  We report on the phototransport properties of microstructurally well
characterized plasma deposited highly crystallized microcrystalline silicon
films. The steady state photoconductivity was measured on a wide
microstructural variety of single-phase undoped microcrystalline silicon films
as a function of temperature and light intensity. The band-tail parameter (kTc)
was calculated from the photoconductivity light intensity exponent values at
different temperatures for a range of quasi-Fermi energies. The localized tail
states distribution in the vicinity of conduction band edge of microcrystalline
silicon was estimated using the values of kTc. Our study shows that
microcrystalline silicon films possessing dissimilar microstructural attributes
exhibit different phototransport behaviors, which are linked to different
features of the density of states maps of the material.
