A new method for luminescent porous silicon formation: reaction-induced vapor-phase stain etch

摘要

We report a new method to form reproducible luminescent porous silicon layers in p-type and n-type substrates of low and high resisivity, with minimum apparatus and maximum simplicity. No equipment, formation of electrical contacts, illumination or addition of surfactants is needed. The porous silicon layer is formed by exposing the Si surface to the vapor generated by a dissolution reaction of a metal or Si in a HF/HNO_3 mixture. The PL spectra of the layers have peaks located from 1.85 eV to 2.1 eV. The current-voltage characteristics of Al/PS/p-Si/Al devices formed on these layers are rectifying and follow an exponential dependence at low forward bias and a power law at high forward bias.