Investigation of the Photon-Enhanced Bias Instability of InGaZnO TFTs for the Application of Transparent AM-OLED Displays

摘要

We investigated the effect of the light-induced bias instability of indium-gallium-zinc oxide(IGZO) thin film transistors. The IGZO TFT exhibited the excellent subthreshold gate swing of 0.12V/decade, Vth of -0.5V, and high Ion/off ratio of >10~9 as well as a high field-effect mobility of 26.7 cm~2/Vs. The Vth is not changed after positive bias illumination stress (PBIS) for 10000sec. However, the Vth is -8V after negative bias illumination stress (NBIS) for 10000sec. This phenomenon can be attributed the trapping of the photon-induced charges into the gate dielectric/active interface. We fabricated transparent AM-OLED driven by highly stable bottom gate IGZO TFT array.