Matsushita Electric Industrial Co., Ltd.

Other

Panasonic Corporation

Yasuhito Takahashi

Yasuo Kitaoka

Hisashi Minemoto

Isao Kidoguchi

Fumio Kawamura

Takatomo Sasaki

Yusuke Mori

Hidekazu Umeda

Eiichi Yasumoto

Yoshiaki Hasegawa

Noboru Taniguchi

Ayumu Tsujimura

Takayuki Negami

Yuji Mukai

Kazuyuki Hamada

Hiroshi Tatsui

Yasutoshi Kawaguchi

Takaharu Gamou

Mototsugu Ogura

Kunihito Mori

Toshimi Nishiyama

Kimihiko Shibuya

Nobuyasu Hase

Shigeru Sakai

Yukiyoshi Ono

Katutosi Tusima

Takumi Kida

Yuko Ishii

An object of the present invention is to obtain, with respect to a semiconductor light-emitting element using a group III nitride semiconductor substrate, a semiconductor light-emitting element having an excellent light extraction property by selecting a specific substrate dopant and controlling the concentration thereof. The semiconductor light-emitting element comprises a substrate composed of a group III nitride semiconductor comprising germanium (Ge) as a dopant, an n-type semiconductor layer composed of a group III nitride semiconductor formed on the substrate, an active layer composed of a group III nitride semiconductor formed on the n-type semiconductor layer, and a p-type semiconductor layer composed of a group III nitride semiconductor formed on the active layer in which the substrate has a germanium (Ge) concentration of 2&#xd7;10to 2&#xd7;10cm. The substrate is produced in a nitrogen-containing atmosphere using a melt comprising at least a group III element, an alkali or alkaline earth metal, and germanium (Ge) and nitrogen.

Semiconductor light emitting element, group III nitride semiconductor substrate and method for manufacturing such group III nitride semiconductor substrate

The present invention provides an acoustooptic device usable even with light in the ultraviolet region, free from laser damage and optical damage, and excellent in acoustooptic performance and an optical imaging apparatus using the same. The acoustooptic device according to the present invention includes a high-frequency signal input part (), a transducer part (), and an acoustooptic medium (). A high-frequency signal input from the high-frequency signal input part () is converted into a mechanical vibration by the transducer part (), and an optical characteristic of the acoustooptic medium () varies depending on the mechanical vibration. The acoustooptic medium is formed of a Group III nitride crystal. The optical imaging apparatus according to the present invention includes a light source, an acoustooptic device, a driving circuit, and an image plane. Light from the light source is diffracted by the acoustooptic device in accordance with a signal from the driving circuit and the resultant diffracted light forms an image on the image plane. An acoustooptic medium of the acoustooptic device is formed of a Group III nitride crystal.

Acoustooptic device and optical imaging apparatus using the same

A method for producing Group-III-element nitride crystals by which an improved growth rate is obtained and large high-quality crystals can be grown in a short time, a producing apparatus used therein, and a semiconductor element obtained using the method and the apparatus are provided. The method is a method for producing Group-III-element nitride crystals that includes a crystal growth process of subjecting a material solution containing a Group III element, nitrogen, and at least one of alkali metal and alkaline-earth metal to pressurizing and heating under an atmosphere of a nitrogen-containing gas so that the nitrogen and the Group III element in the material solution react with each other to grow crystals. The method further includes, prior to the crystal growth process, a material preparation process of preparing the material solution in a manner that under an atmosphere of a nitrogen-containing gas, at least one of an ambient temperature and an ambient pressure is set so as to be higher than is set as a condition for the crystal growth process so that the nitrogen is allowed to dissolve in a melt containing the Group III element and the at least one of alkali metal and alkaline-earth metal. The method according to the present invention can be performed by using, for example, the producing apparatus shown in.

Method for producing III group element nitride crystal, production apparatus for use therein, and semiconductor element produced thereby

A method for manufacturing Group III nitride crystals with high quality is provided. By the method, a crystal raw material solution and gas containing nitrogen are introduced into a reactor vessel, which is heated, and crystals are grown in an atmosphere of pressure applied thereto. The gas is introduced from a gas supplying device to the reactor vessel through a gas inlet of the reactor vessel, and then is exhausted to the inside of a pressure-resistant vessel through a gas outlet of the reactor vessel. Since the gas is introduced directly to the reactor vessel, impurities attached to the pressure-resistant vessel and the like into the crystal growing site can be prevented. Further, the gas flows through the reactor vessel, to suppress aggregation of an evaporating alkali metal, etc., at the gas inlet and reduce flow of the metal vapor into the gas supplying device.

Apparatus for production of crystal of group III element nitride and process for producing crystal of group III element nitride

A solar cell is configured to include: a substrate (); a conductive film () formed on the substrate (); a compound semiconductor layer () formed on the conductive film (), including a p-type semiconductor crystal containing an element of Group Ib, an element of Group IIIb, and an element of Group VIb; a n-type window layer () formed on the compound semiconductor layer (), having apertures (); and a n-type transparent conductive film formed on the n-type window layer () and on portions of the compound semiconductor layer () at the apertures of the n-type window layer (). The compound semiconductor layer () includes high-resistance parts (B), in portions of the compound semiconductor layer () in the vicinity of a surface thereof on a side opposite to the conductive film (), and the high-resistance parts (B) contain a n-type impurity doped in the p-type semiconductor crystal. The high-resistance parts (B) are located under the apertures () of the n-type window layer (), respectively.

Solar cell and production thereof

The present invention provides a method for producing a compound single crystal that can improve a growth rate and grow a large single crystal with high crystal uniformity in a short time, and a production apparatus used for the method. The compound single crystal is grown while stirring a material solution to create a flow from a gas-liquid interface in contact with a source gas toward the inside of the material solution. With this stirring, the source gas can be dissolved easily in the material solution, and supersaturation can be achieved in a short time, thus improving the growth rate of the compound single crystal. Moreover, the flow formed by the stirring goes from the gas-liquid interface where a source gas concentration is high to the inside of the material solution where the source gas concentration is low, so that dissolution of the source gas becomes uniform. Accordingly, it is possible not only to suppress nonuniform nucleation at the gas-liquid interface, but also to improve the quality of the compound single crystal produced.

Method for producing compound single crystal and production apparatus for use therein

A manufacturing apparatus of Group III nitride crystals and a method for manufacturing Group III nitride crystals are provided, by which high quality crystals can be manufactured. For instance, crystals are grown using the apparatus of the present invention as follows. A crystal raw material () and gas containing nitrogen are introduced into a reactor vessel (), to which heat is applied by a heater (), and crystals are grown in an atmosphere of pressure applied thereto. The gas is introduced from a gas supplying device () to the reactor vessel () through a gas inlet of the reactor vessel, and then is exhausted to the inside of a pressure-resistant vessel () through a gas outlet of the reactor vessel. Since the gas is introduced directly to the reactor vessel () without passing through the pressure-resistant vessel (), the mixture of impurities attached to the pressure-resistant vessel () and the like into the site of the crystal growth can be prevented. Further, since the gas flows through the reactor vessel (), there is no aggregation of an evaporating alkali metal, etc., at the gas inlet or the like, and such an alkali metal does not flow into the gas supplying device (). As a result, the quality of Group III nitride crystals obtained can be improved.

A clear ice making apparatus includes: a freezing space; a tray placed in the freezing space and having a lower temperature at a bottom part thereof than at an upper part thereof; and a water supply unit of supplying water to the tray from the top thereof, in which ice is made at an ice making rate of 5 &#x3bc;m/s or lower, a part of a liquid-phase section of water in the tray which part is in contact with atmosphere is frozen to complete the ice making, the liquid-phase section of water is not entirely supercooled before the ice making is completed, and the concentration of air in the liquid-phase section of water in the tray is equal to or lower than an excessive concentration of air.

Clear ice making apparatus, clear ice making method and refrigerator

The present invention provides a compact-sized reservoir with small power consumption. It suppresses possible oxidation of articles and growths of putrefactious aerobic organisms such as bacteria, fungi and the like, by storing the articles under an atmosphere of reduced oxygen concentration created by an oxygen pump device which makes use of an oxygen ion-conductive film. In a case of storing foods, the disclosed reservoir makes their long-term storing possible. The reservoir in accordance with the present invention uses an oxygen pump device provided with an oxygen ion-conductive electrolyte film and a pair of electrodes formed on the both surfaces thereof.

Reservoir and method for storing articles

Gas-permselective gas pump and warmer for using same

An n-ZnMgSSe lower cladding layer, an n-ZnSSe light guiding layer, an undopad CdZnSe active layer, a p-ZnSSe light guiding layer, a p-ZnMgSSe upper cladding layer, and a p-ZnSe cap layer are successively formed on an n-GaAs substrate. Then, grooves and a ridge are formed in the respective p-type layers by etching. A current blocking layer formed by laminating SiO.sub.2 layers and TiO.sub.2 layers in multiple layers is formed so as to bury the grooves. On the top surface of the ridge where the current blocking layer is not formed, an upper electrode is formed. On the bottom surface of the n-GaAs substrate, a lower electrode is formed, and thus the ridge type semiconductor laser is fabricated. This semiconductor laser is capable of emitting blue light with an oscillating wavelength of around 500 nm. The current blocking layer of the lamination of the SiO.sub.2 and TiO.sub.2 layers allows effective confinement of both light and carriers and a drastic decrease in the threshold current for a laser oscillation.

Semiconductor laser and a method for fabricating the same

A blue light emitting semiconductor device includes a first cladding layer, a second cladding layer, and an active layer. The first cladding layer includes a Group II-VI compound semiconductor of a first conduction type. The second cladding layer includes a Group II-VI compound semiconductor of a second conduction type different from the first conduction type. The active layer includes a Group II-VI compound semiconductor of the second conduction type, and extends between the first and second cladding layers a substrate includes a Group III-V compound semiconductor. At least two laminated buffer layers including Group III-V compound semiconductors extend between the first cladding layer and the substrate. An energy band gap at a position in the substrate, the buffer layers, and the first cladding layer varies stepwise as the position moves from the substrate to the first cladding layer via the buffer layers.

Blue light emitting semiconductor device and method of fabricating the

A catalyst for the hydrotreatment of a hydrocarbon oil comprises a carrier of an inorganic oxide and an active component supported on the carrier and formed of at least one member selected from the group consisting of water-soluble compounds of molybdenum, tungsten, and the metal of Group 8 in the Periodic Table of Elements and at least one mercapto (--SH) group-containing organic compound selected from the group consisting a mercaptocarboxylic acids represented by the general formula:

Catalyst for hydrotreatment of hydrocarbons and method for production

A semiconductor laser device has a compound semiconductor substrate, a first semiconductor layer disposed on the compound semiconductor substrate, and a second semiconductor layer disposed on the first semiconductor layer. The second semiconductor layer has at least three thin film layers of at least two different semiconductor compounds, the film layers being laminated with the different semiconductor compound layers alternating. An electrically isolating region extends through the thickness of the second semiconductor layer and electrically divides the second semiconductor layer into first and second portions which differ in quantum level from each other. A third semiconductor layer is disposed on the second semiconductor layer, and first and second electrodes are disposed on the third semiconductor layer in positions for supplying current to the first and second portions, respectively, and a third electrode is disposed on the substrate at the surface thereof opposite to the first and second electrodes. When a voltage is applied between the third and first electrodes and the third and second electrodes, laser beams having different wavelengths are emitted from the first and second portions of the second semiconductor layer, respectively.

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Osaka, Japan

Yasuhito Takahashi