Influence of surface states on the photoluminescence from silicon nanostructures

Abstract

We report a phenomenological model to analyze the room temperature photoluminescence (PL) spectra observed from silicon nanostructures. We have explicitly incorporated the effects of localized surface states along with quantum confinement effects to obtain an analytical expression for the photoluminescence spectra. Normal as well as log-normal crystallite size distributions are considered for PL intensity calculations. Experimental PL data on a variety of nanocystalline silicon structures with directly measured crystallite size distribution have been analyzed. Our model is able to deduce size distribution parameters from PL data that agree well with the experiments.