Molten salt electrodeposition of crystalline silicon (Si) films from silicon dioxide (SiO₂) in molten calcium chloride (CaCl₂)-calcium oxide (CaO) has been systematically investigated. The dissolution-electrodeposition mechanism was studied by cyclic voltammetry (CV), in situ X-ray diffraction (XRD), and in situ Raman spectroscopy. The results show that different silicate ions, including SiO₃²⁻, SiO₄⁴⁻, would be generated in molten salt and could be influenced by the molar ratios of additive SiO₂ and CaO, as well as the electrolytic parameters. In particular, with the increase of electrodeposition time, SiO₄⁴⁻ increased as the dominated silicate ions in molten salt. Furthermore, different current densities, time and substrates would also have vital influences on the electrodeposition process and the electrodeposited Si products. Si products with tunable morphology have been deposited on different substrates by adjusting the electrodeposition conditions. The deposited crystalline Si films exhibit homogeneous epitaxial structures, in particular, the epitaxial Si film grown on the 110-oriented Si wafer possesses uniform inverted pyramid structure. The ohmic resistivity test and microstructure analysis results show that the electrodeposited epitaxial crystalline Si films have the similar properties and characteristics as their single crystal Si wafer substrates. In general, the investigation of the dissolution-electrodeposition mechanism and its epitaxial growth behavior helps the progress of this one-step CaO-assisted dissolution-electrodeposition process for the production of epitaxial Si films.

已经系统地研究了熔融氯化钙（CaCl _{2 ）-氧化钙（CaO）中二氧化硅（SiO 2} ）的结晶硅（Si）膜的熔盐电沉积。通过循环伏安法 (CV)、原位X 射线衍射 (XRD) 和原位拉曼光谱研究了溶解-电沉积机理。结果表明，熔盐中会生成不同的硅酸盐离子，包括SiO ₃ ^2-、SiO ₄ ^4-，并且会受到添加剂SiO ₂和CaO的摩尔比以及电解参数的影响。特别是随着电沉积时间的增加，SiO ₄⁴⁻随着熔盐中占主导地位的硅酸盐离子的增加而增加。此外，不同的电流密度、时间和基板也会对电沉积过程和电沉积的硅产品产生重大影响。通过调整电沉积条件，已将具有可调形态的硅产品沉积在不同的基板上。沉积的结晶硅薄膜具有均匀的外延结构，特别是在110取向硅片上生长的外延硅薄膜具有均匀的倒金字塔结构。欧姆电阻率测试和微观结构分析结果表明，电沉积外延晶硅薄膜具有与其单晶硅晶片衬底相似的性能和特性。一般来说，