Material for organic electroluminescent element, and manufacturing method thereof

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a method for producing a material for an organic electroluminescence device by injecting a luminescent center-forming compound by molecular injection using a laser, a material for an organic electroluminescence device obtained by the method, and the organic electroluminescence thereof. The present invention relates to an organic electroluminescence device using a material for a device.

【0002】

[Conventional technology]

Conventionally, electroluminescence devices (hereinafter, sometimes referred to as EL devices) are classified into inorganic EL devices and organic EL devices according to the material used. Inorganic EL devices that use inorganic phosphor molecules have been partially put into practical use and are used in clock backlights and the like. On the other hand, organic EL devices are superior to inorganic EL devices in terms of high brightness, high efficiency, and high-speed responsiveness, and are therefore expected to be put into practical use.

【0003】

The electroluminescence device is composed of a compound having an electron transport function, a hole transport function, and a light emitting center forming function. As the structure, a single layer type in which one layer has all the above functions, a multi-layer type in which different layers have each function, and the like have been reported. The principle of light emission is considered to be based on the fact that electrons or holes injected from a pair of electrodes recombine in the light emitting layer to generate excitons, which excite light emitting material molecules constituting the light emitting layer. There is.

【0004】

As the compound constituting each layer, a low molecular weight compound having high luminous efficiency, a polymer compound having high physical strength, and the like are used. When a low molecular weight compound is used, a film is formed by a vapor deposition method, whereas in the case of a polymer compound, a film is often formed by applying a solution.

【0005】

JP-A-8-96959 and JP-A-9-63770 include a single-layer light emitting layer in which a plurality of types of fluorescent dyes are dispersed in a polymer binder having an electron transport function and a hole transport function. Organic EL devices are disclosed. It has been reported that each luminescent compound of these organic EL devices emits light independently and exhibits white light as a whole. Further, the emission intensity is less likely to decrease as compared with the organic EL element having a multi-layer structure.

【0006】

Since these organic EL elements form a film by a solution coating method in which a polymer binder and a fluorescent dye are dispersed in a specific solvent and applied to a substrate, fine patterning, particularly multicolor patterning (full colorization), is performed. Is difficult.

【0007】

As multicolor patterning methods, color filter method, color conversion method, inkjet method by TR Hebner et al. (Appl.Phys.Lett.72,5 (1998) p.519), photobleaching method by Kido et al., Etc. have been reported. There is.

【0008】

However, although the color filter method and the color conversion method have an advantage that the patterning of the light emitting layer is not required, the conversion efficiency is lowered because the light emitting layer is passed through the filter. In the inkjet method, the pattern formed by inkjet has a conical shape with a high center and is inferior in surface smoothness, so that it is difficult to form electrodes uniformly. The ideal cross-sectional pattern is a quadrangle, but the inkjet method has a circular shape. Furthermore, the size of the pattern largely depends on the drying conditions and the concentration of the solution. In the photobleaching method, only a special luminescent center compound that loses fluorescence due to UV oxidation can be used, and the colors that can be expressed are limited.

【0009】

As described above, in the conventional film-forming method by coating with a solution, it is possible to use a polymer compound having high physical strength, but fine patterning is difficult. Further, even in the above patterning method, not only the compounds that can be used are limited, but also a film having surface smoothness suitable for an organic EL device cannot be obtained.

【0010】

As a molecular injection method, Japanese Patent Application Laid-Open No. 6-297457 states that a solid material (A) containing a functional material or a functional material and a solid material (B) into which a functional component is injected are opposed to each other. Discloses a method of injecting a functional component into a solid material (B) by irradiating a pulsed laser. This document describes that the injection position of the functional component can be controlled by adjusting the irradiation position of the laser.

【0011】

Further, Japanese Patent Application Laid-Open No. 8-106006 describes a source film in which a dye capable of absorbing pulsed laser light is dispersed in an organic polymer compound and a target film composed of an organic polymer compound capable of transmitting a pulsed laser. A method is disclosed in which the dye is injected into the target film by irradiating the target film with a pulsed laser beam at an intensity equal to or lower than the ablation threshold of the source film. This document describes that the molecular injection method can be used for creating color filters for display and the like. Further, this document describes that an image can be formed by moving the spot position of the laser or the source film and the target film, and in the embodiment, the sample is translated to form a linear image.

【0012】

In WO00 / 13470, a source containing a luminescent center-forming compound capable of absorbing laser light and a target having an electron transport function and / or a hole transport function are brought into contact with each other, and a pulse laser has an intensity equal to or lower than the ablation threshold of the source. A method for producing a material for an organic electroluminescence device by irradiating light and injecting a light emitting center forming compound into a target is disclosed.

【0013】

[Problems to be Solved by the Invention]

Therefore, an object of the present invention is an organic EL device material (particularly organic) that enables fine patterning even when a polymer compound is used as the EL device material, and can easily and efficiently inject a light emitting center-forming compound. The purpose of the present invention is to provide a film for an EL element) and a method for manufacturing the same.

【0014】

Another object of the present invention is to provide a material for an organic EL device having excellent surface smoothness and good contact with an electrode, and an organic EL device using the same.

【0015】

[Means for solving problems]

As a result of diligent studies to achieve the above-mentioned problems, the present inventors have made fine particles by moving the laser beam relative to the target in the molecular injection method using a source composed of a luminescent center-forming compound. We have found that patterning can be performed easily and efficiently, and completed the present invention.

【0016】

That is, in the method for producing a material for an organic EL device of the present invention, a luminescent center-forming compound constituting a source is irradiated with a laser beam to a target having at least one function selected from an electron transport function and a hole transport function. Is a method for producing a material for an organic electroluminescence device having a light emitting center by injecting a laser beam, which is irradiated by moving a laser beam at least relative to a target to form a light emitting center in a predetermined pattern. Further, the source and the target in contact with each other may be moved with respect to the laser beam to form a light emitting center in a predetermined pattern. Laser light may be irradiated through the waveguide. Laser light may be irradiated using an optical fiber. The laser beam may be moved relative to the target to irradiate the target, and the source may be moved relative to the laser beam to form a light emitting center. Laser light may be irradiated with an intensity equal to or lower than the ablation threshold of the source. The laser light may be a pulsed laser light, or the laser light may be moved relative to the target in synchronization with the pulse period. The target may be an organic polymer. The target may be composed of a compound having at least one function selected from an electron transport function and a hole transport function, and an organic polymer having a film-forming ability. The compound may be an oxadiazole derivative having an electron transport function and / or an aromatic tertiary amine having a hole transport function.

【0017】

The present invention also includes a material for an organic EL device obtained by the above manufacturing method, and an organic EL device using the material for the organic EL device.

【0018】

BEST MODE FOR CARRYING OUT THE INVENTION

[Source (A)] The source may contain at least a luminescent center-forming compound, and may be composed of the luminescent center-forming compound alone or a luminescent center-forming compound and a binder.

【0019】

[Light-emitting center-forming compound] The light-emitting center-forming compound has a function as a light-emitting center compound for an organic EL element and is excited by a compound capable of absorbing laser light, particularly electrons and / or holes. Luminescent compounds can be used. Examples of the luminescent center-forming compound include bis (C) such as 2,5-bis (5-tert-butyl-2-benzoxazoyl) -thiophene._1-6Coumarins such as alkyl-benzoxazoyl) thiophene, nile red, coumarin 6, coumarin 7, 4- (p-dimethylaminostyryl) -4H-pyran such as 4- (dicyanomethylene) -2-methyl-6- Dicyano C_1-4Alkylene) -2-C_1-4Alkyl-6- (p-di C_1-4Alkylaminostyryl) -4H-Heterocyclic compounds containing oxygen atoms such as pyrane and quinacridone, and at least one heteroatom selected from nitrogen and sulfur atoms; fused polycyclic hydrocarbons such as rubrene and perylene; 1, Tetra C such as 1,4,4-tetraphenyl-1,3-butadiene (TPB)_6-12Aryl-1,3-butadiene; 1,4-bis (2- (4-ethylphenyl) ethynyl) benzene and other bis (2- (4-C)_1-4Alkylphenyl) C_2-4Alkyne) Benzene; 4,4'-bis (2,2'-diphenylvinyl) Biphenyl and other bis (2,2'-diC_6-12Aryl vinyl) Biphenyl and the like. Of these, Nile Red and Coumarin 6 are particularly preferable.

【0020】

The structures of Nile Red and Coumarin 6 are shown below.

【0021】

[Chemical 1]

<img file="JP2002190386A_D0001.tif" />【0022】

The emission wavelength of Nile Red is 580 nm (red emission), and the emission wavelength of Coumarin 6 is 490 nm (green emission).

【0023】

These luminescent center-forming compounds may be used alone or in combination of two or more.

【0024】

[Binder] As the binder, a resin having a film-forming ability (thermoplastic resin, thermosetting resin) can be usually used.

【0025】

Examples of the thermoplastic resin include olefin resins such as polyethylene, polypropylene, ethylene-propylene copolymer, and polybutene; polystyrene, rubber-modified polystyrene (HIPS), acrylonitrile-styrene copolymer, and acrylonitrile-butadiene-styrene copolymer. Styrene-based resins such as; acrylic-based resins [(meth) acrylic monomers (eg, C such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate)_1-6Hydroxy C such as alkyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate_2-4Alkyl (meth) acrylate, glycidyl (meth) acrylate, (meth) acrylic acid, (meth) acrylonitrile, etc.) alone or in a copolymer, the above-mentioned (meth) acrylate-based monomer and copolymerizable monomer (for example, Copolymers with aromatic vinyl monomers such as styrene (methyl methacrylate-styrene copolymers, etc.)]; Vinyl alcohol-based polymers such as polyvinyl alcohol, ethylene-vinyl alcohol copolymers, polyvinyl chloride, Vinyl-based resins such as vinyl chloride-vinyl acetate copolymer, polyvinylidene chloride, polyvinyl acetate, ethylene-vinyl acetate copolymer, polyvinylacetyl; 6-nylon, 6,6-nylon, 6,10-nylon, 6 , 12-Polymer resin such as nylon; Polyester resin [for example, polyalkylene terephthalate (polyethylene terephthalate, polybutylene terephthalate, etc.), alkylene allylate resin such as polyalkylene naphthalate or alkylene allylate copolymer resin]; fluororesin; Polycarbonate; polyacetal; polyphenylene ether; polyphenylene sulfide; polyether sulfone; polyether ketone; thermoplastic polyimide; thermoplastic polyurethane; norbornene-based polymer and the like.

【0026】

Examples of the thermosetting resin include phenol resin, amino resin (urea resin, melamine resin, etc.), thermosetting acrylic resin, unsaturated polyester resin, alkyd resin, diallyl phthalate resin, epoxy resin, silicone resin and the like.

【0027】

These binders may be used alone or in combination of two or more.

【0028】

The content of the luminescent center-forming compound in the source is not particularly limited, and is about 0.1 to 100% by weight, preferably 1 to 90% by weight, and more preferably about 5 to 80% by weight. When the source is composed of a luminescent center-forming compound and a binder, the content of the luminescent center-forming compound is not particularly limited, but for example, 0.1 to 60 parts by weight, preferably 1 to 1 to 100 parts by weight of the binder. It is about 30 parts by weight, more preferably about 3 to 20 parts by weight.

【0029】

The source is usually used in the form of a film. Further, the source may be the light emitting center forming compound alone or a coating film of the light emitting center forming compound and the binder formed on the substrate or the target. When irradiating the laser beam from the source side, the substrate may be transparent enough to transmit the laser beam, for example, a glass plate such as soda glass, non-alkali glass, or quartz glass, or polyester, polystyrene, or acrylic. Examples thereof include polymer sheets or films such as based resins, vinyl-based resins (polyvinyl acetal, etc.), polysulfones, and polyethersulfones.

【0030】

The method for producing the source film is not particularly limited, and is a conventional method (for example, a dry method such as a vapor deposition method (vacuum vapor deposition method), a wet coating method using a solvent such as spin coating, dip coating, die coating, etc.). And so on. The film may be formed by a conventional film manufacturing method (for example, casting method, extrusion method, etc.).

【0031】

If necessary, the coating agent (coating liquid) for forming the source film (coating liquid) contains a solvent (for example, water; alcohols such as methanol and ethanol; esters such as ethyl acetate and isobutyl acetate; acetone and methyl ethyl ketone. Ketones such as; aromatic hydrocarbons such as toluene; alicyclic hydrocarbons such as cyclohexane; halogenated hydrocarbons such as chloroform and chlorobenzene; ethers; cellosolves; carbitols, etc.) You may. The thickness of the film (or film) is not particularly limited, but may be 0.01 to 50 μm, preferably 0.1 to 30 μm, and more preferably about 0.5 to 20 μm.

【0032】

Further, the source may not be formed in a pattern, but may be formed in a predetermined pattern by itself, and a coating film having a pattern formed on a substrate (base material) or a target, if necessary, may be used as a source. You may use it. For example, a film or sheet containing a luminescent center-forming compound may be patterned by a method such as punching to obtain a source. The substrate may be transparent enough to transmit laser light, for example, a glass plate such as soda glass, non-alkali glass, or quartz glass, or polyester, polystyrene, acrylic resin, or vinyl resin (polyvinyl). (Acetal, etc.), polymer sheets or films such as polysulfone, polyethersulfone, etc. may be mentioned.

【0033】

When formed into a source pattern, the pattern is selected according to the desired application, for example, a one-dimensional pattern [dot-like (dot-like), linear (for example, parallel-line, random, grid-like, etc.)], It may be any of two-dimensional patterns [planar shape (for example, a polygonal shape such as a circle, an ellipse, a triangle, a quadrangle, a star shape, etc.)]. As a method of forming a predetermined pattern on the substrate, for example, a predetermined pattern is formed on the substrate or a target by printing such as screen printing, an inkjet method, a melt transfer or thermal transfer method, or a vapor deposition method (sublimation printing) performed in combination with masking. A pattern can be formed.

【0034】

[Target (B)] The target is not particularly limited as long as it has at least one function selected from the electron transport function and the hole transport function, and is selected from (I) the electron transport function and the hole transport function. A resin composition obtained by imparting at least one function selected from the electron transport function and the hole transport function to a resin having at least one function or (II) a resin not having the electron transport function and the hole transport function. May be good. As the resin used in (I) and (II), a resin (binder) having a film-forming ability is preferable. Further, when the laser light is incident from the target side, the target can transmit the laser light.

【0035】

Examples of the resin (I) having at least one function selected from the electron transport function and the hole transport function include polyphenylene vinylenes [for example, polyphenylene vinylene, poly (2,5-dimethoxyphenylene vinylene), and polynaphthalene vinylene. Substituents such as (C_1-10May have an alkoxy group) C_6-12Alone or copolymer of arylene vinylene]; Polyphenylenes (particularly polyparaphenylenes) [eg, substituents such as polyparaphenylene, poly 2,5-dimethoxyparaphenylene (C)_1-10Phenylene alone or copolymer which may have an alkoxy group)]; Polythiophenes [Poly C such as poly (3-alkylthiophene)_1-20Poly C such as alkyl thiophenes and poly (3-cyclohexylthiophene)_3-20Substituents (C) such as cycloalkylthiophenes, poly (3- (4-n-hexylphenyl) thiophene)_1-10Alkyl group) may have C_6-20Arylthiophenes alone or copolymers]; Poly C_1-20Polyfluorenes such as alkylfluorene; poly-N-vinylcarbazole (PVK), poly-4-N, N-diphenylaminostyrene, poly (N- (p-diphenylamino) phenylmethacrylate), poly (N, N) '-Diphenyl-N, N'-bis (3-methylphenyl) -1,1'-biphenyl-4,4'-diaminomethacrylamide) (PTPDMA), poly-4- (5-naphthyl-1,3, 4-Oxaziazole) A vinyl-based polymer having at least one functional group selected from a hole-transporting functional group and an electron-transporting functional group in the main chain or side chain such as styrene; polyC such as polymethylphenylsilane._1-4Examples thereof include alkylphenylsilane; a polymer having an aromatic amine derivative in a side chain or a main chain; or a copolymer thereof. These resins may be used alone or in combination of two or more. Preferred targets include a copolymer containing poly-N-vinylcarbazole or N-vinylcarbazole as a main component (50% by weight or more, preferably about 60 to 98% by weight), and an aromatic amine derivative as a side chain or main chain. Examples include the polymer possessed by.

【0036】

PVK is amorphous and has excellent heat resistance (glass transition temperature Tg: 224 ° C). The degree of polymerization of the PVK is not particularly limited, but is, for example, about 200 to 5000 (for example, 300 to 3000), preferably about 500 to 2000 (for example, 500 to 1500).

【0037】

Further, if necessary, the resin (I) may be provided with an electron transport function or a hole transport function.

【0038】

Examples of the compound having an electron transport function include oxadiazole derivatives [for example, 2- (4-biphenyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole (PBD), 2,5-bis (1-naphthyl) -1,3,4-oxadiazole (BND), 1,3-bis [5- (4-tert-butylphenyl) -1,3,4-oxadiazole ] Benzene (BPOB), 1,3,5-Tris [5- (4-tert-butylphenyl) -1,3,4-oxadiaol] Benzene (TPOB), 1,3,5-Tris [5- (1-naphthyl) -1,3,4-oxadiazole] C which may have a substituent such as benzene (TNOB)_6-20Oxadiazole derivatives with aryl groups]; Diphenoquinones [eg, substituents such as 3,5,3', 5'-tetrakis-tert-butyldiphenoquinone (C)_1-10Diphenoquinones which may have (alkyl group, etc.); 1,2,3,4,5-pentaphenyl-1,3-cyclopentadiene (PPCP); tris (8-quinolinolato) aluminum (III) complex, bis Examples thereof include quinolinic acid complexes such as (benzoquinolinolato) berylium complex and tris (10-hydroxybenzo [h] quinolylate) beryllium complex. In particular, PBD is preferred.

【0039】

Examples of the compound having a hole transport function include N, N'-diphenyl-N, N'-bis (3-methylphenyl) -1,1'-biphenyl-4,4'-diamine (TPD), N, N'-diphenyl-N, N'-bis (1-naphthyl) -1,1'-biphenyl-4,4'-diamine (NPD), 1,1-bis [(di-4-tolylamino) phenyl] cyclohexane , N, N, N', N'-tetra (3-methylphenyl) -1,3-diaminobenzene (PDA), 4,4', 4 "-tris (3-methylphenylphenylamino) triphenylamine ( m-MTDATA), 4,4', 4 -tris (1-naphthylphenylamino) triphenylamine (1-TNATA), 4,4', 4-tris (2-naphthylphenylamino) triphenylamine ( 2-TNATA), 4,4', 4 -tri (N-carbazolyl) triphenylamine (TCTA), 1,3,5-tris [4- (3-methylphenylphenylamino) phenyl] benzene (m- MTDAPB), aromatic tertiary amines such as triphenylamine; phthalocyanines and the like.

【0040】

The compounds may be used alone or in combination of two or more. Among these compounds, a compound that is excited by electrons and / or holes to emit light may be used as a light emitting center forming compound.

【0041】

The ratio of the above components contained in the resin (I) (for example, PVK) can be selected within a range that does not impair the function as a material for an organic EL device. For example, 10 to 100 parts by weight of the resin (I). It is about 300 parts by weight, preferably about 20 to 200 parts by weight.

【0042】

When the target is composed of the resin (I) and the compound, a single-layer structure is possible in the organic EL device described later, which not only improves the luminous efficiency but also is economically advantageous.

【0043】

The resin used in the resin composition (II) is not particularly limited, and for example, various binders (thermoplastic resin, thermosetting resin, etc.) having the above-exemplified film-forming ability can be used. These resins may be imparted with at least one of an electron transport function and a hole transport function. Examples of the compound used for imparting the electron transport function and / or the hole transport function include the same compounds as described above.

【0044】

The amount of the compound having an electron transport function or a hole transport function added is 10 to 300 parts by weight (for example, 10 to 200 parts by weight), preferably 20 to 100 parts by weight (for example, 20) with respect to 100 parts by weight of the binder resin. ~ 80 parts by weight).

【0045】

Further, the resin (I) and the resin composition (II) may be used in combination, and at least one of the electron transport function and the hole transport function may be imparted.

【0046】

The form of the target is not particularly limited, but is usually used in the form of a film. In addition, the target is formed in the same manner as the source, and is usually formed on the above-exemplified substrate.

【0047】

[Method for Manufacturing Material for Organic EL Device (Molecular Injection Method)] The method for manufacturing the material for organic EL device of the present invention is a method of irradiating a laser beam and injecting a light emitting center-forming compound in a source into the target. By moving the laser beam at least relative to the target, the emission center is formed in a predetermined pattern. The laser light may be emitted from the source (A) side or the target (B) side. A film is usually used as a target, and a film for an organic EL element is manufactured. Moreover, the target and the source may be in contact with each other.

【0048】

The laser light used in the present invention varies depending on the type of the emission center forming compound used, and examples thereof include laser light having an oscillation wavelength in the range of 190 to 1100 nm as a wavelength. When pulsed laser light is used, the frequency is, for example, about 0.5 to 50 Hz, preferably about 0.5 to 30 Hz. The pulse width varies depending on the wavelength of the laser light and the like, but is about 10 ps to 10 μs (for example, 10 ps to 1 μs), preferably about 50 ps to 100 ns (for example, 100 ps to 50 ns). The shorter the pulse width, the more the decomposition of the luminescent center-forming compound can be suppressed and the less likely it is to be damaged.

【0049】

Laser light sources include, for example, gas lasers [ArF excimer laser (193 nm), KrF excimer laser (248 nm), XeCl excimer laser (308 nm), XeF excimer laser (351 nm), nitrogen laser (337 nm)], dye laser (nitrogen laser). , Eximer laser, or YAG laser excitation, 300-1000nm), solid-state laser [(Nd: YAG excitation, semiconductor laser excitation, etc.); ruby laser (694nm), semiconductor laser (650-980nm), tunable diode laser (630 ~ 1550nm), titanium sapphire laser (Nd: YAG excitation, 345 ~ 500nm, 690 ~ 1000nm), Nd: YAG laser (FHG: 266nm, THG: 354nm, SHG: 532nm, fundamental wave: 1064nm)].

【0050】

In the production method of the present invention, the luminescent center-forming compound can be efficiently injected into the target by irradiating the laser beam with an intensity equal to or lower than the ablation threshold of the source (that is, the luminescent center-forming compound or the binder). The injection amount can be controlled by adjusting the laser intensity, wavelength, number of irradiations, and the like.

【0051】

The ablation threshold of the source (A) depends on the type of luminescent center-forming compound constituting the source. It also depends on the wavelength and pulse width of the laser beam. Therefore, in the present invention, the ablation threshold is defined as follows.

【0052】

When the same source and laser used in the present invention are used to irradiate the source with one shot of laser light and the source is observed with a contact-type surface shape measuring device (for example, DEKTAK 3030ST manufactured by SLOAN). , The minimum laser light intensity (mJ / cm) on the irradiated surface where the shape change of 50 nm or more can occur on the laser light irradiated surface.²) Is defined as the ablation threshold in the present invention.

【0053】

Hereinafter, a method for producing the material for an organic EL device (particularly, a film for an organic EL device) of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view showing a manufacturing method of the present invention. The source (1), the target (2), the luminescent center-forming compound (3), the target-side substrate (4), and the source-side substrate (5) are shown.

【0054】

First, the source (1) formed on the substrate (5) and the target (2) formed on the substrate (4) are brought into contact with or in close contact with each other, and the source (1) side is below the ablation threshold of the source. Intense laser light is moved relative to the target to irradiate. Then, the luminescent center-forming compound that has absorbed the laser light has high translational energy and is injected undecomposed into the target (2) to obtain a material for an organic EL device (particularly a film).

【0055】

The number of irradiations is usually 1 to 200 times, preferably 1 to 150 times, and more preferably 1 to 100 times (for example, 5 to 100 times). Further, the laser beam may be irradiated from the target side. The source may be formed directly on the target as a surface layer. The source formed on the target can be removed from the target after injecting the luminescent center-forming compound. The source may also be formed of a removable or peelable surface layer.

【0056】

The substrate to be used may be transparent enough to transmit laser light, and for example, the above-exemplified substrate (glass plate such as quartz glass, polymer sheet, film, etc.) can be used. As the substrate, the substrate used for forming the source or target film may be used as it is, or may be newly produced.

【0057】

In the method for producing the material for an organic EL element of the present invention, the cross-sectional shape of the laser beam is not particularly limited, and may be a circular shape, an elliptical shape, a polygonal shape (triangle, quadrangle, etc.) or the like. The average beam area of the laser is not particularly limited and can be selected from a wide range according to the purpose. For example, 0.01 ~ 5000 μm², Preferably 0.1-4000 μm², More preferably 1-3000 μm²Degree. A pattern may be formed by narrowing the beam area of the laser light to a desired size and scanning a predetermined pattern, or by increasing the beam area of the laser light and using a source formed in a pattern in advance. Alternatively, the luminescent center-forming compound may be injected into the target in a predetermined region by relatively scanning the laser beam with a photomask interposed therebetween.

【0058】

Also, a plurality of sources having different emission center forming compounds may be used. For example, if a compound capable of emitting light in the visible light region (a compound capable of emitting light such as yellow, red, green, or blue) is used, a desired emission color can be obtained. Therefore, according to the present invention, it is possible to obtain a material for an organic EL device having a multicolored and variously shaped patterns.

【0059】

A feature of the present invention is that at least the laser beam is moved relative to the target, and the emission center-forming compound of the source is injected into the target in a predetermined pattern. In this method, the source and target are positioned in contact with each other, the source and target may move with each other, or the source may move relative to the target. When the source and target are in contact with each other, the irradiation of the laser beam is, for example, (1) a method of moving the optical path of the laser beam with respect to the source and the target, and (2) the source and the target with respect to the optical path of the laser beam. It may be any of the methods of moving the. Further, in these methods, the optical path of the laser beam can be moved not only by the relative movement of the laser light source but also by (3) means for controlling the optical path.

【0060】

(3) As means for controlling the optical path, physical or physical optical means (for example, optical fiber, reflecting mirror (total reflection mirror, half mirror, etc.), lens (condensing lens, etc.), deflection prism, etc." A method using an optical element (or an optical member) or a combination thereof), an optical path of a light beam in a waveguide using an electro-optical means (for example, applying a voltage to an electro-optical crystal (double refraction crystal)) There are a method of moving the optics, a method of using ultrasonic waves, and the like. As a method of using ultrasonic waves, for example, water, chalcogenide-based vitreous material, PbMoO₄, TeO₂, Ge, LiNbO₃A crystalline material such as GaP is used as a medium, and a piezoelectric thin film transducer (for example, LiNbO) is used in this medium.₃By applying a voltage through a piezoelectric element such as ZnO or ZnO), ultrasonic waves can be generated in the medium to move the waveguide.

【0061】

In the physical or physical optics means, when the optical path of the laser light is moved by using an optical fiber, the propagation loss of the laser light can be reduced, and fine patterning can be performed efficiently and easily.

【0062】

In the method of the present invention, the laser beam can be moved not only linearly but also at least two-dimensionally relative to the target. Therefore, the luminescence center-forming compound of the source can be efficiently injected into the target in a desired pattern, and the luminescence center can be formed in a two-dimensional pattern.

【0063】

For example, the source and the target are brought into contact with each other and fixed to a table that can be moved in the XY-axis direction with the target surface or the source surface facing up, in the X-axis and Y-axis directions from the reference position of the target (or source). By providing a sensor that detects the displacement of the source and moving the table in the X-axis and Y-axis directions in response to the detection signal of the sensor, advanced positioning can be easily performed and two-dimensional fine patterning is possible. Is. If necessary, patterning can be easily performed by providing a memory that stores the pattern data and a controller that moves the laser and / or the table in response to the pattern signal.

【0064】

When a pulsed laser is used as the laser light, when the laser light is moved relative to the target at least by the above method in synchronization with the pulse period, the target and the laser light are relatively shifted and emitted. The center-forming compound can be efficiently injected into the target. In this method, the target may be moved with respect to the laser beam, but usually, the laser beam or the optical path of the laser beam is often controlled in synchronization with the pulse period.

【0065】

Further, in the present invention, at least the laser light may be moved relative to the target, and the source may be moved relative to the laser light. When the same part of the source is repeatedly irradiated with the laser beam, the light emitting center forming compound is consumed, and the light emitting center cannot be effectively formed. In such a case, if the laser light is moved relative to the target to irradiate and the source is moved relative to the laser light, the emission center forming compound can be effectively and efficiently injected into the target.

【0066】

For example, a plurality of emission centers having different emission colors (for example, full-color emission centers) can be efficiently formed. According to the present invention, in the source, a plurality of regions composed of each luminescence center-forming compound, for example, a region composed of a yellow luminescence center-forming compound, a region composed of a red luminescence center-forming compound, and blue luminescence center formation. Regions composed of compounds may be formed. With such sources, multiple sources with different emission colors can be used with a single source by moving the source relative to the laser beam and / or the target in the X-axis and / or Y-axis directions. Can form the emission center of.

【0067】

FIG. 6 is a schematic view showing another manufacturing method of the present invention. In this example, the light path (light source or waveguide) of the laser beam is moved longitudinally and / or laterally with respect to the target to irradiate the region of the source composed of the green emission center-forming compound with the laser beam. After forming the green emission center as the target, the source is moved with respect to the laser light, and then the laser light is irradiated to the region composed of the red emission center forming compound to form the red emission center as the target. .. Further, by forming the blue light emitting center as a target in the same manner, it is possible to manufacture an organic EL device material capable of emitting light in full color. Further, in this method, the pulse laser is irradiated to the target through the source while scanning in the vertical direction and / or the horizontal direction, and the source 1 and the target 2 can come into contact with each other at the irradiation site of the laser beam. Is. The source 1 can be moved in the X-axis and / or Y-axis directions by the feed mechanism.

【0068】

By moving the source with respect to the laser beam in this way, it is possible to form a plurality of emission centers having different emission colors by using a single source, and the emission center forming compound can be used without waste, so that the emission centers can be efficiently used. Since the forming compound can be injected, it is also advantageous in terms of cost. Further, the source may be formed of a film having an indefinite length or the like, and by using such a film, a luminescent center-forming compound can be continuously produced.

【0069】

Further, according to the production method of the present invention, the injected luminescent center-forming compound is not in a dispersed or diffused form in the target, but in a step type (that is, a rectangular shape in which the injection into the target has a uniform depth. It can be injected in the form). The depth varies depending on the emission center forming compound, the type of target, the laser intensity, and the like, but is, for example, 10 to 300 nm, preferably 15 to 200 nm, and more preferably about 20 to 100 nm. Further, if the irradiation is equal to or less than the ablation threshold value, the light emitting center forming compound can be efficiently injected without deteriorating the smoothness of the surface of the material for the organic EL device.

【0070】

[Organic Electroluminescent Device] The organic electroluminescent device of the present invention is a pair with a material for an organic EL device obtained by the above method (particularly, a light emitting layer composed of a target film in which a light emitting center forming compound is injected). It is composed of electrodes.

【0071】

As the anode, a transparent electrode (for example, indium-tin-oxide (ITO) electrode) formed by a vacuum vapor deposition method or the like is used, and as the cathode, a highly conductive metal having a small work function (for example, magnesium, etc.) is used. Lithium, aluminum or silver, etc.) are used. When magnesium is used as the cathode, it may be co-deposited with a small amount (for example, 1 to 10% by weight) of silver in order to improve the adhesiveness with the film for an organic EL device.

【0072】

When the light emitting layer has an electron transport function and a hole transport function, the organic EL device of the present invention can have a single layer structure. In addition, when any of the electron transport function and the hole transport function is not provided, or when each function is to be improved, a layer having that function is subjected to a conventional thin-film deposition method, solution coating method, or the like. It may be laminated. These layers may be low molecular weight compounds or high molecular weight compounds. The structure of the organic EL device can be, for example, a single-layer or multi-layer structure shown in FIGS. 2 to 5.

【0073】

That is, as shown in FIG. 2, an organic EL device in which an anode (11) is formed on a substrate (10) and a light emitting layer (12) and a cathode (13) are laminated in this order, as shown in FIG. An organic EL device may be an organic EL device in which an anode (21) is formed on a substrate (20), and a hole transport layer (24), a light emitting layer (22), and a cathode (23) are laminated in this order on the anode (21). Further, as shown in FIG. 4, an organic EL device in which an anode (31) is formed on a substrate (30), and a light emitting layer (32), an electron transporting layer (35), and a cathode (33) are laminated in this order on the anode (31). , As shown in FIG. 5, an anode (41) is formed on the substrate (40), and a hole transport layer (44), a light emitting layer (42), an electron transport layer (45), and a cathode (43) are formed on the anode (41). It may be an organic EL element laminated in order.

【0074】

The film thickness of each layer constituting the organic EL device is not particularly limited, but is 10 nm to 1 μm (for example, 10 to 500 nm), preferably 30 to 300 nm, more preferably 30 to 200 nm, and particularly about 50 to 200 nm. When a film is used, the film thickness can be selected from the same range as described above.

【0075】

As the substrate, the above-exemplified substrate, for example, a substrate transparent enough to transmit laser light (for example, a glass plate such as soda glass, non-alkali glass, quartz glass, etc., or polyester, polysulfone, polyethersulfone, etc.) Polysulfone sheets or films such as) can be used. When producing a flexible organic EL device, a polymer film is preferable. As the substrate, the substrate used at the time of molecular injection may be used as it is, or a new substrate may be produced.

【0076】

According to the method of the present invention, in an organic EL device, fine multicolor patterning, which has been difficult in the conventional organic EL device using a polymer compound, is possible. Further, the material for an organic EL device (particularly, a film for an organic EL device) of the present invention has excellent surface smoothness, so that it has good adhesiveness to an electrode, and a light emitting center forming compound is injected stepwise. Therefore, not only voltage unevenness does not occur when a voltage is applied, but also a desired pattern can be formed with high accuracy.

【0077】

[Effect of the invention]

In the present invention, advanced positioning is possible by moving the laser light at least relative to the target, fine patterning can be easily performed, and if an optical fiber or the like is used, high precision and fineness can be achieved. Patterning is possible. Further, by moving the laser light at least relative to the target and moving the source with respect to the laser light, the emission center forming compound can be efficiently injected.

【0078】

[Example]

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

【0079】

Example 1 (Preparation of source film) Polybutyl methacrylate (manufactured by Aldrich, molecular weight 3.4 × 10) containing 5% by weight coumarin 6 (manufactured by Nippon Photosensitive Dye Co., Ltd.)⁵) Was dissolved in chlorobenzene, and a film having a thickness of 1 μm was prepared on a quartz substrate by a spin coating method. (Preparation of target film) 500 mg of poly-N-vinylcarbazole (PVK: manufactured by Kanto Chemical Co., Inc.) having a hole transport function and 2- (4-biphenyl) -5- (4-tert-butylphenyl) having an electron transport function. ) -1,3,4-Oxadiazole (PBD: manufactured by Aldrich) 500 mg was dissolved in 10 mL of 1,2-dichloroethane. On the other hand, an indium-tin-oxide (ITO) film was formed on the glass substrate. A target film having an electron / hole transport function with a film thickness of 100 nm was prepared on the ITO film by a dip coating method using the above 1,2-dichloroethane solution. (Molecular injection) The source film obtained as described above and the target film are brought into contact with each other and fixed to a table that can move in the X-axis and Y-axis directions with the target film surface facing up, and the beam area is 20 mm.²Then, using a laser processing device capable of oscillating an XeF excimer laser (wavelength 351 nm) with a pulse width of 10 ns, the table was moved in the XY axis direction with respect to the laser light to 20 mm.²The luminescent center-forming compound was injected into the pattern of. (Organic EL device) An Al / Li electrode with a thickness of 200 nm (manufactured by High Purity Chemical Co., Ltd., Li content 0.78% by weight) was prepared by vacuum deposition on a target film (Sample 1) in which molecules were injected, and an organic EL device Got one.

【0080】

Using the ITO electrode of the organic EL element as an anode and the Al / Li electrode layer as a cathode, a DC electric field was applied between the two electrodes in the atmosphere to cause light emission. It was confirmed that the organic EL element 1 emits light from a voltage of about 18 V. In the area where coumarin 6 was injected, green luminescence of coumarin 6 was confirmed. Blue emission of PVK was confirmed in the part other than the above region.

[Simple explanation of drawings]

[Figure 1]

FIG. 1 is a schematic diagram for explaining a method of injecting a luminescent center-forming compound.

[Figure 2]

FIG. 2 is a schematic cross-sectional view showing an example (single layer structure) of the organic electroluminescence device of the present invention.

[Fig. 3]

FIG. 3 is a schematic cross-sectional view showing another example (multilayer structure) of the organic electroluminescence device of the present invention.

[Fig. 4]

FIG. 4 is a schematic cross-sectional view showing still another example (multilayer structure) of the organic electroluminescence device of the present invention.

[Fig. 5]

FIG. 5 is a schematic cross-sectional view showing another example (multilayer structure) of the organic electroluminescence device of the present invention.

[Fig. 6]

FIG. 6 is a schematic view for explaining another manufacturing method of the present invention.

[Explanation of symbols]

1 ... source 2 ... Target film 3 ... Luminescent center forming compound 4,5 ... board 10,20,30,40 ... board 11,21,31,41 ... Anode 12,22,32,42 ... light emitting layer 13,23,33,43 ... Cathode 24,44 ... Hall transport layer 35,45 ... electron transport layer