Boron Removal from Metallurgical Silicon using Si-Al-Sn Ternary Alloy

Abstract

Numerous studies have searched for methods of Si refining for the production of photovoltaic cells to alleviate the global shortage of solar-grade Si. An alloy refining progress with a Si–Al–Sn melt was developed in this paper. To elucidate the relationship between Sn and B, the interaction parameter between them at 1173 K was determined as 2506 ± 143. This result indicated the strongly repulsive force between Sn and B. Thermodynamic analysis and experiments showed that the purification efficiency of Si–Al–Sn alloy weakened with increased Sn content in the melt.

Keywords:

• alloy refining
• segregation coefficient
• Si–Al–Sn alloy
• solar-grade silicon

ACKNOWLEDGEMENTS

The authors thank National Natural Science Funds of China (Grant No. 51104028). The authors are also grateful to Professor Martin A. Green (the University of New South Wales, Australia) for helpful discussions.

Notes

Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/lsst.