3) full colorization is difficult (especially blue is a problem), and 4) peripheral drive circuit costs are high. ing.

However, in recent years, in order to improve the above problems,
EL devices using organic thin films have been developed. In particular, the electrode type was optimized for the purpose of improving the efficiency of carrier injection from the electrode in order to increase the light emission efficiency, and the organic hole transport layer made of an aromatic diamine and the organic light emission made of an aluminum complex of 8-hydroxyquinoline. Of an organic electroluminescent device having a layer (Appl. Phy
s. Lett. , 51, p. 913, 1987), the luminous efficiency has been greatly improved as compared with the conventional EL device using a single crystal such as anthracene, and is close to practical characteristics.

However, when manufacturing a multicolor panel, a big problem is how to arrange elements having different emission colors. As a method for manufacturing a multicolor panel, a wall having a thickness larger than that of an organic electroluminescent element is provided between pixels, and when the luminescent material is vapor-deposited, the shadow of the wall is utilized by forming an angle between the source and the substrate. Vapor deposition method (Japanese Patent Laid-Open No.
No. 258859) has been reported, but the problem is that the spread of the source must be suppressed in order to make it uniform, the deposition rate becomes slow, and the substrate angle must be adjusted accurately. Becomes As described above, the current level is that the organic electroluminescent device has not reached a practical level in terms of multicoloring.

[0005]

However, the method of manufacturing an organic electroluminescent device disclosed thus far has a drawback that it is difficult to manufacture a multicolored panel.

[0006]

In view of the above situation, the inventors of the present invention have conducted extensive studies for the purpose of producing organic electroluminescent elements having different emission colors on the same substrate, and as a result, an anode and an anode are formed on the substrate. In an organic electroluminescent device having at least an organic light emitting layer between cathodes, when producing devices having different emission colors on a substrate, the emission color is changed by doping a dye, and the organic light emission is performed using a dry film resist. The inventors have found that it is preferable to form the layer by a lift-off method, and have completed the present invention.

That is, the gist of the present invention is an organic electroluminescent device having at least an organic light emitting layer between an anode and a cathode, which is provided on a substrate, and on which a device having different emission colors is provided. In manufacturing such an organic electroluminescent device, there is provided a method for manufacturing an organic electroluminescent device, characterized in that an organic light emitting layer having a changed emission color is manufactured by a lift-off method using a dry film resist.

The organic electroluminescent device of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view schematically showing a structural example of a three-color organic electroluminescence device of the present invention, in which 1 is a substrate, 2 is an anode, 3 3 ′ and 3 ″ are organic hole transport layers, 4 Represents an organic electron transport layer, and 5 represents a cathode.

The substrate 1 serves as a support for the organic electroluminescent device of the present invention, and a plate of quartz or glass, a metal plate or metal foil, a plastic film or sheet, etc. are used, and particularly, a glass plate, polyester, A transparent synthetic resin plate such as polymethylmethacrylate, polycarbonate, or polysulfone is preferable.

An anode 2 is provided on the substrate 1. Anode 2
Plays a role of injecting holes into the organic light emitting layer.
This anode 2 is usually a metal such as aluminum, gold, silver, nickel, palladium, platinum, a metal oxide such as an oxide of indium and / or tin, copper iodide, carbon black, or poly (3-methyl). (Thiophene), polypyrrole, polyaniline and other conductive polymers. Of these, an anode made of an oxide of indium and / or tin is particularly preferable. The thickness of the anode 2 varies depending on the required transparency, but when the transparency is required, it is desirable that the visible light transmittance is 60% or more, preferably 80% or more. Is usually 5 to 1000 nm, preferably 10 to 500
It is about nm.

[0011] These anodes are
Usually some kind of cleaning is performed. For example, after cleaning with a commercially available detergent, ultrasonic cleaning is performed with deionized water and isopropyl alcohol (hereinafter abbreviated as IPA), and finally exposed to toluene vapor (JP-A-4-233195), medium. After cleaning with a mild detergent, acetone, IPA
Ultrasonic cleaning is performed therein, and finally, it is immersed in boiling IPA and naturally dried (Japanese Patent Application Laid-Open No. 5-299174). In addition to this, plasma treatment (Japanese Patent Laid-Open No.
-135877), ultraviolet / ozone cleaning (JP-A-6-88072), and the surface of the anode is treated with an acid (JP-A-4-14795).

An organic light emitting layer is laminated on the substrate thus treated. Hereinafter, the case where the organic hole transport layer is composed of an organic hole transport layer and an organic electron transport layer and emits light will be described as an example, but the present invention is not limited thereto.
Further, in the case where charge injection and transport are separated, the configuration shown in FIG. 2 can be adopted. Hereinafter, description will be given with reference to FIG. The hole injection layers 3 a, 3 are formed on the anode 2.
a ′, 3a ″ are provided. The conditions required for the material used for the hole injecting layer are that it can form a uniform thin film with good contact with the anode and is thermally stable, that is, its melting point or glass transition temperature. Is required, the melting point is 300 ° C. or higher, and the glass transition temperature is 100 ° C. or higher.In addition, the ionization potential is low, hole injection from the anode is easy, and the hole mobility is high. Examples of these materials include porphyrin derivatives (Japanese Patent Laid-Open No. 63-295695) and starburst type amines (Proceedings of the 54th Annual Meeting of the Applied Physics Society of Japan, 29p-A).
C-15) and the like are used. Further, if sufficient characteristics can be obtained without the hole injection layer, this layer can be partially or entirely omitted. 3a, 3a ', 3a "
May be the same substance or different substances.

Hole transport layers 3b, 3b 'and 3b "are formed on the hole injection layer or the anode. The hole transport layer has a large hole mobility and further stability. Excellent,
Impurities that become traps are required to be less likely to occur during manufacturing or use. As such a hole transport material,
For example, an aromatic diamine compound in which a tertiary aromatic amine unit such as 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane is linked (JP-A-59-1943).
No. 93), 4,4′-bis [N- (1-naphthyl).
Aromatic amines containing two or more tertiary amines represented by -N-phenylamino] biphenyl and having two or more condensed aromatic rings substituted with nitrogen atoms (Japanese Patent Laid-Open No. 234681/1993), triphenylbenzene Derivatives of Aromatic Triamines with Starburst Structure (US Pat.
3,774), aromatic diamines such as N, N'-diphenyl-N, N'-bis (3-methylphenyl) biphenyl-4,4'-diamine (US Pat. No. 4,764,62).
No. 5), α, α, α ′, α′-tetramethyl-α, α ′
-Bis (4-di-p-tolylaminophenyl) -p-xylene (JP-A-3-269084), triphenylamine derivative which is sterically asymmetric as a whole molecule (JP-A-4-12971), pyrenyl A compound in which a plurality of aromatic diamino groups are substituted in the group (Japanese Patent Laid-Open No. 4-17539).
5), an aromatic diamine in which a tertiary aromatic amine unit is linked by an ethylene group (JP-A-4-264189), and an aromatic diamine having a styryl structure (JP-A-4).
No. 290851), one in which an aromatic tertiary amine unit is linked by a thiophene group (JP-A-4-304466).
No. 3), a starburst type aromatic triamine (JP-A-4-308688), a benzylphenyl compound (JP-A-4-364153), and a fluorene group containing 3
A compound in which a primary amine is linked (JP-A-5-25473), a triamine compound (JP-A-5-239455), and bisdipyridylaminobiphenyl (JP-A-5-3).
20634), N, N, N-triphenylamine derivatives (JP-A-6-1972), aromatic diamines having a phenoxazine structure (Japanese Patent Application No. 5-290728).
No.), a diaminophenylphenanthridine derivative (Japanese Patent Application No. 6-45669), a hydrazone compound (Japanese Patent Application Laid-Open No. 2-311591), and a silazane compound (US Pat. No. 4,950,950).
Gazette), silanamine derivatives (JP-A-6-49079), phosphamine derivatives (JP-A-6-25659), quinacridone compounds and the like. These compounds may be used alone or, if necessary, may be mixed and used.

In addition to the above compounds, polyvinylcarbazole and polysilane (App
l. Phys. Lett. , 59, 2760, 19
1991), polyphosphazene (JP-A-5-310949)
No.), polyamide (JP-A-5-310949), polyvinyltriphenylamine (Japanese Patent Application No. 5-20).
5377), a polymer having a triphenylamine skeleton (JP-A-4-133605), and a polymer in which triphenylamine units are linked by a methylene group or the like (Synthe).
tic Metals, 55-57, 4163, 1
993), polymethacrylates containing aromatic amines (J. Polym. Sci., Polym. Che.
m. Ed. 21: pp. 969, 1983).

In order to change the emission color, a dopant is usually used. As the dopant, a dye having a high fluorescence yield such as a scintillation dye, a dye laser dye, or the like is used. For example, merocyanine dyes,
Coumarin dyes, azacoumarin dyes, xanthine dyes, rhodamine dyes, oxazole dyes, benzoxazole dyes, oxadiazole dyes, furan dyes, benzofuran dyes, oligophenylene dyes,
Cyanine dye, acridine dye, azine dye, quinolone dye, azaquinolone dye, pyrazoline dye, phthalimide dye, naphthalimide dye, pteridine dye, condensed polycyclic dye, pigment fluorescent dye, complex dye Can be mentioned. To give a concrete example,
Examples of the red pigment include phenoxazone 9, phenoxazone 660, DCM1, Eu (ttfa) _{3 and} other commonly known pigment groups, and green pigments include quinacridone, coumarin 7, coumarin 540, coumarin 153, Fluorescein 27, Rhodamine 11
No. 0, Rhodamine B, and other commonly known dye groups, and examples of blue dyes include bis-MSB, coumarin 4, coumarin 120, coumarin 2, and coumarin 46.
6, coumarin 102, POPOP, coumarin 339, coumarin 1, coumarin 138, and the like, which are known by popular names, can be given. Dopant concentration is usually 10
^{-3 to} 20% by weight.

The above organic hole transport material and dopant are laminated on the anode or the hole injection layer by a coating method or a vacuum deposition method to form a hole transport layer.
In the case of coating, a coating solution prepared by adding one or more organic hole-transporting compounds and a binder resin that does not become a hole trap, if necessary, and an additive such as a coating property improving agent such as a leveling agent, is dissolved. The organic hole-transporting layer is formed by preparing the composition, coating the same on the anode or the hole-injecting layer by a method such as spin coating, and drying. Examples of the binder resin include polycarbonate, polyarylate, polyester and the like. The addition amount of the binder resin decreases the hole mobility when it is added in a large amount. Therefore, it is preferable that the addition amount is 50% by weight or less. Further, when the hole injection layer is present, it is necessary to properly select the solvent so that the solvent used does not reduce the surface roughness of the hole injection layer.

In the case of the vacuum vapor deposition method, the hole transport material is put in a crucible installed in a vacuum container, and the inside of the vacuum container is about 10 ⁻⁶ Torr (about 10 ⁻⁴ Pa) with an appropriate vacuum pump.
After evacuating to 0, the crucible is heated to evaporate the hole transport material and form a layer on the substrate placed facing the crucible.

When forming the hole transport layer as described above, patterning is performed by the lift-off method using a dry film resist. The dry film resist is a film-shaped resist having a property of being capable of patterning by changing properties when irradiated with radiation such as light, and has a feature that it does not require a solvent. The dry film resist generally contains a polymer binder, an addition polymerizable unsaturated compound and a photopolymerization initiator as essential components. The polymer binder is a component that imparts film properties to the resist, and an acrylic copolymer or the like is used.
The polymer binder is usually copolymerized with a carboxyl group-containing monomer such as acrylic acid, methacrylic acid or itaconic acid in order to have alkali developability. Other copolymerization components include various monofunctional vinyl compounds such as acrylic acid alkyl esters and methacrylic acid alkyl esters. The addition-polymerizable compound is a compound that is polymerized by irradiation with radiation such as light, and is, for example, a (meth) polyol such as ethylene glycol di (meth) acrylate.
Acrylic esters, (meth) acrylamides such as methylenebis (meth) acrylamide, compounds containing urethane groups such as di (2-methacryloxyethyl) -2,4-tolylenediurethane, bisphenol A-epichlorohydrin type epoxy resin Examples thereof include (meth) acrylic acid esters modified and induced from bisphenol A such as a reaction product of a prepolymer and (meth) acrylic acid. Photopolymerization initiators are components that generate active radicals by absorption of radiation such as light, and are roughly classified into intramolecular cleavage type and charge transfer complex type. The intramolecular cleavage type is a type in which radicals are generated by cleavage in the molecule by light energy, and 1-phenyl-1,2-propanedione-o-benzoyloxime and 2,2-diethoxyacetophenone are exemplified. it can. The charge transfer complex type is a type in which an electron donor and an electron acceptor form a complex in an excited state, and finally a radical is generated by a hydrogen abstraction reaction. As an electron donor, 4,4′-bis ( Examples of the amines include diethylamino) benzophenone (DEABP), dimethylaminobenzoic acid alkyl ester, methyldiethanolamine and triethylamine, and examples of the electron acceptor include benzophenone (BP) and thioxanthone. A typical combination of an electron donor and an electron acceptor includes a set of DEABP and BP. Such a dry film resist is available under the trade name of Liston 472.
0, Liston 4713 (Dupont), Audil A
P-938, Audil AF-725 (manufactured by Tokyo Ohka Kogyo Co., Ltd.), Nigo ALPOH 1050 (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) and the like are commercially available.

Hereinafter, the hole transport layer 3 will be described with reference to FIG.
b, 3b ′, 3b ″ will be described. First, the anode (3-2) is patterned in a stripe pattern on the substrate (3-1) (FIG. A), and then the dry film resist (3) is formed. -3) is laminated (FIG. B), a desired pattern is exposed and developed (FIG. C), and the first hole transport layer (3-4) is laminated thereon (FIG. D). The resist is peeled off to form the first hole transport layer 3b (E
Figure). Next, a protective layer is vapor-deposited if necessary. This protective layer is a layer used for the purpose of protecting the hole transport layer from sticking to the dry film resist and preventing the hole transport layer from peeling from the substrate at the time of peeling. Those that are easily dissolved are preferred. Examples of the material of the protective layer include a metal complex of 8-hydroxyquinoline and a metal complex of oxadiazole. Following this, the dry film resist is laminated again, and the second hole transport layer 3 is subjected to the same steps.
b ′ and the third hole transport layer 3b ″ are formed. In the case of producing one having two emission colors, it is sufficient to form up to the second hole transport layer, and in the case of four or more colors, the emission color The number of hole transport layers is formed according to the number.

An electron transport layer 4 is provided on the hole transport layers 3b, 3b ', 3b "(see FIG. 2).
Is formed of a compound capable of efficiently transporting electrons from the cathode 5 in the direction of the hole transport layers 3b, 3b ′, 3b ″ between the electrodes to which an electric field is applied.

The organic electron transport compound needs to be a compound having a high electron injection efficiency from the cathode 5 and capable of efficiently transporting the injected electrons. For that purpose, it is required that the compound has a high electron affinity, a high electron mobility, excellent stability, and an impurity that becomes a trap and is less likely to be generated at the time of production or use.

As a material satisfying such a condition, an aromatic compound such as tetraphenyl butadiene (Japanese Patent Application Laid-Open No. Sho 5 (1999) -58138)
7-51781), a metal complex such as an aluminum complex of 8-hydroxyquinoline (JP-A-59-1943).
93), a cyclopentadiene derivative (JP-A-2-
289675), perinone derivatives (JP-A-2-2)
No. 89676), an oxadiazole derivative (JP-A-2-216791), and a bisstyrylbenzene derivative (JP-A 1-245087, 2-222248).
4), perylene derivative (JP-A-2-189890).
JP-A No. 3-791, JP), coumarin compound (JP-A-2-191694-, JP-A-3-792), rare earth complex (JP-A-1-256584), distyrylpyrazine derivative (JP-A-2). -252793),
p-phenylene compound (JP-A-3-33183), thiadiazolopyridine derivative (JP-A-3-372)
92), a pyrrolopyridine derivative (JP-A-3-37).
293), naphthyridine derivatives (JP-A-3-20).
3982).

The electron transport layer 4 using these compounds is
Although it mainly plays a role of transporting electrons, it may play a role of providing light emission at the same time. The electron transport layer 4 can also be formed by a method similar to that of the hole transport layer 3b, but a vacuum vapor deposition method is usually used.

As a method for further improving the luminous efficiency of the organic electroluminescence device, another electron transport layer 4b may be laminated on the electron transport layer 4a as shown in FIG. The compound used for the electron transporting layer 4b is required to be capable of easily injecting electrons from the cathode and have a higher electron transporting ability. As such an electron transport material,

[0025]

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[0026]

Embedded image

Oxadiazole derivatives such as (App
l. Phys. Lett. , 55, 1489, 19
1989; Jpn. J. Appl. Phys. , 31 volumes,
1812, 1992) or a system in which they are dispersed in a resin such as polymethylmethacrylate (Appl. Phys.
Lett. , 61, 2793, 1992), or n-type hydrogenated amorphous silicon carbide, n-type zinc sulfide, n
Examples include type zinc selenide. The thickness of the electron transport layer 4b is usually 5 to 200 nm, preferably 10 to 100 n.
m.

It is also possible to provide an interface layer 4c between the electron transport layer 4b and the cathode 5 (see FIG. 5). The role of the interface layer is that it has an affinity with the organic light-emitting layer and at the same time has good adhesion to the cathode, and is chemically stable, allowing the reaction between the organic light-emitting layer and the cathode during and / or after formation of the cathode. It has a suppressing effect. It is also important to provide a uniform thin film shape from the viewpoint of adhesion with the cathode.
As a material that plays such a role, an aromatic amine compound (JP-A-5-048075) and a compound having a phenylcarbazole skeleton (Japanese Patent Application No. 6-199562).
No.), polyvinylcarbazole derivative (Japanese Patent Application No. 6-20
0942) and the like.

Further, the interface layer 4c is formed without including the electron transport layer 4b.
A structure including is also possible, and the material used in this case includes the aforementioned substances. When forming the interface layer shown above, these compounds may be mixed and used.
Further, other fluorescent dyes, light emitting materials and the like may be mixed for the purpose of improving the stability of the film of the interface layer. Examples of the materials to be mixed include compounds consisting of aromatic amines, laser dyes such as coumarin derivatives, polycyclic aromatic dyes such as perylene and rubrene, organic pigments such as quinacridone, and 8-hydroxyquinoline metal complexes. Can be mentioned.

A cathode 5 is provided on the electron transport layer or the interface layer. The cathode is required to form a stable film because it is easy to inject electrons into the electron transport layer and the interface layer described above. For this reason, low work function metals are usually used,
Usually, a metal having a work function of 4 eV or less is applied. Preferred metals include beryllium, magnesium, calcium, scandium, titanium, manganese, gallium, indium and the like, particularly preferably magnesium,
Examples include calcium, scandium, and indium.
However, if a low work function cathode is used alone, it is easily oxidized and easily deteriorates. Therefore, these elements usually contain an element having a work function of 4 eV or more as the second metal. The second metal is usually aluminum, vanadium, chromium,
Iron, cobalt, nickel, copper, zinc, germanium, selenium, ruthenium, rhodium, palladium, silver, cadmium, tin, antimony, tellurium, rhenium, osmium, iridium, platinum, gold, lead, bismuth, etc., and preferably. , Aluminum, copper, silver, gold, tin, lead,
Examples include bismuth, tellurium and antimony. It is also possible to further stack a metal on the cathode to stabilize the cathode. Further, as a particularly preferable combination of the cathode and the interface layer, an interface layer containing phenylcarbazole and silver, or a cathode mainly composed of silver can be cited (JP-A-6-199562 and JP-A-6-196562). 22
No. 0343).

The film thickness of the cathode 5 is usually the same as that of the anode 2. Although not shown in FIG. 1, a substrate similar to the substrate 1 may be further provided on the cathode 5. However, it is necessary for at least one of the anode 2 and the cathode 5 to have good transparency as an electroluminescent device. From this, the anode 2
One of the cathode 5 and the cathode 5 preferably has a film thickness of 10 to 500 nm, and is desired to have good transparency.

In the above description, the method of emitting light in the organic hole transporting layer and changing the emission color by doping the organic hole transporting layer with a dye has been described, but the present invention is not limited to this. Instead, for example, a method of causing the hole transport layer to emit light and doping the electron transport layer with a dye to change the color tone, or a method of changing the constituent color of the hole transport layer to change the emission color may be used. However, when the emission color is changed by changing the material of the light emitting layer, the brightness may be different for each color. Therefore, it is more preferable to change the emission color by doping a dye. When the color is changed in the electron transport layer, the electron transport layer is formed by a lift-off method using a dry film resist.

[0033]

EXAMPLES Next, the present invention will be described more specifically by way of examples, but the present invention is not limited to the description of the following examples unless it exceeds the gist. Example 1 An organic electroluminescent device was produced by the following method. 1 Indium tin oxide (ITO) transparent conductive film on glass substrate
The 20 nm-deposited product was ultrasonically cleaned with acetone and isopropyl alcohol for 10 minutes, then dried by blowing dry nitrogen, and then UV / ozone cleaning was performed.

Then, a dry film photoresist (manufactured by DuPont: trade name "Liston") was laminated and exposed to ultraviolet rays through a mask. The exposure amount at this time was 100 mJ / cm ² . This was developed in a tetramethylammonium hydroxide (TMAH) aqueous solution having a concentration of 3% for 1 minute, rinsed in demineralized water, carefully blown with dry nitrogen, and dried. This was placed in a vacuum vapor deposition apparatus and evacuated using an oil diffusion pump until the degree of vacuum in the apparatus became 1 × 10 ⁻⁶ Torr or less. On this substrate, an aromatic amine compound (H-1) as an organic hole transport layer material

[0035]

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[0036] was placed in a ceramic crucible and heated by a tantalum wire heater around the crucible for vapor deposition. The temperature of the crucible at this time was controlled in the range of 180 to 230 ° C. The degree of vacuum during vapor deposition was 1.4 × 10 ⁻⁶ Torr, and the organic hole transport layer 3 having a film thickness of 60 nm was obtained with the vapor deposition time of 2 minutes and 30 seconds.

This was taken out, the resist was peeled off in a TMAH aqueous solution having a concentration of 20%, and a pattern was formed by lift-off. After peeling, after rinsing in demineralized water, it was carefully dried by blowing dry nitrogen. This was installed in a vacuum evaporation system and the degree of vacuum in the system was 1 × 10 ^-6 Torr.
It was evacuated using an oil diffusion pump until the following: On this substrate, a protective layer of aluminum 8 shown in the following structural formula
- hydroxyquinoline complex _{Al (C 9 H 6 NO)} 3 (E-
1)

[0038]

[Chemical 4]

[0039] was placed in a ceramic crucible and heated by a tantalum wire heater around the crucible for vapor deposition. The temperature of the crucible at this time was controlled in the range of 350 ° C to 380 ° C. The degree of vacuum at the time of vapor deposition was 5 × 10 ⁻⁶ Torr and the vapor deposition time was 1 minute and 30 seconds to obtain a protective layer having a film thickness of 75 nm. This substrate was taken out from the vapor deposition apparatus, and a dry film resist was laminated again, a desired pattern was exposed, and development, rinsing and drying were performed as described above. This substrate is installed again in the vacuum evaporation system, and the vacuum degree in the system is 1 × 10 ⁻⁶ T.
It was evacuated using an oil diffusion pump until it became below orr.

H- was used as an organic hole transport layer material on this substrate.
1 was put in a ceramic crucible and vapor deposition was performed. This time,
Rubrene shown in the following structural formula for the purpose of changing the emission color

[0041]

Embedded image

[0042] was placed in another crucible as a dopant and vapor deposition was performed by a co-evaporation method. At this time, the temperature of the crucible was controlled to 210 ° C to 230 ° C and 130 ° C to 150 ° C, respectively.
The degree of vacuum during vapor deposition was 6 × 10 ⁻⁷ Torr, and the vapor deposition time was 1 minute to obtain an organic hole transport layer 3 ′ having a film thickness of 60 nm and a doping concentration of 10%.

This was taken out again, and TMA with a concentration of 20% was used.
Stripping, rinsing and drying were performed as described above using the H aqueous solution. This substrate was set in the vacuum vapor deposition apparatus again, and exhausted using an oil diffusion pump until the degree of vacuum in the apparatus became 1 × 10 ⁻⁶ Torr or less. Then, E-1 as a material of the organic electron transport layer 4 was vapor-deposited on the organic hole transport layers 3 and 3 '. The temperature of the crucible at this time is 320 ℃ ~
Control was performed in the range of 340 ° C. The degree of vacuum during vapor deposition is 3 × 10
^-6 Torr, vapor deposition time was 2 minutes, and film thickness was 75 nm. This organic electron transport layer 4 plays a role of a light emitting layer and an electron transport layer in the region of the organic hole transport layer 3 (region in which the dye rubrene is not doped), and the region of the organic hole transport layer 3 ′ ( In the region doped with the dye rubrene), it plays only the role of an electron transport layer.

Finally, as a cathode, an alloy electrode of magnesium and silver was vapor-deposited with a film thickness of 150 nm by a binary vapor deposition method. Vapor deposition uses a molybdenum boat and the degree of vacuum is 7 × 1.
A glossy film was obtained at 0 ^-6 Torr and a vapor deposition time of 2 minutes. The atomic ratio of magnesium to silver was 10: 1.2.

In the organic electroluminescent device thus produced, the ITO electrode (anode) of the portion corresponding to the region of the hole transport layer 3 is positively added, and the magnesium-silver alloy electrode (cathode) is added.
It was measured by applying a negative DC voltage to. When a voltage of 13 V was applied, a current density of 229 mA / cm ² was obtained, the brightness at that time was 51 cd / m ² , and the emission color was green. Similarly, the ITO of the portion corresponding to the region of the hole transport layer 3 '
It was measured by applying a positive DC voltage to the electrodes and a negative DC voltage to the magnesium-silver alloy electrodes. 189m when applying 22V
A current density of A / cm ² was obtained, and the brightness at that time was 128.
It was 0 cd / m ² , and the emission color was yellow.

[0046]

According to the method of manufacturing an organic electroluminescent element of the present invention, a multi-color display device can be easily manufactured. Therefore, the organic electroluminescent device of the present invention can be applied to the field of flat panel displays (for example, for OA computers and wall-mounted televisions), display panels, and marker lights, and its technical value is great.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of an organic electroluminescence device of the present invention.

FIG. 2 is a schematic cross-sectional view showing another example of the organic electroluminescent element of the present invention.

FIG. 3 is a schematic diagram showing an example of a lift-off process of the present invention.

FIG. 4 is a schematic cross-sectional view showing another example of the organic electroluminescent element of the present invention.

FIG. 5 is a schematic cross-sectional view showing another example of the organic electroluminescent element of the present invention.

[Explanation of symbols]

 1 substrate 2 anode 3, 3 ', 3 "hole transport layer 3a, 3a', 3a" hole injection layer 3b, 3b ', 3b "hole transport layer 4a electron transport layer 4b composed of a compound different from 4a Electron transport layer 4c Interface layer 5 Cathode 3-1 Substrate 3-2 Anode 3-3 Film resist 3-4 Hole transport layer

Claims (1)

[Claims] 1. An organic electroluminescent device, which is provided on a substrate and has at least an organic light emitting layer between an anode and a cathode, and in which devices having different emission colors are provided on the substrate. A method for manufacturing an organic electroluminescence device, characterized in that, during manufacturing, an organic light-emitting layer having a different emission color is manufactured by a lift-off method using a dry film resist.