A high-performance self-powered UV photodetector based on SnO2 mesoporous spheres @ TiO2

A novel self-powered UV photodetector (UVPD) based on the photoelectrochemical cell (PECC) has been constructed using the TiO 2 coated SnO 2 mesoporous spheres (SnO 2 -MS@TiO 2 ). This self-powered UVPD displays a higher photocurrent density compared to the UVPD with the pure SnO 2 -MS. By means of external quantum efficiency (EQE), UV-vis absorption, and electrochemical impedance measurements, we scrutinize the intrinsic role of the TiO 2 coating layer on the photocurrent enhancement. Under UV irradiation, this UVPD exhibits a high on/off ratio of 11519, a fast rise time of 0.007 s and decay time of 0.006 s, together with the excellent visible-blind characteristic and linear optical signal response. The self-powered photodetector is a promising candidate for application in high-sensitivity and high-speed UVPDs.