Distribution of the density of electronic states in the energy gap of microcrystalline hydrogenated silicon

Photomodulation spectroscopy was applied to a study of the distribution of the density of electronic states in the energy gap of microcrystalline hydrogenated silicon (muc-Si:H) with a varied level of boron doping. The information on the density-of-states distribution was extracted by analyzing temperature dependences of the constant and modulated components of photoconductivity in a sample exposed to modulated light. The distributions of the density of electronic states in the upper and lower halves of the energy gap of muc-Si:H were determined. The study demonstrated that the tail of the density-of-states distribution near the valence band is less steep than that near the conduction band. (C) 2004 MAIK Nauka/Interperiodica.