Influence of iron, aluminum, calcium, titanium and vanadium impurities removal from silicon based on Cu-catalyzed chemical leaching
Influence of iron, aluminum, calcium, titanium and vanadium impurities removal from silicon based on Cu-catalyzed chemical leaching
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DOI：
10.1016/j.jmrt.2020.12.043
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
F. Xi;Zhao Zhang;Shaoyuan Li;Wenhui Ma;Xiuhua Chen;Zhengjie Chen;K. Wei;Y. Lei;Bin Luo
中科院分区：
文献类型：
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作者：
F. Xi;Zhao Zhang;Shaoyuan Li;Wenhui Ma;Xiuhua Chen;Zhengjie Chen;K. Wei;Y. Lei;Bin Luo
本文研究了新型Cu催化化学浸出（CuCCL）处理下的硅净化过程，考察了不同硅粒度、HF浓度、浸出时间、h2o2浓度、Cu(NO3)2浓度和浸出温度对硅净化过程的影响。分析了硅中典型杂质析出物，发现MG-Si原料中Fe、Al、Ca、Ti和V的主要杂质主要以Si2Fe、Si-Fe-Al、Si-Fe-Al - Ca和Si-Fe-Al - Ti - V相存在。结果表明，CuCCL处理能有效去除MG-Si中主要杂质Fe、Al、Ca、Ti、V，特别是Ca、Ti、V。在适当的实验条件下，MG-Si中主要杂质Fe、Al、Ca、Ti、V的去除率分别达到99.38%、98.64%、100%、100%、100%。研究发现，在CuCCL过程中，硅表面的杂质促进了多孔结构的形成，而生成的多孔结构又使更多的杂质暴露在酸蚀剂中，从而促进了硅表面杂质的去除。此外，通过揭示沉积和蚀刻过程中杂质析出物的演变，获得了CuCCL过程中杂质析出物的浸出行为。本研究的高效硅净化效果可能为实现低成本的太阳能级硅提供一些新的策略。
In this work, silicon purifying process based on the novel Cu-catalyzed chemical leaching (CuCCL) treatment has been investigated as a function of different silicon particle size, HF concentration, leaching time, H2O2concentration, Cu(NO3)2concentration and leaching temperature. Typical impurity precipitate in silicon was analyzed, which revealed that the main impurities of Fe, Al, Ca, Ti, and V mainly exist as Si2Fe, Si–Fe–Al, Si–Fe–Al–Ca, and Si–Fe–Al–Ti–V phases in the MG-Si feedstock. The results showed that the main impurities Fe, Al, Ca, Ti, and V can be effectively eliminated by the CuCCL treatment, especially for Ca, Ti and V. In the appropriate experiment conditions, the removal of main impurities Fe, Al, Ca, Ti, and V from MG-Si significantly reached to 99.38%, 98.64, 100%, 100%, and 100%, respectively. It was found that the impurities on the silicon facilitated the formation of porous structures during the CuCCL process, and the generated porous structures further exposed more impurities to the acid etchants, which promote the impurity removal from silicon. Furthermore, the leaching behaviors of impurity precipitates in the CuCCL process were obtained through revealing their evolution during deposition and etching steps. The high-efficient silicon purification effect of this study may bring some new strategy for achieving the low-cost solar grade silicon.