Highly Stable Zinc Oxynitride Thin-Film Transistors with Field-Effect Mobility Exceeding 100 cm2/Vs

Abstract

Ultra definition, large-area displays with three-dimensional visual effects represent the megatrend in the current and future display industry. On the hardware level, such a “dream” display requires faster pixel switching and higher current driving, which in turn necessitate thin-film transistors (TFTs) with high field-effect mobility values. Amorphous oxide semiconductors (AOSs) such as In-Ga-Zn-O have recently emerged as candidate materials that may satisfy the above requirements, but the trade-off between device performance (i.e., field-effect mobility) and stability (i.e., threshold voltage shift) under illumination critically limits their usability. Here we report on amorphous-like Zn-O-N (ZnON) TFTs that are Indium-free but still exhibit high field-effect mobility exceeding 100 cm2V-1s-1. Such devices have a superior stability over conventional AOS devices with respect to light radiation, which can be understood by studying the fundamental electronic band structure of ZnON. It is anticipated that high-mobility and high-stability ZnON TFTs will be extensively applied to next-generation flat-panel displays.