JP2007220431A - Multi-color luminescent device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color conversion multi-color luminescent device which has high productivity and can be manufactured economically. <P>SOLUTION: The multi-color luminescent device is provided with at least three kinds of color conversion filter layers on a transparent substrate, a gas barrier layer, an electroluminescent element which emits a light when an electric field is impressed. At least one kind of the above color conversion filter layers is a lamination of a color filter layer and a color conversion layer, and the above color conversion layer contains a photochromic compound having functions of absorbing a part of the emitted light from the electroluminescent element and emitting a light of a wavelength different from a wavelength of the absorbed light. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a multicolor light emitting device and a method for manufacturing the same. The light emitting device can be used for display of an image sensor, a personal computer, a word processor, a television, audio, video, car navigation, a telephone, a portable terminal, and an industrial measuring instrument.

  An electroluminescent element is known as an example of a light emitting element applied to a display device. An electroluminescent element is a thin-film self-luminous element and has excellent characteristics such as a low driving voltage, high resolution, and a high viewing angle. Therefore, various studies have been made for their practical use.

  As a method for producing a full-color display using electroluminescent elements, a “three-color light emitting system” in which elements emitting light in red, green and blue are arranged by applying an electric field, and white light is emitted in a specific wavelength region. "Color filter system" which makes red, green and blue light through a color filter that transmits light, and absorbs near-ultraviolet light, blue light, blue-green light or white light and performs wavelength distribution conversion to light in the visible region A “color conversion method” has been proposed in which a color conversion dye that emits light is used as a filter.

  As a white light emitting element used in this color filter system, a host material that emits a primary color of white light emission, a dopant material that emits a complementary color of the emission color of the host material, and the host material that absorbs light emission of the host material There is also a proposal of a white light-emitting element having a light-emitting portion composed of a single layer or a plurality of layers including at least three organic phosphors and a wavelength conversion substance that emits light having a wavelength longer than the emission center wavelength of the material. (For example, refer to Patent Document 1).

  There is also a proposal of a photochromic display element characterized in that light emitted from an electroluminescent element is used as excitation light (see, for example, Patent Document 2).

In addition, there is also a proposal of an organic EL display device in which a photochromic material layer is disposed in a light path from an organic light emitting unit and display definition can be ensured even under strong external light (for example, a patent) Reference 3). The organic EL display device of Patent Document 3 includes a combination of light emitting elements in which the light emitting part emits each of the RBGs, and the photochromic material provided in the light path from the light emitting part is one of the three primary colors from the light emitting part. When the white light is applied to the photochromic material layer, the light of the color is increased and emitted.
Furthermore, there is also a proposal of applying a photochromic material to an organic fluorescent material that forms a light emitting layer of an organic EL element as a simple method for emitting multicolor light without using a third member such as a filter or a color conversion film ( For example, see Patent Document 4.)

JP 2000-243565 A JP 2004-264424 A JP 2005-85683 A JP-A-11-260550

In the three-color light-emitting method, the light-emitting elements are separately applied to red, green, and blue by mask vapor deposition, which increases the difficulty of the process and makes it difficult to increase the size.
In addition, a circularly polarizing plate having a transmittance of 50% or less that prevents reflection of the metal electrode is required, and there is a problem that the cost is high and the loss of efficiency is large.

  In the color filter system using a white light emitting element as described in Patent Document 1, there is a problem that the current dependency of the EL spectrum is increased, and a problem that the light emission balance is easily lost by driving, resulting in a color shift. Therefore, the problem that the lifetime as a full-color organic electroluminescent display falls arises.

  In addition, in the combination of a white light emitting element and a color conversion filter, in the process of forming the color conversion layer, each color filter is separately applied in the photo process, so the number of processes increases, resulting in a decrease in manufacturing efficiency and a resulting increase in cost. In addition, there is a problem that the quality of the color generated from each formed filter layer is not sufficiently good.

  The organic EL display device of Patent Document 3 requires a light emitting element that emits light of each of the three primary colors, and the photochromic material emits as it is without affecting the incident light from the light emitting element. When white light, which is external light, is irradiated, the photochromic material emits white light having the same wavelength as the light incident from the light emitting element, that is, the light of the above color is emitted with increased intensity. It does not convert light.

  In the device configuration used in the method described in Patent Document 4, an organic electroluminescent element can be provided without using a third member such as a filter or a color conversion film. There is a problem that will decrease.

  The present inventors have realized that a multicolor light emitting device using a color conversion layer containing a photochromic compound can realize a high-quality and high-definition full-color display, and use the same coating liquid containing a photochromic compound. In addition, the present inventors have found that a green conversion layer and a red conversion layer can be formed by irradiating ultraviolet light having a specific wavelength, respectively, thereby completing the present invention. That is, an object of the present invention is to provide a multicolor light emitting device that is free from the above-described problems in the prior art, has high productivity, can realize a high-quality, high-definition full-color display, and a manufacturing method thereof. And

  That is, the multicolor light emitting device of the present invention is a multicolor light emitting device in which at least three kinds of color conversion filter layers, a gas barrier layer, and an electroluminescent element that emits light when an electric field is applied are disposed on a transparent substrate. Thus, at least one of the color conversion filter layers is a laminate of a color filter layer and a color conversion layer, and the color conversion layer absorbs part of the light emitted from the electroluminescent element, and what is the wavelength of the absorbed light? It contains a photochromic compound having a function of emitting light of different wavelengths.

  Further, the method for producing a multicolor light emitting device of the present invention includes at least three kinds of color conversion filter layers independently provided on a transparent substrate, and a gas barrier layer and a light emitting element on the transparent substrate on which the color conversion layer is provided. The color conversion filter layer is a laminate of a color filter layer and a color conversion layer, and the color conversion layer emits light from an electroluminescent element. A coating containing a photochromic compound having a function of absorbing a part of the light and emitting light having a wavelength different from the wavelength of the absorbed light, and the color conversion layer containing the photochromic compound on the entire surface of the color filter layer After the liquid is applied, a green conversion layer and a red conversion layer are formed by irradiating ultraviolet light having a specific wavelength to the green conversion site and the red conversion site, respectively.

A full-color display using the multicolor light emitting device of the present invention can be a high-quality and high-definition display, and is excellent in productivity.
In addition, according to the method for manufacturing a multicolor light emitting device of the present invention, the color conversion layer can be formed with a smaller number of steps than in the prior art, and the multicolor light emitting device can be manufactured with a high yield.
Furthermore, since the color conversion layer has a single layer coating, the color conversion layer has smoothness, and compared with the conventional color conversion method device, a flattening layer forming step can be omitted and a multicolor light emitting device can be manufactured with high yield. It is possible.

  FIG. 1 shows a schematic cross-sectional view (for one pixel) of one embodiment of the multicolor light emitting device of the present invention. The multicolor light emitting device of FIG. 1 has a black matrix 5, a color conversion filter layer (a red color filter 6, a green color filter 7, a blue color filter 8, a red conversion layer 9 made of a photochromic material, a photochromic material on a transparent substrate 12. The green conversion layer 10, the photochromic material layer), the gas barrier layer 4, and the light emitting element are stacked. The light emitting element includes an anode 2, an organic light emitter 3, and a cathode 1. The black matrix 2 and the gas barrier layer 10 may be optionally provided, but are preferably provided. Hereinafter, each component will be described.

(Transparent substrate)
As long as the transparent substrate used in the present invention is excellent in visible light transmittance and does not cause deterioration in performance of the color conversion filter or the multicolor light emitting device in the process of forming the color conversion filter and the multicolor light emitting device, any Can also be used. Specific examples of such a transparent substrate include a glass substrate, various plastic substrates, and various films.

(Color conversion filter layer)
In this specification, the color conversion filter layer is a general term for a color filter layer, a color conversion layer, and a laminate of a color filter layer and a color conversion layer. As the color filter used for the color filter layers 6, 7, and 8, those used for a flat panel display such as a liquid crystal display can be applied. In recent years, a pigment dispersion type color in which a pigment is dispersed in a photoresist. Filters are widely used.

  The color conversion filter layer in the present invention comprises at least three kinds of color conversion filter layers having transmission regions in different wavelength ranges, and at least one of the color conversion filter layers is a laminate of the color filter layer and the color conversion layer. . Examples of the three types of color conversion filter layers include red, green, and blue color conversion filter layers.

(Color filter layer)
In the configuration shown in FIG. 1, the color filter layers 6, 7, and 8 are color filter layers having transmission regions in different wavelength ranges. For example, the color filter layer 6 is a red color filter layer that transmits light in the red region (wavelength range of 600 nm or more), and the color filter layer 7 is a green color filter that transmits light in the green region (wavelength region of 500 to 600 nm). The color filter layer 8 can be a blue color filter layer that transmits light in a blue region (wavelength region of 400 to 550 nm). In general, a black matrix that does not transmit light in the visible range is disposed between the color filters mainly for the purpose of improving the contrast.

(Color conversion layer)
The color conversion layer is a layer containing a photochromic material and a matrix resin. As the photochromic material used for the color conversion layer, a material that absorbs light in a predetermined wavelength region of ultraviolet light and visible light, changes from a decolored state to a colored state, and emits light with visible light of 450 to 700 nm is used.

  Examples of the photochromic material include stilbene derivatives, spiropyrans, spirooxazines, diarylethenes, fluorides, cyclophanes, chalcone derivatives, and the like, or a mixture thereof.

  Examples of the diarylethenes include 1,2-bis (2,4-dimethyl-3-thienyl) perfluorocyclopentane, 2,3-bis (2,4,5-trimethyl-3-thienyl) maleic anhydride, 2- (1,2-Dimethyl-3-indolyl) -3- (2,4,5-trimethyl-3-thienyl) maleic anhydride, 2,3-bis (1,2-dimethyl-3-indolyl) anhydride Maleic acid, 2,3-bis (1,2-dimethyl-5-methoxy-3-indolyl) maleic anhydride, 2- (1,2-dimethyl-3-indolyl) -3- (2,4-dimethyl- 5-cyano-3-thienyl) maleic anhydride, 1- (1,2-dimethyl-5-methoxy-3-indolyl) -2- (2,4-dimethyl-5-cyano-3-thienyl) perfluorocyclo Pentane, 1 And 2-bis (2-hexyl-3-thienyl) perfluoro cyclopentane dithieno (thiophene) derivatives.

  Examples of fulgides include 2- [1- (3,5-dimethyl-4-isoxazolyl) ethylidene] -3-isopropylidene succinic anhydride, 2- [1- (5-methyl-2-phenyl-4) -Oxazolyl) ethylidene] -3-isopropylidene succinic anhydride, 2- [1- (2-phenyl-5-methyl-4-oxazolyl) stearylidene] -3-isopropylidene succinic anhydride, 2- [1- (2,5-Dimethyl-1-phenylpyrazolyl) ethylidene] -3-isopropylidene succinic anhydride, 2- [1- (3-methoxy-5-methyl-1-phenyl-4-pyrazolyl) ethylidene] -3 -Isopropylidene succinic anhydride, 2- [1- (2-methyl-5-styryl-3-thienyl) ethylidene] -3-isopropylidene succinic anhydride And so on.

  As the matrix used for the color conversion layer, a resin material having good compatibility with the photochromic compound and excellent in dimensional stability and transparency is preferable. Examples of such resin materials include polyethylene, polystyrene, polymethyl methacrylate, polycarbonate (PC), polyethylene terephthalate (PET), polyethersulfone, polyvinyl butyral, polyphenylene ether, polyamide, polyetherimide, norbornene resin, Thermoplastic resins such as isobutylene maleic anhydride copolymer resin and cyclic olefin resin, epoxy resin, phenol resin, urethane resin, polyfunctional acrylic resin, vinyl ester resin, imide resin, urea resin, melamine resin, etc. Examples include thermosetting resins, polymer hybrids containing polystyrene, polyacrylonitrile, polycarbonate, etc. and functional or tetrafunctional alkoxysilanes, or silicone polymers. Door can be.

  The mixing ratio of the matrix and the photochromic material is not particularly limited as long as sufficient optical density and emission intensity can be obtained, but the amount of the photochromic material in the mixture with the matrix is preferably 5 to 10% by weight. .

  As a method for forming the color conversion layer, for example, a coating solution composed of a green photochromic material, a red photochromic material, and a matrix is formed by a spin coating method, only a green conversion site is exposed using a mask, and ultraviolet light is applied. Color the green photochromic material to form a green conversion layer. Subsequently, a method of forming a red conversion layer by exposing only a red conversion site using a mask and applying ultraviolet light to develop a color of a green photochromic material and a red photochromic material can be exemplified. In this case, since the color to be developed changes depending on the wavelength of the irradiated ultraviolet light, the red conversion site is irradiated with ultraviolet rays having a wavelength that emits red light, and the green conversion site is irradiated with ultraviolet rays having a wavelength that emits green light.

(Gas barrier layer)
The gas barrier layer 4 is a layer intended to prevent moisture and / or oxygen derived from a layer formed thereunder from reaching the organic light emitter 3 and deteriorating the organic light emitter 3. The gas barrier layer 4 has high transparency in the visible region (transmittance of 50% or more in the range of 400 to 700 nm), a glass transition temperature (Tg) of 100 ° C. or more, and a film hardness of 2H or more of pencil hardness. It is formed from a material that does not deteriorate the functions of the formed color conversion filters 6 to 8. For example, an imide-modified silicone resin; a material in which an inorganic metal compound such as TiO, Al ₂ O ₃ , or SiO ₂ is dispersed in acrylic, polyimide, silicone resin, or the like; has a reactive vinyl group such as an acrylate monomer / oligomer / polymer Resin resin; Inorganic compound formed by sol-gel method; Photo-curing resin such as fluorine-based resin and / or thermosetting resin.

  The method for forming the gas barrier layer is not particularly limited, and a conventional method such as a dry method such as a sputtering method, a vapor deposition method, or a CVD method, or a wet method such as a spin coating method, a roll coating method, or a casting method can be employed. .

Further, the gas barrier layer 4 has electrical insulation properties and barrier properties against gases and organic solvents, has high transparency in the visible range (transmittance of 50% or more in the range of 400 to 800 nm), and is formed thereon. As a hardness that can withstand the electrode film formation conditions, a material having a pencil hardness of 2H or more may be preferably used. Examples of such materials include inorganic oxides such as SiO _x , SiN _x , SiN _x O _y , AlO _x , TiO _x , TaO _x , and ZnO _x , and inorganic nitrides. The method for forming the gas barrier layer is not particularly limited, and a conventional method such as a sputtering method, a CVD method, a vacuum deposition method, or a dip method can be employed.

  The gas barrier layer 4 may be a single layer of the above-described material, or may be a laminated structure of a plurality of layers formed from the above-described material.

  When providing the gas barrier layer 4 in the multicolor light emitting device of the present invention, there are important factors to consider. That is, it is necessary to consider the influence of the film thickness of the gas barrier layer on display performance, particularly viewing angle characteristics. An important viewing angle characteristic in a color conversion organic light emitting display is a color change that occurs when the viewing angle is changed with respect to the display.

  When the gas barrier layer 4 that is too thick is formed, the optical path length until the light emitted from the organic light-emitting body 3 passes through the gas barrier layer 4 and reaches the color conversion filter layer becomes long. As a result, when a multicolor light emitting device is viewed from an oblique direction, light leakage (optical crosstalk) to adjacent pixels or subpixels of another color occurs. Considering the display performance of a multicolor light emitting device as a display, it is required to sufficiently reduce the ratio of the light emission amount of adjacent pixels or subpixels due to optical crosstalk to the light emission amount of the original pixels or subpixels. The Considering this point, it is preferable that the film thickness of the gas barrier layer 4 (the total film thickness in the case of a multilayer structure) is 0.1 to 1.0 μm.

(Organic light emitter)
The organic light-emitting body has a structure in which an organic light-emitting layer is sandwiched between a pair of electrodes 1 and 2 and a hole injection layer, a hole transport layer, and / or an electron injection layer are interposed as necessary. More specifically, for example, the following structures are exemplified.
(1) Anode / organic light emitting layer / cathode (2) Anode / hole injection layer / organic light emitting layer / cathode (3) Anode / organic light emitting layer / electron injection layer / cathode (4) Anode / hole injection layer / organic Light emitting layer / electron injection layer / cathode (5) Anode / hole injection layer / hole transport layer / organic light emitting layer / electron injection layer / cathode

In the above structures (1) to (5), it is desirable that at least one of the anode and the cathode is transparent in the wavelength range of light emitted from the organic light emitter, and emits light through the transparent electrode. Light is incident on the complementary color layer. In this technique, it is known that it is easy to make the anode transparent, and in the present invention, the anode 2 is preferably transparent.
The cathode 1 is preferably a reflective electrode.

The transparent electrode of the anode 2 is formed by stacking conductive metal oxides such as SnO ₂ , In ₂ O ₃ , ITO, IZO, ZnO: Al by sputtering. The transmittance of the transparent electrode is preferably 50% or more, and more preferably 85% or more with respect to light having a wavelength of 400 to 800 nm. It is desirable that the anode 11 has a thickness in the range of usually 50 nm or more, preferably 50 nm to 1 μm, more preferably 100 to 300 nm.

  The reflective electrode of the cathode 1 is preferably formed using a highly reflective metal, amorphous alloy, microcrystalline alloy, or the like. Examples of the highly reflective metal include Al, Ag, Mo, W, Ni, and Cr. Examples of the high reflectivity amorphous alloy include NiP, NiB, CrP, and CrB. Examples of the highly reflective microcrystalline alloy include NiAl. Alternatively, other alloys (for example, Mg / Ag alloy) containing the above-described highly reflective metal can be used.

  The anode and cathode patterns may be formed from a plurality of parallel stripe-shaped partial electrodes, and the stripe-shaped partial electrodes of the anode and the stripe-shaped partial electrodes of the cathode may intersect with each other, preferably orthogonally. Good. In that case, the organic light emitting device of the present invention can perform matrix driving. That is, when a voltage is applied to the specific stripe-shaped partial electrode of the anode and the specific stripe-shaped partial electrode of the cathode, the portion where the stripe-shaped partial electrodes intersect in the organic light emitting layer emits light. Therefore, by applying a voltage to the selected stripe-shaped partial electrodes of the anode and the cathode, only the portion where the specific complementary color layer and / or the color conversion filter layer is located can emit light.

  Alternatively, the anode may be a uniform flat electrode without a stripe pattern, and the cathode may be patterned so as to correspond to each pixel. In that case, a so-called active matrix drive can be performed by providing a switching element corresponding to each pixel.

Hereinafter, the present invention will be further described using examples.
<Example 1>
(Color filter)
On a transparent glass substrate (1737 glass: manufactured by Corning), a black matrix material (CK-7001: manufactured by Fujifilm ARCH), a red color filter material (CR-7001: manufactured by Fujifilm ARCH), and a green color filter material (CG-) 7001: FUJIFILM ARCH) and a blue color filter material (CB-7001: FUJIFILM ARCH) were used to form a black matrix 5 and color filters 6, 7, 8 (red, green and blue). The film thickness of the green color filter 7 was 2 μm, and the film thickness of the other filters was 1 μm.

  Each color filter was formed so that a set of red, green, and blue sub-pixels arranged in the horizontal direction was one pixel. The size of each sub-pixel is 300 μm in length × 100 μm in width, and the interval between adjacent sub-pixels is 30 μm in the vertical direction and 10 μm in the horizontal direction. Therefore, one pixel has dimensions of 300 μm in length × 320 μm in width, and the interval between adjacent pixels is 30 μm in the vertical direction and 10 μm in the horizontal direction. In this embodiment, 50 pixels in the vertical direction and 50 pixels in the horizontal direction are arranged to form a total of 2500 pixels.

(Color conversion layer)
2- [1- (3,5-dimethyl-4-isoxazolyl) ethylidene] -3-isopropylidene succinic anhydride (hereinafter abbreviated as PC-2), 2- [1- (2,5-dimethyl- 1-phenylpyrazolyl) ethylidene] -3-isopropylidene succinic anhydride (hereinafter abbreviated as PC-3), and propylene glycol monoethyl acetate (PGMEA) as a solvent for 9 parts by weight of polymethyl methacrylate, respectively. A coating solution was prepared by dissolving in 9 parts by weight, and a layer having a thickness of 5 μm was formed on the color filter formed on the substrate by spin coating. Subsequently, the part other than the green conversion part and the red conversion part is covered with a mask, and the 365 nm ultraviolet light is applied to develop the color of the green photochromic material PC3. The red photochromic material PC2 was colored to form a green conversion layer and a red conversion layer.

(Gas barrier layer)
Next, SiO ₂ was deposited on the color conversion filter layer by sputtering to form a gas barrier layer having a thickness of 0.5 μm. An RF-planar magnetron type apparatus was used as the sputtering apparatus, and SiO ₂ was used as the target. Ar was used as the sputtering gas during film formation, and the substrate temperature during formation was set to 80 ° C.

(Organic light emitter)
Next, an organic light emitter was formed on the gas barrier layer with a six-layer structure of anode / hole injection layer / hole transport layer / organic light emitting layer / electron injection layer / cathode.

  First, a transparent electrode (ITO) was formed on the entire upper surface of the gas barrier layer by sputtering. After applying a resist agent “OFRP-800” (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) on this ITO, patterning is performed by a photolithography method, and the width of each of the red, green, and blue light emitting portions is set. An anode composed of a plurality of parallel stripe-shaped partial electrodes each having a thickness of 105 μm, a pitch of 110 μm, and a thickness of 100 nm was obtained.

Next, the substrate on which the transparent electrode was formed was mounted in a resistance heating vapor deposition apparatus, and a hole injection layer, a hole transport layer, a blue light emitting layer, a red light emitting layer, and an electron injection layer were sequentially formed without breaking the vacuum. . During film formation, the internal pressure of the vacuum chamber was reduced to 1 × 10 ⁻⁴ Pa. As the hole injection layer, copper phthalocyanine (CuPc) having a thickness of 100 nm was stacked. As the hole transport layer, 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (α-NPD) having a thickness of 20 nm was stacked. As the light emitting layer, 4,4′-bis (2,2-diphenylvinyl) biphenyl (DPVBi) having a thickness of 30 nm was laminated. As the electron injection layer, aluminum chelate (Alq) having a thickness of 20 nm was stacked.

  Furthermore, using a mask that can obtain a stripe pattern having a width of 300 μm and a pitch of 330 μm perpendicular to the line of the stripe-shaped partial electrode of the anode without breaking the vacuum, Mg / Ag with a film thickness of 200 nm (weight ratio of 10: 1) A cathode consisting of

  Furthermore, using a mask that can obtain a stripe pattern having a width of 300 μm and a pitch of 330 μm perpendicular to the line of the stripe-shaped partial electrode of the anode without breaking the vacuum, Mg / Ag with a film thickness of 200 nm (weight ratio of 10: 1) A cathode consisting of

  Finally, the obtained laminate is moved into a glove box in a dry nitrogen atmosphere (both oxygen concentration and moisture concentration is 10 ppm or less) and sealed using sealing glass (not shown) and a UV curable adhesive. Thus, a light emitting device was obtained. A schematic cross-sectional view (for one pixel) of the multicolor light emitting device thus obtained is shown in FIG.

<Comparative Example 1>
(Color filter)
On a transparent glass substrate (1737 glass: manufactured by Corning), a black matrix material (CK-7001: manufactured by Fujifilm ARCH), a red color filter material (CR-7001: manufactured by Fujifilm ARCH), and a green color filter material (CG-) 7001: FUJIFILM ARCH) and a blue color filter material (CB-7001: FUJIFILM ARCH) were used to form a black matrix 5 and color filters 6, 7, 8 (red, green and blue). The film thickness of the green color filter 7 was 2 μm, and the film thickness of the other filters was 1 μm.

  Each color filter was formed so that a set of red, green, and blue sub-pixels arranged in the horizontal direction was one pixel. The size of each sub-pixel is 300 μm in length × 100 μm in width, and the interval between adjacent sub-pixels is 30 μm in the vertical direction and 10 μm in the horizontal direction. Therefore, one pixel has dimensions of 300 μm in length × 320 μm in width, and the interval between adjacent pixels is 30 μm in the vertical direction and 10 μm in the horizontal direction. In this embodiment, 50 pixels in the vertical direction and 50 pixels in the horizontal direction are arranged to form a total of 2500 pixels.

(Green conversion layer)
Coumarin 6 (0.7 parts by weight) as a fluorescent dye is dissolved in 120 parts by weight of propylene glycol monoethyl acetate (PGMEA) as a solvent, and then photopolymerizable resin “V259PA / P5” (trade name, Nippon Steel Chemical Co., Ltd.) Kogyo Co., Ltd.) 100 parts by weight was added and dissolved to obtain a coating solution for a green color conversion layer. This coating solution is applied onto a substrate on which a color filter is formed using a spin coating method, patterned by a photolithographic method, and a line having a line width of 134 μm, a pitch of 1016 μm, and a film thickness of 8 μm is formed on the green color filter. A green conversion layer of the pattern was formed.

(Red conversion layer)
Coumarin 6 (0.6 parts by weight), rhodamine 6G (0.3 parts by weight) and basic violet 11 (0.3 parts by weight) are dissolved in 120 parts by weight of propylene glycol monoethyl acetate (PGMEA) as a solvent. Subsequently, 100 parts by weight of a photopolymerizable resin “V259PA / P5” (trade name, Nippon Steel Chemical Co., Ltd.) was added and dissolved to obtain a red conversion layer coating solution. This coating solution is applied onto a substrate on which a color filter is formed by using a spin coating method, and red conversion of a line pattern having a line width of 134 μm, a pitch of 1016 μm, and a film thickness of 8 μm is formed on the red color filter by a photolithographic method. A layer was formed.

(Flattening layer)
A UV curable resin (epoxy-modified acrylate) is applied by spin coating on the red, green, and blue color conversion filter layers thus formed, and a flattening layer having a thickness of 8 μm is formed by irradiation with a high-pressure mercury lamp. did. There was no deformation | transformation of the color conversion filter layer at the time of flattening layer formation, and the flattening layer surface was flat.

  On the planarized layer thus formed, a gas barrier layer, an organic light emitter and a cathode were formed and sealed in the same manner as in Example 1 to obtain a multicolor light emitting device shown in FIG.

The multicolor light emitting devices obtained in Example 1 and Comparative Example 1 were lit at a DC drive of 0.1 A / cm ² and the lighting characteristics of the devices were measured. The results are shown in Table 1. The red, blue and green backlights were turned on under the same conditions. The luminance (white light) was set to 1 in Comparative Example 1.

  As is clear from Table 1, the multicolor light emitting device of the present invention (Example 1) is inferior to the device of Comparative Example 1, which is a conventional color conversion type multicolor light emitting device, and the multicolor light emitting device of the present invention. In the device, as seen in Example 1, there is no need to separately coat the color conversion filter according to the color as in Comparative Example 1, and the formed color conversion filter layer is flattened because the upper surface is flat. It can be seen that the layer forming process can be reduced, and that it is superior to the conventional color conversion type multicolor light emitting device represented by Comparative Example 1 in terms of cost and yield.

  The multi-color light emitting device having the device configuration of the present invention can eliminate the red and green coating process at the time of forming the color conversion layer, which was necessary in the manufacture of the conventional color conversion type multi-color light emitting device. In addition, since the color conversion layers of the respective colors can be made to have the same thickness, the number of steps can be reduced because the planarization layer forming step can be eliminated. Therefore, the yield can be improved and the cost can be reduced.

1 is a schematic cross-sectional view (for one pixel) of a multicolor light emitting device of the present invention It is a schematic sectional drawing (for 1 pixel) of the multicolor light emitting device of the conventional color conversion system.

Explanation of symbols

1: Cathode 2: Anode 3: Organic light emitter 4: Gas barrier layer 5: Black matrix 6: Red color filter 7: Green color filter 8: Blue color filter 9: Red conversion layer 10: Green conversion layer 12: Transparent substrate 13: Flattening layer 14: red conversion layer + red color filter 15: green conversion layer + green color filter 16: blue color filter

Claims (4)

  A multicolor light emitting device comprising at least three kinds of color conversion filter layers, a gas barrier layer, and an electroluminescent element that emits light when an electric field is applied on a transparent substrate, wherein at least one of the color conversion filter layers Is a laminate of a color filter layer and a color conversion layer, and the color conversion layer absorbs part of the light emitted from the electroluminescent element and emits light having a wavelength different from the wavelength of the absorbed light. A multicolor light-emitting device comprising a compound.   The multicolor light-emitting device according to claim 1, wherein the color conversion layer also has a function of a flattening layer.   A method for producing a multicolor light emitting device, wherein at least three kinds of color conversion filter layers are independently arranged on a transparent substrate, and a gas barrier layer and a light emitting element are sequentially arranged on the transparent substrate on which the color conversion layer is arranged. Thus, at least one of the color conversion filter layers is a laminate of a color filter layer and a color conversion layer, and the color conversion layer absorbs part of the light emitted from the electroluminescent element, and what is the wavelength of the absorbed light? It contains a photochromic compound having a function of emitting light of different wavelengths, and after the color conversion layer has applied the coating liquid containing the photochromic compound on the entire surface of the color filter layer, each of the green conversion site and the red conversion site A method for producing a multicolor light emitting device, wherein a green conversion layer and a red conversion layer are formed by irradiating ultraviolet light having a specific wavelength. The method for manufacturing a multicolor light emitting device according to claim 3, wherein the color conversion layer also has a function of a flattening layer.

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