Photo Induced Negative Bias Instability of Zinc Oxide Thin-Film Transistors

Abstract

The relationship between the photo leakage current and photo induced bias stress instability of zinc oxide thin-film transistors (ZnO TFTs) was investigated. As reported in our previous work, electron traps existing near the valence band (EV) affect the photo leakage current of ZnO TFTs. When a negative bias stress was applied under light irradiation, the tendency of the transfer curves to shift in the negative Vgs direction was consistent with the results of the photo leakage current. The electron traps existing near the EV affected not only the photo leakage current, but also the photo induced negative bias stress instability of the ZnO TFTs.