Analysis of the Meyer-Neldel Rule Based on a Temperature-Dependent Model for Thin-Film Transistors

Abstract

Based on the Pao–Sah model and considering the double exponential distribution of traps density of states (DOS) in the bandgap, a unified drain current model is derived for thin-film transistors (TFTs). It is verified by fitting experimental $I$ – $V$ characteristics of both a-InGaZnO TFTs and two types of polycrystalline Si TFTs of different technologies, measured at different drain voltages and temperatures with a set of model parameters independent of temperature. Temperature dependence of TFT subthreshold current follows the well-known Meyer–Neldel rule (MNR). It is clarified that the proposed $I$ – $V$ model is inherently consistent with the MNR, without any intentionally introduced assumptions or parameters. Key parameter, the MN energy, is associated with the inverse slope of the deep traps DOS distribution, while another key parameter, the activation energy, is the averaged energy difference between the band edge and the quasi Fermi-level along the channel depth.