Stain etching of silicon with V2O5 and FeCl3: Effect of etching time on photoluminescence

Abstract

Visible photoluminescence (PL) was observed in porous silicon (pSi) layers etched by a solution of hydrofluoric acid containing Fe3+ and VO2+ ions. Stain films are much easier to produce than anodic etched films and require no special equipment. The role of structures reduced to nano range play a key role in emission of orange luminescence from the samples. Our study shows that the samples etched using VO2+ and Fe3+ oxidants exhibit stable orange luminescence under UV illumination. Also, etching for a particular time keeping same quantity of HF and different ratio of oxidant, a difference in peak was observed. The obtained morphological and optical results have been compared with the porous structure obtained after metal assisted etching on similar silicon substrates. The SEM images of samples fabricated with both the techniques have revealed that samples prepared with MACE results in more uniform order in structure formation.