Jingwei Li1,2,3, Juncheng Li4, Yinhe Lin5, Jian Shi1, Boyuan Ban1, Guicheng Liu6, Woochul Yang6, Jian Chen1. 1. Key Laboratory of Photovoltaic and Energy Conservation Materials, Institute of Applied Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China. 2. State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, China. 3. Department of Materials Science and Engineering, University of Toronto, Toronto, ON M5S 3E4, Canada. 4. School of Material Science and Engineering, Jiangsu University, Zhenjiang 212013, China. 5. School of Chemistry Engineering, Yangtze Normal University, Chongqing 408000, China. 6. Department of Physics, Dongguk University, Seoul 04620, Korea.
Abstract
Separation of refined silicon from Al-Si melt is still a puzzle for the solvent refining process, resulting in considerable waste of acid and silicon powder. A novel modified Czochralski method within the Al-Si alloy is proposed. After the modified Czochralski process, a large amount of refined Si particles was enriched around the seed crystalline Si and separated from the Al-Si melt. As for the Al-28%Si with the pulling rate of 0.001 mm/min, the recovery of refined Si in the pulled-up alloy (PUA) sample is 21.5%, an improvement of 22% compared with the theoretical value, which is much larger 1.99 times than that in the remained alloy (RA) sample. The content of impurities in the PUA is much less than that in the RA sample, which indicates that the modified Czochralski method is effective to improve the removal fraction of impurities. The apparent segregation coefficients of boron (B) and phosphorus (P) in the PUA and RA samples were evaluated. These results demonstrate that the modified Czochralski method for the alloy system is an effective way to enrich and separate refined silicon from the Al-Si melt, which provide a potential and clean production of solar grade silicon (SoG-Si) for the future industrial application.
Sepan class="Chemical">ran class="Chemical">tion of refined silicon from Al-Simelt is still a puzzle for the solvent refining process, resulting in considerable waste of acid and silicon powder. A novel modified Czochralski method within the Al-Sialloy is proposed. After the modified Czochralski process, a large amount of refined Si particles was enriched around the seed crystalline Si and separated from the Al-Simelt. As for the Al-28%Si with the pulling rate of 0.001 mm/min, the recovery of refined Si in the pulled-up alloy (PUA) sample is 21.5%, an improvement of 22% compared with the theoretical value, which is much larger 1.99 times than that in the remained alloy (RA) sample. The content of impurities in the PUA is much less than that in the RA sample, which indicates that the modified Czochralski method is effective to improve the removal fraction of impurities. The apparent segregation coefficients of boron (B) and phosphorus (P) in the PUA and RA samples were evaluated. These results demonstrate that the modified Czochralski method for the alloy system is an effective way to enrich and separate refined silicon from the Al-Simelt, which provide a potential and clean production of solar grade silicon (SoG-Si) for the future industrial application.
Entities:
Keywords:
Al–Si alloy; boron and phosphorus removals; distribution mechanism; modified Czochralski method; refined Si separation