Effect of Preparation Conditions on Evaluation of Porous Silicon’s Morphology and Coalition with its Optical Property

Abstract

This article presents the dependence of porous silicon (PSi) morphology on preparation conditions and the coalition between morphology and optical properties. p-type (100) silicon wafers were etched in an electrolyte incorporating 1:1 (by volume) ethanol and aqueous solution of hydrofluoric acid (40 wt. %) at various etching current densities and times. Detailed information about evolution of PSi morphology with variation of preparation conditions was investigated by field emission scanning electron microscopy (FESEM) and atomic force microscope (AFM). The results have shown that the pore sizes of PSi are gradually increasing, and the thicknesses of PSi layer are increased with the speed of about 11-12 nm/s as the etching duration increased. Addition, the optimal photoluminescence of PSi is achieved in room temperature with the strongest photoluminescence spectra when the corrosion current density was 30 mA / cm2 with 30 min etching time.