The role of oxidation on porous silicon photoluminescence and its excitation

Abstract

The effect of preparation regimes on the oxide composition, the number of dangling bonds, the photoluminescence and its excitation spectra have been investigated. The influence of the oxidation process during aging of porous silicon at ambient atmosphere and annealing in dry oxygen has been investigated via photoluminescence (PL), PL excitation (PLE), electron paramagnetic resonance (EPR) and X-ray photoelectron emission spectroscopy (XPS). Results indicate a direct correlation between the suboxide content and the PL intensity, while no correlation was noted between the PL intensity and the concentration of Si dangling bonds (non-radiative recombination centers). These results given further support to a suboxide-related color center as the source of the intense red luminescence.