Regenerative Electroless Etching of Silicon

Abstract

Regenerative electroless etching (ReEtching), described herein for the first time, is a method of producing nanostructured semiconductors in which an oxidant (Ox₁ ) is used as a catalytic agent to facilitate the reaction between a semiconductor and a second oxidant (Ox₂ ) that would be unreactive in the primary reaction. Ox₂ is used to regenerate Ox₁ , which is capable of initiating etching by injecting holes into the semiconductor valence band. Therefore, the extent of reaction is controlled by the amount of Ox₂ added, and the rate of reaction is controlled by the injection rate of Ox₂ . This general strategy is demonstrated specifically for the production of highly luminescent, nanocrystalline porous Si from the reaction of V₂ O₅ in HF(aq) as Ox₁ and H₂ O₂ (aq) as Ox₂ with Si powder and wafers.

Keywords: electrochemistry; electroless etching; nanostructures; photoluminescence; porous silicon.