The dependence of hydrofluoric acid concentration during anodization on photoluminescence of porous silicon

Abstract

The mixture of hydro¯uoric (HF) acid and ethanol is used as an electrolyte during anodization of silicon. We investigated the effect of the ratio of HF acid to ethanol on photoluminescence. It is concluded that porous silicon anodized with the electrolyte containing 35 or 40% HF acid provides strong photoluminescence. The fact implies the existence of a chemical reaction including ethanol during anodization other than electrochemical reaction. q

An Overview of the Evolution of the Porous Silicon material: A review

“…The images show that PSi has a sponge like structure and the porous width increased as the etching time increased, as noted in Table (3). As can be seen from Figure (10), the width and porosity of the pores increased with increasing etching time when HF concentration and current density were kept constant. This is attributed to the interaction of chemical dissolution of PSi layer in HF solution leading to PSi owing to its large surface area.…”

“…They exhibited a shift in the luminescence spectrum when the growth conditions changed. Furthermore, the effect of HF concentration mixed with ethanol on PL was investigated by Ohmukai and Collins in 2001 [10]. They concluded that the strong PL was produced when the PSi anodized with the electrolyte containing 35 or 40% HF acid Foll et al in 2002 [11] showed that photo-generation in heterostructures (Ni/PSi/p-Si/Ni) occurs in both regions of a thin PSL and Psi base.…”