New Optical Properties of Porosity Layer Controlled by Laser-Induced Etching

Three different power densities and fixed irradiation times have been used to prepare porous silicon using laserinduced etching process to control the size and shape of nanostructure. There are new optical properties of porous silicon. Scanning electron microscopy was used to study surface morphology after the etching process. Porous silicon was characterized using spectroscopic studies. There is shift in Raman peak position as a result of the increase of power densities. The photoluminescence spectra (PL) tend to blue shift in peak position due to etching conditions. Raman and PL data were explained using appropriate dimensional confinement of size and size distributions of nanocrystallites. There has been an agreement between the results of Raman and PL spectroscopic studies of the PS samples.