Effective density of states map of undoped microcrystalline Si films: a combined experimental and numerical simulation approach

The phototransport properties of plasma deposited highly crystalline undoped hydrogenated microcrystalline silicon films were studied by measuring the steady state photoconductivity (SSPC) as a function of temperature and light intensity. The films possessing different thicknesses and microstructures had been well characterized by various microstructural probes. Microcrystalline Si films possessing dissimilar microstructural attributes were found to exhibit different phototransport behaviors. We have employed numerical modeling of SSPC to corroborate and further elucidate the experimental results. Our study indicates that the different phototransport behaviors are linked to different features of the proposed density of states maps of the material which are different for microcrystalline Si films having different types of microstructure.