▎ 摘　　要

The performance of a Schottky metal-semiconductor-metal (MSM) ultraviolet (UV) photodetector is limited by the insufficient gain and the uncontrollable noise current. A remarkable detectivity UV detector is demonstrated based on graphene oxide (GO) modified TiO2 with high gain and low noise. The GO layer completely prevents the flow of electrons forming a hole-only device thus decreasing the dark current and noise current. Furthermore, gain of the holes is promoted under UV illumination. Moreover, the GO layer efficiently extracts the holes therefore reducing the fall time. Under a bias of 6 V, the responsivity value reaches 826.8 A W-1 and the noise current is only 1.8 pA, thereby, our device provides a detectivity of 2.82 x 10(13) cm Hz(1/2) W-1 at 280 nm. The results offer an effective approach to enhance the performance of a UV detector.