Patents by Inventor Koichiro Niira

Koichiro Niira 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: 20110036394
    Abstract: Provided is a superstrate type a-Si:H thin film solar cell of which the device characteristics are improved as compared with conventional ones. The solar cell device is manufactured by a process comprising depositing phosphorus on a transparent conductive film formed on a transparent substrate and sequentially forming a p-type layer, an i-type layer, and an n-type layer which are formed of a-Si:H on the transparent conductive film by a plasma CVD method. The phosphorus is deposited, for example, by plasmatization of phosphorus-containing gas. Alternatively, the phosphorus is deposited by etching a phosphorus source provided in a margin region where a plasma excitation voltage is applied but no transparent substrate is placed, with hydrogen plasma at the start of the formation of the p-type layer by the plasma CVD method.
    Type: Application
    Filed: February 6, 2009
    Publication date: February 17, 2011
    Applicant: KYOCERA CORPORATION
    Inventors: Koichiro Niira, Takehiro Nishimura, Norikazu Ito, Shinichiro Inaba
  • Publication number: 20110000532
    Abstract: A high-efficiency solar cell device producible in a simplified manner, and a method of manufacturing the same are provided. An insulation layer is formed on the back surface side of a semiconductor substrate of a first conductivity type. Removing part of the insulation layer exposes part of the semiconductor substrate to form a plurality of first through holes. A first layer of the first conductivity type is formed on the insulation layer and on the part of the semiconductor substrate exposed in the plurality of first through holes, whereby first junction regions are formed. Removing part of the first layer and the insulation layer exposes part of the semiconductor substrate to form a plurality of second through holes. A second layer of an opposite conductivity type is formed on the first layer and on the part of the semiconductor substrate exposed in the plurality of second through holes, whereby second junction regions are formed.
    Type: Application
    Filed: January 30, 2009
    Publication date: January 6, 2011
    Applicant: KYOCERA CORPORATION
    Inventors: Koichiro Niira, Kazuaki Iwameji, Manabu Komoda
  • Publication number: 20090272423
    Abstract: In a photoelectric conversion device, in a contact between a p-type semiconductor 3a and an electrode 2, an n-type semiconductor 6 of a conductivity type opposite to that of the p-type semiconductor is provided between the p-type semiconductor 3a and the electrode 2. The existence of the n-type semiconductor 6 allows a recombination rate of photo-generated carriers excited by incident light to be effectively reduced, and allows a dark current component to be effectively prevented from being produced. Therefore, it is possible to improve photoelectric conversion efficiency as well as to stabilize characteristics. Further, a tunnel junction is realized by increasing the concentration of a doping element in at least one or preferably both of the p-type semiconductor 3a and the n-type semiconductor 6 in a region where they are in contact with each other, thereby keeping ohmic characteristics between the semiconductor and the electrode good.
    Type: Application
    Filed: June 8, 2009
    Publication date: November 5, 2009
    Applicant: KYOCERA CORPORATION
    Inventors: Koichiro NIIRA, Hirofumi SENTA, Hideki HAKUMA
  • Publication number: 20090266396
    Abstract: Disclosed is a polycrystalline silicon substrate having a region wherein concentrations of impurities contained therein satisfy the following relations: [Oi]?2E17 [atoms/cm3] (under condition 1a and [C]?1E17 [atoms/cm3] (Condition 2)) where [Oi] is the interstitial oxygen concentration determined by Fourier transform infrared spectroscopy and [C] is the total carbon concentration determined by secondary ion mass spectrometry. This polycrystalline silicon substrate has high strength adequate for a thinner substrate, while having good quality and high photoelectric conversion efficiency. Such a polycrystalline silicon substrate enables to produce a resource-saving, highly efficient polycrystalline silicon solar cell at low cost.
    Type: Application
    Filed: March 27, 2006
    Publication date: October 29, 2009
    Applicant: KYOCERA CORPORATION
    Inventors: Koichiro Niira, Shigeru Gotoh
  • Publication number: 20090223562
    Abstract: A solar cell element and method of manufacturing same is disclosed. A reverse-conductive-type layer is formed on at least one part of a first surface side of a one-conductive-type semiconductor substrate. A conductive layer is formed on the reverse-conductive-type layer. A contact region for electrically connecting the conductive layer and the one-conductive-type semiconductor substrate is formed by heating and melting at least one part of the conductive layer. The solar cell element can be manufactured without conducting complicated treatments, such as removal by etching and re-growing of a silicon thin layer.
    Type: Application
    Filed: April 27, 2009
    Publication date: September 10, 2009
    Applicant: KYOCERA CORPORATION
    Inventors: Koichiro Niira, Manabu Komoda
  • Publication number: 20090211635
    Abstract: A photovoltaic conversion element includes a one conductivity-type crystalline Si semiconductor; an opposite conductivity-type semiconductor which is joined to the crystalline Si semiconductor to form a pn junction therebetween; an electrode provided on the opposite conductivity-type semiconductor; and a depletion region formed from the side of the one conductivity-type crystalline Si semiconductor to the side of the opposite conductivity-type semiconductor across the pn junction formed therebetween. The depletion region has a first depletion region located inside the crystalline Si semiconductor and under the electrode, and the first depletion region has an oxygen concentration of 1E18 [atoms/cm3] or less.
    Type: Application
    Filed: March 24, 2006
    Publication date: August 27, 2009
    Applicant: Kyocera Corporation
    Inventors: Koichiro Niira, Tomonari Sakamoto, Norihiko Matsushima
  • Patent number: 7560750
    Abstract: In a photoelectric conversion device, in a contact between a p-type semiconductor 3a and an electrode 2, an n-type semiconductor 6 of a conductivity type opposite to that of the p-type semiconductor is provided between the p-type semiconductor 3a and the electrode 2. The existence of the n-type semiconductor 6 allows a recombination rate of photo-generated carriers excited by incident light to be effectively reduced, and allows a dark current component to be effectively prevented from being produced. Therefore, it is possible to improve photoelectric conversion efficiency as well as to stabilize characteristics. Further, a tunnel junction is realized by increasing the concentration of a doping element in at least one or preferably both of the p-type semiconductor 3a and the n-type semiconductor 6 in a region where they are in contact with each other, thereby keeping ohmic characteristics between the semiconductor and the electrode good.
    Type: Grant
    Filed: June 25, 2004
    Date of Patent: July 14, 2009
    Assignee: Kyocera Corporation
    Inventors: Koichiro Niira, Hirofumi Senta, Hideki Hakuma
  • Patent number: 7317237
    Abstract: There is disclosed a photovoltaic conversion device constructed using a p-type crystalline silicon substrate 404 doped with boron, which comprises a bulk substrate region 404, regions other than the bulk substrate region including an n-type region 403a joining to a light receiving surface of the bulk surface region, a BSF region 405 joining to a back surface of the bulk surface region, wherein with regions other than the bulk substrate region 404 being removed, when a minority carrier diffusion length of the bulk substrate region 404 is measured from the light receiving surface of the bulk surface region, 0.
    Type: Grant
    Filed: December 22, 2004
    Date of Patent: January 8, 2008
    Assignee: Kyocera Corporation
    Inventors: Koichiro Niira, Shigeru Gotoh
  • Publication number: 20070295381
    Abstract: A surface electrode (5) is installed on the light receiving surface of a solar cell element, the surface electrode (5) comprises three bus bar electrodes (5a) for extracting light-produced at the solar cell element to the outside and collecting finger electrodes (5b) connected to these bus bar electrodes (5a), and the bus bar electrodes (5a) are not less than 0.5 mm and not more than 2 mm in width and the finger electrodes (5b) are not less than 0.05 mm and not more than 0.1 mm in width. A high-efficient solar cell module can be obtained with substantially lowered resistance by increasing the number of bus bar electrode (5a) and thereby decreasing the lengths of the finger electrodes (5b).
    Type: Application
    Filed: March 29, 2005
    Publication date: December 27, 2007
    Applicant: Kyocera Corporation
    Inventors: Shuichi Fujii, Yosuke Inomata, Tomonari Sakamoto, Koichiro Niira, Yuko Fukawa, Hiroshi Morita, Koji Nishi, Tatsuya Yashi, Mitsuo Yamashita, Kenji Fukui
  • Patent number: 7001831
    Abstract: A non-Si non-C-based gas is heated by a thermal catalysis body provided in a gas introduction channel, and the heated non-Si non-C-based gas and a material-based gas comprising Si and/or C are separately introduced into a film deposition space through a showerhead having a plurality of gas effusion ports, and in the film deposition space, a plasma space is formed by a nonplanar electrode connected to a radio frequency power supply, thereby forming a film on a substrate. Formation of high-quality Si-based films and C-based films can thus be accomplished at high deposition rate over large area with uniform film thickness and homogeneous quality. Also, highly efficient devices including photoelectric conversion devices represented by solar cells can be manufactured at low-cost by the use of such films.
    Type: Grant
    Filed: February 20, 2003
    Date of Patent: February 21, 2006
    Assignee: Kyocera Corporation
    Inventors: Koichiro Niira, Hirofumi Senta, Hideki Hakuma, Hiroki Okui
  • Publication number: 20050160970
    Abstract: There is disclosed a photovoltaic conversion device constructed using a p-type crystalline silicon substrate 404 doped with boron, which comprises a bulk substrate region 404, regions other than the bulk substrate region including an n-type region 403a joining to a light receiving surface of the bulk surface region, a BSF region 405 joining to a back surface of the bulk surface region, wherein with regions other than the bulk substrate region 404 being removed, when a minority carrier diffusion length of the bulk substrate region 404 is measured from the light receiving surface of the bulk surface region, 0.
    Type: Application
    Filed: December 22, 2004
    Publication date: July 28, 2005
    Inventors: Koichiro Niira, Shigeru Gotoh
  • Publication number: 20050012095
    Abstract: In a photoelectric conversion device, in a contact between a p-type semiconductor 3a and an electrode 2, an n-type semiconductor 6 of a conductivity type opposite to that of the p-type semiconductor is provided between the p-type semiconductor 3a and the electrode 2. The existence of the n-type semiconductor 6 allows a recombination rate of photo-generated carriers excited by incident light to be effectively reduced, and allows a dark current component to be effectively prevented from being produced. Therefore, it is possible to improve photoelectric conversion efficiency as well as to stabilize characteristics. Further, a tunnel junction is realized by increasing the concentration of a doping element in at least one or preferably both of the p-type semiconductor 3a and the n-type semiconductor 6 in a region where they are in contact with each other, thereby keeping ohmic characteristics between the semiconductor and the electrode good.
    Type: Application
    Filed: June 25, 2004
    Publication date: January 20, 2005
    Inventors: Koichiro Niira, Hirofumi Senta, Hideki Hakuma
  • Publication number: 20030176011
    Abstract: A non-Si non-C-based gas is heated by a thermal catalysis body provided in a gas introduction channel, and the heated non-Si non-C-based gas and a material-based gas comprising Si and/or C are separately introduced into a film deposition space through a showerhead having a plurality of gas effusion ports, and in the film deposition space, a plasma space is formed by a nonplanar electrode connected to a radio frequency power supply, thereby forming a film on a substrate. Formation of high-quality Si-based films and C-based films can thus be accomplished at high deposition rate over large area with uniform film thickness and homogeneous quality. Also, highly efficient devices including photoelectric conversion devices represented by solar cells can be manufactured at low-cost by the use of such films.
    Type: Application
    Filed: February 20, 2003
    Publication date: September 18, 2003
    Applicant: KYOCERA CORPORATION
    Inventors: Koichiro Niira, Hirofumi Senta, Hideki Hakuma, Hiroki Okui