High performance thin film transistors using low-temperature solution-processed Li-incorporated In2O3/ZrO2 stacks

Abstract

We improved the performance of low-temperature solution-processed thin film transistors (TFTs) by lithium doping of In2O3/ZrO2 gate stacks. Li incorporation into In2O3 reduced interface diffusion of ZrO2 and improved channel mobility. Enhanced crystallization of Li-doped In2O3 thin films as well as the small equivalent oxide thickness of ZrO2 were determined to be key factors in the observed improvement in device performance. An increase in the [Li+]/[In3+] ratio over the optimum value resulted in performance degradation, which we attributed to the formation of higher energy barriers due to grain boundaries.