An Analytical Surface Potential and Effective Charge Density Approach Based Drain Current Model for Amorphous InGaZnO Thin-Film Transistors

An analytical surface-potential-based drain current model for amorphous indium–gallium–zinc–oxide (a-InGaZnO) thin film transistors (TFTs) is proposed by introducing an effective charge density approach in this paper. This gives two initial approximate values of the state and thermal voltage using dominant free total density, then obtains a high-precision one-exponent equivalent transformation three-exponent density. Based on approach, we have solved problem that physical meaning transition area regional method not clear one-piece surface potential solution to Poisson’s equation successfully derived. Furthermore, also explicitly derived from sheet I-V characteristics a-InGaZnO TFTs are reproduced above obtained model. Finally, accurate surface-potential verified experimental data, respectively. Good verification results prove could become suitable tool being embedded into circuit simulation.