The Stoichiometry of Electroless Silicon Etching in Solutions of V2O5 and HF

Performance by an oxidant in a leading role: In the electroless etching of silicon to form nanocrystalline porous‐silicon thin films, the oxidant extracts one electron from the silicon valence band to initiate etching and then a second from the conduction band to suppress H2 formation. This discovery overturns the conventional wisdom regarding the role of the oxidant in stain etching, the stoichiometry of which was derived from the UV/Vis spectra shown.