Ultraviolet sensor-based TiO2 nanorods/PProDOT-Pz conducting polymer using different bias voltage

The ideal material for detecting ultraviolet(UV) is TiO2 nanorods (TiO2 NRs). However, the photosensitive response speed and response speed of TiO2 NRs are affected by its surface defects. We need to choose an appropriate method to solve this problem. In this study, TiO2 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 TiO2 NRs and the homogeneous distribution of polymer on the TiO2 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 × 1011 Jones) fast time pulse response (Trise = 6.2 s, Tdecay = 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 TiO2 NRs and PProDOT-Pz heterojunction is proved to be an excellent candidate device with high sensitivity and fast response for UV signal. •ProDOT-Pz was synthesized for the first time.•Composite shows superior UV detection performance under 3 V bias voltage.•The polymer can form coordination bond with TiO2 to enhance the UV detection ability.