Cadmium Containing Patents (Class 136/260)
  • Patent number: 6025252
    Abstract: In order to easily and accurately manufacture a micromachine comprising a member which is made of a single-crystalline material and having a complicated structure, an uppermost layer (1104) of a single-crystalline Si substrate (1102) whose (100) plane is upwardly directed is irradiated with Ne atom currents from a plurality of prescribed directions, so that the crystal orientation of the uppermost layer (1104) is converted to such orientation that the (111) plane is upwardly directed. A masking member (106) is employed as a shielding member to anisotropically etch the substrate (1102) from its bottom surface, thereby forming a V-shaped groove (1112). At this time, the uppermost layer (1104) serves as an etching stopper. Thus, it is possible to easily manufacture a micromachine having a single-crystalline diaphragm having a uniform thickness. A micromachine having a complicated member such as a diagram which is made of a single-crystalline material can be easily manufactured through no junction.
    Type: Grant
    Filed: August 25, 1997
    Date of Patent: February 15, 2000
    Assignee: Mega Chips Corporation
    Inventors: Masahiro Shindo, Daisuke Kosaka, Tetsuo Hikawa, Akira Takata, Yukihiro Ukai, Takashi Sawada, Toshifumi Asakawa
  • Patent number: 6023020
    Abstract: A solar cell utilizing a chalcopyrite semiconductor and reducing the density of defects on the junction interface of pn junctions is provided. This solar cell includes a substrate, a back electrode formed on the substrate, a p-type chalcopyrite semiconductor thin film formed on the back electrode, an n-type semiconductor thin film formed so as to constitute a pn junction with the p-type chalcopyrite semiconductor thin film, and a transparent electrode formed on the n-type semiconductor thin film. A material having a higher resistivity than the p-type chalcopyrite semiconductor is formed between the p-type chalcopyrite semiconductor thin film and the n-type semiconductor thin film. A thin film made of this material may be formed by deposition from a solution. For example, CuInS.sub.2 is formed on the surface of a p-type chalcopyrite based semiconductor such as CuInSe.sub.
    Type: Grant
    Filed: October 14, 1997
    Date of Patent: February 8, 2000
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Mikihiko Nishitani, Takayuki Negami, Naoki Kohara, Takahiro Wada, Yasuhiro Hashimoto
  • Patent number: 6015951
    Abstract: This invention relates to a photoelectric transfer device which comprises a photoelectric transfer element, a cholesteric liquid crystal layer and an ultraviolet cut-off layer, said cholesteric liquid crystal layer being arranged between said photoelectric transfer element and said ultraviolet cut-off layer and said ultraviolet cut-off layer being arranged at the side for the incidence of light. According to this invention, there is provided a colorful photoelectric transfer device which is prepared at an inexpensive cost without a marked decrease in the generation efficiency of the photoelectric transfer element and is fit to be used over a prolonged period.
    Type: Grant
    Filed: November 20, 1997
    Date of Patent: January 18, 2000
    Assignee: Nippon Oil Company, Limited
    Inventors: Keizo Ikai, Mitsuo Matsuno
  • Patent number: 5994642
    Abstract: A method for forming a CdTe film of good quality by an improved close-spaced sublimation process is disclosed. This method comprises: a step of applying a paste which contains material for CdTe semiconductor on a supporting member, thereby to form a coating film which contains the material for the semiconductor on the surface of the supporting member; a step of closely arranging the supporting member and a substrate on which a CdTe film is to be formed, to make the coating film to face the surface of the substrate; and a step of forming a CdTe film on the substrate, by heating the coating film and the substrate, and causing the material for the semiconductor in the coating film to evaporate.
    Type: Grant
    Filed: March 13, 1998
    Date of Patent: November 30, 1999
    Assignee: Matsushita Battery Industrial Co., Ltd.
    Inventors: Hiroshi Higuchi, Seiji Kumazawa, Takashi Arita, Akira Hanafusa, Mikio Murozono, Tetsuya Aramoto
  • Patent number: 5990415
    Abstract: A multilayer solar cell with bypass diodes includes a stack of alternating p and n type semiconductor layers 10, 11, 12, 13, 14 arranged to form a plurality of rectifying photovoltaic junctions 15, 16, 17, 18. Contact is made to underlying layers by way of a buried contact structure comprising grooves extending down through all of the active layers, the walls of each groove being doped 33, 34 with n-or p-type impurities depending upon the layers to which the respective contact is to be connected and the grooves being filled with metal contact material 31, 32. One or more bypass diodes are provided by increasing the doping levels on either side 10, 13 of one or more portions of the junctions 16 of the cell such that quantum mechanical tunnelling provides a reverse bias characteristic whereby conduction occurs under predetermined reverse bias conditions. Ideally, the doping levels in the bypass diodes is 10.sup.18 atoms/cm.sup.3 or greater and the junction area is small.
    Type: Grant
    Filed: May 29, 1997
    Date of Patent: November 23, 1999
    Assignee: Pacific Solar Pty Ltd
    Inventors: Martin Andrew Green, Stuart Ross Wenham
  • Patent number: 5986205
    Abstract: The stainless steel sheet useful as a substrate for non-single crystalline semiconductor solar cells has minute ripples with undulations along a rolling direction, and its surface roughness is controlled in the range of R.sub.z 0.3-1.4 .mu.m and R.sub.max 0.5-1.7 .mu.m. It is manufactured by finish cold rolling a stainless steel strip with a reduction ratio of at least 20% at a rolling speed of at least 400 m/min. using work rolls polished with abrasives of gage #100-#400 at a final pass, annealing the rolled strip in an open-air atmosphere and then electrolytically pickling the annealed strip in a nitric acid solution. Since minute ripples with undulations are formed on the surface of the stainless steel sheet, an energy conversion efficiency is increased by acceleration of scattering and multiple reflection of incident light rays projected into a non-single crystalline semiconductor layer.
    Type: Grant
    Filed: September 4, 1997
    Date of Patent: November 16, 1999
    Assignees: Nisshin Steel Co., Ltd., Canon Kabushiki Kaisha
    Inventors: Hisashi Matsune, Yasushi Nishimura, Takuji Okiyama, Masafumi Sano
  • Patent number: 5955772
    Abstract: A heterostructure thermionic cooler and a method for making thermionic coolers, employing a barrier layer of varying conduction bandedge for n-type material, or varying valence bandedge for p-type material, that is placed between two layers of material. The barrier layer has a high enough barrier for the cold side to only allow "hot" electrons, or electrons of high enough energy, across the barrier. The barrier layer is constructed to have an internal electric field such that the electrons that make it over the initial barrier are assisted in travel to the anode. Once electrons drop to the energy level of the anode, they lose energy to the lattice, thus heating the lattice at the anode. The barrier height of the barrier layer is high enough to prevent the electrons from traveling in the reverse direction.
    Type: Grant
    Filed: December 17, 1996
    Date of Patent: September 21, 1999
    Assignee: The Regents of the University of California
    Inventors: Ali Shakouri, John E. Bowers
  • Patent number: 5922142
    Abstract: A photovoltaic device having a substrate, a layer of Cd.sub.2 SnO.sub.4 disposed on said substrate as a front contact, a thin film comprising two or more layers of semiconductor materials disposed on said layer of Cd.sub.2 SnO.sub.4, and an electrically conductive film disposed on said thin film of semiconductor materials to form a rear electrical contact to said thin film. The device is formed by RF sputter coating a Cd.sub.2 SnO.sub.4 layer onto a substrate, depositing a thin film of semiconductor materials onto the layer of Cd.sub.2 SnO.sub.4, and depositing an electrically conductive film onto the thin film of semiconductor materials.
    Type: Grant
    Filed: November 18, 1996
    Date of Patent: July 13, 1999
    Assignee: Midwest Research Institute
    Inventors: Xuanzhi Wu, Timothy J. Coutts, Peter Sheldon, Douglas H. Rose
  • Patent number: 5868869
    Abstract: Provided is a thin film photovoltaic device and a method of manufacturing the device. The thin film photovoltaic device comprises a film layer having particles which are smaller than about 30 microns in size held in an electrically insulating matrix material to reduce the potential for electrical shorting through the film layer. The film layer may be provided by depositing preformed particles onto a surrogate substrate and binding the particles in a film-forming matrix material to form a flexible sheet with the film layer. The flexible sheet may be separated from the surrogate substrate and cut into flexible strips. A plurality of the flexible strips may be located adjacent to and supported by a common supporting substrate to form a photovoltaic module having a plurality of electrically interconnected photovoltaic cells.
    Type: Grant
    Filed: October 7, 1997
    Date of Patent: February 9, 1999
    Assignee: Photon Energy, Inc.
    Inventors: Scot P. Albright, Rhodes Chamberlin
  • Patent number: 5738731
    Abstract: A solar cell comprising:a first junction part having a first conductivity type first semiconductor film and a second conductivity type second semiconductor film formed on an upper surface of said first semiconductor film; anda second junction part having a first conductivity type third semiconductor film formed on an upper surface of said second semiconductor film and a second conductivity type fourth semiconductor formed on an upper surface of said third semiconductor film,said junction parts arranged from that having a larger forbidden band width along the direction of progress of light through said semiconductor layers,said first, second, third, and fourth semiconductor films being formed of single-crystalline filming;wherein an interlayer conductor prepared from a metal forming ohmic junctions with each of said junction parts and having a thickness capable of transmitting light therethrough is interposed between said first and second junction parts; andwherein said second semiconductor film arranged on on
    Type: Grant
    Filed: August 31, 1994
    Date of Patent: April 14, 1998
    Assignees: Mega Chips Corporation, Crystal Device Corporation
    Inventors: Masahiro Shindo, Daisuke Kosaka, Tetsuo Hikawa, Akira Takata, Yukihiro Ukai, Takashi Sawada, Toshifumi Asakawa
  • Patent number: 5731031
    Abstract: A process for chemical bath deposition of selenide and sulfide salts as films and powders employable as precursors for the fabrication of solar cell devices. The films and powders include (1) Cu.sub.x Se.sub.n, wherein x=1-2 and n=1-3; (2) Cu.sub.x Ga.sub.y Se.sub.n, wherein x=1-2, y=0-1 and n=1-3; (3) Cu.sub.x In.sub.y Se.sub.n, wherein x=1-2.27, y=0.72-2 and n=1-3; (4) Cu.sub.x (InGa).sub.y Se.sub.n, wherein x=1-2.17, y=0.96-2 and n=1-3; (5) In.sub.y Se.sub.n, wherein y=1-2.3 and n=1-3; (6) Cu.sub.x S.sub.n, wherein x=1-2 and n=1-3; and (7) Cu.sub.x (InGa).sub.y (SeS).sub.n, wherein x=1-2, y=0.07-2 and n=0.663-3.
    Type: Grant
    Filed: December 20, 1995
    Date of Patent: March 24, 1998
    Assignee: Midwest Research Institute
    Inventors: Raghu Nath Bhattacharya, Rommel Noufi, Li Wang
  • Patent number: 5714391
    Abstract: This invention relates to a manufacturing method of a compound semiconductor thin film derived from a metal sulfide produced by thermal decomposition of a sulfur-containing metal organic compound, the compound containing at least one functional group having at least one metal atom selected from the group consisting of copper, zinc, cadmium, mercury, and lead, and the functional group also containing at least one sulfur atom. Since the obtained metal sulfides are of high-purity and dense, they can be utilized in various photoelectric devices. Particularly, the photoelectric conversion efficiency of a CdS/CdTe system thin film compound semiconductor solar cell can be improved remarkably by employing a layer made of a CdS thin film as a window of the solar cell.
    Type: Grant
    Filed: May 16, 1996
    Date of Patent: February 3, 1998
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kuniyoshi Omura, Tsuyoshi Nishio, Satoshi Shibutani, Shigeo Kondoh, Mikio Murozono, Akira Hanafusa, Hideaki Oyama
  • Patent number: 5712187
    Abstract: A method of depositing a semiconductor material on a substrate. The method sequentially comprises (a) providing the semiconductor material in a depositable state such as a vapor for deposition on the substrate; (b) depositing the semiconductor material on the substrate while heating the substrate to a first temperature sufficient to cause the semiconductor material to form a first film layer having a first grain size; (c) continually depositing the semiconductor material on the substrate while cooling the substrate to a second temperature sufficient to cause the semiconductor material to form a second film layer deposited on the first film layer and having a second grain size smaller than the first grain size; and (d) raising the substrate temperature, while either continuing or not continuing to deposit semiconductor material to form a third film layer, to thereby anneal the film layers into a single layer having favorable efficiency characteristics in photovoltaic applications.
    Type: Grant
    Filed: November 9, 1995
    Date of Patent: January 27, 1998
    Assignee: Midwest Research Institute
    Inventors: Xiaonan Li, Peter Sheldon
  • Patent number: 5674325
    Abstract: Provided is a thin film photovoltaic device and a method of manufacturing the device. The thin film photovoltaic device comprises a film layer having particles which are smaller than about 30 microns in size held in an electrically insulating matrix material to reduce the potential for electrical shorting through the film layer. The film layer may be provided by depositing preformed particles onto a surrogate substrate and binding the particles in a film-forming matrix material to form a flexible sheet with the film layer. The flexible sheet may be separated from the surrogate substrate and cut into flexible strips. A plurality of the flexible strips may be located adjacent to and supported by a common supporting substrate to form a photovoltaic module having a plurality of electrically interconnected photovoltaic cells.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: October 7, 1997
    Assignee: Photon Energy, Inc.
    Inventors: Scot P. Albright, Rhodes Chamberlin
  • Patent number: 5567469
    Abstract: A chalcopyrite compound, for instance, CuInS.sub.2 or CuInSe.sub.2, is prepared by subjecting a thin film containing copper metal, indium metal, and an indium compound or a compound which contains both indium and copper, selected from the group consisting of oxides, sulfides and selenides, with heat under a reducing atmosphere containing at least one of the Group VIb element or under an atmosphere containing a reducing compound of at least one of the Group VIb element, thereby converting said thin film into a chalcopyrite compound.
    Type: Grant
    Filed: June 1, 1995
    Date of Patent: October 22, 1996
    Assignee: Matsuhita Electric Co., Ltd.
    Inventors: Takahiro Wada, Mikihiko Nishitani, Takayuki Negami
  • Patent number: 5565041
    Abstract: A polysilane composition containing conductor or semiconductor particles useful as a portion of a non-linear optical device.
    Type: Grant
    Filed: May 26, 1995
    Date of Patent: October 15, 1996
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toshiro Hiraoka, Shin-ichi Nakamura, Yoshihiko Nakano, Shinji Murai, Shuzi Hayase
  • Patent number: 5541118
    Abstract: A process for producing a layer of cadmium sulfide on a cadmium telluride surface to be employed in a photovoltaic device. The process comprises providing a cadmium telluride surface which is exposed to a hydrogen sulfide plasma at an exposure flow rate, an exposure time and an exposure temperature sufficient to permit reaction between the hydrogen sulfide and cadmium telluride to thereby form a cadmium sulfide layer on the cadmium telluride surface and accomplish passivation. In addition to passivation, a heterojunction at the interface of the cadmium sulfide and the cadmium telluride can be formed when the layer of cadmium sulfide formed on the cadmium telluride is of sufficient thickness.
    Type: Grant
    Filed: May 22, 1995
    Date of Patent: July 30, 1996
    Assignee: Midwest Research Institute
    Inventors: Dean H. Levi, Art J. Nelson, Richard K. Ahrenkiel
  • Patent number: 5538903
    Abstract: A method of manufacturing a solar cell, comprising the steps of forming a layer of n-type compound semiconductor, a layer of p-type compound semiconductor, and an electrode layer on a glass substrate, wherein at least one of said steps of forming a layer of compound semiconductor layer comprises preparing a paste by mixing a semiconductor raw material and a viscous agent, applying said paste to said substrate, drying said paste to harden it, and firing the dried paste, and vibrating said substrate during or after the application of the paste, to remove the bubbles in the paste, resulting in a semiconductor layer which is smooth, dense, and having good adhesion, thus realizing a solar cell with improved and uniform characteristics.
    Type: Grant
    Filed: November 18, 1994
    Date of Patent: July 23, 1996
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tetsuya Aramoto, Nobuo Nakayama, Kuniyoshi Omura, Mikio Murozono
  • Patent number: 5536333
    Abstract: A process and apparatus (70) for making a large area photovoltaic device (22) that is capable of generating low cost electrical power. The apparatus (70) for performing the process includes an enclosure (126) providing a controlled environment in which an oven (156) is located. At least one and preferably a plurality of deposition stations (74,76,78) provide heated vapors of semiconductor material within the oven (156) for continuous elevated temperature deposition of semiconductor material on a sheet substrate (24) including a glass sheet (26) conveyed within the oven. The sheet substrate (24) is conveyed on a roller conveyor (184) within the oven (156) and the semiconductor material whose main layer (82) is cadmium telluride is deposited on an upwardly facing surface (28) of the substrate by each deposition station from a location within the oven above the roller conveyor.
    Type: Grant
    Filed: August 15, 1995
    Date of Patent: July 16, 1996
    Assignee: Solar Cells, Inc.
    Inventors: James B. Foote, Steven A. F. Kaake, Peter V. Meyers, James F. Nolan
  • Patent number: 5501744
    Abstract: A photovoltaic cell has an n-type polycrystalline layer and a p-type polycrystalline layer adjoining the n-type polycrystalline layer to form a photovoltaic junction. The p-type polycrystalline layer comprises a substantially planar layer portion having relatively large crystals adjoining the n-type polycrystalline layer. The planar layer portion includes oxidized impurities which contribute to obtainment of p-type electrical properties in the planar layer portion.
    Type: Grant
    Filed: July 12, 1994
    Date of Patent: March 26, 1996
    Assignee: Photon Energy, Inc.
    Inventors: Scot P. Albright, Rhodes R. Chamberlin
  • Patent number: 5500056
    Abstract: A solar cell includes a compound semiconductor, which is a laminated film having compound semiconductor layers, and low melting point glass. When the solar cell is heated by fire, the low melting point glass melts to seal the compound semiconductor so that toxic substances contained in the compound semiconductor are not released into the air.
    Type: Grant
    Filed: July 18, 1994
    Date of Patent: March 19, 1996
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Takahiro Wada, Mitsusuke Ikeda, Mikihiko Nishitani, Masaharu Terauchi, Takayuki Negami, Naoki Kohara
  • Patent number: 5484736
    Abstract: A process for producing a cadmium telluride polycrystalline film having grain sizes greater than about 20 .mu.m. The process comprises providing a substrate upon which cadmium telluride can be deposited and placing that substrate within a vacuum chamber containing a cadmium telluride effusion cell. A polycrystalline film is then deposited on the substrate through the steps of evacuating the vacuum chamber to a pressure of at least 10.sup.-6 torr.; heating the effusion cell to a temperature whereat the cell releases stoichiometric amounts of cadmium telluride usable as a molecular beam source for growth of grains on the substrate; heating the substrate to a temperature whereat a stoichiometric film of cadmium telluride can be deposited; and releasing cadmium telluride from the effusion cell for deposition as a film on the substrate.
    Type: Grant
    Filed: September 19, 1994
    Date of Patent: January 16, 1996
    Assignee: Midwest Research Institute
    Inventors: Falah S. Hasoon, Art J. Nelson
  • Patent number: 5472910
    Abstract: Ohmic contacts to p-type IIB/VIB semiconductor are obtained by a process which includes the step of depositing a viscous liquid containing a Group IB metal salt on a surface of a semiconductor, substantially free of oxide groups, heating to form a dried layer, removing the dried layer, washing the surface to remove residual by-products and drying the surface.
    Type: Grant
    Filed: March 16, 1994
    Date of Patent: December 5, 1995
    Assignee: BP Solar Limited
    Inventors: Daniel R. Johnson, Sener Oktik, Mehmet E. Ozsan, Michael H. Patterson
  • Patent number: 5470397
    Abstract: A process and apparatus (70) for making a large area photovoltaic device (22) that is capable of generating low cost electrical power. The apparatus (70) for performing the process includes an enclosure (126) providing a controlled environment in which an oven (156) is located. At least one and preferably a plurality of deposition stations (74,76,78) provide heated vapors of semiconductor material within the oven (156) for continuous elevated temperature deposition of semiconductor material on a sheet substrate (24) including a glass sheet (26) conveyed within the oven. The sheet substrate (24) is conveyed on a roller conveyor (184) within the oven (156) and the semiconductor material whose main layer (82) is cadmium telluride is deposited on an upwardly facing surface (28) of the substrate by each deposition station from a location within the oven above the roller conveyor.
    Type: Grant
    Filed: September 2, 1994
    Date of Patent: November 28, 1995
    Assignee: Solar Cells, Inc.
    Inventors: James B. Foote, Steven A. F. Kaake, Peter V. Meyers, James F. Nolan
  • Patent number: 5436204
    Abstract: A process for fabricating slightly Cu-poor thin-films of Cu(In,Ga)Se.sub.2 on a substrate for semiconductor device applications includes the steps of forming initially a slightly Cu-rich, phase separated, mixture of Cu(In,Ga)Se.sub.2 :Cu.sub.x Se on the substrate in solid form followed by exposure of the Cu(In,Ga)Se.sub.2 :Cu.sub.x Se solid mixture to an overpressure of Se vapor and (In,Ga) vapor for deposition on the Cu(In,Ga)Se.sub.2 :Cu.sub.x Se solid mixture while simultaneously increasing the temperature of the solid mixture toward a recrystallization temperature (about 550.degree. C.) at which Cu(In,Ga)Se.sub.2 is solid and Cu.sub.x Se is liquid. The (In,Ga) flux is terminated while the Se overpressure flux and the recrystallization temperature are maintained to recrystallize the Cu.sub.x Se with the (In, Ga) that was deposited during the temperature transition and with the Se vapor to form the thin-film of slightly Cu-poor Cu.sub.x (In,Ga).sub.y Se.sub.z.
    Type: Grant
    Filed: August 22, 1994
    Date of Patent: July 25, 1995
    Assignee: Midwest Research Institute
    Inventors: David S. Albin, Jeffrey J. Carapella, John R. Tuttle, Miguel A. Contreras, Andrew M. Gabor, Rommel Noufi, Andrew L. Tennant
  • Patent number: 5411601
    Abstract: A solar cell is constructed using a heterojunction formed by layering an n-type compound semiconductor followed by a p-type compound semiconductor on an insulator layer containing titanium oxide which has been formed on one side of a glass plate. The insulator layer can improve the photoelectric conversion efficiency of the solar cell by lowering the sheet resistance of the n-type semiconductor film which is used as the window material of the solar cell. In addition, light transmittance is improved.
    Type: Grant
    Filed: November 2, 1993
    Date of Patent: May 2, 1995
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hiroshi Higuchi, Takashi Arita, Sotoyuki Kitamura, Mikio Murozono
  • Patent number: 5393675
    Abstract: A thin film photovoltaic cell having a semiconductor layer of cadmium sulfide and a semiconductor layer of cadmium telluride is manufactured in a process in which the cadmium sulfide and the cadmium telluride are deposited onto a conductive layer of a substrate by RF sputtering. A layer of cadmium sulfide is deposited on the conducting layer of the substrate by RF magnetron sputtering. After the cadmium sulfide is deposited, a layer of cadmium telluride is deposited by RF magnetron sputtering. The RF sputtering deposition of the two semiconductor layers increases the efficiency of the cell and is conducive to a large scale manufacturing process. The photovoltaic cell may include only two semiconductor layers forming a p-n junction. A third semiconductor layer, typically zinc telluride, may be added to the cell to form a p-i-n junction. The efficiency of the cell is further increased by treatment with cadmium chloride and annealing in dry air.
    Type: Grant
    Filed: May 10, 1993
    Date of Patent: February 28, 1995
    Assignee: The University of Toledo
    Inventor: Alvin D. Compaan
  • Patent number: 5356839
    Abstract: Enhanced quality thin films of Cu.sub.w (In,Ga.sub.y)Se.sub.z for semiconductor device applications are fabricated by initially forming a Cu-rich, phase-separated compound mixture comprising Cu(In,Ga):Cu.sub.x Se on a substrate to form a large-grain precursor and then converting the excess Cu.sub.x Se to Cu(In,Ga)Se.sub.2 by exposing it to an activity of In and/or Ga, either in vapor In and/or Ga form or in solid (In,Ga).sub.y Se.sub.z. Alternatively, the conversion can be made by sequential deposition of In and/or Ga and Se onto the phase-separated precursor. The conversion process is preferably performed in the temperature range of about 300.degree.-600.degree. C., where the Cu(In,Ga)Se.sub.2 remains solid, while the excess Cu.sub.x Se is in a liquid flux. The characteristic of the resulting Cu.sub.w (In,Ga).sub.y Se.sub.z can be controlled by the temperature. Higher temperatures, such as 500.degree.-600.degree. C., result in a nearly stoichiometric Cu(In,Ga)Se.sub.
    Type: Grant
    Filed: April 12, 1993
    Date of Patent: October 18, 1994
    Assignee: Midwest Research Institute
    Inventors: John R. Tuttle, Miguel A. Contreras, Rommel Noufi, David S. Albin
  • Patent number: 5304499
    Abstract: A method of making pn CdTe/CdS thin film solar cells, in which a transparent TCO layer is deposited as a front contact on a transparent substrate in the form of inexpensive soda-lime glass, and is preferably provided with an ultra-thin indium layer, which is in turn coated with the CdS layer, wherein the thus coated substrate is brought to the CdTe coating at a temperature between 480.degree. C. and 520.degree. C., which is maintained during the ensuing rapid CdTe deposition using the close-spaced sublimation method with a preferred rate of deposition of 5 to 15 .mu.m/min in an inert atmosphere. The indium layer dissolves during this deposition and effects the necessary n-doping of the CdS layer, without an additional method step. Solar cells can be made in this way with high efficiency in an inexpensive method, suitable for mass production.
    Type: Grant
    Filed: September 28, 1992
    Date of Patent: April 19, 1994
    Assignee: Battelle-Institut e.V.
    Inventors: Dieter Bonnet, Beate Henrichs, Karlheinz Jager, Hilmar Richter
  • Patent number: 5279678
    Abstract: An improved photovoltaic panel and method of forming a photovoltaic panel are disclosed for producing a high efficiency CdS/CdTe photovoltaic cell. The photovoltaic panel of the present invention is initially formed with a substantially thick Cds layer, and the effective thickness of the CdS layer is substantially reduced during regrowth to both form larger diameter CdTe crystals and substantially reduce the effective thickness of the CThis invention was made with Government support under Subcontract No. ZL-7-06031-3 awarded by the Department of Energy. The Government has certain rights in this invention.
    Type: Grant
    Filed: January 13, 1992
    Date of Patent: January 18, 1994
    Assignee: Photon Energy, Inc.
    Inventors: John F. Jordan, Scot P. Albright
  • Patent number: 5261968
    Abstract: An improved photovoltaic panel and method of forming a photovoltaic panel are disclosed for producing a high efficiency CdS/CdTe photovoltaic cell. The photovoltaic panel of the present invention is initially formed with a substantially thick CdS layer, and the effective thickness of the CdS layer is substantially reduced during regrowth to both form large diameter CdTe crystals and substantially reduce the effective thickness of the CdS layer by diffusion into the CdTe layer such that a majority of sunlight having a wavelength less than 520 nm passes through the CdS layer to the photovoltaic junction. Shorting of individual cells is substantially minimized by providing a conductive layer which is formed from two tin oxide layers, each having substantially dissimilar electrical conductivity, such that an electrically-conductive tin oxide layer interconnects the plurality of photovoltaic cells, while the comparatively high resistivity tin oxide layer prevents shorting of a cell.
    Type: Grant
    Filed: January 13, 1992
    Date of Patent: November 16, 1993
    Assignee: Photon Energy, Inc.
    Inventor: John F. Jordan
  • Patent number: 5248349
    Abstract: A process and apparatus (70) for making a large area photovoltaic device (22) that is capable of generating low cost electrical power. The apparatus (70) for performing the process includes an enclosure (126) providing a controlled environment in which an oven (156) is located. At least one and preferably a plurality of deposition stations (74,76,78) provide heated vapors of semiconductor material within the oven (156) for continuous elevated temperature deposition of semiconductor material on a sheet substrate (24) including a glass sheet (26) conveyed within the oven. The sheet substrate (24) is conveyed on a roller conveyor (184) within the oven (156) and the semiconductor material whose main layer (82) is cadmium telluride is deposited on an upwardly facing surface (28) of the substrate by each deposition station from a location within the oven above the roller conveyor.
    Type: Grant
    Filed: May 12, 1992
    Date of Patent: September 28, 1993
    Assignee: Solar Cells, Inc.
    Inventors: James B. Foote, Steven A. F. Kaake, Peter V. Meyers, James F. Nolan
  • Patent number: 5141564
    Abstract: A thin film heterojunction solar cell and a method of making it has a p-type layer of mixed ternary I-III-VI.sub.2 semiconductor material in contact with an n-type layer of mixed binary II-VI semiconductor material. The p-type semiconductor material includes a low resistivity copper-rich region adjacent the back metal contact of the cell and a composition gradient providing a minority carrier mirror that improves the photovoltaic performance of the cell. The p-type semiconductor material preferably is CuInGaSe.sub.2 or CuIn(SSe).sub.2.
    Type: Grant
    Filed: January 17, 1991
    Date of Patent: August 25, 1992
    Assignee: The Boeing Company
    Inventors: Wen S. Chen, John M. Stewart
  • Patent number: 5112410
    Abstract: A process for depositing thin layers of a II-VI compound cadmium zinc sulfide (CdZnS) by an aqueous solution growth technique with quality suitable for high efficiency photovoltaic or other devices which can benefit from the band edge shift resulting from the inclusion of Zn in the sulfide. A first solution comprising CdCl.sub.2 2.5H.sub.2 O, NH.sub.4 Cl, NH.sub.4 OH and ZnCl.sub.2, and a second solution comprising thiourea ((NH.sub.2).sub.2 CS) are combined and placed in a deposition cell, along with a substrate to form a thin i.e. 10 nm film of CdZnS on the substrate. This process can be sequentially repeated with to achieve deposition of independent multiple layers having different Zn concentrations.
    Type: Grant
    Filed: August 7, 1990
    Date of Patent: May 12, 1992
    Assignee: The Boeing Company
    Inventor: Wen S. Chen
  • Patent number: 5078804
    Abstract: A thin film I-III-VI.sub.2 based solar cell having a first layer of copper indium gallium selenide, a second layer of cadmium zinc sulfide, a double layer of zinc oxide, and a metallization structure comprised of a layer of nickel covered by a layer of aluminum. An optional antireflective coating may be placed on said metallization structure. The cadmium zinc sulfide layer is deposited by means of an aqueous solution growth deposition process and may actually consist of two layers: a low zinc content layer and a high zinc content layer. Photovoltaic efficiencies of 12.5% at Air Mass 1.5 illumination conditions and 10.4% under AMO illumination can be achieved.
    Type: Grant
    Filed: August 17, 1990
    Date of Patent: January 7, 1992
    Assignee: The Boeing Company
    Inventors: Wen S. Chen, John M. Stewart
  • Patent number: 5078803
    Abstract: Transparent conductors for use in a variety of different photovoltaic devices are disclosed, comprising at least one ZnO transparent conductor layer having a predetermined level of haziness achieved, e.g., through appropriate variation in the parameters employed in formation of the transparent conductor (for example, by chemical vapor deposition) and/or through treatment of the transparent conductor subsequent to its formation. The concentration and/or relative rate of introduction of dopant during the deposition of the transparent conductor may be adjusted to prepare films having the desired morphology and/or structure. Alternatively, the morphology, composition and/or structure of the transparent conductor may be modified by suitable post-formation treatments. A combination of at least two transparent layers may also be employed, comprising at least a first layer designed primarily to maximize the optical properties and at least a second layer designed to maximize the electrical properties.
    Type: Grant
    Filed: September 22, 1989
    Date of Patent: January 7, 1992
    Assignee: Siemens Solar Industries L.P.
    Inventors: David N. Pier, Charles F. Gay, Robert D. Wieting, Heidi J. Langeberg
  • Patent number: 5028274
    Abstract: This invention relates to an improved thin film solar cell with excellent electrical and mechanical integrity. The device comprises a substrate, a Group I-III-VI.sub.2 semiconductor absorber layer and a transparent window layer. The mechanical bond between the substrate and the Group I-III-VI.sub.2 semiconductor layer is enhanced by an intermediate layer between the substrate and the Group I-III-VI.sub.2 semiconductor film being grown. The intermediate layer contains tellurium or substitutes therefor, such as Se, Sn, or Pb. The intermediate layer improves the morphology and electrical characteristics of the Group I-III-VI.sub.2 semiconductor layer.
    Type: Grant
    Filed: June 7, 1989
    Date of Patent: July 2, 1991
    Assignee: International Solar Electric Technology, Inc.
    Inventors: Bulent M. Basol, Vijay K. Kapur
  • Patent number: 4959106
    Abstract: A photovoltaic element which generates photoelectromotive force by the contact of a p-type semiconductor layer and an n-type semiconductor layer, characterized in that at least one of said semiconductor layers is made up from a deposited film composed of zinc atoms, selenium atoms, optional tellurium atoms, and at least hydrogen atoms, said deposited film containing a p-type or n-type doping agent, containing 1 to 4 atomic % of hydrogen atoms, containing selenium atoms and tellurium atoms in a ratio of 1:9 to 3:7 (in terms of number of atoms), and also containing crystal grains in a ratio of 65 to 85 vol % per unit volume.
    Type: Grant
    Filed: August 28, 1989
    Date of Patent: September 25, 1990
    Assignee: Canon Kabushiki Kaisha
    Inventors: Katsumi Nakagawa, Masahiro Kanai, Shunichi Ishihara, Kozo Arao, Yasushi Fujioka, Akira Sakai, Tsutomu Murakami
  • Patent number: 4915745
    Abstract: A structure for, and method of making, thin films of Group I-III-VI compound semiconductors such as copper indium diselenide for use in heterojunction photovoltaic devices fabricated on metal substrates. An interfacial film containing gallium is first deposited upon the substrate. Thereafter, copper and indium films are deposited and the resulting stacked film is heated in the presence of a source of selenium to form copper indium diselenide semiconductor material with improved adhesion to the substrate and improved performance.
    Type: Grant
    Filed: September 22, 1988
    Date of Patent: April 10, 1990
    Assignee: Atlantic Richfield Company
    Inventors: Gary A. Pollock, Kim W. Mitchell, James H. Ermer
  • Patent number: 4909857
    Abstract: A method of electrodepositing a doped compound semiconductor film including tellurium and a metal selected from Group IIB of the Period Table of Elements by adding an effective concentration of dopant ions to the electrolyte bath. Cadmium telluride, mercury cadmium telluride and zinc cadmium telluride may be doped with copper, silver and gold. The conductivity type of the electrodeposited doped layers may be changed by a heat treatment. Thin film photovoltaic cells incorporating the doped layer to form a heterojunction with a semiconductor layer of the opposite conductivity type show substantial improvements in open circuit voltage, fill factor and efficiency over similar devices employing undoped electrodeposited layers.
    Type: Grant
    Filed: December 21, 1988
    Date of Patent: March 20, 1990
    Assignee: Standard Oil Company
    Inventors: Miroslav Ondris, Marty A. Pichler, Richard E. Brownfield
  • Patent number: 4888062
    Abstract: An improved pin junction photovoltaic element which generates photoelectromotive force by the junction of a p-type semiconductor layer, an i-type semiconductor layer and an n-type semiconductor layer, characterized in that at least said i-type semiconductor layer comprises a member selected from the group consisting of a ZnSe:H deposited film containing the hydrogen atoms in an amount of 1 to 4 atomic % and crystal grain domains in a proportion of 65 to 85 vol % per unit volume and a ZnSe.sub.1-x Te.sub.x :H deposited film containing the hydrogen atoms in an amount of 1 to 4 atomic % and crystal grain domains in a proportion of 65 to 85 vol % per unit volume and also containing the selenium atoms and the tellurium atoms in a Se/Te quantitative ratio of 1:9 to 3:7.The pin junction photovoltaic element exhibits an improved photoelectric conversion efficiency for short-wavelength light and has a high open-circuit voltage.
    Type: Grant
    Filed: August 26, 1988
    Date of Patent: December 19, 1989
    Assignee: Canon Kabushiki Kaisha
    Inventors: Katsumi Nakagawa, Masahiro Kanai, Shunichi Ishihara, Kozo Arao, Yasushi Fujioka, Akira Sakai, Tsutomu Murakami
  • Patent number: 4873198
    Abstract: A method of making a multi-layer photovoltaic cell containing a heat-treated layer including Cd and Te, comprising the sequential steps of applying a chloride to the layer, heat-treating the layer with the chloride thereon, and subsequently depositing another semiconductor layer thereon.
    Type: Grant
    Filed: June 2, 1988
    Date of Patent: October 10, 1989
    Assignee: Ametek, Inc.
    Inventors: Peter V. Meyers, Chung-Heng Liu, Timothy J. Frey
  • Patent number: 4828875
    Abstract: Sintered films of Cd.sub.1-x Zn.sub.x S (0.ltoreq.x<1) with high optical transmittance are provided. These films are produced by applying a paste composed of powdered CdS and CdCl.sub.2 or of a mixture of CdS, ZnS and CdCl.sub.2 onto an appropriate substrate such as borosilicate glass, under an inert gas atmosphere containing ZnCl.sub.2 vapor or thereafter resintering the paste on the substrate under a nitrogen atmosphere.The ZnCl.sub.2 vapor is produced by heating ZnCl.sub.2 at 400.degree. C. or higher but below the temperature of 500.degree.-700.degree. C. to which the specimen is heated.The resulting sintered films have optical transmittance of 80% at long wavelength ranges or higher and can be used as a window layer having a superior optical transmittance in solar cells.
    Type: Grant
    Filed: March 18, 1988
    Date of Patent: May 9, 1989
    Assignee: Korea Advanced Institute of Science & Tech.
    Inventors: Ho-Bin Im, Kyu-Charn Park
  • Patent number: 4816120
    Abstract: A method of electrodepositing a doped compound semiconductor film including tellurium and a metal selected from Group IIB of the Period Table of Elements by adding an effective concentration of dopant ions to the electrolyte bath. Cadmium telluride, mercury cadmium telluride and zinc cadmium telluride may be doped with copper, silver and gold. The conductivity type of the electrodeposited doped layers may be changed by a heat treatment. Thin film photovoltaic cells incorporating the doped layer to form a heterojunction with a semiconductor layer of the opposite conductivity type show substantial improvements in open circuit voltage, fill factor and efficiency over similar devices employing undoped electrodeposited layers.
    Type: Grant
    Filed: January 26, 1988
    Date of Patent: March 28, 1989
    Assignee: The Standard Oil Company
    Inventors: Miroslav Ondris, Marty A. Pichler, Richard E. Brownfield
  • Patent number: 4812416
    Abstract: In order to be able to check whether or not a glow procedure is executed properly, i.e. reproducibly, the temporal course of the formation of characteristic stable reaction products is traced mass spectrometrically.
    Type: Grant
    Filed: November 28, 1986
    Date of Patent: March 14, 1989
    Inventors: Gerd Hewig, Berthold Schum, Jorg Worner
  • Patent number: 4759951
    Abstract: A process for producing a photoelectric conversion film comprising heat-treating a coating (A) of a photoconductive material composed chiefly of at least one of CdSe, CdS, CdTe, CdS.sub.x Se.sub.1-x and CdS.sub.x Te.sub.1-x wherein x is a real number of less than 1, opposite from a coating (B) in proximity thereto, the coating (B) being made of a material composed chiefly of CdS and a Cd halide.
    Type: Grant
    Filed: September 23, 1986
    Date of Patent: July 26, 1988
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Masataka Itoh, Masaya Nagata, Shuhei Tsuchimoto, Atsushi Yoshinouchi, Hiroshi Wada, Katsushi Okibayashi, Soji Ohhara
  • Patent number: 4753684
    Abstract: A three layer, photovoltaic structure having polycrystalline semiconductor layers disposed in series optically and in sequential touching contact includes a relatively wide optical bandgap energy window layer, a light-absorbing layer and a third, relatively wide bandgap energy layer that forms a minority carrier mirror with the light-absorbing layer. All three layers have different compositions so that the structure includes two heterojunctions. The light-absorbing layer and third layer are of the same conductivity type. The structure is conveniently realized using II-VI semiconductor compounds such as a cadmium sulfide or zinc sulfide window layer, a mercury cadmium telluride, cadmium telluride, zinc cadmium telluride or mercury zinc telluride light-absorbing layer and a third layer of cadmium telluride, zinc telluride, zinc cadmium telluride, mercury cadmium telluride or cadmium manganese telluride. Cadmium is present in at least two of the three layers of the novel structures.
    Type: Grant
    Filed: October 31, 1986
    Date of Patent: June 28, 1988
    Assignee: The Standard Oil Company
    Inventors: Miroslav Ondris, Marty A. Pichler
  • Patent number: 4735662
    Abstract: A stable ohmic contact for thin films of p-type tellurium-containing II-VI semiconductors and photovoltaic devices incorporating such contacts. An ohmic contact according to the invention includes a contact-forming layer deposited on a p-type thin film of a tellurium-contacting II-VI semiconductor. Preferably, the contact-forming layer is copper having a thickness of about 2 nanometers. An isolation layer is deposited on the contact-forming to isolate subsequently deposited layers from the thin film. The isolation layer may be carbon or a thin layer of nickel. A connection layer for attaching an external electrical conductor is deposited on the isolation layer. The connection layer may be aluminum, chromium or a layer of copper, provided a copper layer is covered with one of silver, aluminum or a thin layer of nickel, preferably covered with aluminum.
    Type: Grant
    Filed: January 6, 1987
    Date of Patent: April 5, 1988
    Assignee: The Standard Oil Company
    Inventors: Louis F. Szabo, William J. Biter
  • Patent number: 4735909
    Abstract: Improved techniques are provided for forming a very thin polycrystalline layer of a semiconductor material on a glass substrate. The film material may be formed from a slurry of a semiconductor powder and a liquid carrier, and the slurry economically applied at room temperature by spraying techniques. Once dried, the film is compressed by the application of a substantial mechanical force. The compressed film is regrown in a heated atmosphere, forming a polycrystalline film comprised of large mean diameter crystals, with many crystals having a mean diameter in excess of the film thickness. A high quality cadmium sulfide polycrystalline film suitable for forming a photovoltaic cells may be inexpensively manufactured according to these techniques.
    Type: Grant
    Filed: October 14, 1986
    Date of Patent: April 5, 1988
    Assignee: Photon Energy, Inc.
    Inventors: Scot P. Albright, David K. Brown, John F. Jordon
  • Patent number: 4734381
    Abstract: A phosphorous doped layer of cadmium telluride is deposited onto a conductive window layer to form a thin film cadmium telluride solar cell. Back contacts to the solar cell are made by first depositing a layer of p conductivity type lead telluride upon the cadmium telluride and then depositing the metallic back contacts onto the lead telluride.
    Type: Grant
    Filed: October 14, 1986
    Date of Patent: March 29, 1988
    Assignee: Atlantic Richfield Company
    Inventor: Kim W. Mitchell