A self-consistent analysis of temperature-dependent field-effect measurements in hydrogenated amorphous silicon thin-film transistors

Abstract

We calculated a more accurate density of states (DOS) profile from field-effect (FE) measurements in hydrogenated amorphous silicon thin-film transistors, taking into account the anomalously changing conductivity prefactor in accordance with the Meyer–Neldel (MN) rule. We present a self-consistent analysis of the density of gap states profile, where the MN rule is, for the first time, properly considered in relation to the nonuniform shift of the Fermi level as induced by the field effect. Moreover, the calculation yields the correct flat-band voltage and the corresponding flat-band activation energy. The determination of conductivity activation energies free from any initial band bending effects is of importance in all types of transport measurements.