Silicon surface texturing by electro-deoxidation of a thin silica layer in molten salt

Abstract

A new method of silicon surface texturing is reported, which is based on thin silica layer electrochemical reduction in molten salts. A thermal silica layer grown on p-type silicon was potentiostatically reduced in molten calcium chloride at 850 °C. Typical nano–micro-formations obtained at different stages of electrolysis were demonstrated by SEM. X-ray diffraction measurements confirmed conversion of the amorphous thermal silica layer into crystalline silicon. The proposed approach shows promise in photovoltaic applications, for instance, for production of antireflection coatings in silicon solar cells.