The Fabrication of Large-Area Upgraded Metallurgical Grade Multi-Crystalline Silicon Solar Cells in a Production Line

Abstract:

Upgraded metallurgical grade (UMG) silicon has been researched both on the purification methods and its material properties for years, indicating that it is the most promising choice as low-cost feedstock for photovoltaics. In this work, UMG multi-crystalline silicon (mc-Si) prepared by cold crucible refining and electron beam melting was investigated. Solar cells based on such silicon wafers were fabricated in a 156 x 156 mm² production line and their photovoltaic properties were characterized. Compared with the conventional mc-Si solar cells fabricated in the same commercial production line, the UMG mc-Si solar cells with two busbars presented higher average open circuit voltage (V_oc) and average fill factor (FF), which were 628 mV and 78.6 % separately. Although the UMG mc-Si solar cells showed a lower shot-circuit current density (J_sc) of 32.7 A/cm² in the average and an early reverse breakdown voltage at around 11 V which was due to higher impurities content. The average conversion efficiency of the UMG mc-Si solar cells reached 16.14 %, and the highest conversion efficiency was up to 16.31 %. In addition, the UMG mc-Si solar cells presented relatively low light induced degradation (LID) due to the material properties. Consequently, in consideration of low cost, our UMG mc-Si solar cells substantially met the requirements of commercial manufacturing and had a great potential application for photovoltaic industry.

• Periodical: Materials Science Forum (Volumes 743-744)
• Pages: 863-869
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.743-744.863
• Online since: January 2013
• Authors: Teng Chen, You Wen Zhao, Zhi Yuan Don, Jun Wang, Tong Liu, Hui Xie
• Keywords: Metallurigical, Multi-Crystalline Silicon (mc-Si), Solar Cell

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