Multiple Quantum Well Structure (epo) Patents (Class 257/E31.033)
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Publication number: 20120274771Abstract: An image pickup device, a visibility support apparatus, a night vision device, a navigation support apparatus, and a monitoring device are provided in which noise and dark current are suppressed to thereby provide clear images regardless of whether it is day or night. The device includes a light-receiving layer 3 having a multi-quantum well structure and a diffusion concentration distribution control layer 4 disposed on the light-receiving layer so as to be opposite an InP substrate 1, wherein the light-receiving layer has a band gap wavelength of 1.65 to 3 ?m, the diffusion concentration distribution control layer has a lower band gap energy than InP, a pn junction is formed for each light-receiving element by selective diffusion of an impurity element, and the impurity selectively diffused in the light-receiving layer has a concentration of 5×1016/cm3 or less.Type: ApplicationFiled: July 13, 2012Publication date: November 1, 2012Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Youichi Nagai, Yasuhiro Iguchi
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Publication number: 20120261639Abstract: Inorganic semiconducting materials such as silicon are used as a host matrix in which quantum dots reside to provide an energy conversion device that may be used to convert various types of radiation to electricity.Type: ApplicationFiled: July 11, 2011Publication date: October 18, 2012Applicant: WEINBERG MEDICAL PHYSICS LLCInventors: Irving N. WEINBERG, Pavel STEPANOV, Mario G. URDANETA
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Publication number: 20120248410Abstract: An electron transporting surfactant is added to a raw material solution such that the electron transporting surfactant is coordinated on the surfaces of quantum dots, and after the dispersion solvent is evaporated by vacuum drying, the immersion in a solvent containing a hole transporting surfactant prepares a quantum dot dispersed solution with a portion of the electron transporting surfactant replaced with the hole transporting surfactant. The quantum dot dispersed solution is applied onto a substrate to prepare a hole transport layer and a quantum dot layer at the same time, and thereby to achieve a thin film which has a two-layer structure.Type: ApplicationFiled: June 15, 2012Publication date: October 4, 2012Applicant: Murata Manufacturing Co., Ltd.Inventor: Koji Murayama
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Publication number: 20120248413Abstract: A resonant tunneling device includes a first semiconductor material with an energy difference between valence and conduction bands of Eg1, and a second semiconductor material with an energy difference between valence and conduction bands of Eg2, wherein Eg1 and Eg2 are different from one another. The device further includes an energy selectively transmissive interface connecting the first and second semiconductor materials.Type: ApplicationFiled: March 30, 2011Publication date: October 4, 2012Inventors: James Andrew Robert Dimmock, Stephen Day, Matthias Kauer, Jonathan Heffernan
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Publication number: 20120248412Abstract: Devices (e.g., optoelectronic devices such as solar cells and infrared or THz photodetectors) with a nanomaterial having vertically correlated quantum dots with built-in charge (VC Q-BIC) and methods of making such devices. The VC Q-BIC material has two or more quantum dot layers, where the layers have quantum dots (individual quantum dots or quantum dot clusters) in a semiconductor material, and adjacent quantum dot layers are separated by a spacer layer of doped semiconductor material. The VC-QBIC nanomaterial provides long photocarrier lifetime, which improves the responsivity and sensitivity of detectors or conversion efficiency in solar cells as compared to previous comparable devices.Type: ApplicationFiled: March 27, 2012Publication date: October 4, 2012Inventors: Vladimir Mitin, Andrei Sergeyev, Gottfried Strasser
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Patent number: 8279904Abstract: A semiconductor light-emitting device including an active layer is provided. The light-emitting device includes an active layer between an n-type semiconductor layer and a p-type semiconductor layer. The active layer includes a quantum well layer formed of Inx1Ga(1?x1)N, where 0<x1?1, barrier layers formed of Inx2Ga(1?x2)N, where 0?x2<1, on opposite surfaces of the quantum well layer, and a diffusion preventing layer formed between the quantum well layer and at least one of the barrier layers. Due to the diffusion preventing layer between the quantum well layer and the barrier layers in the active layer, the light emission efficiency increases.Type: GrantFiled: June 19, 2007Date of Patent: October 2, 2012Assignee: Samsung Electronics Co., Ltd.Inventors: Tan Sakong, Joong-kon Son, Ho-sun Paek, Sung-nam Lee
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Publication number: 20120241723Abstract: An optoelectronic device includes a first electrode, a quantum dot layer disposed on the first electrode including a plurality of quantum dots, a fullerene layer disposed directly on the quantum dot layer wherein the quantum dot layer and the fullerene layer form an electronic heterojunction, and a second electrode disposed on the fullerene layer. The device may include an electron blocking layer. The quantum dot layer may be modified by a chemical treatment to exhibit in creased charge carrier mobility.Type: ApplicationFiled: September 29, 2010Publication date: September 27, 2012Applicant: RESEARCH TRIANGLE INSTITUTE, INTERNATIONALInventors: Ethan Klem, John Lewis
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Publication number: 20120236307Abstract: There is provided a photoconductive element capable of increasing an output and detection sensitivity by increasing resistivity as the entire element. The photoconductive element is a photoconductive element capable of generating or detecting an electromagnetic wave when light is emitted thereto. The photoconductive element includes a photoconductive layer having a semiconductor layer whose resistivity changes when light is emitted to thereby generate or detect an electromagnetic wave; and a plurality of electrodes provided in contact with the semiconductor layer. The resistivity of the semiconductor layer changes in a thickness direction of intersecting a surface of the semiconductor layer contacting the electrodes. Assuming that the semiconductor layer includes a first region and a second region which is farther away from the electrodes in the thickness direction than the first region, the resistivity in the first region is greater than the resistivity in the second region.Type: ApplicationFiled: March 9, 2012Publication date: September 20, 2012Applicant: CANON KABUSHIKI KAISHAInventor: Ryota Sekiguchi
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Publication number: 20120231569Abstract: An optoelectronic component with three-dimension quantum well structure and a method for producing the same are provided, wherein the optoelectronic component comprises a substrate, a first semiconductor layer, a transition layer, and a quantum well structure. The first semiconductor layer is disposed on the substrate. The transition layer is grown on the first semiconductor layer, contains a first nitride compound semiconductor material, and has at least a texture, wherein the texture has at least a first protrusion with at least an inclined facet, at least a first trench with at least an inclined facet and at least a shoulder facet connected between the inclined facets. The quantum well structure is grown on the texture and shaped by the protrusion, the trench and the shoulder facet.Type: ApplicationFiled: May 17, 2012Publication date: September 13, 2012Applicant: HERMES-EPITEK CORP.Inventors: BENSON CHAO, CHUNG-HUA FU, SHIH-CHIEH JANG
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Publication number: 20120223290Abstract: A light-receiving element includes a group III-V compound semiconductor stacked structure that includes an absorption layer having a pn-junction therein. The stacked structure is formed on a group III-V compound semiconductor substrate. The absorption layer has a multi- quantum well structure composed of group III-V compound semiconductors, and the pn-junction is formed by selectively diffusing an impurity element into the absorption layer. A diffusion concentration distribution control layer composed of a III-V group semiconductor is disposed in contact with the absorption layer on a side of the absorption layer opposite the side adjacent to the group III-V compound semiconductor substrate. The bandgap energy of the diffusion concentration distribution control layer is smaller than that of the group III-V compound semiconductor substrate. The concentration of the impurity element selectively diffused in the diffusion concentration distribution control layer is 5×1016/cm3 or less toward the absorption layer.Type: ApplicationFiled: April 19, 2012Publication date: September 6, 2012Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Yasuhiro Iguchi, Kohei Miura, Hiroshi Inada, Youichi Nagai
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Publication number: 20120217478Abstract: Provided are a semiconductor device and an optical sensor device, each having reduced dark current, and detectivity extended toward longer wavelengths in the near-infrared. Further, a method for manufacturing the semiconductor device is provided. The semiconductor device 50 includes an absorption layer 3 of a type II (GaAsSb/InGaAs) MQW structure located on an InP substrate 1, and an InP contact layer 5 located on the MQW structure. In the MQW structure, a composition x (%) of GaAsSb is not smaller than 44%, a thickness z (nm) thereof is not smaller than 3 nm, and z??0.4x+24.6 is satisfied.Type: ApplicationFiled: May 19, 2011Publication date: August 30, 2012Applicant: Sumitomo Electric Industries, Ltd.Inventors: Kei Fujii, Katsushi Akita, Takashi Ishizuka, Hideaki Nakahata, Yasuhiro Iguchi, Hiroshi Inada, Youichi Nagai
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Patent number: 8247265Abstract: The present invention provides an optoelectronic memory device, the method for manufacturing and evaluating the same. The optoelectronic memory device according to the present invention includes a substrate, an insulation layer, an active layer, source electrode and drain electrode. The substrate includes a gate, and the insulation layer is formed on the substrate. The active layer is formed on the insulation layer, and more particularly, the active layer is formed of a composite material comprising conjugated conductive polymers and quantum dots. Moreover, both of the source and the drain are formed on the insulation layer, and electrically connected to the active layer.Type: GrantFiled: January 13, 2012Date of Patent: August 21, 2012Assignee: National Chiao Tung UniversityInventors: Kung-Hwa Wei, Jeng-Tzong Sheu, Chen-Chia Chen, Mao-Yuan Chiu
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Publication number: 20120205624Abstract: A composite material is described. The composite material comprises semiconductor nanocrystals, and organic molecules that passivate the surfaces of the semiconductor nanocrystals. One or more properties of the organic molecules facilitate the transfer of charge between the semiconductor nanocrystals. A semiconductor material is described that comprises p-type semiconductor material including semiconductor nanocrystals. At least one property of the semiconductor material results in a mobility of electrons in the semiconductor material being greater than or equal to a mobility of holes. A semiconductor material is described that comprises n-type semiconductor material including semiconductor nanocrystals. At least one property of the semiconductor material results in a mobility of holes in the semiconductor material being greater than or equal to a mobility of electrons.Type: ApplicationFiled: September 16, 2011Publication date: August 16, 2012Inventors: Edward Hatley Sargent, Ghada Koleilat, Larissa Levina
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Publication number: 20120205541Abstract: A plasmonic detector is described which can resonantly enhance the performance of infrared detectors. More specifically, the disclosure is directed to enhancing the quantum efficiency of semiconductor infrared detectors by increasing coupling to the incident radiation field as a result of resonant coupling to surface plasma waves supported by the metal/semiconductor interface, without impacting the dark current of the device, resulting in an improved detectivity over the surface plasma wave spectral bandwidth.Type: ApplicationFiled: October 21, 2010Publication date: August 16, 2012Inventors: Seung-Chang Lee, Sanjay Krishna, Steven Brueck
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Publication number: 20120192934Abstract: An embodiment of nanostructure includes a conductive substrate; an insulating layer on the conductive substrate, metal nanoparticles, and elongated single crystal nanostructures. The insulating layer includes an array of pore channels. The metal nanoparticles are located at bottoms of the pore channels. The elongated single crystal nanostructures contact the metal nanoparticles and extend out of the pore channels. An embodiment of a photovoltaic device includes the nanostructure and a photoabsorption layer. An embodiment of a method of fabricating a nanostructure includes forming an insulating layer on a conductive substrate. The insulating layer has pore channels arranged in an array. Metal nanoparticles are formed in the pore channels. The metal nanoparticles conductively couple to the conductive layer. Elongated single crystal nanostructures are formed in the pore channels.Type: ApplicationFiled: June 18, 2010Publication date: August 2, 2012Applicant: The Regents of the University of CaliforniaInventors: Zhiyong Fan, Ali Javey
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Publication number: 20120196398Abstract: Provided are a photodiode array and its manufacturing method, which maintain the crystalline quality of an absorption layer formed on a group III-V semiconductor substrate to obtain excellent characteristics, and which improve the crystallinity at the surface of a window layer; an epitaxial wafer used for manufacturing the photodiode array; and a method for manufacturing the epitaxial wafer. A method for manufacturing a photodiode array 1 having a plurality of absorption regions 21, includes the steps of: growing an absorption layer 7 on an n-type InP substrate 3; growing an InP window layer on the absorption layer 7; and diffusing a p-type impurity in regions, in the window layer 11, corresponding to the plurality of absorption regions 21. The window layer 11 is grown by MOVPE using only metal-organic sources, at a growth temperature equal to or lower than that of the absorption layer 7.Type: ApplicationFiled: April 13, 2012Publication date: August 2, 2012Applicant: Sumitomo Electric Industries, Ltd.Inventors: Katsushi AKITA, Takashi ISHIZUKA, Kei FUJII, Youichi NAGAI, Hideaki NAKAHATA
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Publication number: 20120180856Abstract: A composite material is described. The composite material comprises semiconductor nanocrystals, and organic molecules that passivate the surfaces of the semiconductor nanocrystals. One or more properties of the organic molecules facilitate the transfer of charge between the semiconductor nanocrystals. A semiconductor material is described that comprises p-type semiconductor material including semiconductor nanocrystals. At least one property of the semiconductor material results in a mobility of electrons in the semiconductor material being greater than or equal to a mobility of holes. A semiconductor material is described that comprises n-type semiconductor material including semiconductor nanocrystals. At least one property of the semiconductor material results in a mobility of holes in the semiconductor material being greater than or equal to a mobility of electrons.Type: ApplicationFiled: September 16, 2011Publication date: July 19, 2012Inventors: Edward Hartley Sargent, Keith William Johnston, Andras Geza Pattantyus-Abraham, Jason Paul Clifford
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Publication number: 20120175593Abstract: A quantum dot, which is an ultrafine grain, has a core-shell structure having a core portion and a shell portion protecting the core portion. The surface of the shell portion is covered with two kinds of surfactants, a hole-transporting surfactant and an electron-transporting surfactant, which are concurrently present. Moreover, the hole-transporting surfactant has a HOMO level which tunneling-resonates with the valence band of the quantum dot and the electron-transporting surfactant has a LUMO level which tunneling-resonates with the transfer band of the quantum dot. Thus, a nanograin material which has good carrier transport efficiency and is suitable for use in a photoelectric conversion device is achieved.Type: ApplicationFiled: March 26, 2012Publication date: July 12, 2012Applicant: MURATA MANUFACTURING CO., LTD.Inventor: Koji Murayama
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Publication number: 20120145996Abstract: A superlattice-based infrared absorber and the matching electron-blocking and hole-blocking unipolar barriers, absorbers and barriers with graded band gaps, high-performance infrared detectors, and methods of manufacturing such devices are provided herein. The infrared absorber material is made from a superlattice (periodic structure) where each period consists of two or more layers of InAs, InSb, InSbAs, or InGaAs. The layer widths and alloy compositions are chosen to yield the desired energy band gap, absorption strength, and strain balance for the particular application. Furthermore, the periodicity of the superlattice can be “chirped” (varied) to create a material with a graded or varying energy band gap.Type: ApplicationFiled: August 3, 2011Publication date: June 14, 2012Applicant: California Institute of TechnologyInventors: David Z. Ting, Arezou Khoshakhlagh, Alexander Soibel, Cory J. Hill, Sarath D. Gunapala
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Publication number: 20120132891Abstract: Precision quantum dot clusters and methods for producing and tuning quantum dot clusters are described herein. Also described herein are materials and devices, including photovoltaic devices, that may include one or more quantum dot clusters.Type: ApplicationFiled: July 14, 2011Publication date: May 31, 2012Applicant: UNIVERSITY OF UTAH RESEARCH FOUNDATIONInventors: Leonard F. Pease, III, Jeeseong C. Hwang
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Publication number: 20120120478Abstract: Electro-optical components are disclosed having intersubband transitions by quantum confinement between two Group III nitride elements, typically by means of GaN/AlN. Related devices or systems are also disclosed including such components, as well as to a method for manufacturing such a component. Such a component includes at least one active area that includes at least two so-called outer barrier layers surrounding one or more N-doped quantum well structures, and said quantum well structure(s) are each surrounded by two barrier areas that are unintentionally doped at a thickness of at least five monoatomic layers.Type: ApplicationFiled: July 30, 2010Publication date: May 17, 2012Applicants: CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE, UNIVERSITE PARIS-SUD 11Inventors: François Julien, Anatole Lupu, Maria Tchernycheva, Laurent Nevou
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Patent number: 8178866Abstract: The present invention provides an optoelectronic memory device, the method for manufacturing and evaluating the same. The optoelectronic memory device according to the present invention includes a substrate, an insulation layer, an active layer, source electrode and drain electrode. The substrate includes a gate, and the insulation layer is formed on the substrate. The active layer is formed on the insulation layer, and more particularly, the active layer is formed of a composite material comprising conjugated conductive polymers and quantum dots. Moreover, both of the source and the drain are formed on the insulation layer, and electrically connected to the active layer.Type: GrantFiled: June 15, 2009Date of Patent: May 15, 2012Assignee: National Chiao Tung UniversityInventors: Kung-Hwa Wei, Jeng-Tzong Sheu, Chen-Chia Chen, Mao-Yuan Chiu
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Publication number: 20120112165Abstract: An improved optoelectronic device is described, which employs optically responsive nanoparticles and utilises a non-radiative energy transfer mechanism. The nanoparticles are disposed on the sidewalls of one or more cavities, which extend from the surface of the device through the electronic structure and penetrate the energy transfer region. The nanoparticles are located in close spatial proximity to an energy transfer region, whereby energy is transferred non-radiatively to or from the electronic structure through non-contact dipole-dipole interaction. According to the mode of operation, the device can absorb light energy received from the device surface via the cavity and then transfer this non-radiatively or can transfer energy non-radiatively and then emit light energy towards the surface of the device via the cavity. As such, the deice finds application in light emitting devices, photovoltaic (solar) cells, displays, photodetectors, lasers and single photon devices.Type: ApplicationFiled: February 16, 2010Publication date: May 10, 2012Applicant: University of SouthamptonInventors: Martin David Brian Charlton, Pavlos Lagoudakis, Soontorn Chanyawadee
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Publication number: 20120104535Abstract: A photodetector includes a substrate, a first electrode layer, a first light absorbing layer, a second electrode layer, a second light absorbing layer, and a third electrode layer that are laminated on the substrate, a first electrode wire that intercouples the first electrode layer and the second electrode layer, a second electrode wire that intercouples the second electrode layer and the third electrode layer, a first diode formed at a place where the second electrode layer and the first electrode wire are mutually brought into contact, and a second diode formed at a place where the second electrode layer and the second electrode wire are mutually brought into contact.Type: ApplicationFiled: October 27, 2011Publication date: May 3, 2012Applicant: FUJITSU LIMITEDInventors: Shinichiro KAWAKAMI, Yasuo MATSUMIYA
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Publication number: 20120097224Abstract: The present invention provides a non-vacuum method of depositing a photovoltaic absorber layer based on electrophoretic deposition of a mixture of nanoparticles with a controlled atomic ratio between the elements. The nanoparticles are first dispersed in a liquid medium to form a colloidal suspension and then electrophoretically deposited onto a substrate to form a thin film photovoltaic absorber layer. The absorber layer may be subjected to optional post-deposition treatments for photovoltaic absorption.Type: ApplicationFiled: October 25, 2010Publication date: April 26, 2012Inventors: Wei GUO, Yu Jin, Bing Liu, Yong Che
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Patent number: 8164092Abstract: Provided herein are PIN structures including a layer of amorphous n-type silicon, a layer of intrinsic GaAs disposed over the layer of amorphous n-type silicon, and a layer of amorphous p-type silicon disposed over the layer of intrinsic GaAs. The layer of intrinsic GaAs may be engineered by the disclosed methods to exhibit a variety of structural properties that enhance light absorption and charge carrier mobility, including oriented polycrystalline intrinsic GaAs, embedded particles of intrinsic GaAs, and textured surfaces. Also provided are devices incorporating the PIN structures, including photovoltaic devices.Type: GrantFiled: January 12, 2011Date of Patent: April 24, 2012Assignee: The University of Utah Research FoundationInventors: Ashutosh Tiwari, Makarand Karmarkar, Nathan Wheeler Gray
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Publication number: 20120058594Abstract: A method for manufacturing an array-type nanotube layer for a thin-film solar cell comprises the steps of: preparing an isotropic Si-substrate; sputtering a metal Ti layer onto the isotropic Si-substrate; heat-treating the Ti-coated Si-substrate in a vacuum heat-treatment environment; annealing the Ti-coated Si-substrate in an annealing heat-treatment environment to produce an intermediate-phase metal Ti layer ; anodizing the intermediate-phase metal Ti layer so as to transform the intermediate-phase metal Ti layer into an array-type nanotube layer for the solar cell; and finally applying a reverse voltage to separate the array-type nanotube layer from the isotropic Si-substrate.Type: ApplicationFiled: February 23, 2011Publication date: March 8, 2012Inventor: NAN-HUI YEH
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Publication number: 20120058595Abstract: Electronic device quality Aluminum Antimonide (AlSb)-based single crystals produced by controlled atmospheric annealing are utilized in various configurations for solar cell applications. Like that of a GaAs-based solar cell devices, the AlSb-based solar cell devices as disclosed herein provides direct conversion of solar energy to electrical power.Type: ApplicationFiled: October 24, 2011Publication date: March 8, 2012Inventors: John W. Sherohman, Jick Hong Yee, Arthur W. Combs, III
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Publication number: 20120056160Abstract: A photodetector is described along with corresponding materials, systems, and methods. The photodetector comprises an integrated circuit and at least two optically sensitive layers. A first optically sensitive layer is over at least a portion of the integrated circuit, and a second optically sensitive layer is over the first optically sensitive layer. Each optically sensitive layer is interposed between two electrodes. The two electrodes include a respective first electrode and a respective second electrode. The integrated circuit selectively applies a bias to the electrodes and reads signals from the optically sensitive layers. The signal is related to the number of photons received by the respective optically sensitive layer.Type: ApplicationFiled: August 26, 2011Publication date: March 8, 2012Applicant: InVisage Technologies, Inc.Inventors: Hui Tian, Edward Sargent
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Patent number: 8124432Abstract: In an InGaN-based nitride semiconductor optical device having a long wavelength (440 nm or more) equal to or more than that of blue, the increase of a wavelength is realized while suppressing In (Indium) segregation and deterioration of crystallinity. In the manufacture of an InGaN-based nitride semiconductor optical device having an InGaN-based quantum well active layer including an InGaN well layer and an InGaN barrier layer, a step of growing the InGaN barrier layer includes: a first step of adding hydrogen at 1% or more to a gas atmosphere composed of nitrogen and ammonia and growing a GaN layer in the gas atmosphere; and a second step of growing the InGaN barrier layer in a gas atmosphere composed of nitrogen and ammonia.Type: GrantFiled: December 3, 2009Date of Patent: February 28, 2012Assignee: Opnext Japan, Inc.Inventors: Tomonobu Tsuchiya, Shigehisa Tanaka, Akihisa Terano, Kouji Nakahara
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Patent number: 8120014Abstract: Nanoscaled, tunable detector devices for ultrasensitive detection of terahertz (THz) radiation based on the fabrication of one-dimensional (1D) plasma devices having clouds of strongly correlated and spatially confined electronic charge carriers are disclosed. These one-dimensional collective excitations (“plasmons”) are realized using coaxial semiconducting core-shell nanowires or by electrostatically confining a two dimensional charge to one dimension. By exploiting the properties of plasmons confined to reduced dimensions and under a selected device configuration, conventional limitations on carrier drift and transit times that dictate the speed and sensitivity of transistors can be circumvented, and detector sensitivity can be improved. 1D devices with sub-picosecond response times will be important for a range of applications in diverse areas such as remote sensing and imaging, molecular spectroscopy, biotechnology, and in a range of the spectrum that has been difficult to detect.Type: GrantFiled: December 15, 2005Date of Patent: February 21, 2012Assignee: Drexel UniversityInventors: Bahram Nabet, Jonathan E. Spanier
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Publication number: 20120037887Abstract: A photodetector is described along with corresponding materials, systems, and methods. The photodetector comprises an integrated circuit and at least two optically sensitive layers. A first optically sensitive layer is over at least a portion of the integrated circuit, and a second optically sensitive layer is over the first optically sensitive layer. Each optically sensitive layer is interposed between two electrodes. The two electrodes include a respective first electrode and a respective second electrode. The integrated circuit selectively applies a bias to the electrodes and reads signals from the optically sensitive layers. The signal is related to the number of photons received by the respective optically sensitive layer.Type: ApplicationFiled: August 22, 2011Publication date: February 16, 2012Applicant: InVisage Technologies, Inc.Inventors: Hui Tian, Edward Sargent
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Publication number: 20120032147Abstract: Provided is a biological component detection device with which a biological component can be detected at high sensitivity by using an InP-based photodiode in which a dark current is reduced without using a cooling mechanism and the sensitivity is extended to a wavelength of 1.8 ?m or more. An absorption layer 3 has a multiple quantum well structure composed of group III-V semiconductors, a pn-junction 15 is formed by selectively diffusing an impurity element in the absorption layer, and the concentration of the impurity element in the absorption layer is 5×1016/cm3 or less, the diffusion concentration distribution control layer has an n-type impurity concentration of 2×1015/cm3 or less before the diffusion, the diffusion concentration distribution control layer having a portion adjacent to the absorption layer, the portion having a low impurity concentration.Type: ApplicationFiled: July 30, 2009Publication date: February 9, 2012Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Youichi Nagai, Yasuhiro Iguchi
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Publication number: 20120032145Abstract: A detection device includes a light-receiving element array and a read-out integrated circuit (CMOS), bumps of the light-receiving element array being bonded to bumps of the read-out integrated circuit, and at least one of the light-receiving element array and the read-out integrated circuit having a concaved surface which faces the other. The bonded bumps positioned in a region near the periphery of the arrangement region of the bonded bumps have a larger diameter and a lower height than those of the bumps positioned in a central region. Therefore, it is possible to prevent bonding failure and insulation failure in the bumps from occurring due to a difference in coefficient of thermal expansion, while securing a small size and low cost.Type: ApplicationFiled: August 3, 2011Publication date: February 9, 2012Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Youichi NAGAI, Hiroki MORI
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Publication number: 20120032148Abstract: A multi junction photovoltaic cell for converting light into electrical energy, comprising a substrate (3) having a surface (31), wherein a region (4) at the surface (31) of the substrate (3) is doped such that a first p-n junction is formed in the substrate (3). The photovoltaic cell has a nanowire (2) that is arranged on the surface (31) of the substrate (3) at a position where the doped region (4) is located in the substrate (3), such that a second p-n junction is formed at the nanowire (2) and in series connection with the first p-n junction.Type: ApplicationFiled: April 13, 2010Publication date: February 9, 2012Applicant: SOL VOLTAICS ABInventor: Jerry M. Olson
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Patent number: 8106510Abstract: A semiconductor structure having: an electrically and thermally conductive layer disposed on one surface of the semiconductor structure; an electrically and thermally conductive heat sink; a electrically and thermally conductive carrier layer; a plurality of electrically and thermally nano-tubes, a first portion of the plurality of nano-tubes having proximal ends disposed on a first surface of the carrier layer and a second portion of the plurality of nano-tubes having proximal ends disposed on an opposite surface of the carrier layer; and a plurality of electrically and thermally conductive heat conductive tips disposed on distal ends of the plurality of nano-tubes, the plurality of heat conductive tips on the first portion of the plurality of nano-tubes being attached to the conductive layer, the plurality of heat conductive tips on the second portion of the plurality of nano-tubes being attached to the heat sink.Type: GrantFiled: August 4, 2009Date of Patent: January 31, 2012Assignee: Raytheon CompanyInventors: David H. Altman, Erik F. Nordhausen, Steven D. Bernstein, Robert P. Molfino, Steven B. Wakefield
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Publication number: 20120015469Abstract: A monolithic, multi-bandgap, tandem solar photovoltaic converter has at least one, and preferably at least two, subcells grown lattice-matched on a substrate with a bandgap in medium to high energy portions of the solar spectrum and at least one subcell grown lattice-mismatched to the substrate with a bandgap in the low energy portion of the solar spectrum, for example, about 1 eV.Type: ApplicationFiled: September 23, 2011Publication date: January 19, 2012Applicant: ALLIANCE FOR SUSTAINABLE ENERGY, LLCInventor: Mark W. Wanlass
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Patent number: 8093581Abstract: There is provided an optical semiconductor device having a first optical semiconductor element including an InP substrate, a lower cladding layer formed on the InP substrate, a lower optical guide layer which is formed on the lower cladding layer and is composed of AlGaInAs, an active layer which is formed on the lower optical guide layer and has a multiple quantum well structure where a well layer and a barrier layer that is formed of AlGaInAs are alternately stacked, an upper optical guide layer which is formed on the active layer and is composed of InGaAsP, and an upper cladding layer formed on the upper optical guide layer.Type: GrantFiled: August 19, 2008Date of Patent: January 10, 2012Assignee: Fujitsu LimitedInventors: Kan Takada, Tsuyoshi Yamamoto
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QUANTUM DOT SENSITIZED WIDE BANDGAP SEMICONDUCTOR PHOTOVOLTAIC DEVICES & METHODS OF FABRICATING SAME
Publication number: 20120003773Abstract: A quantum dot (QD) sensitized wide bandgap (WBG) semiconductor heterojunction photovoltaic (PV) device comprises an electron conductive layer; an active photovoltaic (PV) layer adjacent the electron conductive layer; a hole conductive layer adjacent the active PV layer; and an electrode layer adjacent the hole conductive layer. The active PV layer comprises a wide bandgap (WBG) semiconductor material with Eg>2.0 eV, in the form of a 2-dimensional matrix defining at least two open spaces, and a narrower bandgap semiconductor material with Eg<2.0 eV, in the form of quantum dots (QD's) filling each open space defined by the matrix of WBG semiconductor material and establishing a heterojunction therewith. The active PV layer is preferably fabricated by a co-sputter deposition process, and the QD's constitute from about 40 to about 90 vol. % of the active PV layer.Type: ApplicationFiled: June 28, 2011Publication date: January 5, 2012Applicant: SEAGATE TECHNOLOGY LLCInventors: Samuel D. Harkness, IV, Hans J. Richter -
Publication number: 20110309330Abstract: One, groups of several or many parallel vertical quantum wires arranged as 2-dimensional array interconnecting the source and drain of a transistor, are modulated with respect to their quantum-mechanical conductivity via the strength of an applied field. The Ohmic resistance of the source-drain connection via the quantum wire array is in the conducting state practically zero and the quantum wire field effect transistor's response time is solely determined by the switching time of the gate-field, which can be magnetic, electric, electroacoustic or optical. Applications for large arrays (>1010 parallel QWs) is a power transistor, for small arrays (single or few parallel QWs) it is non-volatile information-storage e.g. mediated via ferromagnetic/ferroelectric layers and/or nanoparticles, where due to the properties of 1-dimensional quantized conductivity multi-level logic is realized.Type: ApplicationFiled: March 3, 2009Publication date: December 22, 2011Inventor: Frank M. Ohnesorge
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Publication number: 20110303269Abstract: A method of fabricating a transparent electrode for use in a quantum dot sensitized solar cell, and a quantum dot sensitized solar cell fabricated according to the method are provided.Type: ApplicationFiled: December 15, 2010Publication date: December 15, 2011Applicant: Korea Institute of Science & TechnologyInventors: Jaehoon KIM, Byoung Koun MIN, Jae-Duck KIM, Jong Min PARK, Wonho JANG
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Publication number: 20110303898Abstract: A photodetector is described along with corresponding materials, systems, and methods. The photodetector comprises an integrated circuit and at least two optically sensitive layers. A first optically sensitive layer is over at least a portion of the integrated circuit, and a second optically sensitive layer is over the first optically sensitive layer. Each optically sensitive layer is interposed between two electrodes. The two electrodes include a respective first electrode and a respective second electrode. The integrated circuit selectively applies a bias to the electrodes and reads signals from the optically sensitive layers. The signal is related to the number of photons received by the respective optically sensitive layer.Type: ApplicationFiled: August 24, 2011Publication date: December 15, 2011Applicant: InVisage Technologies, Inc.Inventors: Hui Tian, Edward Sargent
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Publication number: 20110297915Abstract: A photodetector is described along with corresponding materials, systems, and methods. The photodetector comprises an integrated circuit and at least two optically sensitive layers. A first optically sensitive layer is over at least a portion of the integrated circuit, and a second optically sensitive layer is over the first optically sensitive layer. Each optically sensitive layer is interposed between two electrodes. The two electrodes include a respective first electrode and a respective second electrode. The integrated circuit selectively applies a bias to the electrodes and reads signals from the optically sensitive layers. The signal is related to the number of photons received by the respective optically sensitive layer.Type: ApplicationFiled: August 22, 2011Publication date: December 8, 2011Applicant: InVisage Technologies, Inc.Inventors: Hui Tian, Edward Sargent
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Publication number: 20110297214Abstract: Nanostructure array optoelectronic devices are disclosed. The optoelectronic device may be a multi junction solar cell. The optoelectronic device may have a bi-layer electrical interconnect that is physically and electrically connected to sidewalls of the array of nanostructures. The optoelectronic device may be operated as a multi junction solar cell, wherein each junction is associated with one portion of the device. The bi-layer electrical interconnect allows current to pass from one portion to the next. Thus, the bi-layer electrical interconnect may serve as a replacement for a tunnel junction, which is used in some conventional multi junction solar cells.Type: ApplicationFiled: June 8, 2010Publication date: December 8, 2011Applicant: SUNDIODE INC.Inventors: James C. Kim, Sungsoo Yi, Danny E. Mars
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Patent number: 8063396Abstract: Devices, methods, and techniques for frequency-dependent optical switching are provided. In one embodiment, a device includes a substrate, a first and a second optical-field confining structures located on the substrate, and a quantum structure disposed between the first and the second optical-field confining structures. The first optical-field confining structure may include a surface to receive photons. The second optical-field confining structure may be spaced apart from the first optical-field confining structure. The first and the second optical-field confining structures may be configured to substantially confine therebetween an optical field of the photons.Type: GrantFiled: April 30, 2009Date of Patent: November 22, 2011Assignee: University of Seoul Industry Cooperation FoundationInventor: Doyeol Ahn
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Publication number: 20110278541Abstract: Photoconductive optoelectronic devices, such as photodetectors and photovoltaics, are provided. The devices are sensitized to a particular wavelength (or range of wavelengths) of electromagnetic radiation such that the devices provide increased performance efficiency (e.g., external quantum efficiency) at the wavelength. The devices include a photoconductive semiconductor layer spanning an electrode gap between two electrodes to provide a photoconductive electrical conduit. Abutting the semiconductor layer is a plurality of plasmonic nanoparticles. The improved efficiency of the devices results from wavelength-dependent plasmonic enhancement of device photosensitivity by the plasmonic nanoparticles.Type: ApplicationFiled: May 17, 2011Publication date: November 17, 2011Applicant: University of Washington through its Center for CommercializationInventors: Ludan Huang, Lih Y. Lin
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Patent number: 8053758Abstract: A semiconductor device for correcting an input signal and outputting a corrected signal are provided. The semiconductor device includes a semiconductor layer, a plurality of first conductors formed on one of faces of the semiconductor layer and serving as input terminals to which a signal is input, second conductors of the number larger than that of the first conductors at density higher than that of the first conductors, formed on the other face of the semiconductor layer, a high impurity concentration region provided on the semiconductor layer side of an interface between the second conductor and the semiconductor layer, an insulating layer formed on the other face, and a plurality of third conductors formed on the insulating layer and serving as output terminals for outputting the processed signal.Type: GrantFiled: August 27, 2009Date of Patent: November 8, 2011Assignee: Kabushiki Kaisha ToshibaInventors: Takashi Yamauchi, Yoshifumi Nishi, Hiroto Honda, Kei Masunishi, Shinji Murai, Masumi Saitoh
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Patent number: 8039369Abstract: There is provided a semiconductor light-emitting element and a method of producing the same including high density and high quality quantum dots emitting light at a wavelength of 1.3 ?m. A semiconductor light-emitting element has a first GaAs layer, a second InAs thin film layer having the plurality of InAs quantum dots formed on the first GaAs layer, a third InGaAs layer formed on the second InAs thin film layer having the plurality of InAs quantum dots, and a fourth GaAs layer formed on the third InGaAs layer, wherein the As source is As2.Type: GrantFiled: August 27, 2008Date of Patent: October 18, 2011Assignee: National Institute of Advanced Industrial Science and TechnologyInventor: Takeru Amano
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Patent number: 8021909Abstract: Disclosed is a method for making a silicon quantum dot planar concentrating solar cell. At first, silicon nitride or silicon oxide mixed with silicon quantum dots is provided on a transparent substrate. By piling, there is formed a planar optical waveguide for concentrating sunlit into a small dot cast on a small solar cell.Type: GrantFiled: January 13, 2010Date of Patent: September 20, 2011Assignee: Atomic Energy Council - Institute of Nuclear ResearchInventor: Tsun-Neng Yang
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Patent number: 8022391Abstract: A composite material is described. The composite material comprises semiconductor nanocrystals, and organic molecules that passivate the surfaces of the semiconductor nanocrystals. One or more properties of the organic molecules facilitate the transfer of charge between the semiconductor nanocrystals. A semiconductor material is described that comprises p-type semiconductor material including semiconductor nanocrystals. At least one property of the semiconductor material results in a mobility of electrons in the semiconductor material being greater than or equal to a mobility of holes. A semiconductor material is described that comprises n-type semiconductor material including semiconductor nanocrystals. At least one property of the semiconductor material results in a mobility of holes in the semiconductor material being greater than or equal to a mobility of electrons.Type: GrantFiled: April 20, 2009Date of Patent: September 20, 2011Assignee: InVisage Technologies, Inc.Inventors: Edward Hartley Sargent, Ghada Koleilat, Jiang Tang, Keith William Johnston, Andras Geza Pattantyus-Abraham, Gerasimos Konstantatos, Ethan Jacob Dukenfield Klem, Stefan Myrskog, Dean Delehanty MacNeil, Jason Paul Clifford, Larissa Levina