Patents by Inventor Shigeru Niki

Shigeru Niki 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).

  • Patent number: 9496433
    Abstract: The inventive photoelectric conversion device includes a substrate, a lower electrode layer provided on the substrate, a CIGS compound semiconductor layer provided on the lower electrode layer as covering the lower electrode layer, and a transparent electrode layer provided on the compound semiconductor layer, wherein the compound semiconductor layer has a maximum Ga content variation of not less than 5% as measured in a layer thickness direction, and a maximum In content variation of not less than 6% as measured in the layer thickness direction.
    Type: Grant
    Filed: October 10, 2013
    Date of Patent: November 15, 2016
    Assignees: ROHM CO., LTD., NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY
    Inventors: Takuji Maekawa, Shigeru Niki, Shogo Ishizuka, Hajime Shibata
  • Patent number: 9202962
    Abstract: A solid state imaging device includes a circuit unit formed on a substrate and a photoelectric conversion unit. The photoelectric conversion circuit includes a lower electrode layer placed on the circuit unit, a compound semiconductor thin film of chalcopyrite structure which is placed on the lower electrode layer and functions as an optical absorption layer, and an optical transparent electrode layer placed on the compound semiconductor thin film. The lower electrode layer, the compound semiconductor thin film, and the optical transparent electrode layer are laminated one after another on the circuit unit.
    Type: Grant
    Filed: October 4, 2012
    Date of Patent: December 1, 2015
    Assignees: Rohm Co., Ltd., National Institute of Advanced Industrial Science and Technology
    Inventors: Osamu Matsushima, Masaki Takaoka, Kenichi Miyazaki, Shogo Ishizuka, Keiichiro Sakurai, Shigeru Niki
  • Publication number: 20150303330
    Abstract: The inventive photoelectric conversion device includes a substrate, a lower electrode layer provided on the substrate, a CIGS compound semiconductor layer provided on the lower electrode layer as covering the lower electrode layer, and a transparent electrode layer provided on the compound semiconductor layer, wherein the compound semiconductor layer has a maximum Ga content variation of not less than 5% as measured in a layer thickness direction, and a maximum In content variation of not less than 6% as measured in the layer thickness direction.
    Type: Application
    Filed: October 10, 2013
    Publication date: October 22, 2015
    Applicants: ROHM CO., LTD., National Institute of Advanced Industrial science and Technology
    Inventors: Takuji MAEKAWA, Shigeru NIKI, Shogo ISHIZUKA, Hajime SHIBATA
  • Patent number: 8921691
    Abstract: There is provided a solar cell in which a lower electrode layer, a photoelectric conversion layer having a chalcopyrite structure that includes a Group Ib element, a Group IIIb element, and a Group VIb element, and an upper electrode layer are sequentially formed on top of a substrate, wherein the solar cell is provided with a silicate layer between the substrate and the lower electrode layer.
    Type: Grant
    Filed: March 19, 2009
    Date of Patent: December 30, 2014
    Assignee: National Institute of Advanced Industrial Science and Technology
    Inventors: Shogo Ishizuka, Shigeru Niki, Nobuaki Kido, Hiroyuki Honmoto
  • Patent number: 8895463
    Abstract: A glass substrate for a CIGS solar cell, having high cell efficiency and high glass transition temperature is provided. The glass substrate for a vapor-deposited CIGS film solar cell has a glass transition temperature of at least 580° C. and an average thermal expansion coefficient of from 70×10?7 to 100×10?7/° C., wherein the ratio of the average total amount of Ca, Sr and Ba within from 10 to 40 nm in depth from the surface of the glass substrate to the total amount of Ca, Sr and Ba at 5,000 nm in depth from the surface of the glass substrate is at most 0.35, and the ratio of the average Na amount within from 10 to 40 nm in depth from the surface of the glass substrate after heat treatment to such average Na amount before the heat treatment is at least 1.5.
    Type: Grant
    Filed: January 28, 2013
    Date of Patent: November 25, 2014
    Assignee: Asahi Glass Company, Limited
    Inventors: Yutaka Kuroiwa, Yuichi Yamamoto, Tomomi Abe, Tetsuya Nakashima, Yasushi Kawamoto, Shigeru Niki, Shogo Ishizuka
  • Patent number: 8592933
    Abstract: A photoelectric conversion device has a high S/N ratio and can increase the detection efficiency even under a low luminance. The photoelectric conversion device generates an increased electric charge by impact ionization in a photoelectric conversion unit formed from a chalcopyrite type semiconductor, so as to improve dark current characteristic.
    Type: Grant
    Filed: March 30, 2009
    Date of Patent: November 26, 2013
    Assignees: Rohm Co., Ltd., National Institute of Advanced Industrial Science and Technology
    Inventors: Kenichi Miyazaki, Osamu Matsushima, Shigeru Niki, Keiichiro Sakurai, Shogo Ishizuka
  • Patent number: 8304804
    Abstract: An object of the present invention is to increase the light emission efficiency of a ZnO-based optical semiconductor device. An optical semiconductor device B has a structure which includes n-type Zn1-zMgzO (barrier layer) 11/Zn1-zMgxO (active layer) 15/p-type Zn1-yMgyO (barrier layer) 17, and light is emitted from the active layer 15. Electrodes 23, 21 are respectively formed on barrier layers 11, 17. By applying a voltage between the two electrodes 23, 21, light is emitted from ZnO (active layer) 15. Here, there are a relationship of x<y and a relationship of x<z. For instance, such values as x=0.1, y=0.15 and z=0.16 can be chosen. Otherwise, such values as x=0.15, y=0.25 and z=0.24 can be choose as well. In this case, by increasing the value x of the active layer, it is possible to shift its light emission wavelength to the shorter wavelength side. In addition, as shown in the above-described results, by increasing the value x, it is possible to enhance its light emission efficiency.
    Type: Grant
    Filed: May 13, 2008
    Date of Patent: November 6, 2012
    Assignee: National Institute of Advanced Industrial Science and Technology
    Inventors: Hajime Shibata, Hitoshi Tampo, Koji Matsubara, Akimasa Yamada, Keiichiro Sakurai, Shogo Ishizuka, Shigeru Niki
  • Patent number: 8299510
    Abstract: A solid state imaging device with an easy structure in which have the high sensitivity which reaches the wide wavelength region from visible light to near infrared light wavelength region, and dark current is reduced, and a fabrication method for the same, are provided. A solid state imaging device and a fabrication method for the same, the solid state imaging device comprising: a circuit unit formed on a substrate; and a photoelectric conversion unit including a lower electrode layer placed on the circuit unit, a compound semiconductor thin film of chalcopyrite structure which is placed on the lower electrode layer and functions as an optical absorption layer, and an optical transparent electrode layer placed on the compound semiconductor thin film, wherein the lower electrode layer, the compound semiconductor thin film, and the optical transparent electrode layer are laminated one after another on the circuit unit.
    Type: Grant
    Filed: February 1, 2008
    Date of Patent: October 30, 2012
    Assignees: Rohm Co., Ltd., National Institute of Advanced Industrial Science and Technology
    Inventors: Osamu Matsushima, Masaki Takaoka, Kenichi Miyazaki, Shogo Ishizuka, Keiichiro Sakurai, Shigeru Niki
  • Publication number: 20120199203
    Abstract: Provided are a glass sheet for a CIGS solar cell which satisfies both of high power generation efficiency and high glass transition temperature, and a CIGS solar cell having high power generation efficiency. A glass sheet for a Cu—In—Ga—Se solar cell containing, in terms of mol % on the basis of the following oxides, 60 to 75% of SiO2, 3 to 10% of Al2O3, 0 to 3% of B2O3, 5 to 18% of MgO, 0 to 5% of CaO, 4 to 18.5% of Na2O, 0 to 17% of K2O, and 0% or more and less than 10% of SrO+BaO+ZrO2, wherein K2O/(Na2O+K2O) is 0 to 0.5, and the glass sheet has a glass transition temperature (Tg) of more than 550° C.
    Type: Application
    Filed: April 18, 2012
    Publication date: August 9, 2012
    Applicant: ASAHI GLASS COMPANY, LIMITED
    Inventors: Manabu Nishizawa, Yuichi Kuroki, Tatsuo Nagashima, Yasushi Kawamoto, Shigeru Niki, Shogo Ishizuka
  • Patent number: 8012546
    Abstract: A method for producing a semiconductor film having a chalcopyrite structure including a Ib group element, a IIIb group element and a VIb group element including selenium, the method including cracking selenium with plasma to generate radical selenium, and using the radical selenium in the process of forming the semiconductor film.
    Type: Grant
    Filed: August 23, 2007
    Date of Patent: September 6, 2011
    Assignee: National Institute of Advanced Industrial Science and Technology
    Inventors: Shogo Ishizuka, Shigeru Niki, Keiichiro Sakurai, Akimasa Yamada, Koji Matsubara
  • Publication number: 20110023963
    Abstract: There is provided a solar cell in which a lower electrode layer, a photoelectric conversion layer having a chalcopyrite structure that includes a Group Ib element, a Group IIIb element, and a Group VIb element, and an upper electrode layer are sequentially formed on top of a substrate, wherein the solar cell is provided with a silicate layer between the substrate and the lower electrode layer.
    Type: Application
    Filed: March 19, 2009
    Publication date: February 3, 2011
    Inventors: Shogo Ishizuka, Shigeru Niki, Nobuaki Kido, Hiroyuki Honmoto
  • Publication number: 20110024859
    Abstract: A photoelectric conversion device has a high S/N ratio and can increase the detection efficiency even under a low luminance. The photoelectric conversion device generates an increased electric charge by impact ionization in a photoelectric conversion unit formed from a chalcopyrite type semiconductor, so as to improve dark current characteristic.
    Type: Application
    Filed: March 30, 2009
    Publication date: February 3, 2011
    Applicant: Rohm Co., Ltd
    Inventors: Kenichi Miyazaki, Osamu Matsushima, Shigeru Niki, Keiichiro Sakurai, Shogo Ishizuka
  • Publication number: 20100163864
    Abstract: An object of the present invention is to increase the light emission efficiency of a ZnO-based optical semiconductor device. An optical semiconductor device B has a structure which includes n-type Zn1-zMgzO (barrier layer) 11/Zn1-zMgxO (active layer) 15/p-type Zn1-yMgyO (barrier layer) 17, and light is emitted from the active layer 15. Electrodes 23, 21 are respectively formed on barrier layers 11, 17. By applying a voltage between the two electrodes 23, 21, light is emitted from ZnO (active layer) 15. Here, there are a relationship of x<y and a relationship of x<z. For instance, such values as x=0.1, y=0.15 and z=0.16 can be chosen. Otherwise, such values as x=0.15, y=0.25 and z=0.24 can be choose as well. In this case, by increasing the value x of the active layer, it is possible to shift its light emission wavelength to the shorter wavelength side. In addition, as shown in the above-described results, by increasing the value x, it is possible to enhance its light emission efficiency.
    Type: Application
    Filed: May 13, 2008
    Publication date: July 1, 2010
    Inventors: Hajime Shibata, Hitoshi Tampo, Koji Matsubara, Akimasa Yamada, Keiichiro Sakurai, Shogo Ishizuka, Shigeru Niki
  • Publication number: 20100102368
    Abstract: A solid state imaging device with an easy structure in which have the high sensitivity which reaches the wide wavelength region from visible light to near infrared light wavelength region, and dark current is reduced, and a fabrication method for the same, are provided. A solid state imaging device and a fabrication method for the same, the solid state imaging device comprising: a circuit unit (30) formed on a substrate; and a photoelectric conversion unit (28) including a lower electrode layer (25) placed on the circuit unit (30), a compound semiconductor thin film (24) of chalcopyrite structure which is placed on the lower electrode layer (25) and functions as an optical absorption layer, and an optical transparent electrode layer (26) placed on the compound semiconductor thin film (24), wherein the lower electrode layer (25), the compound semiconductor thin film (24), and the optical transparent electrode layer (26) are laminated one after another on the circuit unit (30).
    Type: Application
    Filed: February 1, 2008
    Publication date: April 29, 2010
    Inventors: Osamu Matsushima, Masaki Takaoka, Kenichi Miyazaki, Shogo Ishizuka, Keiichiro Sakurai, Shigeru Niki
  • Publication number: 20090301558
    Abstract: A photoelectric converter includes a lower electrode layer, a compound semiconductor thin film of a chalcopyrite structure functioning as a photoabsorption layer and a light transmitting electrode layer that are sequentially laminated on a substrate. An end portion of the of compound semiconductor thin film is positioned outward beyond an end of the light transmitting electrode layer.
    Type: Application
    Filed: October 31, 2006
    Publication date: December 10, 2009
    Applicant: Rohm Co Ltd
    Inventors: Masaki Takaoka, Osamu Matsushima, Shogo Ishizuka, Shigeru Niki, Keiichiro Sakurai
  • Patent number: 7605012
    Abstract: A light emitting device includes a silicon substrate (1), a silicon nitride film (2) formed on the surface of the silicon substrate (1), at least an n-type layer (3), (4) and a p-type layer (6), (7) which are formed on the silicon nitride film (2) and also which are made of a ZnO based compound semiconductor, and a semiconductor layer lamination (11) in which layers are laminated to form a light emitting layer. Preferably this silicon nitride film (2) is formed by thermal treatment conducted in an atmosphere containing nitrogen such as an ammonium gas. Also, in another embodiment, a light emitting device is formed by growing a ZnO based compound semiconductor layer on a main face of a sapphire substrate, the main face being perpendicular to the C-face thereof. As a result, it is possible to obtain a device using a ZnO based compound with high properties such as an LED very excellent in crystallinity and having a high light emitting efficiency.
    Type: Grant
    Filed: June 27, 2005
    Date of Patent: October 20, 2009
    Assignees: National Institute of Advanced Industrial Science & Tech., Rohm Co., Ltd.
    Inventors: Shigeru Niki, Paul Fons, Kakuya Iwata, Tetsuhiro Tanabe, Hidemi Takasu, Ken Nakahara
  • Publication number: 20090217969
    Abstract: Disclosed is a method for manufacturing a photoelectric converter wherein a lower electrode layer, a compound semiconductor thin film having a chalcopyrite structure which serves as a light absorptive layer and a light-transmitting electrode layer that are laminated to form layers are each patterned by photolithography, thereby minimizing damages to the crystals of the compound semiconductor thin film.
    Type: Application
    Filed: October 31, 2006
    Publication date: September 3, 2009
    Applicant: ROHM CO., LTD.
    Inventors: Osamu Matsushima, Masaki Takaoka, Shogo Ishizuka, Shigeru Niki, Keiichiro Sakurai
  • Publication number: 20080072962
    Abstract: A method for producing a semiconductor film having a chalcopyrite structure including a Ib group element, a IIIb group element and a VIb group element including selenium, the method including cracking selenium with plasma to generate radical selenium, and using the radical selenium in the process of forming the semiconductor film.
    Type: Application
    Filed: August 23, 2007
    Publication date: March 27, 2008
    Inventors: Shogo ISHIZUKA, Shigeru NIKI, Keiichiro SAKURAI, Akimasa YAMADA, Koji MATSUBARA
  • Publication number: 20070125119
    Abstract: A refrigerator stated is characterized in that it includes a machine room (14) formed on a lower part of a rear of a main body of the refrigerator; a refrigerant compressor (12) installed offset to one side in the machine room (14) in a width direction; and a cooler (9) for receiving a refrigerant from the refrigerant compressor (12) and cooling an inside of a storage chamber; wherein the cooler (9) is arranged inside the refrigerator via a heat insulating wall (3a) of the main body above the refrigerant compressor (12) arranged on one side of the machine room (14) and at a position on an opposite side of the refrigerant compressor (12) in a width direction; and control and power source boards (21) of the refrigerator are arranged in another wide space of the refrigerant compressor (12) in the machine room (14) in a width direction.
    Type: Application
    Filed: August 25, 2004
    Publication date: June 7, 2007
    Applicants: KABUSHIKI KAISHA TOSHIBA, Toshiba Consumer Marketing Corporation, TOSHIGA HA PRODUCTS CO., LTD.
    Inventors: Yoshiro Naemura, Shigeru Niki, Kunio Nii, Yasushi Takagi, Ryousuke Yamamoto, Kosaku Adachi, Koji Mishima
  • Patent number: 6987029
    Abstract: A light emitting device includes a silicon substrate (1), a silicon nitride film (2) formed on the surface of the silicon substrate (1), at least an n-type layer (3), (4) and a p-type layer (6), (7) which are formed on the silicon nitride film (2) and also which are made of a ZnO based compound semiconductor, and a semiconductor layer lamination (11) in which layers are laminated to form a light emitting layer. Preferably this silicon nitride film (2) is formed by thermal treatment conducted in an atmosphere containing nitrogen such as an ammonium gas. Also, in another embodiment, a light emitting device is formed by growing a ZnO based compound semiconductor layer on a main face of a sapphire substrate, the main face being perpendicular to the C-face thereof. As a result, it is possible to obtain a device using a ZnO based compound with high properties such as an LED very excellent in crystallinity and having a high light emitting efficiency.
    Type: Grant
    Filed: November 17, 2003
    Date of Patent: January 17, 2006
    Assignees: National Institute of Advanced Industrial Science and Technology, Rohm Co., Ltd.
    Inventors: Shigeru Niki, Paul Fons, Kakuya Iwata, Tetsuhiro Tanabe, Hidemi Takasu, Ken Nakahara