Tokuyama Corporation

Stanley Electric Co., Ltd

Sumitomo Osaka Cement Co., Ltd.

Japan Aerospace Exploration Agency

Tokyo University of Agriculture and Technology

Hexatech, Inc.

Toru Kinoshita

Kazuya Takada

Toru Nagashima

Toshiyuki Obata

Yoshinao Kumagai

Yoichi Sato

Ryosuke Nakamura

Akinori Koukitu

Jinqiao Xie

Hisashi Murakami

Yoshitsugu Sone

Hiroyuki Yanagi

Tsutomu Nozoe

Zlatko Sitar

Rafael F Dalmau

Masato Sakurai

Raoul Schlesser

Tetsuya Nakabeppu

Baxter F Moody

Yasuyuki Kurino

Naoki Takamiya

Yoshizumi Ishikawa

Asuka Shima

Yoshitaka Yamamoto

Hiroshi Furuya

Minoru Umeda

Keiichiro Hironaka

Ryota Shinozaki

Yuki Kubota

Naoki Tamari

Tsuyoshi Kawase

Yuko Katsube

An optical semiconductor element includes a single crystal AlN substrate; an n-type semiconductor layer having an AlGaN layer, the AlGaN layer being grown on the AlN substrate and being pseudomorphic with the AlN substrate, an Al composition of the AlGaN layer being reduced with an increase in distance from the AlN substrate; an active layer grown on the n-type semiconductor layer and having a multiple quantum well structure which includes a plurality of well layers and barrier layers; and a p-type semiconductor layer which is grown on the active layer. The single crystal AlN substrate has a dislocation density being 10cmor less.

Optical semiconductor element comprising n-type AlGaN graded layer

An optical semiconductor element comprises: an AlN substrate; an n-type semiconductor layer composed of an AlGaN layer, the AlGaN layer being grown on the AlN substrate and being pseudomorphic with the AlN substrate, an Al composition or the AlGaN layer being reduced with an increase in distance from the AlN substrate; an active layer which is grown on the n-type semiconductor layer; and a p-type semiconductor layer which is grown on the active layer.

Optical semiconductor element comprising n-type algan graded layer

A group III nitride laminate having monocrystalline n-type AlGaN (0.7&#x2264;X&#x2264;1.0) and an electrode is provided. The group III nitride laminate is characterized in that an n-type contact layer made of (AlGa)O(0.0&#x2264;Y&#x3c;0.3) is provided between the monocrystalline n-type AlGaN (0.7&#x2264;X&#x2264;1.0) and the electrode. Furthermore, a vertical semiconductor device including the above-described group III nitride laminate is provided.

Group III nitride laminate and vertical semiconductor device having the laminate

A vertical ultraviolet light-emitting diode has, on an aluminum polar plane of an n-type AlN single crystal substrate, a layer represented by n-type AlGaN (wherein X is a rational number satisfying 0.5&#x2264;X&#x2264;1.0), an active layer, a layer represented by p-type AlGaN (wherein Y is a rational number satisfying 0.5&#x2264;Y&#x2264;1.0) and a p-type GaN layer in this order and which is equipped with a p-electrode formed on the p-type GaN layer and an n-electrode partially provided on a plane on the opposite side to the aluminum polar plane of the n-type AlN single crystal substrate, preferably an n-electrode formed by providing at least one opening functioning as a light extraction window, wherein the shortest distance between the n-electrode and an arbitrary point in a portion where the n-electrode is not provided, is not more than 400 &#x3bc;m.

Vertical-type ultraviolet light-emitting diode

Provided is a group III nitride stacked body having an n-type AlGaN (0.5&#x2264;X&#x3c;1) layer formed on an AlN single crystal substrate while being lattice-matched to the AlN single crystal substrate wherein the n-type AlGaN (0.5&#x2264;X&#x3c;1) layer has at least a stacked structure in which a first n-type AlGaN (0.5&#x2264;X1&#x3c;1) layer, a second n-type AlGaN (0.5&#x2264;X2&#x3c;1) layer, and a third n-type AlGaN (0.5&#x2264;X3&#x3c;1) layer are stacked in this order from the AlN single crystal substrate side, and X1, X2, and X3 indicating the Al compositions of the respective layers satisfy 0&#x3c;|X1&#x2212;X2|&#x2264;0.1, and satisfy 0&#x3c;|X2&#x2212;X3|&#x2264;0.1.

Group III nitride stacked body, and semiconductor device having the stacked body

A group III nitride laminate includes, on an AlN single crystal substrate, a multilayer structure having an AlGaN layer (0&#x3c;X&#x2264;1) that is lattice-matched to the AlN single crystal substrate, and wherein a GaN layer that has a film thickness of 5-400 nm and a dislocation density of less than 5&#xd7;10cmor a half width of the X-ray omega rocking curve of 50-300 seconds is laminated on the AlGaN layer (0&#x3c;X&#x2264;1).

Group III nitride laminate, luminescence element comprising said laminate, and method of producing group III nitride laminate

There are provided: a solid polymer power generation or electrolysis method that does not require injection of energy from the outside and maintenance of a high temperature, and is capable of converting carbon dioxide to a useful hydrocarbon while producing energy, controlling the production amounts of the hydrocarbons or the like and a ratio sorted by kind of the hydrocarbons, improving utilization efficiency of a product, and simplifying equipment for separation and recovery; and a system for implementing the solid polymer power generation or electrolysis method. Carbon dioxide is supplied to the side of one electrodeof a reactorhaving a membrane electrode assembly, hydrogen is supplied to the side of the other electrode, and the amounts of the hydrocarbons produced per unit time and the ratio sorted by kind of the hydrocarbons are changed by controlling a power generation voltage of the reactor

Solid polymer power generation or electrolysis method and system

The invention provides highly transparent single crystalline AlN layers as device substrates for light emitting diodes in order to improve the output and operational degradation of light emitting devices. The highly transparent single crystalline AlN layers have a refractive index in the a-axis direction in the range of 2.250 to 2.400 and an absorption coefficient less than or equal to 15 cm-1 at a wavelength of 265 nm. The invention also provides a method for growing highly transparent single crystalline AlN layers, the method including the steps of maintaining the amount of Al contained in wall deposits formed in a flow channel of a reactor at a level lower than or equal to 30% of the total amount of aluminum fed into the reactor, and maintaining the wall temperature in the flow channel at less than or equal to 1200&#xb0; C.

Highly transparent aluminum nitride single crystalline layers and devices made therefrom

A silicon-doped n-type aluminum nitride monocrystalline substrate wherein, at a photoluminescence measurement at 23&#xb0; C., a ratio (I1/I2) between the emission spectrum intensity (I1) having a peak within 370 to 390 nm and the emission peak intensity (I2) of the band edge of aluminum nitride is 0.5 or less; a thickness is from 25 to 500 &#x3bc;m; and a ratio (electron concentration/silicon concentration) between the electron concentration and the silicon concentration at 23&#xb0; C. is from 0.0005 to 0.001.

N-type aluminum nitride monocrystalline substrate

A vertical nitride semiconductor device includes an n-type aluminum nitride single-crystal substrate having an Si content of 3&#xd7;10to 1&#xd7;10cmand a dislocation density of 10cmor less. An ohmic electrode layer is formed on an N-polarity side of the n-type aluminum nitride single-crystal substrate.

N-type aluminum nitride single-crystal substrate and vertical nitride semiconductor device

A composite wavelength conversion powder and a resin composition containing a composite wavelength conversion powder which have high utilization efficiency of light and high utilization efficiency of a constituent material, and are able to make highly efficient light emission and high reliability compatible are provided. The composite wavelength conversion powder is formed by dispersing phosphor particles having a refractive index of 1.6 or more in matrix particles containing fine magnesium fluoride particles or fine calcium fluoride particles. In addition, a light emitting device which is able to improve utilization efficiency of light due to the phosphor particles excited by primary irradiation light emitted by a light emitting element, is able to improve the optical output of light emission by increasing an the amount of secondary irradiation light generated from the phosphor particles, and is able to suppress limit the occurrence of color unevenness or a color variation device in light emitted to the outside of the device is provided. A light emitting device () includes a substrate (), a light emitting element () mounted on a front surface of the substrate (), and a light transmitting member () formed to cover the light emitting element (), and the light transmitting member () contains phosphor particles having an average particle diameter of 500 nm or less, and composite wavelength conversion particles () formed of inorganic particles having an average particle diameter of 500 nm or less which are transparent with respect to visible light.

Composite wavelength conversion powder, resin composition containing composite wavelength conversion powder, and light emitting device

A substrate includes aluminum nitride, wherein the aluminum nitride substrate has on at least a surface thereof an aluminum nitride single-crystal layer having as a principal plane a plane that is inclined 0.05&#xb0; to 0.40&#xb0; in the m-axis direction from the (0001) plane of a wurzite structure.

Aluminum nitride substrate and group-III nitride laminate

A layered body having a single crystal layer including a group III nitride having a composition AlGaInN (wherein, X, Y and Z are rational numbers respectively satisfying 0.9&#x2266;X&#x2266;1.0, 0.0&#x2266;Y&#x2266;0.1, 0.0&#x2266;Z&#x2266;0.1, and X+Y+Z=1.0) on a sapphire substrate. The layered body includes an initial single crystal layer that includes the group III nitride composition, an oxygen concentration of 1&#xd7;10cmor more and 5&#xd7;10cm&#x2212;3 or less and a thickness of 15 nm or more and 40 nm or less on the sapphire substrate and a second group III nitride single crystal layer including the group III nitride composition and having a reduced oxygen concentration than the initial single crystal layer.

Layered body having a single crystal layer

A method for forming an n-type contact electrode, which includes an n-type nitride semiconductor such as AlInGaN (with x, y, and z being rational numbers that sum to 1.0 and fulfill the relations 0&#x3c;x&#x2266;1.0, 0&#x2266;y&#x2266;0.1, and 0&#x2266;z&#x3c;1.0), includes: a step in which a first electrode metal layer including at least one metal selected from titanium, vanadium, and tantalum is formed on a layer of the aforementioned n-type semiconductor and then heat-treated at a temperature between 800&#xb0; C. and 1200&#xb0; C.; and a step in which a second electrode metal layer is formed on top of the first electrode metal layer and then heat-treated at a temperature between 700&#xb0; C. and 1000&#xb0; C. The second electrode metal layer contains a layer comprising a metal, such as aluminum, that has a work function between 4.0 and 4.8 eV and a resistivity between 1.5&#xd7;10&#x3a9;&#xb7;cm and 4.0&#xd7;10&#x3a9;&#xb7;cm.

N-type contact electrode formed on an N-type semiconductor layer and method of forming same using a second metal electrode layer heat-treated after being formed on a first, heat-treated metal electrode layer

Disclosed is a novel method for group III polarity growth on a sapphire substrate. Specifically disclosed is a method for producing a laminate wherein a group III nitride single crystal layer is laminated on a sapphire substrate by an MOCVD method. The method for producing a laminate comprises: a pretreatment step in which an oxygen source gas is supplied onto the sapphire substrate; a first growth step in which an initial single crystal layer that contains oxygen at a concentration of 5&#xd7;10cmor more but 5&#xd7;10cmor less is grown with a thickness of 3 nm or more but less than 15 nm by supplying the oxygen source gas onto the sapphire substrate together with a starting material gas for the growth of the group III nitride; and a second growth step in which a group III nitride single crystal layer that is reduced in the oxygen concentration in comparison to the initial single crystal layer is grown by supplying the starting material gas onto the initial single crystal layer without supplying the oxygen source thereto, or alternatively by supplying the oxygen source, together with the starting material gas, at a lower supply rate than that in the first growth step.

Growing community of inventors

Yamaguchi, Japan

Toru Kinoshita