Raman Scattering in Electrochemically Prepared Porous Silicon

Porous silicon of various porosity has been prepared by electrochemical etching of silicon with different doping levels. Room temperature photoluminescence in the visible range is observed from the powder scraped from the top layer of the etched samples. In this paper we use Raman scattering to characterize the source of the high efficiency photoluminescence. We have also studied microcrystalline silicon prepared by thermal annealing of hydrogenated amorphous silicon/amorphous silicon oxide multilayers.