Ultraviolet photoresponse of ZnO thin-film transistor fabricated at room temperature

Abstract

Transparent thin-film transistor (TFT) with ZnO film as a channel layer is fabricated at room temperature. ZnO film has a high absorption in the UV region and ZnO-TFT is sensitive to the UV illumination. We investigate the ultraviolet photoresponse of ZnO-TFT and find that the illumination with 254 nm light results in an evident photoresponse. The residual conductivity is observed in ZnO channel even the UV light was removed one week before. The UV illumination can induce the formation of oxygen vacancy defects which will act as donors in ZnO channel.