Low-cost solar grade silicon purification process with Al–Si system using a powder metallurgy technique
Low-cost solar grade silicon purification process with Al–Si system using a powder metallurgy technique
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DOI：
10.1016/j.seppur.2010.11.016
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发表时间：
2011-02
影响因子：
8.6
通讯作者：
X. Gu;Xuegong Yu;Deren Yang
中科院分区：
文献类型：
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作者：
X. Gu;Xuegong Yu;Deren Yang
硅太阳能电池是最清洁、最有潜力的可再生资源之一。然而，高昂的原材料成本阻碍了硅太阳能电池的发展。本文采用粉末冶金技术，研究了一种低成本太阳能级硅的提纯工艺。研究发现，通过调节外压和保护气氛，可以在较低的温度下实现Al-Si混合粉末的合金化。根据铝硅熔体中硅的形态特征，探讨了铝硅熔体中硅的提纯机理。提纯硅产品的杂质含量可控制在很低的水平（≤ 3ppmw）。同时，阐明了采用粉末冶金技术提纯硅产品的收率高于无外压或无保护气氛的常规铝硅提纯技术。该工艺具有为光伏产业提供低成本太阳能级硅原料的潜力。
Silicon solar cell is one of the cleanest and most potential renewable resources. However, the high cost of raw material is impeding the development of silicon solar cell. In this paper, we have investigated a purification process designed for low-cost solar grade silicon with Al–Si system, using a powder metallurgy technique. It is found that by modulating the external pressure and/or protection ambient, the alloying of Al–Si powder mixture is easily accomplished at a relatively lower temperature. The mechanism of Si products purified from the Al–Si melt has been discussed based on their morphological characterizations. The impurity contents of the purified Si products can be controlled at a very low level (∼3ppmw). Meanwhile, the yield of the purified Si products using the powder metallurgy technique is clarified to be higher than that of the conventional Al–Si purification technique without external pressure or protecting ambient. The process is quite potential of providing low-cost solar grade silicon feedstock for photovoltaic industry.