太阳能电池中B作为受主杂质在硅基体中的含量不得超过0.3×10-6.造渣氧化精炼是有效的除硼方法之一,综述了CaO-SiO2基造渣剂除硼的研究进展.研究发现,向融硅中连续不断地加入60％ CaO-40％ SiO2造渣剂,原料硅中的B含量可从40×10-6降至1×10-6.硼分离系数(LB)在低碱度(0.55)到高碱度(1.21)呈明显抛物线形状.添加少量CaF2会增加渣的实际碱度比,但过量的CaF2则起到稀释渣的有效成分和降低渣熔点的作用.本实验室利用CaO-SiO2-CaF2体系进行造渣实验也获得很好的除硼效果.%As an acceptor of solar cell, boron concentration in silicon should be less than 0. 3X10-6. Slag refining is one of the effective methods for boron removal. Research progress on boron removal by slag refining with CaO-SiO2 based slag system has been summarized. Boron in silicon can be decreased from 40 X 10-6 to 1X 10-6 by continuously adding slag of 60% CaO-40% SiO2 into molten silicon. The partition coefficient of boron, Lb, shows an obvious parabolic curve relationship with basicity of 0. 55 to 1. 21. The addition of small amount of CaF2 will enlarge the basicity of slag, while excess amount of CaF2 will dilute the active ingredients of slag and decrease the melting temperature of slag. Slag refining with CaO-SiO2-CaF2 has been carried out by the present authors, and good boron removal has been achieved as well.
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