三层液电解精炼提纯冶金级硅研究  

PURIFICATION AND CHARACTERIZATION OF METALLURGICAL GRADE SILICON BY THREE-LAYER ELECTROREFINING

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

机构地区：[1]中南大学冶金科学与工程学院,长沙410083

出　　处：《太阳能学报》2010年第8期1068-1072,共5页Acta Energiae Solaris Sinica

基　　金：高等学校博士学科点专项科研基金(200805331120);湖南省研究生科研创新项目;中南大学研究生学位论文创新基金

摘　　要：在氟化物熔盐电解质体系下,把Cu与冶金级多晶硅熔配成合金作为阳极硅源,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:电解过程平稳,且电流效率保持95%以上;阴极电沉积硅呈颗粒状,尺寸约为100μm;随着电解时间的延长,分散的硅的颗粒有聚集成大尺寸硅球的趋势。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12.7mg/kg降低到2.4mg/kg,磷含量由98.6mg/kg减少到4.3mg/kg。A creative and simple three-layer method and apparatus were developed for electmrefining of silicon for solar cells. According to the larger liquid electrode reactive surface, high current density was possible during electmrefining and current efficiency above 95% was obtained with optimum K2SiF6 concentration of 10wt%-15wt%. Two typical deposited morphologies were found for coherent layer and osteopomsis layer, and around 100μm deposited silicon particles were found in electrolyte. Furthermore, with increasing operation time and current density, a larger size silicon ball of 2cm was yielded by re-combination of silicon particles. The ICP-AES analysis indicates that refined silicon shows a re-markable reduction of B and P concentration, from 12.7 to 2.4mg/kg and 98.6 to 4.3m/kg, respectively.

关 键 词：多晶硅 熔盐 电解精炼 电流效率 定向凝固 

分 类 号：TF111.522[冶金工程—冶金物理化学]