ZnO/TiO₂ Nanorods Heterojunction Ultraviolet Photodetector

Abstract

TiO 2 nanorods (NRs) were synthesized on fluorine-doped tin oxide (FTO) glass substrates by typical hydrothermal method, and then ZnO film deposited to form ZnO/TiO 2 NRs heterojunction ultraviolet (UV) photodetector (PD). The ZnO/TiO 2 NRs heterojunction UV PD exhibits a very low dark current, showing more than 3 orders of magnitude photo-to-dark current ratio. Also, the heterojunction UV PD shows a higher responsivity of 0.18A/mW and a larger detectivity of $\boldsymbol{2.79}\times \boldsymbol{10^{13}}$ Jones at -3V. Furthermore, the heterojunction UV PD shows good stability and repeatability of the photoelectric response.