Explicit solution of channel potential and drain current model in symmetric double-gate polysilicon TFTs

Abstract

A physical and explicit surface potential model for undoped symmetric double-gate polysilicon thinfilm transistors has been derived based on an effective charge density approach of Poisson's equation with both exponential deep and tail state terms included. The proposed surface potential calculation is single-piece and eliminates the regional approach. Model predictions are compared to numerical simulations with close agreement, having absolute error in the millivolt range. Furthermore, expressions of the drain current are given for a wide range of operation regions, which have been justified by thorough comparisons with experimental data.