Theoretical Analysis of Amorphous-Silicon Field-Effect-Transistors

Static characteristics of amorphous-silicon field-effect transistors have been analyzed under the assumption that the localized state density distribution (LSDD) in amorphous-silicon with respect to energy takes on an exponential or uniform form. In the case of an exponential LSDD, logarithmic drain current I D vs logarithmic gate voltage V G characteristics of the FET for large V G is found to be linear, the slope of which yields the characteristic temperature of the exponential LSDD. While, in the case of a uniform LSDD, log ( I D V G )– V G curves for large V G are found to be linear. The experimental data is qualitatively in good agreement with the theoretical results of the exponential LSDD.