Sample records for kaihatsu jigyo kankyo

  1. β-FeSi II as a Kankyo (environmentally friendly) semiconductor for solar cells in the space application

    NASA Astrophysics Data System (ADS)

    Makita, Yunosuke; Ootsuka, Teruhisa; Fukuzawa, Yasuhiro; Otogawa, Naotaka; Abe, Hironori; Liu, Zhengxin; Nakayama, Yasuhiko

    2006-04-01

    β-FeSi II defined as a Kankyo (Environmentally Friendly) semiconductor is regarded as one of the 3-rd generation semiconductors after Si and GaAs. Versatile features about β-FeSi II are, i) high optical absorption coefficient (>10 5cm -1), ii) chemical stability at temperatures as high as 937°C, iii) high thermoelectric power (Seebeck coefficient of k ~ 10 -4/K), iv) a direct energy band-gap of 0.85 eV, corresponding to 1.5μm of quartz optical fiber communication, v) lattice constant nearly well-matched to Si substrate, vi) high resistance against the humidity, chemical attacks and oxidization. Using β-FeSi II films, one can fabricate various devices such as Si photosensors, solar cells and thermoelectric generators that can be integrated basically on Si-LSI circuits. β-FeSi II has high resistance against the exposition of cosmic rays and radioactive rays owing to the large electron-empty space existing in the electron cloud pertinent to β-FeSi II. Further, the specific gravity of β-FeSi II (4.93) is placed between Si (2.33) and GaAs ((5.33). These features together with the aforementioned high optical absorption coefficient are ideal for the fabrication of solar cells to be used in the space. To demonstrate fascinating capabilities of β-FeSi II, one has to prepare high quality β-FeSi II films. We in this report summarize the current status of β-FeSi II film preparation technologies. Modified MBE and facing-target sputtering (FTS) methods are principally discussed. High quality β-FeSi II films have been formed on Si substrates by these methods. Preliminary structures of n-β-FeSi II /p-Si and p-β-FeSi II /n-Si solar cells indicated an energy conversion efficiency of 3.7%, implying that β-FeSi II is practically a promising semiconductor for a photovoltaic device.

  2. Challenges in the Japan Beyond-Brittle Project (JBBP) for EGS development beyond the brittle-ductile transition

    NASA Astrophysics Data System (ADS)

    Asanuma, H.; Muraoka, H.; Tsuchiya, N.; Ito, H.

    2013-12-01

    isolated from the hydrothermal system. Discussions on exploration/monitoring of the BDT rock mass and JBBP reservoirs, and engineering development have been also made in the workshop. We finally identified scientific/technological challenges for the JBBP and established roadmap and implementation plan. The workshop report is available at http://jbbp.kankyo.tohoku.ac.jp/jbbp Conceptual model of the JBBP

  3. Prime Contract Awards Alphabetically by Contractor, by State or Country, and Place, Fiscal Year 1987. Part 14. Okinawa Kankyo-Pultrusions Corporation.

    DTIC Science & Technology

    1987-01-01

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