Bias stability of solution-processed In2O3 thin film transistors

Abstract

We report the effect of bias stress on the drain current and threshold voltage of n-channel thin-film transistors based on solution processed In _2 O _3 layers. Application of a positive gate bias for variable time-periods led to displacements of the transfer curves in the positive gate bias direction. On switching off the gate bias, the transfer curves returned close to their pre-stress state on a timescale similar to that when the gate bias was switched on. The time dependence of the threshold voltage shift is described well by a stretched-exponential model. The temporal behaviour of the threshold voltage shifts is consistent with charge trapping as the dominant effect, although some defect formation cannot be ruled out.

Keywords

• solution processed
• indium oxide TFTs
• bias stress
• threshold voltage