A High-Performance UVA Photodetector Based on Polycrystalline Perovskite MAPbCl(3)/TiO(2) Nanorods Heterojunctions

The application of TiO(2) nanorods in the field of ultraviolet (UV) photodetectors is hindered by a high dark current, which is attributed to crystal surface defects and intrinsic excitation by carrier thermal diffusion. Here, a photodetector based on polycrystalline perovskite MAPbCl(3)/TiO(2) nanorods heterojunctions has been fabricated to overcome the shortcoming. The structure was composed of horizontal MAPbCl(3) polycrystalline and vertically aligned TiO(2) nanorods array. Many localized depletion regions at the MAPbCl(3)/TiO(2) interface can reduce the dark current. The TiO(2)/MAPbCl(3) detector shows high performance including a high ratio of light-dark current of about six orders of magnitude, which is much larger than that of the TiO(2) detector. This study indicates the potential in the TiO(2)/MAPbCl(3) heterojunction to fabricate high-performance UV detectors.