We present the most common methods for preparation of porous silicon by means of the electrochemical etching of crystalline silicon in hydrofluoric acid and ethanol mixture. Although porous silicon is a material with many applications in various fields, the detailed mechanism of its electrochemical formation is not clarified yet.
Present models are based on experimental observations that the etching of crystalline silicon results in its partial dissolution and a release of hydrogen. Results of porous silicon electrochemical preparation in electrolyte of various HF concentration and gravimetric characterization are presented.