Simulation of Amorphous-InGaZnO Thin Film Transistors Driven OLED Pixel Circuit

The problem of OLED current decrease with threshold voltage( Vth) shift of a-IGZO TFTs still remains to be solved. In this paper,we continued to investigate the compensation effect for Vth shift in AMOLED pixel circuits based on a-IGZO TFTs. With the device models extracted from the experimental data on a-IGZO TFTs prepared in our lab,two kinds of pixel circuits,i. e 2T1 C and4T1C were comparatively studied. The results show that 4T1 C pixel circuit has excellent compensation effect for bias-stress instability,and the increasing storage capacitor and W /L of driving TFTs might lead to better holding capacity of this circuit.