Anodisation Time-Related Nanocrystallite Size of Porous Silicon Template Studied by Raman Spectroscopy, Photoluminescence and Fourier Transforms Infrared Spectroscopy

Abstract

Nanostructured Porous Silicon templates (NPSiT) were prepared by photo-electrochemical anodization of p-type crystalline silicon in HF electrolyte at different etching time. Five samples were prepared with etching time varied from 10 to 50 minutes at 20 mA/cm2 of current density. The effects of etching time on NPSiT were observed based on nanocrystallite size, photon energy and surface distribution. These studied was demonstrated by Raman spectroscopy, photoluminescence (PL) and Fourier transforms infrared spectroscopy (FTIR). It was found that NPSiT sample with large pore diameter, which is smaller nanocrystallites size of Si between pore. The optical properties of NPSiT were investigated by photoluminescence (PL) and PL peak broadening and shifting towards higher energy can be observed with increasing etching time. The optimum etching time with respect to PL intensity was obtained at 30 minutes, for which uniform pores and a shift of the PL maximum to a higher energy of 1.9 eV is observed.