Electrodeposition of Crystalline and Photoactive Silicon Directly from Silicon Dioxide Nanoparticles in Molten CaCl2

Silicon for solar cells: Relatively pure, polycrystalline, and photoactive silicon was directly obtained from silicon dioxide nanoparticles (NP) by electrodeposition in molten CaCl2 salt on a silver electrode (see picture). This process is based on the formation of liquid droplets of a silver–silicon eutectic alloy and the continuous reduction of SiO2 to silicon. The deposited silicon shows a p‐type behavior in photoelectrochemical measurements.