With Heterojunction (e.g., Algan/gan) (epo) Patents (Class 257/E33.034)
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Publication number: 20110037088Abstract: A nitride-based semiconductor light-emitting device 100 includes: a GaN substrate 10 with an m-plane surface 12; a semiconductor multilayer structure 20 provided on the m-plane surface 12 of the GaN substrate 10; and an electrode 30 provided on the semiconductor multilayer structure 20. The electrode 30 includes an Mg layer 32 and an Ag layer 34 provided on the Mg layer 32. The Mg layer 32 is in contact with a surface of a p-type semiconductor region of the semiconductor multilayer structure 20.Type: ApplicationFiled: March 17, 2010Publication date: February 17, 2011Inventors: Mitsuaki Oya, Toshiya Yokogawa, Atsushi Yamada, Akihiro Isozaki
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Patent number: 7888670Abstract: There is provided a nitride semiconductor light emitting device including: an n-type semiconductor region; an active layer formed on the n-type semiconductor region; a p-type semiconductor region formed on the active layer; an n-electrode disposed in contact with the n-type semiconductor region; a p-electrode formed on the p-type semiconductor region; and at least one intermediate layer formed in at least one of the n-type semiconductor region and the p-type semiconductor region, the intermediate layer disposed above the n-electrode, wherein the intermediate layer is formed of a multi-layer structure where at least three layers with different band gaps from one another are deposited, wherein the multi-layer structure includes one of an AlGaN layer/GaN layer/InGaN layer stack and an InGaN layer/GaN layer/AlGaN layer stack.Type: GrantFiled: April 14, 2008Date of Patent: February 15, 2011Assignee: Samsung LED Co., Ltd.Inventors: Sang Heon Han, Sang Won Kang, Jeong Tak Oh, Seung Beom Seo, Dong Joon Kim, Hyun Wook Shim
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Patent number: 7884388Abstract: A light emitting diode (LED) and a method for fabricating the same, capable of improving brightness by forming a InGaN layer having a low concentration of indium, and whose lattice constant is similar to that of an active layer of the LED, is provided. The LED includes: a buffer layer disposed on a sapphire substrate; a GaN layer disposed on the buffer layer; a doped GaN layer disposed on the GaN layer; a GaN layer having indium disposed on the GaN layer; an active layer disposed on the GaN layer having indium; and a P-type GaN disposed on the active layer. Here, an empirical formula of the GaN layer having indium is given by In(x)Ga(1?x)N and a range of x is given by 0<x<2, and a thickness of the GaN layer having indium is 50-200 ?.Type: GrantFiled: November 23, 2009Date of Patent: February 8, 2011Assignee: LG Innotek Co., LtdInventor: Seong Jae Kim
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Publication number: 20110018010Abstract: Provided is an infrared light emitting device in which dark current and diffusion current caused by thermally excited holes are suppressed. Thermally excited carriers (holes) generated in a first n-type compound semiconductor layer (102) tend to diffuse in the direction of a ? layer (105). But, the dark current by holes is reduced by providing an n-type wide band gap layer (103) with a larger band gap than the first layer (102) and the ? layer (105) that suppresses the hole diffusion between the first layer (102) and the ? layer (105). The wide band gap layer (103) has a band gap shifted relatively to valence band direction by n-type doping and thereby more effectively functions as a diffusion barrier for the thermally excited holes. Namely, the band gap and n-type doping of the wide band gap layer (103) are adjusted to suppress diffusion of the thermally excited carriers.Type: ApplicationFiled: March 13, 2009Publication date: January 27, 2011Inventors: Koichiro Ueno, Naohiro Kuze
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Publication number: 20110012146Abstract: There is provided a light-emitting device including a second electrode which exhibits a stable behavior in a process for manufacturing a light-emitting device or during an operation of a light-emitting device. A light-emitting device includes a first compound semiconductor layer 11 with an n-type conductivity type, an active layer 12 formed on the first compound semiconductor layer 11 and composed of a compound semiconductor, a second compound semiconductor layer 13 with a p-type conductivity type formed on the active layer 12, a first electrode 15 electrically connected to the first compound semiconductor layer 11, and a second electrode 14 formed on the second compound semiconductor layer 13, wherein the second electrode 14 is composed of a titanium oxide, has an electron concentration of 4×1021/cm3 or more, and reflects light emitted from the active layer.Type: ApplicationFiled: March 13, 2009Publication date: January 20, 2011Applicant: SONY CORPORATIONInventors: Yukihisa Hitsuda, Tatsuo Ohashi
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Patent number: 7872269Abstract: Provided is a gallium nitride semiconductor light emitting element capable of stabilizing a drive voltage by reducing carrier depletion attributable to spontaneous polarization and piezo polarization generated at the interface between an AlGaN semiconductor layer and a GaN semiconductor layer. A gallium nitride semiconductor crystal 2 including a light emitting region is formed on the R plane of a sapphire substrate 1. In addition, in another constitution, a gallium nitride semiconductor crystal 2 is formed on the A plane of a GaN substrate 3 or on the M plane of a GaN substrate 4. The growth surface of these gallium nitride semiconductor crystals 2 are not an N (nitrogen) polar face or a Ga polar face but are non-polar faces. This can decrease the strength of an electric field caused by spontaneous polarization and piezo polarization generated at the interface of GaN/AlGaN at the p side. Thus, carrier depletion can be avoided.Type: GrantFiled: November 29, 2006Date of Patent: January 18, 2011Assignee: ROHM Co., Ltd.Inventor: Ken Nakahara
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Publication number: 20110008923Abstract: A light emitting diode comprising an epitaxial layer structure, a first electrode, and a second electrode. The first and second electrodes are separately disposed on the epitaxial layer structure, and the epitaxial layer structure has a root-means-square (RMS) roughness less than about 3 at a surface whereon the first electrode is formed.Type: ApplicationFiled: July 12, 2010Publication date: January 13, 2011Applicant: Bridgelux, Inc.Inventors: Chao-Kun Lin, Heng Liu
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Publication number: 20110006319Abstract: One embodiment of the present invention provides a gallium nitride (GaN)-based semiconductor light-emitting device (LED) which includes an n-type GaN-based semiconductor layer (n-type layer); an active layer; and a p-type GaN-based semiconductor layer (p-type layer). The n-type layer is epitaxially grown by using ammonia gas (NH3) as the nitrogen source prior to growing the active layer and the p-type layer. The flow rate ratio between group V and group III elements is gradually reduced from an initial value to a final value. The GaN-based LED exhibits a reverse breakdown voltage equal to or greater than 60 volts.Type: ApplicationFiled: August 31, 2007Publication date: January 13, 2011Applicant: LATTICE POWER (JIANGXI) CORPORATIONInventors: Fengyi Jiang, Li Wang, Wenqing Fang, Chunlan Mo, Yong Pu, Chuanbing Xiong
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Publication number: 20110006320Abstract: There is provided a light emitting device using a compound semiconductor, which can improve electrical characteristics and internal quantum efficiency by maximizing the recombination rate of electrons and holes in an active layer. The light emitting device using a compound semiconductor includes a substrate; a compound semiconductor layer formed on the substrate, the compound semiconductor layer comprising an active layer; and a current spreading layer formed on at least one of the top and bottom surfaces of the active layer, the current spreading layer allowing electrons or holes to be uniformly spread into the active layer.Type: ApplicationFiled: December 2, 2008Publication date: January 13, 2011Applicant: WOOREE LST CO., LTD.Inventors: Bun-Hei Koo, Jae-Eung Oh
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Patent number: 7868316Abstract: There is provided a nitride semiconductor device.Type: GrantFiled: January 7, 2009Date of Patent: January 11, 2011Assignee: Samsung Electro-Mechanics Co., LtdInventors: Suk Ho Yoon, Ki Ho Park, Joong Kon Son
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Publication number: 20110003416Abstract: An LED having vertical topology and a method of making the same is capable of improving a luminous efficiency and reliability, and is also capable of achieving mass productivity. The method includes forming a semiconductor layer on a substrate; forming a first electrode on the semiconductor layer; forming a supporting layer on the first electrode; generating an acoustic stress wave at the interface between the substrate and semiconductor layer, thereby separating the substrate from the semiconductor layer; and forming a second electrode on the semiconductor layer exposed by the separation of the substrate.Type: ApplicationFiled: September 13, 2010Publication date: January 6, 2011Inventors: Jun Ho JANG, Jae Wan Choi, Duk Kyu Bae, Hyun Kyong Cho, Jong Kook Park, Sun Jung Kim, Jeong Soo Lee
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Publication number: 20110001163Abstract: A method for producing a group III nitride semiconductor light-emitting device including: an intermediate layer formation step in which an intermediate layer containing group III nitride is formed on a substrate by sputtering, and a laminate semiconductor formation step in which an n-type semiconductor layer having a base layer, a light-emitting layer, and a p-type semiconductor layer are laminated on the intermediate layer in this order, wherein the method includes a pretreatment step in which the intermediate layer is treated using plasma between the intermediate layer formation step and the laminate semiconductor formation step, and a formation step for the base layer which is included in the laminate semiconductor formation step is a step for laminating the base layer by sputtering.Type: ApplicationFiled: February 7, 2008Publication date: January 6, 2011Applicant: SHOWA DENKO K.K.Inventors: Yasumasa Sasaki, Hisayuki Miki
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Patent number: 7858963Abstract: In the nitride based semiconductor optical device LE1, the strained well layers 21 extend along a reference plane SR1 tilting at a tilt angle ? from the plane that is orthogonal to a reference axis extending in the direction of the c-axis. The tilt angle ? is in the range of greater than 59 degrees to less than 80 degrees or greater than 150 degrees to less than 180 degrees. A gallium nitride based semiconductor layer P is adjacent to a light-emitting layer SP? with a negative piezoelectric field and has a band gap larger than that of a barrier layer. The direction of the piezoelectric field in the well layer W3 is directed in a direction from the n-type layer to the p-type layer, and the piezoelectric field in the gallium nitride based semiconductor layer P is directed in a direction from the p-type layer to the n-type layer. Consequently, the valence band, not the conduction band, has a dip at the interface between the light-emitting layer SP? and the gallium nitride based semiconductor layer P.Type: GrantFiled: April 1, 2010Date of Patent: December 28, 2010Assignee: Sumitomo Electric Industries, Ltd.Inventors: Masaki Ueno, Yohei Enya, Takashi Kyono, Katsushi Akita, Yusuke Yoshizumi, Takamichi Sumitomo, Takao Nakamura
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Patent number: 7851243Abstract: In the nitride based semiconductor optical device LE1, the strained well layers 21 extend along a reference plane SR1 tilting at a tilt angle ? from the plane that is orthogonal to a reference axis extending in the direction of the c-axis. The tilt angle ? is in the range of greater than 59 degrees to less than 80 degrees or greater than 150 degrees to less than 180 degrees. A gallium nitride based semiconductor layer P is adjacent to a light-emitting layer SP? with a negative piezoelectric field and has a band gap larger than that of a barrier layer. The direction of the piezoelectric field in the well layer W3 is directed in a direction from the n-type layer to the p-type layer, and the piezoelectric field in the gallium nitride based semiconductor layer P is directed in a direction from the p-type layer to the n-type layer. Consequently, the valence band, not the conduction band, has a dip at the interface between the light-emitting layer SP? and the gallium nitride based semiconductor layer P.Type: GrantFiled: August 6, 2010Date of Patent: December 14, 2010Assignee: Sumitomo Electric Industries, Ltd.Inventors: Masaki Ueno, Yohei Enya, Takashi Kyono, Katsushi Akita, Yusuke Yoshizumi, Takamichi Sumitomo, Takao Nakamura
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Patent number: 7851821Abstract: A group III nitride semiconductor device having a gallium nitride based semiconductor film with an excellent surface morphology is provided. A group III nitride optical semiconductor device 11a includes a group III nitride semiconductor supporting base 13, a GaN based semiconductor region 15, an active layer active layer 17, and a GaN semiconductor region 19. The primary surface 13a of the group III nitride semiconductor supporting base 13 is not any polar plane, and forms a finite angle with a reference plane Sc that is orthogonal to a reference axis Cx extending in the direction of a c-axis of the group III nitride semiconductor. The GaN based semiconductor region 15 is grown on the semipolar primary surface 13a. A GaN based semiconductor layer 21 of the GaN based semiconductor region 15 is, for example, an n-type GaN based semiconductor, and the n-type GaN based semiconductor is doped with silicon.Type: GrantFiled: February 26, 2010Date of Patent: December 14, 2010Assignee: Sumitomo Electric Industries, Ltd.Inventors: Takashi Kyono, Yusuke Yoshizumi, Yohei Enya, Katsushi Akita, Masaki Ueno, Takamichi Sumitomo, Takao Nakamura
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Publication number: 20100308347Abstract: A light emitting device includes a plurality of micro diodes, which are electrically connected to constitute a bridge rectifier circuit. Each branch of the bridge rectifier circuit includes a single micro diode or a plurality of micro diodes. The light emitting device is electrically connected to an AC power source, which alternately drives the light emitting device in two current loops. Therefore, the micro diodes in two current loops of the bridge rectifier circuit emit light by turns.Type: ApplicationFiled: June 7, 2010Publication date: December 9, 2010Applicants: INDUSTRIAL TECHNOLOGY RESEARCH CORPORATION, EPISTAR CORPORATIONInventors: Wen-Yung Yeh, Hsi-Hsuan Yen, Tse-Peng Chen
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Patent number: 7842531Abstract: A gallium nitride-based device has a first GaN layer and a type II quantum well active region over the GaN layer. The type II quantum well active region comprises at least one InGaN layer and at least one GaNAs layer comprising 1.5 to 8% As concentration. The type II quantum well emits in the 400 to 700 nm region with reduced polarization affect.Type: GrantFiled: March 5, 2009Date of Patent: November 30, 2010Assignee: Lehigh UniversityInventors: Nelson Tansu, Ronald A. Arif, Yik Khoon Ee
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Patent number: 7825428Abstract: There is provided a GaN-based semiconductor light emitting device including: a substrate; and an n-type GaN-based semiconductor layer, an active layer and a p-type GaN-based semiconductor layer sequentially deposited on the substrate, wherein the active layer includes: a first barrier layer including AlxInyGa1?x?yN, where 0<x<1, 0<y<1, and 0<x+y<1; a second barrier layer having an energy band higher than an energy band of the first barrier layer and including one of InxGa1?xN, where 0<x<0.2, and GaN; a well layer including InxGa1?xN, where 0<x<1; a third barrier layer including one of InxGa1?xN, where 0<x<0.2 and GaN; and a lattice mismatch relaxation layer including one of AlxInyGa1?x?yN, where 0<x<1, 0<y<1, and 0<x+y<1, AlxGa1?xN, where 0<x<1, and GaN, the lattice mismatch relaxation layer having a lattice constant greater than a lattice constant of the well layer and smaller than a lattice constant of the p-type GaN-based semiconductor layer.Type: GrantFiled: October 15, 2008Date of Patent: November 2, 2010Assignee: Samsung LED Co., Ltd.Inventors: Tan Sakong, Cheol Soo Sone, Ho Sun Paek, Suk Ho Yoon, Jeong Wook Lee
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Patent number: 7804100Abstract: A device structure includes a III-nitride wurtzite semiconductor light emitting region disposed between a p-type region and an n-type region. A bonded interface is disposed between two surfaces, one of the surfaces being a surface of the device structure. The bonded interface facilitates an orientation of the wurtzite c-axis in the light emitting region that confines carriers in the light emitting region, potentially increasing efficiency at high current density.Type: GrantFiled: March 14, 2005Date of Patent: September 28, 2010Assignees: Philips Lumileds Lighting Company, LLC, Koninklijke Philips Electronics N.V.Inventors: Jonathan J. Wierer, Jr., M. George Craford, John E. Epler, Michael R. Krames
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Patent number: 7799585Abstract: Light-emitting device methods are disclosed.Type: GrantFiled: November 17, 2008Date of Patent: September 21, 2010Assignee: Luminus Devices, Inc.Inventors: Alexei A. Erchak, John W. Graff, Michael Gregory Brown, Scott W. Duncan, Milan S. Minsky
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Patent number: 7795630Abstract: A semiconductor device, which includes an active layer made of a first semiconductor layer formed on a substrate, is designed so that a first oxidized area made of an oxide layer is formed on the active layer. The first oxidized area further aids in reducing a reactive current so that it becomes possible to achieve a semiconductor device having superior device characteristics.Type: GrantFiled: August 6, 2004Date of Patent: September 14, 2010Assignee: Panasonic CorporationInventors: Hisashi Nakayama, Tetsuzo Ueda, Masaaki Yuri, Toshiyuki Takizawa
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Publication number: 20100224852Abstract: Embodiments of the invention include a III-nitride semiconductor structure comprising a light emitting region disposed between an n-type region and a p-type region. At least one layer in the light emitting region is Bx(InyGa1-y)1-xN. In some embodiments, x is less than 14%. In some embodiments, the BN composition is selected such that the Bx(InyGa1-y)1-xN layer has the same band gap energy as a comparable InGaN layer, with a bulk lattice constant that is the same or smaller than the comparable InGaN layer.Type: ApplicationFiled: March 4, 2009Publication date: September 9, 2010Applicant: KONINKLIJKE PHILIPS ELECTRONICS N.V.Inventor: Melvin B. McLaurin
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Patent number: 7781796Abstract: A nitride semiconductor laser element includes a substrate and a nitride semiconductor layer in which a first semiconductor layer, an active layer, and a second semiconductor layer are laminated in this order on the substrate. At least one of the first semiconductor layer and the second semiconductor layer includes a first section forming recessed and raised portions and a second section embedding the recessed and raised portions of the first section. A region with a higher aluminum mixed crystal ratio than the second section that embeds the recessed and raised portions is disposed on top faces of the raised portions. The nitride semiconductor layer defines resonant planes, and the recessed and raised portions are formed in a shape of stripes that extend substantially parallel to the resonant planes.Type: GrantFiled: June 14, 2007Date of Patent: August 24, 2010Assignee: Nichia CorporationInventors: Shingo Masui, Kazutaka Tsukayama
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Publication number: 20100176406Abstract: A nitride semiconductor light emitting device is provided. The nitride semiconductor light emitting device includes a first nitride layer comprising at least N-type nitride layer. An insulating member is formed on the first nitride layer having a predetermined pattern. An active layer is formed in both sides of the insulating member on the first nitride layer to emit light. A second nitride layer is formed in both sides of the insulating member on the active layer and the second nitride layer comprises at least a P-type nitride layer.Type: ApplicationFiled: March 23, 2010Publication date: July 15, 2010Inventor: Sang Youl LEE
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Patent number: 7755172Abstract: A method for growing III-V nitride films having an N-face or M-plane using an ammonothermal growth technique. The method comprises using an autoclave, heating the autoclave, and introducing ammonia into the autoclave to produce smooth N-face or M-plane Gallium Nitride films and bulk GaN.Type: GrantFiled: June 20, 2007Date of Patent: July 13, 2010Assignees: The Regents of the University of California, Japan Science and Technology AgencyInventors: Tadao Hashimoto, Hitoshi Sato, Shuji Nakamura
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Patent number: 7750355Abstract: The object of this invention is to provide a high-output type nitride light emitting device. The nitride light emitting device comprises an n-type nitride semiconductor layer or layers, a p-type nitride semiconductor layer or layers and an active layer therebetween, wherein a gallium-containing nitride substrate is obtained from a gallium-containing nitride bulk single crystal, provided with an epitaxial growth face with dislocation density of 105/cm2 or less, and A-plane or M-plane which is parallel to C-axis of hexagonal structure for an epitaxial face, wherein the n-type semiconductor layer or layers are formed directly on the A-plane or M-plane. In case that the active layer comprises a nitride semiconductor containing In, an end face film of single crystal AlxGa1-xN (0?x?1) can be formed at a low temperature not causing damage to the active layer.Type: GrantFiled: October 28, 2002Date of Patent: July 6, 2010Assignees: AMMONO Sp. z o.o., Nichia CorporationInventors: Robert Dwilinski, Roman Doradzinski, Jerzy Garczynski, Leszek Sierzputowski, Yasuo Kanbara
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Patent number: 7736935Abstract: The present invention provides, in part, methods producing multilayer semiconductor structures having one or more at least partially relaxed strained layers, where the strained layer is at least partially relaxed by annealing. In particular, the invention forms diffusion barriers that prevent diffusion of contaminants during annealing. The invention also includes embodiments where the at least partially relaxed strained layer is patterned into islands by etching trenches and the like. The invention also provides semiconductor structures resulting from these methods, and further, provides such structures where the semiconductor materials are suitable for application to LED devices, laser devices, photovoltaic devices, and other optoelectronic devices.Type: GrantFiled: December 22, 2008Date of Patent: June 15, 2010Assignee: S.O.I.Tec Silicon on Insulator TechnologiesInventors: Bruce Faure, Pascal Guenard
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Patent number: 7732832Abstract: This pn-junction compound semiconductor light-emitting device includes a crystal substrate; an n-type light-emitting layer formed of a hexagonal n-type Group III nitride semiconductor and provided on the crystal substrate; a p-type Group III nitride semiconductor layer formed of a hexagonal p-type Group III nitride semiconductor and provided on the n-type light-emitting layer; a p-type boron-phosphide-based semiconductor layer having a sphalerite crystal type and provided on the p-type Group III nitride semiconductor layer; and a thin-film layer composed of an undoped hexagonal Group III nitride semiconductor formed on the p-type Group III nitride semiconductor layer, wherein the p-type boron-phosphide-based semiconductor layer is joined to the thin-film layer composed of an undoped hexagonal Group III nitride semiconductor.Type: GrantFiled: April 27, 2005Date of Patent: June 8, 2010Assignee: Showa Denko K.K.Inventor: Takashi Udagawa
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Patent number: 7728348Abstract: There is provided a method of producing a thin GaN film-joined substrate, including the steps of: joining on a GaN bulk crystalline body a substrate different in type or chemical composition from GaN; and dividing the GaN bulk crystalline body at a plane having a distance of at least 0.1 ?m and at most 100 ?m from an interface thereof with the substrate different in type, to provide a thin film of GaN on the substrate different in type, wherein the GaN bulk crystalline body had a surface joined to the substrate different in type, that has a maximum surface roughness Rmax of at most 20 ?m. Thus a GaN-based semiconductor device including a thin GaN film-joined substrate including a substrate different in type and a thin film of GaN joined firmly on the substrate different in type, and at least one GaN-based semiconductor layer deposited on the thin film of GaN, can be fabricated at low cost.Type: GrantFiled: June 28, 2007Date of Patent: June 1, 2010Assignee: Sumitomo Electric Industries, Ltd.Inventors: Hitoshi Kasai, Akihiro Hachigo, Yoshiki Miura, Katsushi Akita
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Patent number: 7714350Abstract: A gallium nitride based semiconductor device comprises: a first gallium nitride based semiconductor film doped with magnesium; and a second gallium nitride based semiconductor film provided on the first gallium nitride based semiconductor film and doped with magnesium. The first gallium nitride based semiconductor film has substantially flat distributions of magnesium concentration and hydrogen atom concentration, and the magnesium concentration is higher than the hydrogen atom concentration. The second gallium nitride based semiconductor film has a first region in which the magnesium concentration decreases and the hydrogen atom concentration increases toward the surface, and the magnesium concentration in the first region is higher than the hydrogen atom concentration in the first region and higher than the magnesium concentration in the first gallium nitride based semiconductor film.Type: GrantFiled: April 4, 2006Date of Patent: May 11, 2010Assignee: Kabushiki Kaisha ToshibaInventors: Hideto Sugawara, Chie Hongo
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Patent number: 7709848Abstract: A group III nitride semiconductor light emitting device according to the present invention includes an intermediate layer formed of AlxGa1-x-yInyN(0<X<1, 0<y<1, x+y<1) between an active layer and a cladding layer and an electron blocking layer formed of p-type group III nitride semiconductor having a smaller electron affinity than that of the intermediate layer so as to be in contact with the intermediate layer. The semiconductor light emitting layer may be a laser diode or a LED.Type: GrantFiled: November 16, 2006Date of Patent: May 4, 2010Assignee: Panasonic CorporationInventor: Katsumi Sugiura
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Patent number: 7709847Abstract: A nitride semiconductor light emitting device is provided. The nitride semiconductor light emitting device includes a first nitride layer comprising at least N-type nitride layer. An insulating member is formed on the first nitride layer having a predetermined pattern. An active layer is formed in both sides of the insulating member on the first nitride layer to emit light. A second nitride layer is formed in both sides of the insulating member on the active layer and the second nitride layer comprises at least a P-type nitride layer.Type: GrantFiled: October 16, 2006Date of Patent: May 4, 2010Assignee: LG Innotek Co., Ltd.Inventor: Sang Youl Lee
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Patent number: 7709287Abstract: A method of forming a multijunction solar cell includes providing a substrate, forming a first subcell by depositing a nucleation layer over the substrate and a buffer layer including gallium arsenide (GaAs) over the nucleation layer, forming a middle second subcell having a heterojunction base and emitter disposed over the first subcell and forming first and second tunnel junction layers between the first and second subcells. The first tunnel junction layer includes GaAs over the first subcell and the second tunnel junction layer includes aluminum gallium arsenide (AlGaAs) over the first tunnel junction layer. The method further includes forming a third subcell having a homojunction base and emitter disposed over the middle subcell.Type: GrantFiled: April 10, 2006Date of Patent: May 4, 2010Assignee: Emcore Solar Power, Inc.Inventors: Navid Fatemi, Daniel J. Aiken, Mark A. Stan
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Patent number: 7687820Abstract: A light emitting device includes an n-type cladding layer. a p-type cladding layer. an active layer interposed between the n-type cladding layer and the p-type cladding layer and an ohmic contact layer contacting the p-type cladding layer or the n-type cladding layer. The ohmic contact layer includes a first film that includes a transparent conductive zinc oxide doped with a rare earth metal and including a one-dimensional nano structure. The one-dimensional nano structure is one of a nano-column, a nano rod and a nano wire.Type: GrantFiled: August 11, 2006Date of Patent: March 30, 2010Assignee: Samsung Electronics Co., Ltd.Inventor: June O Song
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Patent number: 7671383Abstract: A semiconductor device, includes: a first conductivity type semiconductor base having a main face; a hetero semiconductor region contacting the main face of the semiconductor base and forming a hetero junction in combination with the semiconductor base, the semiconductor base and the hetero semiconductor region in combination defining a junction end part; a gate insulating film defining a junction face in contact with the semiconductor base and having a thickness; and a gate electrode disposed adjacent to the junction end part via the gate insulating film and defining a shortest point in a position away from the junction end part by a shortest interval, a line extending from the shortest point to a contact point vertically relative to the junction face, forming such a distance between the contact point and the junction end part as to be smaller than the thickness of the gate insulating film contacting the semiconductor base.Type: GrantFiled: March 6, 2007Date of Patent: March 2, 2010Assignee: Nissan Motor Co., Ltd.Inventors: Tetsuya Hayashi, Masakatsu Hoshi, Yoshio Shimoida, Hideaki Tanaka, Shigeharu Yamagami
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Patent number: 7667240Abstract: A radiation-emitting semiconductor chip having an absorbent brightness setting layer between a connection region and a current injection region and/or, as seen from the connection region, outside the current injection region on a front-side radiation coupling-out area of the semiconductor layer sequence. The brightness setting layer absorbs in a targeted manner part of the radiation generated in the semiconductor layer sequence. In another embodiment, a partly insulating brightness setting layer is arranged between the connection region and the active layer.Type: GrantFiled: June 30, 2004Date of Patent: February 23, 2010Assignee: Osram Opto Semiconductors GmbHInventors: Michael Zoelfl, Wilhelm Stein, Ralph Wirth
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Patent number: 7663157Abstract: An epitaxial growth system comprises a housing around an epitaxial growth chamber. A substrate support is located within the growth chamber. A gallium source introduces gallium into the growth chamber and directs the gallium towards the substrate. An activated nitrogen source introduces activated nitrogen into the growth chamber and directs the activated nitrogen towards the substrate. The activated nitrogen comprises ionic nitrogen species and atomic nitrogen species. An external magnet and/or an exit aperture control the amount of atomic nitrogen species and ionic nitrogen species reaching the substrate.Type: GrantFiled: January 26, 2007Date of Patent: February 16, 2010Assignee: The Trustees of Boston UniversityInventor: Theodore D. Moustakas
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Patent number: 7663138Abstract: A n-type layer, a multiquantum well active layer comprising a plurality of pairs of an InGaN well layer/InGaN barrier layer, and a p-type layer are laminated on a substrate to provide a nitride semiconductor light emitting element. A composition of the InGaN barrier included in the multiquantum well active layer is expressed by InxGa1-xN (0.04?x?0.1), and a total thickness of InGaN layers comprising an In composition ratio within a range of 0.04 to 0.1 in the light emitting element including the InGaN barrier layers is not greater than 60 nm.Type: GrantFiled: March 13, 2007Date of Patent: February 16, 2010Assignee: Hitachi Cable, Ltd.Inventor: Hajime Fujikura
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Patent number: 7652299Abstract: A nitride semiconductor light-emitting device includes a substrate and a nitride semiconductor layer including a light-emitting layer stacked on the substrate, wherein a normal line relative to a lateral face of the nitride semiconductor layer is not perpendicular to a normal line relative to a principal plane of the substrate. A method for the production of a nitride semiconductor light-emitting device that includes a substrate and a nitride semiconductor layer including a light-emitting layer stacked on the substrate includes the steps of covering a first surface of the nitride semiconductor layer with a mask provided with a prescribed pattern, removing the nitride semiconductor layer in regions to be divided into component devices till the substrate, subjecting the nitride semiconductor layer to wet-etching treatment and dividing the nitride semiconductor layer into the component devices.Type: GrantFiled: February 13, 2006Date of Patent: January 26, 2010Assignee: Showa Denko K.K.Inventors: Yasuhito Urashima, Katsuki Kusunoki
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Patent number: 7646024Abstract: A structure is disclosed that reduces the forward voltage across the interface between silicon carbide and Group III nitride layers. The structure includes a conductive silicon carbide substrate and a conductive layer of aluminum gallium nitride on the silicon carbide substrate. The aluminum gallium nitride layer has a mole fraction of aluminum that is sufficient to bring the conduction bands of the silicon carbide substrate and the aluminum gallium nitride into close proximity, but less than a mole fraction of aluminum that would render the aluminum gallium nitride layer resistive.Type: GrantFiled: August 18, 2006Date of Patent: January 12, 2010Assignee: Cree, Inc.Inventor: Adam William Saxler
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Patent number: 7642542Abstract: A semiconductor light-emitting device includes: a first semiconductor layer; a light-emitting layer being disposed on the first semiconductor layer; a second semiconductor layer being disposed on the light-emitting layer, and metal electrodes connected to the first semiconductor layer and the second semiconductor layer. The light-emitting layer is lower in refractive index than the first semiconductor layer. The second semiconductor layer is lower in refractive index than the light-emitting layer. The metal electrodes supply a current to the light-emitting layer.Type: GrantFiled: September 13, 2006Date of Patent: January 5, 2010Assignee: Kabushiki Kaisha ToshibaInventors: Mariko Suzuki, Tomio Ono, Tadashi Sakai, Naoshi Sakuma, Hiroaki Yoshida
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Patent number: 7629619Abstract: A Group III nitride-based compound semiconductor light-emitting device having a quantum well structure, includes a well layer, a first layer formed on one surface of the well layer, a second layer formed on the other surface of the well layer, a first region provided in the vicinity of the interface between the first layer and the well layer, and a second region provided in the vicinity of the interface between the second layer and the well layer. A composition of the first and second regions gradually changes such that the lattice constants of the first and second layers approach the lattice constant of the well layer as a position approaches said well layer.Type: GrantFiled: January 27, 2006Date of Patent: December 8, 2009Assignee: Toyota Gosei Co., Ltd.Inventors: Tetsuya Taki, Mitsuhisa Narukawa, Masato Aoki, Koji Okuno, Yusuke Toyoda, Kazuki Nishijima, Shuhei Yamada
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Patent number: 7612363Abstract: An n-type Group III nitride semiconductor stacked layer structure including a first n-type layer which includes a layer containing n-type impurity atoms at a high concentration and a layer containing n-type impurity atoms at a low concentration, a second n-type layer containing n-type impurity atoms at an average concentration smaller than that of the first n-type layer, the second n-type layer neighboring the layer containing n-type impurity atoms at a low concentration in the first n-type layer.Type: GrantFiled: September 13, 2005Date of Patent: November 3, 2009Assignee: Showa Denko K.K.Inventors: Hitoshi Takeda, Hisayuki Miki
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Patent number: 7601985Abstract: A semiconductor light-emitting device includes: a substrate; a first conductivity type layer formed on the substrate and including a plurality of group III-V nitride semiconductor layers of a first conductivity type; an active layer formed on the first conductivity type layer; and a second conductivity type layer formed on the active layer and including a group III-V nitride semiconductor layer of a second conductivity type. The first conductivity type layer includes an intermediate layer made of AlxGa1?x?yInyN (wherein 0.001?x<0.1, 0<y<1 and x+y<1).Type: GrantFiled: September 15, 2006Date of Patent: October 13, 2009Assignee: Panasonic CorporationInventors: Yoshitaka Kinoshita, Hidenori Kamei
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Patent number: 7592629Abstract: A gallium nitride thin film on sapphire substrate having reduced bending deformation and a method for manufacturing the same. An etching trench structure is formed on a sapphire substrate by primary nitradation and HCl treatment and a gallium nitride film is grown thereon by secondary nitradation. The gallium nitride thin film on sapphire substrate comprises an etching trench structure formed on a sapphire substrate, wherein a function graph of a curvature radius Y according to a thickness X of a gallium nitride film satisfies Equation 1 below, and corresponds to or is located above a function graph drawn when Y0 is 6.23±1.15, A is 70.04 ±1.92, and T is 1.59±0.12: Y=Y0+A·e?(X?1)/T,??[Equation 1] where Y is the curvature radius m, X is the thickness of the gallium nitride film, and Y0, A, and T are positive numbers.Type: GrantFiled: October 6, 2006Date of Patent: September 22, 2009Assignee: Samsung Corning Co., Ltd.Inventors: Chang Ho Lee, Sun Hwan Kong
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Patent number: 7589346Abstract: A GaN based semiconductor light-emitting device is provided. The light-emitting device includes a first GaN based compound semiconductor layer of an n-conductivity type; an active layer; a second GaN based compound semiconductor layer; an underlying layer composed of a GaN based compound semiconductor, the underlying layer being disposed between the first GaN based compound semiconductor layer and the active layer; and a superlattice layer composed of a GaN based compound semiconductor doped with a p-type dopant, the superlattice layer being disposed between the active layer and the second GaN based compound semiconductor layer.Type: GrantFiled: September 12, 2006Date of Patent: September 15, 2009Assignee: Sony CorporationInventors: Goshi Biwa, Hiroyuki Okuyama
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Patent number: 7589345Abstract: A nitride-based compound semiconductor substrate mainly used for an epitaxial growth of a nitride semiconductor and a method for fabricating the same are disclosed. The nitride-based compound semiconductor substrate has a composition of AlxGa1-xN (0<x<1), a principal plane of C face, an area of 2 cm2 or more, and a thickness of 200 ?m or more. The substrate having this structure is fabricated by a HVPE (hydride vapor phase epitaxy) method by using an organic Al compound such as TMA (trimethyl aluminum) or TEA (trimethyl aluminum) as an Al source, A stable crystal growth can be obtained without damaging a reacting furnace, and a large-sized AlGaN crystal substrate with an excellent crystallinity can be obtained.Type: GrantFiled: January 12, 2006Date of Patent: September 15, 2009Assignee: Hitachi Cable, Ltd.Inventor: Yuichi Oshima
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Patent number: 7576351Abstract: A nitride semiconductor light generating device comprises an n-type gallium nitride based semiconductor layer, a quantum well active layer including an InX1AlY1Ga1-X1-Y1N (1>X1>0, 1>Y1>0) well layer and an InX2AlY2Ga1-X2-Y2N (1>X2>0, 1>Y2>0) barrier layer, an InX3AlY3Ga1-X3-Y3N (1>X3>0, 1>Y3>0) layer provided between the quantum well active layer and the n-type gallium nitride based semiconductor layer, and a p-type AlGaN layer having a bandgap energy greater than that of the InX2AlY2Ga1-X2-Y2N barrier layer. The indium composition X3 is greater than an indium composition X1. The indium composition X3 is greater than an indium composition X2. The aluminum composition Y2 is smaller than an aluminum composition Y3. The aluminum composition Y1 is smaller than an aluminum composition Y3. The oxygen concentration of the quantum well active layer is lower than that of the InX3AlY3Ga1-X3-Y3N layer.Type: GrantFiled: January 26, 2007Date of Patent: August 18, 2009Assignees: Sumitomo Electric Industries, Ltd., RikenInventors: Takashi Kyono, Hideki Hirayama
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Patent number: 7569862Abstract: A method of manufacturing a semiconductor light-emitting device comprises selectively etching a semiconductor layer structure (16) fabricated in a nitride materials system and including an aluminum-containing cladding region or an aluminum-containing optical guiding region (5). The etching step forms a mesa (17), and also exposes one or more portions of the aluminum-containing cladding region or the aluminum-containing optical guiding region (5). The or each exposed portion of the aluminum-containing cladding region or the aluminum-containing optical guiding region (5) is then oxidized to form a current blocking layer (18) laterally adjacent to and extending laterally from the mesa. When an electrically conductive contact layer (11) is deposited, the current blocking layer (18) will prevent the contact layer (11) from making direct contact with the buffer layer (3).Type: GrantFiled: January 7, 2005Date of Patent: August 4, 2009Assignee: Sharp Kabushiki KaishaInventors: Katherine L. Johnson, Stewart Hooper, Valerie Bousquet, Matthias Kauer, Jonathan Heffernan
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Patent number: 7560725Abstract: A first Group III nitride compound semiconductor layer 31 is etched, to thereby form an island-like structure such as a dot-like, stripe-shaped, or grid-like structure, so as to provide a trench/post. Thus, a second Group III nitride compound layer 32 can be epitaxially grown, vertically and laterally, from a top surface of the post and a sidewall/sidewalls of the trench serving as a nucleus for epitaxial growth, to thereby bury the trench and also grow the layer in the vertical direction. In this case, propagation of threading dislocations contained in the first Group III nitride compound semiconductor layer 31 can be prevented in the upper portion of the second Group III nitride compound semiconductor 32 that is formed through lateral epitaxial growth. As a result, a region having less threading dislocations is formed at the buried trench.Type: GrantFiled: September 15, 2005Date of Patent: July 14, 2009Assignee: Toyoda Gosei Co., Ltd.Inventors: Masayoshi Koike, Yuta Tezen, Toshio Hiramatsu