Patents by Inventor Homare Hiroi

Homare Hiroi 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).

  • Publication number: 20200105964
    Abstract: A photovoltaic device includes an absorber layer having a back contact formed on the absorber layer, the back contact having an exposed surface free from a substrate. It further includes a top contact formed in contact with a transparent conductive layer opposite the back contact and a stressor layer forming a superstrate on the absorber layer opposite the back contact.
    Type: Application
    Filed: December 3, 2019
    Publication date: April 2, 2020
    Inventors: Oki Gunawan, Homare Hiroi, Jeehwan Kim, David B. Mitzi, Hiroki Sugimoto
  • Patent number: 10580928
    Abstract: A method for thermal exfoliation includes providing a target layer on a substrate to form a structure. A stressor layer is deposited on the target layer. The structure is placed in a temperature controlled environment to induce differential thermal expansion between the target layer and the substrate. The target layer is exfoliated from the substrate when a critical temperature is achieved such that the target layer is separated from the substrate to produce a standalone, thin film device.
    Type: Grant
    Filed: August 8, 2017
    Date of Patent: March 3, 2020
    Assignees: International Business Machines Corporation, Solar Frontier K.K.
    Inventors: Oki Gunawan, Homare Hiroi, Jeehwan Kim, David B. Mitzi, Hiroki Sugimoto
  • Publication number: 20180308995
    Abstract: A photoelectric conversion element comprises: a first electrode layer 12; a compound-based photoelectric conversion layer 13 disposed on the first electrode layer 12; a buffer layer 15 disposed on the compound-based photoelectric conversion layer 13 comprising a mixed crystal of ZnO and ZnS, wherein a ratio of the number of S atoms to the number of Zn atoms is in a range of 0.290 to 0.493; and a second electrode layer 16 disposed on the buffer layer 15.
    Type: Application
    Filed: September 28, 2016
    Publication date: October 25, 2018
    Applicant: Solar Frontier K.K.
    Inventors: Shunsuke ADACHI, Rui KAMADA, Homare HIROI
  • Publication number: 20170358702
    Abstract: A method for thermal exfoliation includes providing a target layer on a substrate to form a structure. A stressor layer is deposited on the target layer. The structure is placed in a temperature controlled environment to induce differential thermal expansion between the target layer and the substrate. The target layer is exfoliated from the substrate when a critical temperature is achieved such that the target layer is separated from the substrate to produce a standalone, thin film device.
    Type: Application
    Filed: August 8, 2017
    Publication date: December 14, 2017
    Inventors: Oki Gunawan, Homare Hiroi, Jeehwan Kim, David B. Mitzi, Hiroki Sugimoto
  • Patent number: 9799792
    Abstract: A method for thermal exfoliation includes providing a target layer on a substrate to form a structure. A stressor layer is deposited on the target layer. The structure is placed in a temperature controlled environment to induce differential thermal expansion between the target layer and the substrate. The target layer is exfoliated from the substrate when a critical temperature is achieved such that the target layer is separated from the substrate to produce a standalone, thin film device.
    Type: Grant
    Filed: January 14, 2015
    Date of Patent: October 24, 2017
    Assignees: International Business Machines Corporation, Solar Frontier K.K.
    Inventors: Oki Gunawan, Homare Hiroi, Jeehwan Kim, David B. Mitzi, Hiroki Sugimoto
  • Publication number: 20170117424
    Abstract: A method for manufacturing a solar cell includes the following steps: a step in which a first electrode layer is formed on top of a substrate; a step in which a selenium-containing p-type CZTS light-absorbing layer is formed on top of the first electrode layer; a step in which the surface of the CZTS light-absorbing layer is brought into contact with an aqueous solution containing an organic sulfur compound, increasing the concentration of sulfur on the surface of the CZTS light-absorbing layer, and an n-type buffer layer is formed on top of CZTS light-absorbing layer; and a step in which a second electrode layer is formed on top of said buffer layer.
    Type: Application
    Filed: April 15, 2014
    Publication date: April 27, 2017
    Applicant: Solar Frontier K.K.
    Inventors: Homare HIROI, Hiroki SUGIMOTO, Takuya KATOU, Noriyuki SAKAI
  • Publication number: 20160204304
    Abstract: A method for thermal exfoliation includes providing a target layer on a substrate to form a structure. A stressor layer is deposited on the target layer. The structure is placed in a temperature controlled environment to induce differential thermal expansion between the target layer and the substrate. The target layer is exfoliated from the substrate when a critical temperature is achieved such that the target layer is separated from the substrate to produce a standalone, thin film device.
    Type: Application
    Filed: January 14, 2015
    Publication date: July 14, 2016
    Inventors: Oki Gunawan, Homare Hiroi, Jeehwan Kim, David B. Mitzi, Hiroki Sugimoto
  • Publication number: 20160190373
    Abstract: A thin film solar cell comprises a metal rear surface electrode layer formed on a substrate, a p-type CZTS light-absorbing layer formed on the electrode layer, an n-type high-resistance buffer layer containing a zinc compound as a material and formed on the p-type CZTS light-absorbing layer, and an n-type transparent electroconductive film formed on the n-type high-resistance buffer layer. When the Cu—Zn—Sn composition ratio (atom ratio) of the p-type CZTS light-absorbing layer is represented by coordinates with the Cu/(Zn+Sn) ratio shown on the horizontal axis and the Zn/Sn ratio shown on the vertical axis, the ratio is within the region formed by connecting point A (0.825, 1.108), point B (1.004, 0.905), point C (1.004, 1.108), point E (0.75, 1.6), and point D (0.65, 1.5), and the Zn/Sn ratio of the p-type CZTS light-absorbing layer surface in the n-type high-resistance buffer layer is 1.11 or less.
    Type: Application
    Filed: March 3, 2016
    Publication date: June 30, 2016
    Applicant: Solar Frontier K. K.
    Inventors: Hiroki SUGIMOTO, Noriyuki SAKAI, Homare HIROI
  • Patent number: 9240501
    Abstract: A compound-based thin film solar cell which has a high photovoltaic conversion efficiency is obtained. The compound-based thin film solar cell is provided with substrate (1), back surface electrode layer (2) formed on substrate (1), p-type light absorption layer (3) formed on back surface electrode layer (2), n-type high resistance buffer layer (4) formed on p-type light absorption layer (3), and ZnO film (5) formed on n-type high resistance buffer layer (4), where n-type high resistance buffer layer (4) includes a first buffer layer (4A) formed on the p-type light absorption layer (3) and a second buffer layer (4B) formed on the first buffer layer (4A) and where the second buffer layer (4B) is formed by a material which has a lattice constant closer to the lattice constant of the ZnO film (5) than the first buffer layer (4A).
    Type: Grant
    Filed: February 12, 2014
    Date of Patent: January 19, 2016
    Assignee: Solar Frontier K.K.
    Inventors: Homare Hiroi, Hiroki Sugimoto
  • Publication number: 20150228811
    Abstract: A compound-based thin film solar cell which has a high photovoltaic conversion efficiency is obtained. The compound-based thin film solar cell is provided with substrate (1), back surface electrode layer (2) formed on substrate (1), p-type light absorption layer (3) formed on back surface electrode layer (2), n-type high resistance buffer layer (4) formed on p-type light absorption layer (3), and ZnO film (5) formed on n-type high resistance buffer layer (4), where n-type high resistance buffer layer (4) includes a first buffer layer (4A) formed on the p-type light absorption layer (3) and a second buffer layer (4B) formed on the first buffer layer (4A) and where the second buffer layer (4B) is formed by a material which has a lattice constant closer to the lattice constant of the ZnO film (5) than the first buffer layer (4A).
    Type: Application
    Filed: February 12, 2014
    Publication date: August 13, 2015
    Applicant: SHOWA SHELL SEKIYU K.K.
    Inventors: Homare HIROI, Hiroki SUGIMOTO
  • Publication number: 20140315348
    Abstract: A thin-film solar cell which uses an InS-based buffer layer is produced by forming a metal back electrode layer on a substrate, forming a p-type light absorption layer on the metal back electrode layer, oxidizing the p-type light absorption layer surface, forming an InS-based buffer layer as an n-type high resistance buffer layer on the oxidized p-type light absorption layer, and forming an n-type transparent conductive film on the InS-based buffer layer.
    Type: Application
    Filed: November 30, 2012
    Publication date: October 23, 2014
    Inventors: Hiroki Sugimoto, Noriyuki Sakai, Homare Hiroi
  • Publication number: 20140109960
    Abstract: A thin film solar cell comprises a metal rear surface electrode layer formed on a substrate, a p-type CZTS light-absorbing layer formed on the electrode layer, an n-type high-resistance buffer layer containing a zinc compound as a material and formed on the p-type CZTS light-absorbing layer, and an n-type transparent electroconductive film formed on the n-type high-resistance buffer layer. When the Cu—Zn—Sn composition ratio (atom ratio) of the p-type CZTS light-absorbing layer is represented by coordinates with the Cu/(Zn+Sn) ratio shown on the horizontal axis and the Zn/Sn ratio shown on the vertical axis, the ratio is within the region formed by connecting point A (0.825, 1.108), point B (1.004, 0.905), point C (1.004, 1.108), point E (0.75, 1.6), and point D (0.65, 1.5), and the Zn/Sn ratio of the p-type CZTS light-absorbing layer surface in the n-type high-resistance buffer layer is 1.11 or less.
    Type: Application
    Filed: May 31, 2012
    Publication date: April 24, 2014
    Applicant: Showa Shell Sekiyu K.K.
    Inventors: Hiroki Sugimoto, Noriyuki Sakai, Homare Hiroi