Ultraviolet sensor-based TiO 2 nanorods/PProDOT-Pz conducting polymer using different bias voltage

The ideal material for detecting ultraviolet(UV) is TiO 2 nanorods (TiO 2 NRs). However, the photosensitive response speed and response speed of TiO 2 NRs are affected by its surface defects. We need to choose an appropriate method to solve this problem. In this study, TiO 2 NRs and D-A-D type conducting polymer containing pyridazine as the acceptor unit and 3,4-propylenedioxythiophene as the donor unit 3,6-bis (2- (3,4-propylidene dioxythiophenyl)) pyridazine are electrochemically combined to fabricate UV photodetectors. The structure of the material is analyzed by SEM, mapping, XRD, FT-IR, UV–vis and XPS, indicating the strongly enhanced synergistic effect between PProDOT-Pz and TiO 2 NRs and the homogeneous distribution of polymer on the TiO 2 NRs surface. The results show that under the low power (0.35 mW cm −2 ) UV illumination, the hybrid system has high responsivity (342.19 mA W −1 ) large detectivity (1.36 × 10 11 Jones) fast time pulse response (T rise  = 6.2 s, T decay  = 7.7 s) and EQE (110.35%) at the bias voltage of 3 V. More importantly, the photodetector works stably with good repeatability, which shows that the device configuration based on TiO 2 NRs and PProDOT-Pz heterojunction is proved to be an excellent candidate device with high sensitivity and fast response for UV signal.