  We have studied the dark conductivity of a broad microstructural range of
plasma deposited single phase undoped microcrystalline silicon films in a wide
temperature range (15 - 450K) to identify the possible transport mechanisms and
the interrelationship between film microstructure and electrical transport
behavior. Different conduction behaviors seen in films with different
microstructures are explained in the context of underlying transport mechanisms
and microstructural features, for above and below room temperature
measurements. Our microstructural studies have shown that different ranges of
the percentage volume fraction of the constituent large crystallite grains
(Fcl) of the microcrystalline silicon films correspond to characteristically
different and specific microstructures, irrespective of deposition conditions
and thicknesses. Our electrical transport studies demonstrate that each type of
microcrystalline silicon material having a different range of Fcl shows
different electrical transport behaviors.
