Surface-Potential-Based Drain Current Model of Polysilicon TFTs With Gaussian and Exponential DOS Distribution

An explicit approximation for surface potential as a function of terminal voltages is developed for partially depleted polysilicon thin-film transistors. The resulting model has taken both Gaussian deep states and exponential tail states into account, which provides a complete modeling for surface potential. Furthermore, a drain current model based on terms of surface potential is proposed. Surface potential and drain current calculations are successfully verified by comparisons with numerical and experimental ones.