Title:
POLYCRYSTALLINE SILICON FOR SOLAR CELL, AND PROCESS FOR PRODUCTION THEREOF
Document Type and Number:
WIPO Patent Application WO/2011/074321
Kind Code:
A1
Abstract:
Disclosed is a process for producing polycrystalline silicon from which a region that has a surface layer having a carrier lifetime reduced by the action of Fe is substantially eliminated. Specifically disclosed is a process for producing polycrystalline silicon, which comprises applying a mold release agent that is produced by mixing a silicon nitride powder with a binder and a solvent onto a mold uniformly and solidifying molten silicon in the mold. The process is characterized in that variants x and y fulfill the following formulae: x ≤ 5.0, 20 ≤ y ≤ 100 and x×y ≤ 100 wherein x (at.ppm) represents the concentration of Fe contained in the silicon nitride powder as an impurity, and y (μm) represents the thickness of the mol release agent that has been applied onto the mold.
Inventors:
SATO,Kenji (2-3-2Kajicho,Chiyoda-k, Tokyo 44, 〒1010044, JP)
Application Number:
JP2010/068511
Publication Date:
June 23, 2011
Filing Date:
October 20, 2010
Export Citation:
Assignee:
JX Nippon Mining & Metals Corporation (6-3Otemachi 2-chome, Chiyoda-ku Tokyo, 04, 〒1000004, JP)
ＪＸ日鉱日石金属株式会社 (〒04 東京都千代田区大手町二丁目６番３号 Tokyo, 〒1000004, JP)
TOHO TITANIUM CO., LTD. (3-5 Chigasaki 3-chome, Chigasaki-shi Kanagawa, 10, 〒2538510, JP)
東邦チタニウム株式会社 (〒10 神奈川県茅ヶ崎市茅ヶ崎三丁目３番５号 Kanagawa, 〒2538510, JP)
ＪＸ日鉱日石金属株式会社 (〒04 東京都千代田区大手町二丁目６番３号 Tokyo, 〒1000004, JP)
TOHO TITANIUM CO., LTD. (3-5 Chigasaki 3-chome, Chigasaki-shi Kanagawa, 10, 〒2538510, JP)
東邦チタニウム株式会社 (〒10 神奈川県茅ヶ崎市茅ヶ崎三丁目３番５号 Kanagawa, 〒2538510, JP)
International Classes:
C01B33/02; B22C3/00; B22D25/04
Attorney, Agent or Firm:
AXIS Patent International (Yushi Kogyo Kaikan, 13-11Nihonbashi 3-chome,Chuo-k, Tokyo 27, 〒1030027, JP)