Tdk Corporation

Semiconductor Energy Laboratory Co., Ltd.

Tdk Electronics Company, Limited

The Westaim Corporation

Other

Katsuto Nagano

Yoshihiko Yano

Jun Hagiwara

Suguru Takayama

Masato Susukida

Yukihiko Shirakawa

Taku Takeishi

Jun Hirabayashi

Masashi Miwa

Tomoyuki Oike

Yoshio Saita

Michio Arai

Takeshi Nomura

Yukio Yamauchi

Naoya Sakamoto

Masaki Takahashi

Yukie Nakano

Daisuke Iwanaga

Atsushi Yoshida

Syozo Sasa

Takao Noguchi

Mutsuko Nakano

Takashi Nakajima

Kazumi Ishikawa

Kazuhiko Ihaya

Takeshi Nakada

Yukio Asakawa

In a phosphor thin film comprising a matrix material and a luminescence center, the matrix material has the compositional formula: MABOSwherein Mis Zn, Cd or Hg, A is Mg, Ca, Sr, Ba or rare earth element, B is Al, Ga or In, and atomic ratios v, x, y, z and w are 0.005&#x2266;v&#x2266;5, 1&#x2266;x&#x2266;5, 1&#x2266;y&#x2266;15, 0&#x3c;z&#x2266;30, and 0&#x3c;w&#x2266;30. The phosphor thin film of quality is formed at low cost by a low-temperature process, enabling manufacture of full-color EL panels.

Phosphor thin film, preparation method, and EL panel

The present invention aims at providing a phosphor thin film capable of realizing a light-emitting device attaining an excellent response, favorable color purity, and emission with a high luminance; and an EL panel including the same. The EL panel including the phosphor thin film of the present invention comprises a substrate, and a lower electrode, an insulating layer, an EL phosphor laminate thin film, and an upper electrode which are successively laminated on the substrate. In the EL phosphor laminate thin film, buffer thin films are formed on both sides of a phosphor thin film comprising a matrix material which is essentially constituted by magnesium gallate and doped with a rare-earth element or the like, and electron injection thin films are further formed on both sides thereof.

Phosphor thin film, manufacturing method of the same, and electroluminescence panel

The EL device of the present invention has a structure in which a first electrode, a first insulator layer, an electroluminescence-producing light emitting layer, a second insulator layer, and a second electrode layer are successively stacked on an electrical insulating substrate. At least one of the first insulator layer and the second insulator layer has as a main component barium titanate and in addition 0.1 to 3 mole % magnesium oxide, 0.05 to 1.0 mole % manganese oxide, no more than 1 mole % yttrium oxide, 2 to 12 mole % of barium oxide and calcium oxide, and 2-12 mole % silicon oxide.

EL device

The invention aims to solve the problem of prior art EL devices that undesirable defects form in dielectric layers, and especially the problems of EL devices having dielectric layers of lead-base dielectric material including a lowering, variation and change with time of the luminance of light emission, and thereby provide an EL device ensuring high display quality without increasing the cost. Such objects are achieved by an EL device comprising at least an electrically insulating substrate and a structure including an electrode layer , a dielectric layer , a light emitting layer and a transparent electrode layer stacked on the substrate , wherein the dielectric layer is a laminate including a first thick-film ceramic high-permittivity dielectric layer whose composition contains at least lead, a second high-permittivity layer whose composition contains at least lead, and a third high-permittivity layer whose composition is free of at least lead.

The invention aims to provide a method for preparing a composite substrate of substrate/electrode/dielectric layer structure having a thick-film dielectric layer with a smooth surface using a sol-gel solution of high concentration capable of forming a film to a substantial thickness without generating cracks, the composite substrate and an EL device using the same. The object is attained by a method for preparing a composite substrate including in order an electrically insulating substrate, an electrode and an insulator layer formed thereon by a thick film technique, wherein a thin-film insulator layer is formed on the insulator layer by applying to the insulator layer a sol-gel solution obtained by dissolving a metal compound in a diol represented by OH(CH ) OH as a solvent, followed by drying and firing; the composite substrate and an EL device using the same.

Method of making a composite substrate

The invention aims to provide a composite substrate which suppresses reaction of a substrate with a dielectric layer that can otherwise cause degradation of the dielectric layer and which can be sintered at high temperature while minimizing the occurrence of cracks in the dielectric layer, and an EL device using the composite substrate. The object is attained by a composite substrate in which an electrode and a dielectric layer are successively formed on an electrically insulating substrate, the substrate having a coefficient of thermal expansion of 10-20 ppm/K, and an EL device using the composite substrate.

Composite substrate and EL device using the same

The invention has for its object to provide an EL phosphor multilayer thin film and EL device which can emit light with improved luminance. This object is achieved by the provision of an EL phosphor multilayer thin film wherein a phosphor thin film and a dielectric thin film are stacked one upon another. The phosphor thin film comprises a matrix material containing as a main component at least one compound selected from an alkaline earth thioaluminate, an alkaline earth thiogallate and an alkaline earth thioindate, and an rare earth element as a luminescent center, and the dielectric thin film comprises an alkaline earth oxide. There is also provided an EL device comprising such an EL phosphor multilayer thin film.

EL phosphor multilayer thin film and EL device

An EL panel for providing a display of three colors, comprising at least EL phosphor thin films of two types for emitting green and blue colors, and a red light emitting portion, the EL phosphor thin films of two types for emitting green and blue colors comprising an alkaline earth sulfide or oxide. The EL panel, especially full color EL panel can produce light of an improved color purity without a need for a RGB patterned filter.

EL panel

The invention aims to provide a phosphor multilayer eliminating a need for filters, having a satisfactory color purity and useful in white monochromatic EL devices, and an EL panel. Such objects are achieved by a phosphor multilayer comprising at least a first thin film and a second thin film wherein the first thin film is formed of a matrix material comprising barium aluminate as a main component, containing sulfur element and further containing Eu as a luminescent center, and the second thin film is formed of a matrix material comprising zinc sulfide as a main component, and an EL panel using the same.

Phosphor multilayer and EL panel

An object of the invention is to provide an EL phosphor laminate thin film and EL device which can emit light at a high luminance. The object is achieved by stacking a phosphor thin film and a dielectric thin film one on the other wherein the phosphor thin film comprises at least one compound selected from an alkaline earth thioaluminate, an alkaline earth thiogallate and an alkaline earth thioindate as a main component, and a rare earth element as a luminescence center, and the dielectric thin film comprises an alkaline earth-containing oxide and/or a titanium-containing oxide.

EL phosphor laminate thin film and EL device

A composite substrate in which the surface of the insulating layer is not influenced by the electrode layer and which requires neither a grinding process nor a sol-gel process, is easy to produce and can provide a thin-film EL device having a high display quality when used therein; a thin-film EL device using the substrate; and a production process for the device. The thin-film EL device is produced by forming a luminescent layer, other insulating layer and other electrode layer successively on a composite substrate comprising a substrate; an electrode layer embedded in the substrate in such a manner that the electrode layer and the substrate are in one plane; and an insulating layer formed on the surface of a composite comprising the substrate and the electrode layer.

Process for producing a thin film EL device

The invention aims to provide a method for preparing a composite substrate, which prevents an insulating layer surface from becoming rugged under the influence of an electrode layer, and eliminates a polishing step, whereby the composite substrate is easy to manufacture and ensures high display quality when applied to thin-film light emitting devices, the composite substrate and an thin-film EL device using the same. The object is attained by a method for preparing a composite substrate by successively applying an electrode paste and an insulator paste onto an electrically insulating substrate as thick films to form a composite substrate precursor having a green electrode layer and a green insulator layer laminated, subjecting the precursor to pressing treatment for smoothing its surface, and firing; the composite substrate and an EL device using the same.

Composite substrate, method of making, and EL device using the same

The invention aims to provide a phosphor thin film eliminating a need for filters, having a satisfactory color purity and useful as the blue color in full-color EL displays, a method for preparing the same and an EL panel. Such objects are achieved by a phosphor thin film formed of a matrix material comprising barium thioaluminate as a main component to which magnesium is added and rare earth element, Eu is added as a luminescent center, a method for preparing the same, and an EL panel using the same.

The invention aims to solve the problem of prior art EL devices that undesirable defects form in dielectric layers, and especially the problems of EL devices having dielectric layers of lead-base dielectric material including a lowering, variation and change with time of the luminance of light emission, and thereby provide an EL device ensuring high display quality and a method for manufacturing the same at a low cost. Such objects are achieved by an EL device comprising at least an electrically insulating substrate ( ) and a structure including an electrode layer ( ), a dielectric layer ( ), a light emitting layer ( ) and a transparent electrode layer ( ) stacked on the substrate ( ), wherein the dielectric layer is a laminate including a first thick-film ceramic high-permittivity dielectric layer ( ) whose composition contains at least lead, a second high-permittivity layer ( ) whose composition contains at least lead, and a third high-permittivity layer ( ) whose composition is free of at least lead.

EL device and making method

The invention aims to provide, without incurring any cost increase, a thin-film EL device comprising a multilayer dielectric layer formed of a lead-based dielectric material by a solution coating-and-firing process, which has solved problems including light emission luminance drops, luminance variations and changes of light emission luminance with time, thereby achieving high display quality, and a process for the fabrication of the same. The object is accomplished by forming a patterned electrode layer on an electrically insulating substrate and constructing thereon a dielectric layer having a multilayer structure wherein lead-based dielectric layers formed by repeating the solution coating-and-firing process plural times and a non-lead-based, high-permittivity dielectric layer are stacked, the uppermost surface layer of the dielectric layer having a multilayer structure being the non-lead-based, high-permittivity dielectric layer.

Growing community of inventors

Tokyo, Japan

Katsuto Nagano