Noncontact crucible (NOC) method to grow Si ingots with a larger diameter than 45 cm is proposed as a novel crystal growth method, which has several merits comparing with the Czochralski (CZ) method such as larger diameter ratio defined as crystal diameter / crucibles diameter (near 0.9) and lower oxygen concentration. The solar cells prepared by the present Si ingots has the highest conversion efficiency of 19.6% and the average conversion efficiency of 18.9% using the same solar cell structure and process to obtain the conversion efficiency of 20.0% for CZ wafers. Kazuo Nakajima and coworkers at JST succeeded to control temperature in NOC method by using a carbon heat holder.
That is expected to lead about 30% cut in costs for manufacturing a high quality Si wafer.
Researcher Information
MEXT FUTURE-PV Innovation (FUkushima Top-level United center for Renewable Energy research — PhotoVoltaics Innovation)
Research Theme “Si Nano-Wire Solar Cells”
Presentation Information
K. Nakajima, S. Ono, R. Murai, Y. Kaneko, F. Jay, Y. Veschetti, and A. Jouini. “Growth of Si ingots for solar cells with 33 cm diameter using a small crucible with 40 cm diameter by Noncontact crucible method”. PVSEC-25, BEXCO, Busan, Korea, November 15-20 (2015).
Contact
[About Research]
Kazuo Nakajima, Ph.D.
Team Leader, FUTURE-PV Innovation, JST
E-mail: 
URL: http://www.jst.go.jp/renewable/en/index.html
[About Program]
Terutake Koizumi, Ph.D.
FUTURE-PV Innovation, Department of Green Innovation, JST
E-mail: