An accurate CAD model for the ambipolar a-Si: H TFT

The ambipolar output drain current versus drain voltage characteristics of hydrogenated amorphous silicon thin-film transistors are modeled by a method intended for use in computer-aided design programs. An accurate model has been developed that uses a modified experimental sheet conductivity curve to predict the output drain characteristics over many orders of magnitude of the drain current in both the n-channel and p-channel modes of operation. Analytical expressions for the drain current are developed.