Study of melt growth mechanisms of multicrystalline Si by in situ observations

• Project/Area Number: 26246016
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Crystal engineering
• Research Institution: Tohoku University
• Principal Investigator: Fujiwara Kozo 東北大学, 金属材料研究所, 教授 (70332517)
• Co-Investigator(Kenkyū-buntansha): 沓掛 健太朗 東北大学, 金属材料研究所, 助教 (00463795)
• Project Period (FY): 2014-06-27 – 2017-03-31
• Project Status: Completed (Fiscal Year 2016)
• Budget Amount: ¥43,030,000 (Direct Cost: ¥33,100,000、Indirect Cost: ¥9,930,000); Fiscal Year 2016: ¥7,670,000 (Direct Cost: ¥5,900,000、Indirect Cost: ¥1,770,000); Fiscal Year 2015: ¥7,670,000 (Direct Cost: ¥5,900,000、Indirect Cost: ¥1,770,000); Fiscal Year 2014: ¥27,690,000 (Direct Cost: ¥21,300,000、Indirect Cost: ¥6,390,000)
• Keywords: 固液界面 / Si多結晶 / その場観察 / 双晶界面 / 結晶成長 / 不純物偏析 / シリコン / 結晶粒界

Outline of Final Research Achievements

The fundamental melt growth mechanisms of multicrystalline Si (mc-Si) were investigated to obtain valuable information for the development of crystal growth technology of mc-Si ingots for solar cells. We newly developed an in situ observation system for the direct observation of crystal/melt interface at high temperature as 1400℃. The effect of grain boundaries on the crystal growth behaviors was clarified. On the basis fo the fundamental understanding of crystal growth mechanisms, we developed a crystal growth technology for mc-Si ingot. We obtained high quality mc-Si ingot in comparison with the conventional one.

Research Products

• [Journal Article] In situ observation of twin boundary formation at grain-boundary groove during directional solidification of Si (2017)
  • Author(s): K. Fujiwara, R. Maeda, K. Maeda, and H. Morito
  • Journal Title: Scripta Materialia Volume: 133 Pages: 65-69
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Impact of local atomic stress on oxygen segregation at tilt boundaries silicon (2017)
  • Author(s): Y. Ohno, K. Inoue, K. Fujiwara, K. Kutsukake, M. Deura, I. Yonenaga, N. Ebisawa, Y. Shimizu, K. Inoue, Y. Nagai, H. Yoshida, S. Takeda, S. Tanaka, M. Kohyama
  • Journal Title: Applied Physics Letters Volume: 110 Issue: 6
  • DOI: 10.1063/1.4975814
  • Peer Reviewed
• [Journal Article] Liquinert quartz crucible for the growth of multicrystalline Si ingots (2015)
  • Author(s): Kozo Fujiwara, Yukichi Horioka, and Shiro Sakuragi
  • Journal Title: Energy Science & Engineering Volume: 3 Issue: 5 Pages: 419-422
  • DOI: 10.1002/ese3.90
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Three-dimensional evaluation of gettering ability for oxigen atoms at small-angle tilt boundaries in Czochralski-grown silicon crystals (2015)
  • Author(s): Yutaka Ohno, Kaihei Inoue, Kozo Fujiwara, Momoko Deura, Kentaro Kutsukake, Ichiro Yonenaga, Yasuo Shimizu, Koji Inoue, Naoki Ebisawa, and Yasuyoshi Nagai
  • Journal Title: Applied Physics Letters Volume: 106 Issue: 25 Pages: 251603-251603
  • DOI: 10.1063/1.4921742
  • Peer Reviewed
• [Journal Article] Segregation of Ge in B and Ge codoped Czochralski-Si crystal growth (2015)
  • Author(s): Mukannan Arivanandhan, Raira Gotoh, Kozo Fujiwara, Satoshi Uda, and Yasuhiro Hayakawa
  • Journal Title: Journal of Alloys and Compounds Volume: 639 Pages: 588-592
  • DOI: 10.1016/j.jallcom.2015.03.155
  • Peer Reviewed / Int'l Joint Research
• [Presentation] Si多結晶の一方向成長過程における双晶界面の形成過程の直接観察 (2017)
  • Author(s): 前田亮一、前田健作、森戸春彦、藤原航三
  • Organizer: 日本金属学会第160回春期講演大会
  • Place of Presentation: 東京都立大学
  • Invited
• [Presentation] Morphological transformation of crystal/melt interface of silicon (2016)
  • Author(s): Kozo Fujiwara
  • Organizer: 2016 Russia-Japan Conference "Advanced Materials: Synthesis, Processing and Properties of Nanostructures"
  • Place of Presentation: Novosibirsk State University, Russia
  • Int'l Joint Research / Invited
• [Presentation] Development of growth technology of mc-Si ingot suppressing impurity contamination  (2016)
  • Author(s): Kozo Fujiwara, Yukichi Horioka, Siro. Sakuragi
  • Organizer: The 18th International Conference on Crystal Growth and Epitaxy (ICCGE-18)
  • Place of Presentation: Nagoya
  • Int'l Joint Research / Invited
• [Presentation] In situ observations of interface instability and dendrite growth of silicon (2016)
  • Author(s): Kozo Fujiwara
  • Organizer: 5th International Workshop on Directianally Solodified Eutectic Ceramics
  • Place of Presentation: the University of Warsaw, Warsaw, Poland
  • Int'l Joint Research / Invited
• [Presentation] Fabrication of periodically-twinned borate crystal for quasi-phase-matching (2016)
  • Author(s): Kensaku Maeda, Kozo Fujiwara, Satoshi Uda
  • Organizer: The 10th Asia-Pacific Laser Symposium (APLS 2016)
  • Place of Presentation: Seogwipo KAL Hotel, Jejudo,Korea
  • Int'l Joint Research / Invited
• [Presentation] CZ-Si単結晶より高品質なSi多結晶の実現を目指して (2015)
  • Author(s): 藤原航三
  • Organizer: 第3回『各種SiC結晶成長法における高品質化とその応用』
  • Place of Presentation: 名古屋大学（愛知県名古屋市）
  • Year and Date: 2015-12-11
  • Invited
• [Presentation] In situ observations of crystal/melt interface during unidirectional growth of silicon (2015)
  • Author(s): Kozo Fujiwara
  • Organizer: 11th International Conference on Ceramic Materials and Components for Energy and Environmental Applications
  • Place of Presentation: バンクーバー（カナダ）
  • Year and Date: 2015-06-14
  • Int'l Joint Research / Invited
• [Presentation] Ge distribution at grain boundary in unidirectional growth of Si-rich SiGe (2015)
  • Author(s): Morgane Mokhtari, Kozo Fujiwara, Haruhiko Koizumi, Jun Nozawa, Satoshi Uda
  • Organizer: Japan-Russia Joint Seminar "Advanced Materials Synthesis Process and Nanostructure"
  • Place of Presentation: ホテル華乃湯（宮城県仙台市）
  • Year and Date: 2015-03-09 – 2015-03-10
• [Presentation] その場観察が明らかにするシリコンの結晶成長メカニズム (2015)
  • Author(s): 藤原航三
  • Organizer: 第142回結晶工学分科会研究会
  • Place of Presentation: キャンパスプラザ京都（京都市）
  • Year and Date: 2015-02-05
  • Invited
• [Presentation] Siの固液界面不安定化に及ぼす双晶界面の影響 (2014)
  • Author(s): 藤原航三、小泉晴比古、野澤純、宇田聡
  • Organizer: 第44回結晶成長国内会議
  • Place of Presentation: 学習院創立百周年記念会館
  • Year and Date: 2014-11-06 – 2014-11-08
• [Presentation] In situ observation of crystal/melt interface of SiGe (2014)
  • Author(s): M. Mokhtari, K. Fujiwara, H. Koizumi, J. Nozawa, S. Uda
  • Organizer: 第44回結晶成長国内会議
  • Place of Presentation: 学習院創立百周年記念会館
  • Year and Date: 2014-11-06 – 2014-11-08
• [Presentation] In-situ observation of crystal/melt interface of SiGe (2014)
  • Author(s): M. Mokhtari, K. Fujiwara, H. Koizumi, J. Nozawa, S. Uda
  • Organizer: 第38回結晶成長討論会
  • Place of Presentation: 公益財団法人大学セミナーハウス八王子セミナーハウス
  • Year and Date: 2014-09-25 – 2014-09-27
• [Remarks] 藤原研究室
  • URL: http://www.xtalphys.imr.tohoku.ac.jp/
• [Remarks] 結晶物理学研究部門
  • URL: http://www.imr.tohoku.ac.jp/ja/org/research/02.html