Indexed by:Journal Article

Date of Publication:2018-11-01

Journal:SOLAR ENERGY MATERIALS AND SOLAR CELLS

Included Journals:SCIE

Volume:186

Page Number:50-56

ISSN:0927-0248

Key Words:HPMC-Si; UMG-Si; Seed-assisted; Segregation behavior; Conversion efficiency

Abstract:High-performance multicrystalline silicon (HPMC-Si) wafers were produced using upgraded metallurgical-grade silicon (UMG-Si) materials in the seed-assisted growth system at the industrial scale. The HPMC-Si wafers yielded low dislocation density and fine and uniform grain size. We observed that fine grain size suppressed the segregation effect of metal impurities. The effective segregation coefficients of Fe, Al, and total metal impurities approximated 0.265, 0.492, and 0.386, respectively. The concentration of impurities within 10-90% of the solidified fraction in the ingot was relatively uniform based on the improved crystal structure control. The heterogeneous nucleation mechanism of concave and planocera nucleation was discussed intensively. HPMC-Si wafers were obtained under the crystal structure control coupled with behavior regulation of impurity segregation in the seed-assisted growth system. The average conversion efficiency of Al-BSF processed solar cells reached 18.65%.