Patents by Inventor Takaaki Agui
Takaaki Agui has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20190035965Abstract: A Group III-V compound semiconductor solar cell includes a buffer layer (108) and a first cell (131) both between a first electrode (121) and a second electrode (102). The buffer layer (108) has a portion in which first segments (141a, 142a, 143a, 144a) and second segments (141b, 142b, 143b, 144b) are alternately provided. Each of the first segments has a Group III element composition that continuously changes with an increasing thickness of the buffer layer (108) as traced from a side located opposite where the first cell (131) is disposed toward a side where the first cell (131) is disposed. Each of the second segments has a Group III element composition that changes without an increase in the thickness of the buffer layer (108).Type: ApplicationFiled: December 9, 2016Publication date: January 31, 2019Inventor: TAKAAKI AGUI
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Patent number: 8933326Abstract: Disclosed is a multijunction compound semiconductor solar cell having a buffer layer between a first cell and a second cell. In the buffer layer, a plurality of semiconductor layers is arranged such that lattice constants thereof have larger values in order from the first cell side to the second cell side. Of the plurality of semiconductor layers, two layers having the largest difference in lattice constant among each two adjacent layers are disposed closer to the first cell than the center in the thickness direction of the buffer layer.Type: GrantFiled: December 27, 2010Date of Patent: January 13, 2015Assignee: Sharp Kabushiki KaishaInventors: Kazuaki Sasaki, Takaaki Agui
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Publication number: 20140060631Abstract: A compound semiconductor solar battery including a first compound semiconductor photoelectric conversion cell (40a), a second compound semiconductor photoelectric conversion cell (40b) provided on the first compound semiconductor photoelectric conversion cell (40a), and a compound semiconductor buffer layer (41) provided between the first compound semiconductor photoelectric conversion cell (40a) and the second compound semiconductor photoelectric conversion cell (40b), the first compound semiconductor photoelectric conversion cell (40a) and the compound semiconductor buffer layer (41) being provided adjacent to each other, and a ratio of a difference in lattice constant between the first compound semiconductor photoelectric conversion cell (40a) and a compound semiconductor layer (30) provided in a position closest to the first compound semiconductor photoelectric conversion cell (40a) among compound semiconductor layers constituting the compound semiconductor buffer layer (41) being not less than 0.Type: ApplicationFiled: November 6, 2013Publication date: March 6, 2014Applicant: Sharp Kabushiki KaishaInventors: Takaaki AGUI, Tatsuya TAKAMOTO
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Publication number: 20120247547Abstract: Disclosed is a multijunction compound semiconductor solar cell having a buffer layer between a first cell and a second cell. In the buffer layer, a plurality of semiconductor layers is arranged such that lattice constants thereof have larger values in order from the first cell side to the second cell side. Of the plurality of semiconductor layers, two layers having the largest difference in lattice constant among each two adjacent layers are disposed closer to the first cell than the center in the thickness direction of the buffer layer.Type: ApplicationFiled: December 27, 2010Publication date: October 4, 2012Inventors: Kazuaki Sasaki, Takaaki Agui
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Publication number: 20110290312Abstract: A compound semiconductor solar battery including a first compound semiconductor photoelectric conversion cell, a second compound semiconductor photoelectric conversion cell provided on the first compound semiconductor photoelectric conversion cell, and a compound semiconductor buffer layer provided between the first compound semiconductor photoelectric conversion cell and the second compound semiconductor photoelectric conversion cell, the first compound semiconductor photoelectric conversion cell and the compound semiconductor buffer layer being provided adjacent to each other, and a ratio of a difference in lattice constant between the first compound semiconductor photoelectric conversion cell and a compound semiconductor layer provided in a position closest to the first compound semiconductor photoelectric conversion cell among compound semiconductor layers constituting the compound semiconductor buffer layer being not less than 0.15% and not more than 0.Type: ApplicationFiled: February 2, 2010Publication date: December 1, 2011Inventors: Takaaki Agui, Tatsuya Takamoto
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Publication number: 20100279456Abstract: On a surface of a GaAs substrate, layers to be a top cell are formed by epitaxial growth. On the top cell, layers to be a bottom cell are formed. Thereafter, on a surface of the bottom cell, a back surface electrode is formed. Thereafter, a glass plate is adhered to the back surface electrode by wax. Then, the GaAs substrate supported by the glass plate is dipped in an alkali solution, whereby the GaAs substrate is removed. Thereafter, a surface electrode is formed on the top cell. Finally the glass plate is separated from the back surface electrode. In this manner, a compound solar battery that improves efficiency of conversion to electric energy can be obtained.Type: ApplicationFiled: September 15, 2008Publication date: November 4, 2010Applicant: Sharp Kabushiki KaishaInventors: Tatsuya Takamoto, Takaaki Agui
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Patent number: 7635638Abstract: A compound semiconductor device epitaxial growth substrate, wherein a semiconductor substrate, a substrate protective layer made of a material that is different from the material of the substrate, a middle layer for making separation of the semiconductor substrate and a compound semiconductor device layer possible, and a compound semiconductor device layer that is formed through epitaxial growth are layered in this order; and a semiconductor device which uses the compound semiconductor device layer that is gained by separating the semiconductor substrate, the substrate protective layer and the middle layer from this compound semiconductor device epitaxial growth substrate; as well as manufacturing methods for these.Type: GrantFiled: October 29, 2007Date of Patent: December 22, 2009Assignee: Sharp Kabushiki KaishaInventors: Tatsuya Takamoto, Takaaki Agui
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Patent number: 7488890Abstract: On a surface of a GaAs substrate, layers to be a top cell are formed by epitaxial growth. On the top cell, layers to be a bottom cell are formed. Thereafter, on a surface of the bottom cell, a back surface electrode is formed. Thereafter, a glass plate is adhered to the back surface electrode by wax. Then, the GaAs substrate supported by the glass plate is dipped in an alkali solution, whereby the GaAs substrate is removed. Thereafter, a surface electrode is formed on the top cell. Finally the glass plate is separated from the back surface electrode. In this manner, a compound solar battery that improves efficiency of conversion to electric energy can be obtained.Type: GrantFiled: March 22, 2004Date of Patent: February 10, 2009Assignee: Sharp Kabushiki KaishaInventors: Tatsuya Takamoto, Takaaki Agui
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Publication number: 20080070388Abstract: A compound semiconductor device epitaxial growth substrate, wherein a semiconductor substrate, a substrate protective layer made of a material that is different from the material of the substrate, a middle layer for making separation of the semiconductor substrate and a compound semiconductor device layer possible, and a compound semiconductor device layer that is formed through epitaxial growth are layered in this order; and a semiconductor device which uses the compound semiconductor device layer that is gained by separating the semiconductor substrate, the substrate protective layer and the middle layer from this compound semiconductor device epitaxial growth substrate; as well as manufacturing methods for these.Type: ApplicationFiled: October 29, 2007Publication date: March 20, 2008Applicant: Sharp Kabushiki KaishaInventors: Tatsuya Takamoto, Takaaki Agui
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Publication number: 20070199592Abstract: There are provided a solar cell string including a plurality of connected solar cells, each solar cell including a multilayered body having a photoelectric conversion layer, a first electrode formed on the multilayered body, a second electrode formed on the multilayered body, a first interconnector connected to the first electrode, and a second interconnector connected to the second electrode, wherein, in the solar cells adjacent to each other, the first interconnector connected to the first electrode of a first solar cell and the second interconnector connected to the second electrode of a second solar cell are connected via an intermediate member; and a solar cell module including the solar cell string.Type: ApplicationFiled: February 15, 2007Publication date: August 30, 2007Applicant: Sharp Kabushiki KaishaInventors: Takaaki Agui, Naoki Takahashi
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Publication number: 20060180198Abstract: A solar cell includes a first compound semiconductor stacked body with an n-type compound semiconductor layer and a p-type compound semiconductor layer in contact with each other, the first compound semiconductor stacked body has a first electrode of a first polarity and a second electrode of a second polarity, and surfaces of the first electrode and the second electrode are exposed to the same side. A solar cell string using the solar cells and a method of manufacturing the solar cell string are further provided.Type: ApplicationFiled: February 10, 2006Publication date: August 17, 2006Applicant: Sharp Kabushiki KaishaInventors: Tatsuya Takamoto, Takaaki Agui, Hidetoshi Washio, Naoki Takahashi
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Publication number: 20060054900Abstract: A compound semiconductor device epitaxial growth substrate, wherein a semiconductor substrate, a substrate protective layer made of a material that is different from the material of the substrate, a middle layer for making separation of the semiconductor substrate and a compound semiconductor device layer possible, and a compound semiconductor device layer that is formed through epitaxial growth are layered in this order; and a semiconductor device which uses the compound semiconductor device layer that is gained by separating the semiconductor substrate, the substrate protective layer and the middle layer from this compound semiconductor device epitaxial growth substrate; as well as manufacturing methods for these.Type: ApplicationFiled: September 8, 2005Publication date: March 16, 2006Applicant: Sharp Kabushiki KaishaInventors: Tatsuya Takamoto, Takaaki Agui
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Publication number: 20040206389Abstract: On a surface of a GaAs substrate, layers to be a top cell are formed by epitaxial growth. On the top cell, layers to be a bottom cell are formed. Thereafter, on a surface of the bottom cell, a back surface electrode is formed. Thereafter, a glass plate is adhered to the back surface electrode by wax. Then, the GaAs substrate supported by the glass plate is dipped in an alkali solution, whereby the GaAs substrate is removed. Thereafter, a surface electrode is formed on the top cell. Finally the glass plate is separated from the back surface electrode. In this manner, a compound solar battery that improves efficiency of conversion to electric energy can be obtained.Type: ApplicationFiled: March 22, 2004Publication date: October 21, 2004Applicant: Sharp Kabushiki KaishaInventors: Tatsuya Takamoto, Takaaki Agui
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Publication number: 20040187912Abstract: In an InGaP/InGaAs/Ge triple-junction solar cell, efficiency of a multijunction solar cell is improved by adjusting a ratio of an Al composition in an (Al)InGaP cell. According to a current-matching method in a multijunction solar cell, the ratio of the Al composition in an AlInGaP material for a top cell is adjusted in order to achieve matching between photocurrents generated in the top cell and a middle cell in the multijunction solar cell. Here, the multijunction solar cell uses as the top cell a solar cell-formed with the AlInGaP material and having a PN junction, uses as a middle cell a solar cell lattice-matched to the top cell, formed with an (In)GaAs(N) material and having a PN junction, and uses as a bottom cell a solar cell lattice-matched to the middle cell, formed with a Ge material and having a PN junction.Type: ApplicationFiled: March 1, 2004Publication date: September 30, 2004Applicant: Sharp Kabushiki KaishaInventors: Tatsuya Takamoto, Takaaki Agui
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Patent number: 6300558Abstract: A solar cell comprises at least a germanium (Ge) substrate, buffer layers formed on the germanium substrate, a first InxGa1-xAs layer of first conductivity type formed on the buffer layers, and a second InxGa1-xAs layer of second conductivity type formed on the first InxGa1-xAs layer to form pn junction. Because the composition x of In contained in the first InxGa1-xAs layer and the second InxGa1-xAs layer is in a range of 0.005≦x≦0.015, the inexpensive and high conversion efficiency solar cell can be achieved.Type: GrantFiled: April 20, 2000Date of Patent: October 9, 2001Assignee: Japan Energy CorporationInventors: Tatsuya Takamoto, Hiroshi Kurita, Takaaki Agui, Eiji Ikeda
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Patent number: 5916375Abstract: The present invention is directed to a method of manufacturing a photovoltaic cell with high conversion efficiency, wherein a polycrystal CdTe layer with a large grain size can be formed by forming an indium oxide film (20) on a transparent conductive substrate having a transparent conductive film (2) as its surface layer, then forming an n-type CdS layer (3) and a p-type CdTe layer (4) thereon, then attaching cadmium chloride (CdCl.sub.2) on the p-type CdTe layer, and then annealing. The indium oxide film (20) is capable of relaxing strain caused at an interface between the transparent conductive film (2) and the n-type CdS layer (3), so that a good CdS/CdTe junction interface can be formed. The indium oxide film (20) can be formed by forming an indium film on the transparent conductive substrate and then annealing in oxygen containing atmosphere.Type: GrantFiled: April 6, 1998Date of Patent: June 29, 1999Assignee: Japan Energy CorporationInventors: Takaaki Agui, Tatsuya Takamoto