Patents by Inventor Yohei Koi

Yohei Koi 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: 7847186
    Abstract: According to the present invention, sufficient light trapping effect can be exhibited and series resistance can be kept small, by sequentially forming a silicon based low refractive index layer and a thin silicon based interface layer on a backside of a photoelectric conversion layer observed from a light incident side, and as a result a silicon based thin film solar cell may be provided efficiently and at low cost.
    Type: Grant
    Filed: July 12, 2004
    Date of Patent: December 7, 2010
    Assignee: Kaneka Corporation
    Inventors: Toru Sawada, Yohei Koi, Toshiaki Sasaki, Masashi Yoshimi, Masahiro Goto, Kenji Yamamoto
  • Patent number: 7781668
    Abstract: An inexpensive substrate for thin film solar cells having improved performance of a thin film solar cell, and a manufacturing method thereof are provided by increasing light trapping effect due to effective increase in unevenness of a substrate for thin film solar cells. Furthermore, a thin film solar cell having improved performance using the substrate is provided. A substrate for thin film solar cells of the present invention has a transparent insulating substrate and a transparent electrode layer deposited thereon including at least zinc oxide (ZnO), the transparent insulating substrate has a fine surface unevenness having a root-mean-square deviation of the surface (RMS) 5 to 50 nm in an interface by a side of the transparent electrode layer, a projected area thereof consists of a curved surface, and furthermore a haze ratio or a ratio of a diffuse transmittance to a total transmittance as an index of unevenness of a substrate may be set at not less than 20% measured using a C light source.
    Type: Grant
    Filed: March 15, 2005
    Date of Patent: August 24, 2010
    Assignee: Kaneka Corporation
    Inventors: Toshiaki Sasaki, Yohei Koi, Yuko Tawada, Kenji Yamamoto
  • Patent number: 7550665
    Abstract: In a stacked-layer type photoelectric conversion device, a plurality of photoelectric conversion units are stacked on a substrate, each of which includes a one conductivity-type layer, a photoelectric conversion layer of substantially intrinsic semiconductor and an opposite conductivity-type layer in this order from a light-incident side. At least one of the opposite conductivity-type layer in a front photoelectric conversion unit arranged relatively closer to the light-incident side and the one conductivity-type layer in a back photoelectric conversion unit arranged adjacent to the front photoelectric conversion unit includes a silicon composite layer at least in a part thereof. The silicon composite layer has a thickness of more than 20 nm and less than 130 nm and an oxygen concentration of more than 25 atomic % and less than 60 atomic %, and includes silicon-rich phase parts in an amorphous alloy phase of silicon and oxygen.
    Type: Grant
    Filed: July 15, 2004
    Date of Patent: June 23, 2009
    Assignee: Kaneka Corporation
    Inventors: Toshiaki Sasaki, Yohei Koi, Kenji Yamamoto, Masashi Yoshimi, Mitsuru Ichikawa
  • Publication number: 20080185036
    Abstract: An object of the present invention is to provide a substrate for a thin film photoelectric conversion device, in which its properties are not deteriorated when its surface unevenness is effectively increased, and then provide the thin film photoelectric conversion device having its performance improved by using the substrate. According to the present invention, by setting the surface area ratio of a transparent electrode layer in the substrate for the thin film photoelectric conversion device to at least 55% and at most 95%, the surface unevenness are effectively increased to increase the optical confinement effect, while deterioration in properties due to sharpening of the surface level variation is suppressed, whereby making it possible to provide a substrate for a thin film photoelectric conversion device, which can enhance output properties of the thin film photoelectric conversion device.
    Type: Application
    Filed: November 9, 2005
    Publication date: August 7, 2008
    Inventors: Toshiaki Sasaki, Yohei Koi, Yuko Tawada, Takashi Suezaki, Kenji Yamamoto
  • Publication number: 20070169805
    Abstract: An inexpensive substrate for thin film solar cells having improved performance of a thin film solar cell, and a manufacturing method thereof are provided by increasing light trapping effect due to effective increase in unevenness of a substrate for thin film solar cells. Furthermore, a thin film solar cell having improved performance using the substrate is provided. A substrate for thin film solar cells of the present invention has a transparent insulating substrate and a transparent electrode layer deposited thereon including at least zinc oxide (ZnO), the transparent insulating substrate has a fine surface unevenness having a root-mean-square deviation of the surface (RMS) 5 to 50 nm in an interface by a side of the transparent electrode layer, a projected area thereof consists of a curved surface, and furthermore a haze ratio or a ratio of a diffuse transmittance to a total transmittance as an index of unevenness of a substrate may be set at not less than 20% measured using a C light source.
    Type: Application
    Filed: March 15, 2005
    Publication date: July 26, 2007
    Applicant: KANEKA CORPORATION
    Inventors: Toshiaki Sasaki, Yohei Koi, Yuko Tawada, Kenji Yamamoto
  • Publication number: 20060043517
    Abstract: In a stacked-layer type photoelectric conversion device, a plurality of photoelectric conversion units are stacked on a substrate, each of which includes a one conductivity-type layer, a photoelectric conversion layer of substantially intrinsic semiconductor and an opposite conductivity-type layer in this order from a light-incident side. At least one of the opposite conductivity-type layer in a front photoelectric conversion unit arranged relatively closer to the light-incident side and the one conductivity-type layer in a back photoelectric conversion unit arranged adjacent to the front photoelectric conversion unit includes a silicon composite layer at least in a part thereof. The silicon composite layer has a thickness of more than 20 nm and less than 130 nm and an oxygen concentration of more than 25 atomic % and less than 60 atomic %, and includes silicon-rich phase parts in an amorphous alloy phase of silicon and oxygen.
    Type: Application
    Filed: July 15, 2004
    Publication date: March 2, 2006
    Inventors: Toshiaki Sasaki, Yohei Koi, Kenji Yamamoto, Masashi Yoshimi, Mitsuru Ichikawa