Compositional dependence of photoluminescence spectra in hydrogenated amorphous silicon-sulfur alloys

Photoluminescence (PL) measurements were performed on films of amorphous silicon-sulfur alloys with varying sulfur contents. The incorporation of sulfur leads to a decrease in low temperature PL efficiency, indicating an increase in the overall defect density. The full width at half maximum increases while the PL peak position shows no significant change. Together with previous results from photocurrent spectroscopy it is concluded that the valence band tails broaden. In addition PL properties were measured as a function of temperature. With increasing sulfur content a progressively weaker dependence of PL efficiency and peak position on temperature is found.