Understanding Illumination Effect on Saturation Behavior of Thin Film Transistor

Abstract

Thin film transistor (TFT) has been a key device for planal drive display technology, and operating the TFT device in a saturation regime is particularly important for driving the light emission at a stable current. Considering the light emission reaches the TFT planal, it is thereby meaningful to understand the effect of illumination on TFT saturation behavior in order to improve the stability of light emission. Through experiments and simulations, our study shows that the drift current of photogenerated carriers can follow a saturation behavior when the channel conductance is dominated by charges induced by gate bias rather than the charges generated by photons, and vice versa. The obtained device physics insights are beneficial for developing TFT technologies that can drive light emission at a stable current.