Modeling of amorphous InGaZnO thin film transistors using an empirical mobility function based on the exponential deep and tail states

Abstract

We demonstrate that the voltage-dependent average mobility of In–Ga–Zn–O (IGZO) thin-film transistors (TFTs) can be excellently fitted by an empirical mobility function based on the exponential density of deep and tail states. The proposed mobility function needs only 5 parameters and does not need the concept of the threshold voltage which is inherently ambiguous in amorphous oxide TFTs. Both the transfer and output curves of the device are well reproduced by integrating the mobility function.