With Heterojunction Patents (Class 257/90)
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Patent number: 6677617Abstract: This invention provides a light-emitting diode which is capable of extracting white light, manufactured readily and highly reliable. The light-emitting diode is fabricated by laminating a buffer layer 2, an Si (silicon)-doped GaN fluorescent layer 3, an n-GaN layer 4, an MQW emission layer 5 and a p-GaN layer 6 on a sapphire substrate 1 in this order. The Si-doped GaN fluorescent layer 3 is doped higher concentration of Si (silicon) than a conventional Si-doped GaN layer with sufficient good crystallinity. Such a Si-doped GaN fluorescent layer is excited by blue light generated in the MQW emission layer and emits yellow light. The yellow light is the complement for the blue light generated in the MQW emission layer. White light can be obtained by blending and extracting both of blue light and yellow light.Type: GrantFiled: October 30, 2001Date of Patent: January 13, 2004Assignee: Sanyo Electric Co., Ltd.Inventor: Kouji Tominaga
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Publication number: 20040004225Abstract: A light emitting diode and manufacturing method thereof. The light emitting diode comprises a n-type semiconductor layer formed on a substrate, an active layer formed on the n-type semiconductor layer, a p-type cladding layer formed on the active layer, and a hydrogen-adsorbing layer formed on the p-type cladding layer. The hydrogen-adsorbing layer adsorbs the hydrogen atoms near the interface to the p-type cladding layer, thereby enhancing the doping concentration of p-type cladding layer, and forming a low-resist ohmic contact by which the performance and reliability of opto-electronic devices is improved.Type: ApplicationFiled: November 7, 2002Publication date: January 8, 2004Applicant: Arima Optoelectronics Corp.Inventors: Ying-Che Sung, Chi-Wei Lu, Wen-Chieh Huang
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Publication number: 20030234404Abstract: A semiconductor light-emitting device of this invention includes at least a first cladding layer formed on a substrate, a light-emitting structure including an active layer made of In1−X−YGaXAlYN (0≦X, Y≦1, 0≦X+Y<1) and formed on the first cladding layer, and a second cladding layer formed on the light-emitting structure. The active layer is made of a material with a small Auger effect and a small dependency of its band gap energy on environment temperature.Type: ApplicationFiled: April 30, 2003Publication date: December 25, 2003Inventors: Takashi Matsuoka, Hiroshi Okamoto
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Publication number: 20030213967Abstract: A multicolor organic light emitting device employs vertically stacked layers of double heterostructure devices which are fabricated from organic compounds. The vertical stacked structure is formed on a glass base having a transparent coating of ITO or similar metal to provide a substrate. Deposited on the substrate is the vertical stacked arrangement of three double heterostructure devices, each fabricated from a suitable organic material. Stacking is implemented such that the double heterostructure with the longest wavelength is on the top of the stack. This constitutes the device emitting red light on the top with the device having the shortest wavelength, namely, the device emitting blue light, on the bottom of the stack. Located between the red and blue device structures is the green device structure.Type: ApplicationFiled: June 11, 2003Publication date: November 20, 2003Inventors: Stephen R. Forrest, Mark E. Thompson, Paul E. Burrows, Vladimir Bulovic, Gong Gu
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Patent number: 6639249Abstract: A multi-color, solid-state lighting device includes a stack of two or more panels, each panel having an array of light emitting semiconductor components formed thereon. To form the light emitting components, high quality epitaxial layers of monocrystalline materials can be grown overlying a monocrystalline layer of silicon formed on a low cost substrate, such as glass. The growth of the monocrystalline materials is accomplished by forming a compliant substrate for growing the monocrystalline materials. An accommodating buffer layer comprises a layer of monocrystalline oxide spaced apart from a silicon by an amorphous interface layer of silicon oxide. The amorphous interface layer dissipates strain and permits the growth of a high quality monocrystalline oxide accommodating buffer layer.Type: GrantFiled: August 6, 2001Date of Patent: October 28, 2003Assignee: Motorola, Inc.Inventor: George Valliath
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Patent number: 6630690Abstract: An optoelectronic device with a Group III Nitride active layer is disclosed that comprises a silicon carbide substrate; an optoelectronic diode with a Group III nitride active layer; a buffer structure selected from the group consisting of gallium nitride and indium gallium nitride between the silicon carbide substrate and the optoelectronic diode; and a stress-absorbing structure comprising a plurality of predetermined stress-relieving areas within the crystal structure of the buffer structure, so that stress-induced cracking that occurs in the buffer structure occurs at predetermined areas rather than elsewhere in the buffer structure.Type: GrantFiled: September 28, 2001Date of Patent: October 7, 2003Assignee: Cree, Inc.Inventors: John Adam Edmond, Hua-Shuang Kong, Kathleen Marie Doverspike, Michelle Turner Leonard
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Publication number: 20030183830Abstract: A light emitting device having a high definition, a high aperture ratio and a high reliability is provided. The present invention realizes a high definition and a high aperture ratio for a flat panel display of full colors using luminescent colors of red, green and blue without being dependent upon the film formation method and deposition precision of an organic compound layer by forming the laminated sections 21, 22 by means of intentionally and partially overlapping different organic compound layers of adjacent light emitting elements. Moreover, the protective film 32a containing hydrogen is formed and the drawback in the organic compound layer is terminated with hydrogen, thereby realizing the enhancement of the brightness and the reliability.Type: ApplicationFiled: January 22, 2003Publication date: October 2, 2003Applicant: Semiconductor Energy Laboratory Co., Ltd.Inventors: Shunpei Yamazaki, Masaaki Hiroki, Masakazu Murakami, Hideaki Kuwabara
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Patent number: 6627331Abstract: A display device and a method for fabricating the display device. A display device according to the present invention is fabricated from an electrode layer that includes a plurality of electrodes on a substrate. The electrode layer is immersed in a solution of a first precursor polymer in a first solvent. The first precursor polymer includes a plurality of electrochemical polymerizable monomers. Each monomer has first and second polymer-forming active sites that can be joined by electrochemical polymerization and third and fourth polymer-forming active sites that can be joined chemically in solution. The first precursor polymer is soluble in the first solvent whereas a first polymer formed by electrochemical polymerization of the first and second polymer-forming active sites is insoluble in the first solvent.Type: GrantFiled: September 22, 1999Date of Patent: September 30, 2003Assignee: Agilent Technologies, Inc.Inventors: Daniel B. Roitman, Seiji Inaoka, Riogoberto C. Advincula
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Patent number: 6608330Abstract: First and second well layers of a light emitting device emit light of different peak wavelengths so as to produce a mixed light, such as white light having high luminous intensity and high luminous efficiency. A color rendering property of the device can be controlled by adjusting the ratio of the growth numbers of the first and second well layers, and/or the thickness of the barrier layers sandwiching the well layers. The color rendering property can also be controlled by forming the second well layer so as to have a degree of asperity greater than that of the first well layer, or so that a degree of area occupied by dished portions having a thickness which is less than half of an average thickness over a total surface is not less than 10%.Type: GrantFiled: September 21, 1999Date of Patent: August 19, 2003Assignee: Nichia CorporationInventor: Motokazu Yamada
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Publication number: 20030136970Abstract: In a semiconductor light emitting device such as a semiconductor laser using nitride III-V compound semiconductors and having a structure interposing an active layer between an n-side cladding layer and a p-side cladding layer, the p-side cladding layer is made of an undoped or n-type first layer 9 and a p-type second layer 12 that are deposited sequentially from nearer to remoter from the active layer. The first layer 9 is not thinner than 50 nm. The p-type second layer 12 includes a p-type third layer having a larger band gap inserted therein as an electron blocking layer. Thus the semiconductor light emitting device is reduced in operation voltage while keeping a thickness of the p-side cladding layer necessary for ensuring favorable optical properties.Type: ApplicationFiled: January 23, 2003Publication date: July 24, 2003Inventors: Motonobu Takeya, Takeharu Asano, Masao Ikeda
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Patent number: 6590233Abstract: The semiconductor light emitting device has the first semiconductor light emission element 13 for emitting color light in the first wave length range, the second semiconductor light emission element 14 for emitting color light in the second wave length range, the frame electrode 11 for mounting the first and second semiconductor light emission elements, and the package 19 for molding them together. The first semiconductor light emission element 13 is composed of an InGaAlP series material having an active layer 34 composed of a plurality of composite luminous layers 54, 55, 56, and 57 for emitting color light with a different wavelength. Luminescence spectra from the plurality of luminous layers are partially overlapped with each other. Each of the plurality of composite luminous layers 54, 55, 56, and 57 is further composed of a plurality of luminous layers 58 for emitting color light with substantially the same wavelength.Type: GrantFiled: August 28, 2001Date of Patent: July 8, 2003Assignee: Kabushiki Kasiha ToshibaInventor: Hideto Sugawara
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Publication number: 20030099862Abstract: There is provided a light emitter for a display comprising a photoalignment layer; and photoaligned on said photoalignment layer, a light emitting polymer. Also provided are methods for forming the light emitter and the use of the light emitter in displays, backlights, electronic apparatus and security viewers.Type: ApplicationFiled: July 1, 2002Publication date: May 29, 2003Inventors: Mary O'Neill, Stephen Malcolm Kelly, Adam Edward Alexander Contoret, Gary James Richards
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Patent number: 6566688Abstract: A compound semiconductor device is provided that includes a substrate and an active region disposed above the substrate. The active region includes at least two different pseudomorphic layers, the first layer having the form InxGa1−xPyAszSb1−y−z, and the second layer having the form InqGa1−qPrAssSb1−r−s. The first layer includes at least In, Ga, and As, and the second layer includes at least Ga, As, and Sb. It is preferable for the substrate to be GaAs or AlpGa1−pAs (0<p<1), or to have a lattice constant close to or equal to that of GaA For the first layer, it is preferable if x is between 0.05 and 0.7, y is between 0 and 0,35, z is between 0.45 and 1, and 1−y−z is between 0 and 0.25. For the second layer, it is preferable if q is between 0 and 0.25 and 1−r−s is between 0.25 and 1.Type: GrantFiled: May 24, 2001Date of Patent: May 20, 2003Assignee: Arizona Board of RegentsInventors: Yong-Hang Zhang, Philip Dowd, Wolfgang Braun
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Patent number: 6563139Abstract: The present invention discloses a light source of full color LED (light emitted diode) by using die bond and packaging technology. A first mono-color LED chip with reflective metal on the bottom and transparent metal-oxide on the top of the chip is bonded on the PC board by thermal or ultrasonic die bond. A second mono-color LED chip with reflective metal on both sides is bonded in cascade on the first LED chip by thermal or ultrasonic die bond. The first LED chip emits light through the transparent metal-oxide to mix with the second LED light such that a different color light will obtain. The reflective metal reflects all the light to enforce the light intensity. In near field application, a red, a blue and a green LED are die bond in cascade to get a white light or full color light. In far field application, a yellow and a blue LED are die bond in cascade on the PC board, in its side is another cascaded die bond of a red and a green LED to get a white light or full color light.Type: GrantFiled: November 15, 2001Date of Patent: May 13, 2003Inventor: Chang Hsiu Hen
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Patent number: 6559473Abstract: An organic light-emitting diode with high luminance and high efficiency comprising an anode, an organic pn-junction and a cathode layered sequentially in this order, wherein the organic pn-junction emits light by an electric current passing through the diode in an electric field applied between the anode and the cathode, characterized in that the organic pn-junction is composed of an organic p-type luminescent-semiconductor thin film and an organic n-type luminescent-semiconductor thin film, wherein one surface of the organic p-type luminescent-semiconductor thin film is in contact with the anode and another surface of the organic p-type luminescent-semiconductor thin film is in contact with the organic n-type luminescent-semiconductor thin film, and one surface of the organic n-type luminescent-semiconductor thin film is in contact with the cathode and another surface of the organic n-type luminescent-semiconductor thin film is in contact with the organic p-type luminescent-semiconductor thin film and whereiType: GrantFiled: June 16, 1997Date of Patent: May 6, 2003Assignee: Hoechst Japan LimitedInventors: Nu Yu, Wen-Bing Kang, Akihiko Tokida
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Patent number: 6559467Abstract: A method for fabricating p-type, i-type, and n-type III-V compound materials using HVPE techniques is provided. If desired, these materials can be grown directly onto the surface of a substrate without the inclusion of a low temperature buffer layer. By growing multiple layers of differing conductivity, a variety of different device structures can be fabricated including simple p-n homojunction and heterojunction structures as well as more complex structures in which the p-n junction, either homojunction or heterojunction, is interposed between a pair of wide band gap material layers. The provided method can also be used to fabricate a device in which a non-continuous quantum dot layer is grown within the p-n junction. The quantum dot layer is comprised of a plurality of quantum dot regions, each of which is typically between approximately 20 and 30 Angstroms per axis. The quantum dot layer is preferably comprised of AlxByInzGa1-x-y-zN, InGaN1-a-bPaAsb, or AlxByInzGa1-x-y-zN1-a-bPaAsb.Type: GrantFiled: May 17, 2001Date of Patent: May 6, 2003Assignee: Technologies and Devices International, Inc.Inventors: Audrey E. Nikolaev, Yuri V. Melnik, Konstantin V. Vassilevski, Vladimir A. Dmitriev
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Patent number: 6548834Abstract: A semiconductor light emitting element is proposed that improves a light extraction efficiency without requiring any complicated processes and techniques. The semiconductor light emitting element includes an active layer for emitting first light by current injection, and a light absorbing and emitting section for absorbing a part of the first light and for emitting second light having a greater peak wavelength than the first light. A difference in peak wavelength between the first light and the second light is in a range in which a spectrum of a mixture of the first and second light maintains a unimodal characteristic or is smaller than 0.9 times a half width of the spectrum of the first light.Type: GrantFiled: January 25, 2002Date of Patent: April 15, 2003Assignee: Kabushiki Kaisha ToshibaInventors: Hideto Sugawara, Koichi Nitta, Ryo Saeki, Katsufumi Kondo, Masanobu Iwamoto
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Patent number: 6547249Abstract: Series or parallel LED arrays are formed on a highly resistive substrate, such that both the p- and n-contacts for the array are on the same side of the array. The individual LEDs are electrically isolated from each other by trenches or by ion implantation. Interconnects deposited on the array connects the contacts of the individual LEDs in the array. In some embodiments, the LEDs are III-nitride devices formed on sapphire substrates. In one embodiment, two LEDs formed on a single substrate are connected in antiparallel to form a monolithic electrostatic discharge protection circuit. In one embodiment, multiple LEDs formed on a single substrate are connected in series . In one embodiment, multiple LEDs formed on a single substrate are connected in parallel. In some embodiments, a layer of phosphor covers a portion of the substrate on which one or more individual LEDs is formed.Type: GrantFiled: March 29, 2001Date of Patent: April 15, 2003Assignee: Lumileds Lighting U.S., LLCInventors: William David Collins, III, Jerome Chandra Bhat, Daniel Alexander Steigerwald
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Publication number: 20030027017Abstract: A light emitter for a display consisting of a photoalignment layer. A light emitting polymer is photoaligned on the photoalignment layer. Also, methods for forming the light emitter and use of the light emitter in displays, backlights, electronic apparatus and security viewers.Type: ApplicationFiled: July 3, 2001Publication date: February 6, 2003Inventors: Mary O'Neill, Stephen Malcolm Kelly, Adam Edward Alexander Contoret, Gary James Richards
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Publication number: 20030006408Abstract: A semiconductor quantum well laser having separate lateral confinement of injected carriers and the optical mode. A ridge waveguide is used to confine the optical mode. A buried heterostructure confines injected carriers. A preferred embodiment laser of the invention is a layered semiconductor structure including optical confinement layers. A buried heterojunction quantum well within the optical confinement layers is dimensioned and arranged to confine injected carriers during laser operation. A ridge waveguide outside the optical confinement layers is dimensioned and arranged with respect to the buried heterojunction to confine an optical mode during laser operation. An index step created by the buried heterojunction is substantially removed from the optical mode.Type: ApplicationFiled: June 29, 2001Publication date: January 9, 2003Inventors: James J. Coleman, Reuel B. Swint, Mark S. Zediker
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Publication number: 20020179914Abstract: A group III-V element-based flip-chip assembled light-emitting diode structure with electrostatic protection capacity. A first conductive buffer layer and a second conductive buffer layer are formed over a transparent substrate. An active layer structure, a contact layer, an electrode is formed over the first conductive buffer layer. The active layer structure, the contact layer and the electrode together form a light-emitting diode structure. A metallic electrode is formed over the second conductive buffer layer to form a Schottky diode. Alternatively, a doped region is formed within the second conductive buffer layer to form a homo-junction diode structure. The anode and cathode of the diode above the second conductive buffer layer are electrically connected to the cathode and anode of the light-emitting diode, respectively.Type: ApplicationFiled: March 5, 2002Publication date: December 5, 2002Inventor: Jinn-Kong Sheu
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Publication number: 20020175337Abstract: A GaN based three layer buffer on a sapphire substrate provides a template for growth of a high quality I GaN layer as a substitute substrate for growth of a Nitride based LED.Type: ApplicationFiled: July 8, 2002Publication date: November 28, 2002Applicant: AXT, Inc.Inventors: Changhua Chen, James Dong, Heng Liu
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Publication number: 20020145149Abstract: An optical device having a current blocking layer of a buried ridge structure and a fabrication method thereof are disclosed. This invention reduces a leakage current between active layer and ion implant layer in buried ridge structure. To minimize leakage current, a P-N-P current blocking layer and an ion implanting current blocking layer are combined. An optical device of the present invention includes: active layers of a mesa structure in a predetermined region on a substrate; a first current blocking layer of a P-N-P structure, which is placed to cover the mesa structure; and a second current blocking layer of a buried ridge structure, which is placed to surround the environs of the first current blocking layer.Type: ApplicationFiled: April 3, 2002Publication date: October 10, 2002Inventors: Sung Bock Kim, Jeong Soo Kim
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Patent number: 6445007Abstract: The present invention provides a light semiconductor device comprising a substrate and a first semiconductor structure on the substrate. A light emitting structure is on a first portion of the first semiconductor structure. A first contact structure is on a second portion of the first semiconductor structure. The second portion is separated from the first portion of the first semiconductor structure. The first contact structure has a first shape. A second semiconductor structure is on the light emitting structure. A transparent contact is on the second semiconductor structure and has a cut-off portion to expose the portion of the second semiconductor structure and a second shape. A second contact structure is on the cut-off portion of the transparent contact. The second contact structure contacting the second semiconductor has a third shape.Type: GrantFiled: March 19, 2001Date of Patent: September 3, 2002Assignee: Uni Light Technology Inc.Inventors: Bor-Jen Wu, Nae-Guann Yih, Chien-An Chen, Nai-Chuan Chen
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Publication number: 20020106531Abstract: An organic EL device has an anode, a cathode, and a polymer luminescent layer disposed between the anode and the cathode, and containing a host molecule and a luminescent dye molecule, the host molecule being formed of a &pgr;-electron conjugated polymer having a carbon-fluorine bond, at least one type of luminescent dye molecule being selected from the group consisting of a transition metal complex and a linear &pgr;-electron conjugated molecule.Type: ApplicationFiled: December 26, 2001Publication date: August 8, 2002Inventor: Katsuyuki Naito
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Publication number: 20020074558Abstract: In a nitride type compound semiconductor light emitting element, a phosphor layer is formed in a multilayer constituting the light emitting element. A highly-reflective layer is formed at a side plane of the light emitting element. The nitride type compound semiconductor light emitting element can emit white light or multi-colored light, and is superior in mass production and reliability. The wavelength of the emitted light can be converted into a different wavelength by the light emitting element alone.Type: ApplicationFiled: December 3, 2001Publication date: June 20, 2002Inventors: Toshio Hata, Mayuko Fudeta, Daigaku Kimura
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Patent number: 6403985Abstract: Light emitting diodes (LEDs) and LED bars and LED arrays formed of semiconductive material, such as III-V, and particularly AlGaAs/CaAs material, are formed in very thin structures using organometallic vapor deposition (OMCVD). Semiconductor p-n junctions are formed as deposited using carbon as the p-type impurity dopant. Various lift-off methods are described which permit back side processing when the growth substrate is removed and also enable device registration for LED bars and arrays to be maintained.Type: GrantFiled: December 23, 1994Date of Patent: June 11, 2002Assignee: Kopin CorporationInventors: John C. C. Fan, Brenda Dingle, Shambhu Shastry, Mark B. Spitzer, Robert W. McClelland
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Patent number: 6404029Abstract: A photosensitive device includes a semiconductor substrate and a first semiconductor layer, both of a first conductivity type, with the semiconductor layer being formed on the semiconductor substrate and having a lower impurity concentration than that of the semiconductor substrate. A second semiconductor layer, of a second conductivity type, is formed on the first semiconductor layer and at least one diffusion layer of the first conductivity type is formed from the surface of the second semiconductor layer so as to reach the surface of the first semiconductor layer. The diffusion layer subdivides the second semiconductor layer into a plurality of semiconductor regions At least one photodiode portion for converting signal light into an electrical signal is formed at a junction between at least one of the plurality of semiconductor regions and the first semiconductor layer.Type: GrantFiled: September 6, 2000Date of Patent: June 11, 2002Assignee: Sharp Kabushiki KaishaInventors: Makoto Hosokawa, Naoki Fukunaga, Takahiro Takimoto, Masaru Kubo, Toshihiko Fukushima, Isamu Ohkubo
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Patent number: 6403986Abstract: An optical semiconductor device includes an optical semiconductor element, a semiconductor region, and a buried layer. The optical semiconductor element is formed on a semiconductor substrate. The semiconductor region opposes the optical semiconductor element and essentially surrounds the optical semiconductor element to form walls. The buried layer is arranged between the walls of the semiconductor region and the optical semiconductor element and formed by vapor phase epitaxy. In this optical semiconductor device, a distance between the wall of the semiconductor region and a side wall of the optical semiconductor element is larger in a portion in which the growth rate of the vapor phase epitaxy in a horizontal direction from the side wall of the optical semiconductor element and the wall of the semiconductor region is higher.Type: GrantFiled: February 18, 1998Date of Patent: June 11, 2002Assignee: Nippon Telegraph and Telephone CorporationInventors: Fumihiko Kobayashi, Takeo Miyazawa, Hidefumi Mori, Jun-ichi Nakano
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Patent number: 6365270Abstract: A multicolor organic light emitting device employs vertically stacked layers of double heterostructure devices which are fabricated from organic compounds. The vertical stacked structure is formed on a glass base having a transparent coating of ITO or similar metal to provide a substrate. Deposited on the substrate is the vertical stacked arrangement of three double heterostructure devices, each fabricated from a suitable organic material. Stacking is implemented such that the double heterostructure with the longest wavelength is on the top of the stack. This constitutes the device emitting red light on the top with the device having the shortest wavelength, namely, the device emitting blue light, on the bottom of the stack. Located between the red and blue device structures is the green device structure.Type: GrantFiled: December 9, 1999Date of Patent: April 2, 2002Assignee: The Trustees of Princeton UniversityInventors: Stephen Ross Forrest, Mark Edward Thompson, Paul Edward Burrows, Linda Susan Sapochak, Dennis Matthew McCarty
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Patent number: 6365911Abstract: According to the invention, a bidirectional semiconductor light emitting element is provided, which comprises: a first semiconductor region of a first type of conductivity; a second semiconductor region of a second type of conductivity provided on the first semiconductor region; a third semiconductor region of a first conductivity type provided on the second semiconductor region; and a semiconductor light emitting layer interposed in the second semiconductor region, the light emitting layer emitting light by an injection of a tunneling current generated at a reverse-biased p-n junction between the first and second regions or between the second and third regions under an application of a voltage of a first polarity across the first and third semiconductor regions, and the light emitting layer emitting light by an injection of a tunneling current generated at another reverse-biased p-n junction between the first and second regions or between the second and third regions under an application of a voltage of a seType: GrantFiled: July 21, 2000Date of Patent: April 2, 2002Assignee: Kabushiki Kaisha ToshibaInventor: Hideto Furuyama
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Patent number: 6355939Abstract: An infrared detector array includes a plurality of detector pixel structures, each having a plurality of coplanar sections responsive to different bands of infrared radiations. Each section of a pixel structure comprises a plurality of elongate quantum well infrared radiation absorbing photoconductor (QWIP) elements. The group of QWIP elements are spaced such that they comprise a diffraction grating for the received infrared radiation. Top and bottom longitudinal contacts are provided on opposite surfaces of the QWIP elongate elements to provide current flow transverse to the axis of the element to provide the required bias voltage. An infrared radiation reflector is provided to form an optical cavity for receiving infrared radiation. A plurality of detector pixel structures are combined to form a focal plane array. Each pixel structure section produces a signal that is transmitted through a conductive bump to a terminal of a read out integrated circuit.Type: GrantFiled: November 3, 1998Date of Patent: March 12, 2002Assignee: Lockheed Martin CorporationInventor: Mark A. Dodd
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Publication number: 20010045565Abstract: There is provided a light emitting device which enables a color display with good color balance. A triplet compound is used for a light emitting layer of an EL element that emits red color, and a singlet compound is used for a light emitting layer of an EL element that emits green color and a light emitting layer of an EL element that emits blue color. Thus, an operation voltage of the EL element emitting red color may be made the same as the EL element emitting green color and the EL element emitting blue color. Accordingly, the color display with good color balance can be realized.Type: ApplicationFiled: June 4, 2001Publication date: November 29, 2001Inventor: Shunpei Yamazaki
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Publication number: 20010030508Abstract: An organic EL device including; a substrate; a pair of electrodes having electrode lines and overlying the substrate; and an organic film including at least one light emitting layer disposed between the electrodes, wherein the electrode lines are formed by overlapping part of the electrodes. In the present invention, the minute electrode lines as small as 100 &mgr;m pitch can be formed by vacuum evaporation by use of a patterning mask (metal mask).Type: ApplicationFiled: April 17, 2001Publication date: October 18, 2001Applicant: NEC CorporationInventors: Koji Utsugi, Masashi Tamegai
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Publication number: 20010019135Abstract: A sparse-carrier device including a crystal structure (10) formed of a first material and having a crystallographic facet (26) with a width (w) and a length and quantum dots (30) formed of a second material and positioned in at least one row on the crystallographic facet (26). The at least one row of quantum dots (30) extends along the length of the crystallographic facet (26) and is at least one quantum dot (30) wide (w) and a plurality of quantum dots long. The number of quantum dot rows determined by the width (w) of the crystallographic facet (26). The row of quantum dots (30) form a building block for circuits based on sparse or single electron devices.Type: ApplicationFiled: March 19, 2001Publication date: September 6, 2001Inventors: Raymond K. Tsui, Kumar Shiralagi, Herbert Goronkin
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Patent number: 6236065Abstract: The light-emitting diode array of the invention includes: a semiconductor substrate of a first conductivity type and a plurality of light-emitting elements linearly arranged on the substrate of the first conductivity type. Each of the plurality of light-emitting elements includes: a cladding layer of the first conductivity type; a cladding layer of a second conductivity type; an (AlxGa1−x)yIn1−yP (where 0≦x≦1 and 0≦y≦1) active layer interposed between the cladding layer of the first conductivity type and the cladding layer of the second conductivity type; and a current diffusion layer of the second conductivity type deposited on the cladding layer of the second conductivity type. In the light-emitting diode array, at least the current diffusion layer of the second conductivity type and the cladding layer of the second conductivity type are electrically isolated from each other in two adjacent light-emitting elements among the plurality of light-emitting elements.Type: GrantFiled: October 9, 1997Date of Patent: May 22, 2001Assignee: Sharp Kabushiki KaishaInventors: Takahisa Kurahashi, Masahiko Sakata
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Patent number: 6222203Abstract: A selfluminous display device having distinct blue (B), green (G) and red (R) light emission sources wherein the spectra of the light emission sources each have a narrow half band width (30 nm or less) at a level regarded as precursor delta functions, which do not mutually substantially overlap. Because light sources having spectra of limited peak values and extremely narrow limited widths are used, shape changes of the spectrum in each light source are suppressed in the wavelength space and can be regarded as purely magnitude changes. Therefore, it becomes possible to correct just by changing the strength for each light emission source, color reproducibility increases and there ceases to be any change over time in the colors.Type: GrantFiled: June 18, 1997Date of Patent: April 24, 2001Assignee: Sony CorporationInventors: Akira Ishibashi, Norikazu Nakayama
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Patent number: 6215131Abstract: A light-emitting device using a vacuum doughnut to serve as a current blocking layer is disclosed. The light-emitting device comprises: a substrate of a first conductivity type; a buffer layer formed on the substrate; a double heterostructure layer comprising a first cladding layer, an active layer and a second cladding layer, formed on the buffer layer; and a cap layer of a second conductivity type formed on the double heterostructure layer. A vacuum doughnut is formed between the active layer and an electrode formed on the cap layer to block a current flowing from the electrode formed on the cap layer so that the current flows through a region of the double heterostructure layer that is uncovered by the electrode. Furthermore, the vacuum doughnut can also be formed in the second cladding layer instead of forming in the cap layer.Type: GrantFiled: August 11, 1999Date of Patent: April 10, 2001Assignee: Advanced Epitaxy Technology Inc.Inventors: Jian-Tin Chen, Wei-Chih Lai, Tsong-Yu Chen
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Patent number: 6211537Abstract: A 1200 dpi LED may be manufactured without highly accurate mask alignment and provide good light radiation efficiency. A first interlayer dielectric is formed on a semiconductor substrate and has a plurality of first windows formed therein and aligned in a row. A diffusion region is formed in the semiconductor substrate through each of the first windows. An electrode is formed to have an area in contact with the corresponding diffusion region. Another electrode is formed on the other side of the substrate. A second interlayer dielectric is formed on the first interlayer dielectric such that the second interlayer dielectric does not overlap the area of the electrode and does not extend to a first perimeter of the area.Type: GrantFiled: March 18, 1998Date of Patent: April 3, 2001Assignee: Oki Electric Industry Co., Ltd.Inventors: Takatoku Shimizu, Mitsuhiko Ogihara, Masumi Taninaka, Hiroshi Hamano
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Patent number: 6191438Abstract: A light emitting diode array includes a plurality of light emitting elements, provided on a substrate having a first conductivity type, for causing light to pass through a first area thereof. Each of the plurality of light emitting elements includes an active layer; a first cladding layer having the first conductivity type and a second cladding layer having a second conductivity type provided so as to interpose the active layer therebetween; and a current diffusion layer having the second conductivity type. The current diffusion layers respectively included in the plurality of light emitting elements are isolated from one another, and an area including the current diffusion layer is included in the first area.Type: GrantFiled: May 29, 1998Date of Patent: February 20, 2001Assignee: Sharp Kabushiki KaishaInventors: Masahiro Ikehara, Takahiro Obana
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Patent number: 6157047Abstract: A device structure provides improved efficiency of light emission from a light emitting element made of silicon while rendering such emission electrically controllable. Silicon in the light emitting element comprises fine microcrystals, which are miniaturized sufficiently to cause a quantum size effect. The microcrystals may be 10 nanometers (nm) or less in grain size. A dielectric film of 5 nm thick or less is formed containing therein such microcrystals. The microcrystal structure section is disposed between p- and n-type semiconductor layers. These layers are brought into electrical contact with the microcrystal structure only, while causing the remaining portions to be electrically insulative by a dielectric film or the like. Elementary particles of the opposite polarities, e.g. electrons and holes, are injected by tunnel effect into the microcrystals resulting in emission of light rays with increased efficiency.Type: GrantFiled: August 28, 1998Date of Patent: December 5, 2000Assignee: Kabushiki Kaisha ToshibaInventors: Shinobu Fujita, Atsushi Kurobe
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Patent number: 6144043Abstract: A light emitting semiconductor device in which LEDs for emitting light different in wavelength from one another are densely integrated. First to fifth semiconductor layers are AlGaAs layers being different in Al composition ratio, and when it is assumed that the energy band gaps of the first to fifth semiconductor layers are respectively Eg1, Eg2, Eg3, Eg4 and Eg5, they satisfy the relation that Eg1<Eg2<Eg3<Eg4 and Eg1<Eg5. The pn fronts formed by p-type domains and the n-type domain of the semiconductor body are individually formed in the first semiconductor layer, the second semiconductor layer and the third semiconductor layer which form a stacked semiconductor layer. The LEDs emit light having wavelengths corresponding to the energy band gaps of the semiconductor layers in which the pn fronts are formed. These LEDs are integrated at intervals of a pitch between the p-type domains or the p-type electrodes.Type: GrantFiled: November 10, 1998Date of Patent: November 7, 2000Assignee: Oki Electric Industry Co., Ltd.Inventors: Mitsuhiko Ogihara, Yukio Nakamura, Hiroshi Hamano, Masumi Taninaka
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Patent number: 6114715Abstract: A display apparatus using electroluminescence elements has a substrate, a plurality of anodes arranged generally parallel to each other on a surface of the substrate, and the EL element disposed on the substrate and the anodes. In addition, a material layer is located on the substrate and between the anodes. The material layer may be either a black matrix layer constructed of a light shielding film or a highly reflective multilayer film which suppresses optical crosstalk caused by light scattering originated in the EL element. The material layer covers the anodes such that only a part of each anode corresponding to a display area is exposed. The display apparatus may be used in either a simple matrix display system or an active matrix display system.Type: GrantFiled: November 28, 1997Date of Patent: September 5, 2000Assignee: Sanyo Electric Co., Ltd.Inventor: Hiroki Hamada
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Patent number: 6060727Abstract: A light emitting semiconductor device is provided which comprises a common substrate having a support surface, and a plurality of laminate structures formed at different regions on the support surface of the common substrate. Each of the laminate structures has at least one N-type layer, a light emitting layer and at least one P-type layer. The light emitting layer emits light at least perpendicularly to the support surface of the substrate. The laminate structures at the different regions are made to emit light of a different wavelength.Type: GrantFiled: June 26, 1997Date of Patent: May 9, 2000Assignee: Rohm Co., Ltd.Inventor: Yukio Shakuda
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Patent number: 6054724Abstract: A compound semiconductor layer of a first conductivity type is formed on a substrate, and a diffusion region of a second conductivity type is formed on the compound semiconductor layer. The light-emitting diode has a high emitted light power, using a large-diameter wafer.Type: GrantFiled: September 4, 1997Date of Patent: April 25, 2000Assignee: Oki Electric Industry Co., Ltd.Inventors: Mitsuhiko Ogihara, Yukio Nakamura, Masumi Taninaka, Hiroshi Hamano
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Patent number: 6030700Abstract: A multicolor organic light emitting device employs vertically stacked layers of double heterostructure devices which are fabricated from organic compounds. The vertical stacked structure is formed on a glass base having a transparent coating of ITO or similar metal to provide a substrate. Deposited on the substrate is the vertical stacked arrangement of three double heterostructure devices, each fabricated from a suitable organic material. Stacking is implemented such that the double heterostructure with the longest wavelength is on the top of the stack. This constitutes the device emitting red light on the top with the device having the shortest wavelength, namely, the device emitting blue light, on the bottom of the stack. Located between the red and blue device structures is the green device structure.Type: GrantFiled: November 7, 1997Date of Patent: February 29, 2000Assignee: The Trustees of Princeton UniversityInventors: Stephen Ross Forrest, Mark Edward Thompson, Paul Edward Burrows, Linda Susan Sapochak, Dennis Matthew McCarty
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Patent number: 5952681Abstract: A multicolor light emitting diode (MLED) is disclosed which can emit various different colored light at the same time. A R, G, B three color LED is formed in a common crystalline granule (chip), with an ultra violet light crystalline granule formed by GaN grown on a sapphire substrate, and the finished products are all transparent. The surrounding of the granule is plated with an insulated layer and then a reflection layer. The light excited by the light granule is emitted either from the front or the back surface of LED. After the excited light has passed through a wave length converting layer, it can be converted to a colored visible light. The entire crystalline granule may be completely formed into an ultra violet or blue light chip, with wave length converting layers so that the chip can emit red, green and blue colors.Type: GrantFiled: November 24, 1997Date of Patent: September 14, 1999Inventor: Hsing Chen
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Patent number: 5866922Abstract: An integrated matrix of light emitting devices includes a plurality of isolated semiconductor LEDs positioned in a matrix of rows and columns on the surface of a substrate. A plurality of column buses, one each positioned adjacent each column of semiconductor LEDs, is provided with each of the column buses being connected to a first terminal of each semiconductor LED in the adjacent column of semiconductor LEDs and each of the column buses providing an exposed planar surface. A plurality of OEDs is positioned on the exposed planar surface of each column bus with a first terminal of each OED connected to the column bus.Type: GrantFiled: December 23, 1996Date of Patent: February 2, 1999Assignee: Motorola, Inc.Inventors: Rong Ting Huang, Phil Wright, Paige M. Holm, Song Q. Shi
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Patent number: 5757026Abstract: A multicolor organic light emitting device employs vertically stacked layers of double heterostructure devices which are fabricated from organic compounds. The vertical stacked structure is formed on a glass base having a transparent coating of ITO or similar metal to provide a substrate. Deposited on the substrate is the vertical stacked arrangement of three double heterostructure devices, each fabricated from a suitable organic material. Stacking is implemented such that the double heterostructure with the longest wavelength is on the top of the stack. This constitutes the device emitting red light on the top with the device having the shortest wavelength, namely, the device emitting blue light, on the bottom of the stack. Located between the red and blue device structures is the green device structure.Type: GrantFiled: April 15, 1996Date of Patent: May 26, 1998Assignee: The Trustees of Princeton UniversityInventors: Stephen Ross Forrest, Mark Edward Thompson, Paul Edward Burrows, Linda Susan Sapochak, Dennis Matthew McCarty
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Patent number: 5739552Abstract: A method of fabricating a light emitting diode (LED) device producing visible light includes growing layers of an LED emitting blue light to form a blue LED; growing layers of an LED emitting green light to form a green LED; growing layers of an LED emitting red light to form a red LED; and uniting the three LEDs directly to each other by annealing. Therefore, an LED device that can emit light of all three colors from the same region of the LED device with variable light intensity is obtained.Type: GrantFiled: October 24, 1995Date of Patent: April 14, 1998Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Tatsuya Kimura, Zempei Kawazu