A simple model for the threshold voltage of polysilicon TFT which include both grain and grain boundary trapping states

In this paper, a simple procedure for approximate evaluation of threshold voltage of polysilicon TFT is reported. This procedure takes into account the effect of total depletion of polycrystalline grains. Also, the presented model includes both grain and grain boundary trapping states, and assumes different distributions of these states in the energy gap. Calculations of threshold voltage dependencies on grain size, dopant concentration, and temperature have been reported and discussed.