JP2007073532A - Organic electroluminescent display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an EL display unit in which a full color display is made possible, by forming a blue charge transport organic luminescent layer on a neighboring layer through vacuum vapor deposition method, after patterning red and green organic luminescent layers for each pixel by ink-jet method, and provide a manufacturing method of the EL display unit. <P>SOLUTION: An organic EL material, which has been considered impossible to make patterning, is formed and arranged by an ink-jet method to enable arbitrarily patterning an organic luminescent layer having red, green and blue luminous colors on each pixel. Accordingly, an organic EL full color display unit is realized. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an EL display capable of full-color display and a method for manufacturing an EL display using an inkjet method.

  An organic EL device has a structure in which a thin film containing a fluorescent organic compound is sandwiched between a cathode and an anode, and excitons (excitons) are formed by injecting and recombining electrons and holes into the thin film. This is an element that emits light by utilizing light emission (fluorescence / phosphorescence) when the exciton is deactivated.

  The characteristics of this organic EL device are that it can emit surface light with a high luminance of about 100-100000 cd / m @ 2 at a low voltage of 10 V or less, and can emit light from blue to red by selecting the type of fluorescent material. It is a thing.

  Organic EL devices are attracting attention as a means for realizing inexpensive large-area full-color display devices (Technical Report of the Institute of Electronics, Information and Communication Engineers, Vol. 89, No. 106, page 49, 1989). According to reports, bright dyes of blue, green and red are obtained using organic dyes that emit strong fluorescence in the light-emitting layer. This is considered to have realized a high-luminance full-color display by using an organic dye that emits strong fluorescence in a thin film state and has few pinhole defects.

  Furthermore, Japanese Patent Laid-Open No. 5-78655 provides a thin film layer in which a component of an organic light emitting layer is made of a mixture of an organic charge material and an organic light emitting material, prevents concentration quenching, widens the selection range of the light emitting material, and has a high brightness full color. It has been proposed to be an element.

  Appl. Phys. Lett. 64 (1994) p. No. 815 reports that white light emission was obtained when a pigment corresponding to the three primary colors RGB was added using a polyvinylcarbazole (PVK) light emitting layer.

  However, neither report mentions the actual configuration and manufacturing method of a full-color display panel.

  On the other hand, in the ink jet printing technology, it has been the mainstream to use water-based, alcohol-based, or glycol-based inks. The reason is that the ink does not attack the ink flow path and the ink head material. In addition, since organic solvent-based inks are harmful to the human body, many ink jet printers using water-based inks have been developed.

  Therefore, in order to convert the organic EL material into an ink and use it for ink jet patterning, it is more desirable that the material is water-soluble or alcohol and glycol solvent-soluble. Examples of conventional water-soluble organic EL materials include PPV precursors. This precursor becomes a salt and dissolves in water, and is polymerized by heating after film formation to form a light emitting layer. Cyanated PPV emits red light. These are materials having sufficient durability as a light emitting layer.

  The organic EL layer exhibiting blue light emission is generally formed by a vacuum vapor deposition method. Among them, a distil derivative has both excellent light emission luminance and durability (The 54th Japan Society of Applied Physics) Academic Lecture, Lecture Proceedings No. 3, 29p-ZC-10 (1993) 1125).

  Regarding the ink formation, the PPV-based blue light emitting material described above is not practical because it has poor luminance and durability. Therefore, inkjet patterning of blue light emitting materials has been difficult.

  An organic thin film EL element using the above-described organic dye emits blue, green, and red light. However, as is well known, in order to realize a full-color display body, it is necessary to dispose organic light emitting layers that emit three primary colors for each pixel. Conventionally, it has been considered very difficult to pattern organic light emitting layers. The cause is as follows. That is, one is that the metal surface of the reflective electrode material is unstable and the patterning accuracy of vapor deposition is not achieved. Second, the polymer or precursor that forms the hole injection layer and the organic light emitting layer is not resistant to a patterning process such as photolithography.

  In addition, as a conventional PPV-based water-soluble precursor, it is impossible to prepare a blue light emitting material that can guarantee durability and reliability. Therefore, it is difficult to convert the blue light emitting material into ink and perform ink jet patterning.

  The present invention solves the above-described problems, and its purpose is to pattern red and green organic light-emitting layers for each pixel by an ink jet method, and to form a blue charge transporting organic light-emitting layer on the adjacent layer. An object of the present invention is to provide an EL display body capable of full color display and a method for manufacturing the EL display body by forming the film by a vacuum deposition method or the like.

  In the full color organic EL display device of the present invention, at least red, green, and blue transparent pixel electrodes are formed on a transparent substrate, red and green organic light emitting layers only on the red and green transparent pixel electrodes, and the entire surface. In addition, a blue light emitting layer is formed, and a counter electrode is formed on the upper layer.

  At least red, green, and blue transparent pixel electrodes and thin film transistors (hereinafter referred to as TFTs) for driving the pixels are formed on a transparent substrate, and red and green organic light emitting layers are formed only on the red and green transparent pixel electrodes. And a blue light emitting layer is formed on the entire surface, and a counter electrode is formed on the entire upper layer of these layers.

  At least red, green and blue transparent pixel electrodes are formed on the transparent substrate, red and green organic light emitting layers are formed only on the red and green transparent pixel electrodes, and a blue light emitting layer is formed on the entire surface. Further, a counter electrode is formed in the upper layer of these.

  At least red, green, and blue transparent pixel electrodes are formed on a transparent substrate, and red and green polymer organic light-emitting layers are formed only on the red and green transparent pixel electrodes. A layer is formed, and a counter electrode is formed on these layers.

  The polymer organic light emitting layer is a hole injection type material, and the blue light emitting deposition layer formed on the entire surface thereof is a charge transport type material.

  At least red, green, and blue transparent pixel electrodes are formed on a transparent substrate, and red and green hole injection type polymer organic light emitting layers are formed only on the red and green transparent pixel electrodes. A hole injection layer that does not develop color is formed only on the upper surface, a charge transporting blue light-emitting layer is formed on the entire surface, and a counter electrode is formed on the upper layer.

  At least red, green, and blue transparent pixel electrodes are formed on the transparent substrate, and red and green hole-injection polymer organic light-emitting layers are formed only on the red and green transparent pixel electrodes. A hole injecting layer and a charge transporting blue light emitting vapor deposition layer that do not cause color development are formed, and a counter electrode is further formed thereon.

  The red and green high-molecular organic light-emitting layers are polyparaphenylene vinylene (hereinafter referred to as PPV) and derivatives thereof, and copolymers having these as basic units.

  In the EL display, a protective film is formed on the counter electrode.

  The EL display body is characterized in that the counter electrode is sealed with a second substrate via an inert gas or an inert liquid.

  In the method for producing a full-color organic EL display according to the present invention, in the EL display, the red and green organic light-emitting layers are formed by an ink jet method that discharges an arbitrary amount of liquid at an arbitrary position. Features.

  In the EL display manufacturing method, the red and green organic light-emitting layers are formed by dissolving or dispersing an organic light-emitting material or a precursor thereof in a liquid to form a discharge liquid, and discharging the ink by an inkjet method, followed by heating or light. The film is formed and fixed by irradiation.

  In the EL display manufacturing method, red and green organic light-emitting layers are formed by dissolving PPV and its derivatives and copolymers, or precursors thereof in a liquid as a discharge liquid, and discharging the ink by an inkjet method. Thereafter, the film is formed and fixed by heating.

  In the EL display, the non-colored hole injection layer formed only on the blue transparent pixel electrode is formed by an ink jet system that discharges an arbitrary amount of liquid to an arbitrary position.

  In the EL display, the blue light emitting layer and the upper counter electrode are formed by a vacuum deposition method.

  In the EL display, the hole injection layer formed on the entire surface is formed by a vacuum deposition method or a coating method.

  In short, in the present invention, as shown in FIG. 1, a red transparent pixel electrode 101, a green transparent pixel electrode 102, and a blue transparent pixel electrode 103 are formed on a transparent substrate 104, and only on the red and green transparent pixel electrodes 101 and 102. Further, the red organic light emitting layer 106 and the green organic light emitting layer 107, and the blue light emitting layer 109 are formed on the entire surface, and the counter electrode 110 is formed on the upper layer.

  The organic light emitting layer is formed by patterning and applying red and green organic light emitting materials by an ink jet method, and the blue light emitting layer is formed by a vacuum vapor deposition method or the like to realize full color display.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

Example 1
As shown in FIG. 1, ITO transparent pixel electrodes 101, 102, and 103 are formed on a glass substrate 104 by a photolithography technique to form a pattern with a pitch of 100 microns and a thickness of 0.1 microns. The ITO pattern is filled with a resin black resist, and a structure 105 serving as a light blocking layer and an ink dripping prevention wall is formed by photolithography. The black resist has a width of 20 microns and a thickness of 1.0 microns.

  Next, a light emitting material for coloring red and green is patterned and applied by the ink jet printing apparatus 108 to form color developing layers 106 and 107 having a thickness of 0.05 microns. A cyanopolyphenylene vinylene precursor is used for the red light emitting material, and a polyphenylene vinylene precursor is used for the green light emitting material. These organic EL materials are manufactured by Cambridge Display Technology and are available in liquid form. The polymer precursor is polymerized by heat treatment after inkjet discharge, and the light emitting layers 106 and 107 are formed.

  Next, a 0.1 micron charge transporting blue light emitting layer 109 is formed by vacuum deposition of an aluminum quinolinol complex.

  Finally, the MgAg reflective electrode 110 having a thickness of 0.1 to 0.2 microns is formed by vapor deposition.

  Thereby, a direct-view type full-color organic EL display is completed.

(Example 2)
As shown in FIG. 2, ITO transparent pixel electrodes 201, 202, and 203 are formed on a glass substrate 204 by a photolithographic technique to form a pattern with a pitch of 80 microns and a thickness of 0.1 microns. The ITO pattern is filled with a resin black resist, and a structure 205 serving as a light blocking layer and an ink dripping prevention wall is formed by photolithography. The black resist is 10 microns wide and 1 micron thick.

  Next, a light emitting material for coloring red and green is patterned and applied by the ink jet printing apparatus 209 to form the coloring layers 206 and 207. A cyanopolyphenylene vinylene precursor is used for the red light emitting material, and a polyphenylene vinylene precursor is used for the green light emitting material. These organic EL materials are manufactured by Cambridge Display Technology and are available in liquid form. The polymer precursor is polymerized by heat treatment after inkjet discharge, and the light emitting layers 206 and 207 are formed.

  Further, polyvinyl carbazole (PVK) is implanted as a hole injection layer on the transparent electrode 203 by an ink jet printing apparatus to form 208 layers.

  Further, 210 is formed on the entire surface of the substrate by a coating method using a pyrazoline dimer as a blue light emitting layer.

  Finally, an AlLi reflective pixel electrode 211 is formed.

  Thereby, a full-color organic EL display body is completed.

(Example 3)
2,3,6,7-Tetrahydro-11-oxo-1H, 5H, 11H- (1) benzopyrano [6,7,8-ij] -quinolidine-10-carboxylic acid was used as the organic light-emitting material for the organic light-emitting layer Then, 1,1-bis- (4-N, N-ditolylaminophenyl) cyclohexane is used as the organic hole injection layer material, and both are mixed to obtain a green light emitting material.

  Similarly, 2-13 ′, 4′-dihydroxyphenyl) -3,5,7-trihydroxy-1-benzopyrylium perchlorate is mixed with the hole injection layer material as a red organic light-emitting material.

  Furthermore, tris (8-hydroxyquinolinol) aluminum is used as the organic hole injection material for the blue light emitting layer, and 2,3,6,7-tetrahydro-9-methyl-11-oxo-1H, 5H is used as the organic light emitting material. , 11H- (1) benzopyrano [6,7,8-ij] -quinolidine is mixed to produce a luminescent material.

  In the same process as in Example 1 or Example 2, each light emitting layer is locally patterned by an ink jet printer device to produce an organic EL display.

Example 4
As shown in FIG. 3, ITO transparent pixel electrodes 301, 302, and 303 are formed on a glass substrate by a photolithographic technique to form a pattern with a pitch of 80 microns and a thickness of 0.1 microns. Between the ITO patterns is filled with a resin black resist, and a structure 304 serving as a light blocking layer and an ink dripping prevention wall is formed by photolithography. The black resist is 10 microns wide and 1 micron thick.

  Next, a light emitting material for coloring red and green is patterned and applied by the ink jet printing apparatus 307 to form the coloring layers 305 and 306. A cyanopolyphenylene vinylene precursor is used for the red light emitting material, and a polyphenylene vinylene precursor is used for the green light emitting material. These organic EL materials are manufactured by Cambridge Display Technology and are available in liquid form. The polymer precursor is polymerized by heat treatment after inkjet discharge, and light emitting layers 305 and 306 are formed.

  Further, a hole injection layer 308 is formed on the entire surface of the substrate by vacuum deposition of polyvinyl carbazole (PVK).

  Further, a blue light emitting layer 309 is formed on the entire surface of the substrate by applying a distil derivative (manufactured by Idemitsu Kosan).

  Finally, an AlLi reflective pixel electrode 310 is formed.

  Thereby, a full-color organic EL display body is completed.

(Example 5)
As shown in FIG. 4, an organic protective film 407 is formed on the organic EL display produced in Example 1 by spin coating of JSS (made by Japan Synthetic Rubber).

(Example 6)
A thin film transistor is formed on the glass plate, and then an ITO transparent pixel electrode is formed. Thereafter, the same process as in Example 1 is performed. Next, as shown in FIG. 5, the organic EL display is sealed in an argon 506 atmosphere by a peripheral seal 509 and a sealing material 508. Thereby, the lifetime of the full-color organic EL display is greatly increased.

(Example 7)
As shown in FIG. 6, after forming a thin film transistor 604 on a glass plate, an ITO transparent pixel electrode 603 is formed.

  Next, a light emitting material that develops red and green colors is applied by patterning using an inkjet printing apparatus to form color-developing layers 605 and 606 having a thickness of 0.05 microns. A cyanopolyphenylene vinylene precursor is used for the red light emitting material, and a polyphenylene vinylene precursor is used for the green light emitting material. These organic EL materials are manufactured by Cambridge Display Technology and are available in liquid form.

  Thereafter, an active matrix type full-color organic EL display is completed by processing in the same manner as in the first embodiment.

  In addition to the organic EL material used in this example, an aromatic diamine derivative (TPD), an oxydiazole derivative (PBD), an oxydiazole dimer (OXD-8), a distilarylene derivative (DSA), beryllium -Benzoquinolinol complex (Bebq), triphenylamine derivative (MTDATA), rubrene, quinacridone, triazole derivative, polyphenylene, polyalkylfluorene, polyalkylthiophene, azomethine zinc complex, porphyrin zinc complex, benzoxazole zinc complex, phenanthroline europium complex It can be used but is not limited to this.

  Specifically, known ones such as those described in JP-A-63-70257, JP-A-63-175860, JP-A-2-135361, JP-A-2-135359, and JP-A-3-152184 can be used. It is. These compounds may be used alone or in combination of two or more.

  Furthermore, when a 1,2,4-triazole derivative (TAZ) is used as a buffer layer between each layer, it is effective in light emission luminance and lifetime.

  Further, by doping PVK with fluorescent dyes such as 1,1,4,4-triphenyl-1,3-butadiene (blue), coatamine 6 (green) and DCM1 (red), a hole transport type EL material is obtained. Providing is effective in emission brightness and lifetime.

  In addition, spin coating, casting, dipping, bar coating, roll coating, and the like are effective as the coating method for forming the organic layer.

  Conventionally, patterning is possible by forming and arranging organic EL materials that cannot be patterned by an ink-jet method, thereby realizing a full-color organic EL display. As a result, an inexpensive and large-screen full-color display can be manufactured, and the effect is great.

It is a figure which shows the process of the organic electroluminescent display body in the 1st Embodiment of this invention. It is a figure which shows the process of the organic electroluminescent display body in the 2nd Embodiment of this invention. It is a figure which shows the process of the organic electroluminescent display body in the 4th Embodiment of this invention. It is sectional drawing which shows the structure of the organic electroluminescent display body in the 5th Embodiment of this invention. It is sectional drawing which shows the structure of the active matrix type organic electroluminescent display body in the 6th Embodiment of this invention. It is a top view which shows the structure of the active matrix type organic electroluminescent display body in the 7th Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 101 ... Transparent pixel electrode (red), 102 ... Transparent pixel electrode (green), 103 ... Transparent pixel electrode (blue), 104 ... Glass substrate, 105 ... Resin black resist, 106 ... Organic light emitting layer (red), 107 ... Organic Light emitting layer (green), 108 ... inkjet printer head, 109 ... organic light emitting layer (blue), 110 ... counter electrode, 201 ... transparent pixel electrode (red), 202 ... transparent pixel electrode (green), 203 ... transparent pixel electrode ( Blue), 204 ... Glass substrate, 205 ... Resin black resist, 206 ... Organic light emitting layer (red), 207 ... Organic light emitting layer (green), 208 ... Hole transport layer, 209 ... Inkjet printer head, 210 ... Organic light emitting layer (Blue), 211 ... counter electrode, 301 ... transparent pixel electrode (red), 302 ... transparent pixel electrode (green), 303 ... transparent pixel electrode (blue), 304 ... resin block 305 ... Organic light emitting layer (red), 306 ... Organic light emitting layer (green), 307 ... Inkjet printer head, 308 ... Hole transport layer, 309 ... Organic light emitting layer (blue), 310 ... Counter electrode, 401 ... Glass Substrate, 402 ... organic light emitting layer (red), 403 ... organic light emitting layer (green), 404 ... transparent pixel electrode (blue), 405 ... organic light emitting layer (blue), 406 ... counter electrode, 407 ... protective film, 501 ... Glass substrate, 502 ... organic light emitting layer (red), 503 ... organic light emitting layer (green), 504 ... transparent pixel electrode (blue), 505 ... organic light emitting layer (blue), 506 ... counter electrode, 507 ... protective substrate, 508 ... Sealing agent, 509 ... Peripheral seal, 510 ... Silver paste, 511 ... Bus line, 512 ... Argon gas, 601 ... Signal line, 602 ... Gate line, 603 ... Pixel electrode, 604 TFT, 605 ... organic light emitting layer (red), 606 ... organic light-emitting layer (green).

Claims (16)

  At least red, green and blue transparent pixel electrodes are formed on the transparent substrate, red and green organic light emitting layers are formed only on the red and green transparent pixel electrodes, and a blue light emitting layer is formed on the entire surface. A full-color organic EL display device, wherein a counter electrode is formed on the upper layer.   At least red, green, and blue transparent pixel electrodes and thin film transistors (hereinafter referred to as TFTs) for driving the pixels are formed on a transparent substrate, and red and green organic light emitting layers are formed only on the red and green transparent pixel electrodes. And a blue light emitting layer is formed on the entire surface, and a counter electrode is formed on the entire upper surface of these layers.   At least red, green and blue transparent pixel electrodes are formed on the transparent substrate, red and green organic light emitting layers are formed only on the red and green transparent pixel electrodes, and a blue light emitting layer is formed on the entire surface. In addition, a full color organic EL display device in which a counter electrode is formed on the upper layer.   At least red, green, and blue transparent pixel electrodes are formed on a transparent substrate, and red and green polymer organic light-emitting layers are formed only on the red and green transparent pixel electrodes. 4. The full-color organic EL display device according to claim 3, wherein a layer is formed, and a counter electrode is formed on the upper layer.   5. The full color organic EL according to claim 3, wherein the polymer organic light emitting layer is a hole injection type material, and the blue light emitting deposition layer formed on the entire surface thereof is a charge transport type material. Display device.   At least red, green, and blue transparent pixel electrodes are formed on a transparent substrate, and red and green hole injection type polymer organic light emitting layers are formed only on the red and green transparent pixel electrodes. 6. A hole injection layer that does not develop color only on the top, a charge transporting blue light-emitting layer is formed on the entire surface, and a counter electrode is further formed on these layers. Any one of the full-color organic electroluminescent display apparatuses.   At least red, green, and blue transparent pixel electrodes are formed on the transparent substrate, and red and green hole-injection polymer organic light-emitting layers are formed only on the red and green transparent pixel electrodes. 6. A full color organic EL display device according to claim 3, wherein a hole injection layer and a charge transporting blue light emitting vapor deposition layer that do not cause color development are formed, and a counter electrode is further formed thereon. .   8. The red and green high-molecular organic light-emitting layers are polyparaphenylene vinylene (hereinafter referred to as PPV) and derivatives thereof, and copolymers having these as basic units. Full color organic EL display device.   A full-color organic EL display device, wherein a protective film is formed on the counter electrode in the EL display body.   In the EL display, a full color organic EL display device is sealed with a second substrate via an inert gas or an inert liquid on a counter electrode.   In the EL display, a red and green organic light emitting layer is formed by an ink jet method in which an arbitrary amount of liquid is discharged at an arbitrary position.   In the EL display manufacturing method, the red and green organic light-emitting layers are formed by dissolving or dispersing an organic light-emitting material or a precursor thereof in a liquid to form a discharge liquid, and discharging the ink by an inkjet method, followed by heating or light. 12. The method for producing a full color organic EL display device according to claim 11, wherein the film is formed and fixed by irradiation.   In the EL display manufacturing method, red and green organic light-emitting layers are formed by dissolving PPV and its derivatives and copolymers, or precursors thereof in a liquid as a discharge liquid, and discharging the ink by an inkjet method. 12. The method for producing a full-color organic EL display device according to claim 11, wherein the film is formed and fixed by heating.   In the EL display, a full-color organic EL display device characterized in that the non-colored hole injection layer formed only on the blue transparent pixel electrode is formed by an ink jet method that discharges an arbitrary amount of liquid to an arbitrary position. Manufacturing method.   The method for producing a full-color organic EL display device according to any one of Examples 11 to 15, wherein in the EL display body, the blue light emitting layer and the upper counter electrode are formed by a vacuum deposition method.   The method for producing a full-color organic EL display device according to any one of Examples 11 to 16, wherein in the EL display body, the hole injection layer formed on the entire surface is formed by a vacuum deposition method or a coating method.

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