电解精炼制备太阳级硅杂质行为研究  

Study on the removal of impurities in silicon by electrorefining

作　　者：贾明[1] 田忠良[1] 赖延清[1] 李劼[1] 伊继光[1] 闫剑锋[1] 刘业翔[1] 

机构地区：[1]中南大学冶金科学与工程学院,长沙410083

出　　处：《物理学报》2010年第3期1938-1945,共8页Acta Physica Sinica

基　　金：高等学校博士学科点专项科研基金(批准号:200805331120)资助的课题~~

摘　　要：在氟化物电解质体系下,把Cu与冶金级多晶硅熔配成合金作为阳极,利用杂质与硅析出电位的差别,通过控制电解工艺条件和参数,对冶金硅进行了电解精炼提纯研究.结果表明,阳极铜硅合金对硅中的杂质有滞留作用,且在大电流密度下Cu不会随着合金中硅的减少而溶解到电解质中;预电解对电解质净化效果明显,XRF分析表明P含量从10降为1ppmw;阴极电沉积的硅呈颗粒状,并与电解质混杂,随着电解时间的延长,分散的硅的颗粒聚集成1—2cm直径的大尺寸硅球.ICP-AES分析表明,最后得到的产物硅与冶金级硅相比,硼含量由12·7降低到2·2ppmw,磷含量由98·6减少到4·1ppmw,说明电解精炼除杂进行多晶硅的提纯是有效和可行的.The rapid expansion of the photovoltaic （PV） all market requires an abundant supply of silicon feedstock. A creative and simple three-layer method and apparatus have been developed for electrorefining of silicon for solar cell application. The anode is solidified from a hypereutectic solution of copper and metallurgical grade silicon. At the tempera ture of operation （950℃）, elements which have an electronegativity greater than that of silicon （e.g., Cu, B, P, etc.） will remain at the anode and then the Cu- Si phase can be used under certain conditions as a filter for purifying silicon with an electrorefining process. Two typical morphologies of deposit are found as coherent layer and osteoporosis layer, and deposited silicon particles with different grain size are found embedded in electrolyte. Furthermore, with increasing operation time and current density, re-combination of silicon particles is revealed which yields a larger-sized silicon ball of 1—2 cm in size. The analysis of the anode feed and refined silicon shows a remarkable reduction of B and P concentration, from 12.7 to 2.2 ppmw and 98.6 to 4.1 ppmw, respectively.

关 键 词：多晶硅 太阳电池 电解精炼 定向凝固 

分 类 号：TN304.05[电子电信—物理电子学]