Koha Co., Ltd.

Tokyo Shibaura Electric Co., Ltd.

Waseda University

Hokushin Corporation

Other

Nichia Kagaku Kogyo K.k.

Tokyo Shibaura Denki Kabushiki Kaisha

Japan As Represented by Director General of Agency of Industrial Science

Marcon Electronics Company, Ltd.

Nippon Dyne-a-mat Corp.

Noboru Ichinose

Kiyoshi Shimamura

Kazuo Aoki

Encarnacion Antonia Garcia Villora

Yukio Kaneko

Masaki Katsura

Yuji Yokomizo

Takashi Takahashi

Hirohumi Tanaka

Yuhji Yokomizo

Yoshikazu Goto

Toshiaki Ueno

Takashi Tokuda

Hideo Ohkuma

Masayoshi Takei

Sadao Seimiya

Yuji Urano

Hideo Okuma

Kiyoshi Minami

Yoshikazu Tanno

Pierre Layrolle

Satoshi Nakakita

Nobuhiro Izaki

Shingo Kamoshita

Shinsuke Arita

Suezo Sugaike

Hideo Ookuma

Toshiaki Mizutani

Hideaki Hiraki

Haruo Kawamura

Atsuo Ito

Kenji Ojima

Mieko Nishihara

A light emitting element that includes a GaOsubstrate; an AlGaN buffer layer (0&#x2266;&#xd7;&#x2266;1) formed on the GaOsubstrate; an n-GaN layer formed on the AlGaN buffer layer; an p-GaN layer formed on a portion of the n-GaN layer; an n-electrode formed on a portion of the n-GaN layer; and an p-electrode formed on the p-GaN layer.

Light emitting element and method of making same

A light emitting element has a substrate of gallium oxides and a pn-junction formed on the substrate. The substrate is of gallium oxides represented by: (AlInGa)Owhere 0&#x2266;x&#x2266;1, 0&#x2266;y&#x2266;1 and 0&#x2266;x+y&#x2266;1. The pn-junction has first conductivity type substrate, and GaN system compound semiconductor thin film of second conductivity type opposite to the first conductivity type.

A method of growing a p-type thin film of &#x3b2;-GaOincludes preparing a substrate including a &#x3b2;-GaOsingle crystal, and growing a p-type thin film of &#x3b2;-GaOon the substrate. The p-type thin film is grown in a manner that Ga in the thin film is replaced by a p-type dopant selected from H, Li, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, Mn, Fe, Co, Ni, Pd, Cu, Ag, Au, Zn, Cd, Hg, Tl, and Pb.

[object Object]

A light-emitting element includes a &#x3b2;-GaOsubstrate, a GaN-based semiconductor layer formed on the &#x3b2;-GaOsubstrate, and a double-hetero light-emitting layer formed on the GaN-based semiconductor layer.

Semiconductor layer

A thin-film single crystal growing method includes preparing a substrate, irradiating an excitation beam on a metallic target made of a pure metal or an alloy in a predetermined atmosphere, and combining chemical species including any of atoms, molecules, and ions released from the metallic target by irradiation of the excitation beam with atoms contained in the predetermined atmosphere to form a thin film on the substrate.

To provide a semiconductor layer in which a GaN system epitaxial layer having high crystal quality can be obtained. The semiconductor layer includes a &#x3b2;-GaOsubstratemade of a &#x3b2;-GaOsingle crystal, a GaN layerformed by subjecting a surface of the &#x3b2;-GaOsubstrateto nitriding processing, and a GaN growth layerformed on the GaN layerthrough epitaxial growth by utilizing an MOCVD method. Since lattice constants of the GaN layerand the GaN growth layermatch each other, and the GaN growth layergrows so as to succeed to high crystalline of the GaN layer, the GaN growth layerhaving high crystalline is obtained.

To provide a GaOcompound semiconductor device in which a GaOsystem compound is used as a semiconductor, which has an electrode having ohmic characteristics adapted to the GaOsystem compound, and which can make a heat treatment for obtaining the ohmic characteristics unnecessary. An n-side electrodeincluding at least a Ti layer is formed on a lower surface of an n-type &#x3b2;-GaOsubstrateby utilizing a PLD method. This n-side electrodehas ohmic characteristics at 25&#xb0; C. The n-side electrodemay have two layer including a Ti layer and an Au layer, three layers including a Ti layer, an Al layer and an Au layer, or four layers including a Ti layer, an Al layer, a Ni layer and an Au layer.

To provide a method of controlling a conductivity of a GaOsystem single crystal with which a conductive property of a &#x3b2;-GaOsystem single crystal can be efficiently controlled. The light emitting element includes an n-type &#x3b2;-GaOsubstrate, and an n-type &#x3b2;-AlGaOcladding layer, an active layer, a p-type &#x3b2;-AlGaOcladding layer and a p-type &#x3b2;-GaOcontact layer which are formed in order on the n-type &#x3b2;-GaOsubstrate. A resistivity is controlled to fall within the range of 2.0&#xd7;10to 8&#xd7;10&#x3a9;cm and a carrier concentration is controlled to fall within the range of 5.5&#xd7;10to 2.0&#xd7;10/cmby changing a Si concentration within the range of 1&#xd7;10to 1 mol %.

A method for growing a &#x3b2;-GaOsingle includes preparing a &#x3b2;-GaOseed crystal and growing the &#x3b2;-GaOsingle crystal from the &#x3b2;-GaOseed crystal in a predetermined direction.

A method for growing a &#x3b2;-GaOsingle crystal hardly cracking and having a weakened twinning tendency and an improved crystallinity, a method for growing a thin-film single crystal with high quality, a GaOlight-emitting device capable of emitting a light in the ultraviolet region, and its manufacturing method are disclosed. In an infrared-heating single crystal manufacturing system, a seed crystal and polycrystalline material are rotated in mutually opposite directions and heated, and a &#x3b2;-GaOsingle crystal is grown in one direction selected from among the a-axis &#x3c;100&#x3e; direction, the b-axis &#x3c;010&#x3e; direction, and the c-axis &#x3c;001&#x3e; direction. A thin film of a &#x3b2;-GaOsingle crystal is formed by PLD. A laser beam is applied to a target to excite atoms constituting the target Ga atoms are released from the target by thermal and photochemical actions. The free Ga atoms are bonded to radicals in the atmosphere in the chamber. Thus, a thin film of a &#x3b2;-GaOsingle crystal is grown on a substrate of a &#x3b2;-GaOsingle crystal A light-emitting device comprises an n-type substrate produced by doping a &#x3b2;-GaOsingle crystal with an n-type dopant and a p-type layer produced by doping the &#x3b2;-GaOsingle crystal with a p-type dopant and junctioned to the top of the n-type substrate. The light-emitting device emits a light from the junction portion.

The invention provides a fluoride single crystal for detecting radiation having high luminescence intensity, a scintillator, a radiation detector employing the single crystal and a method for detecting radiation. The fluoride single crystal for detecting radiation contains Ce and at least one element (R) of Lu and Gd, wherein the single crystal is represented by CeRF(0.001&#x2266;x&#x2266;0.5).

Fluoride single crystal for detecting radiation, scintillator and radiation detector using the single crystal, and method for detecting radiation

Growing community of inventors

Tokyo, Japan

Noboru Ichinose