Self-Powered Photodetector with High Sensitivity Based on a CeO₂/TiO₂ Thin Film

This work reports the growth of a CeO 2 /TiO 2 thin film (TF) using an electron beam evaporator for photodetector application. Field emission gun scanning electron microscopy confirms the uniform growth of CeO 2 /TiO 2 TF. The CeO 2 /TiO 2 TF device exhibited excellent rectification characteristics under dark and light illumination conditions. Under illumination, the generation of photocurrent arises from the effective separation of photogenerated electron–hole pairs within the built-in electric field at the interface of the CeO 2 /TiO 2 TF device. It was found that the fabricated device exhibits a dark current of 5.4 × 10 –10 A, a sensitivity of 732, and a rectification ratio of 556. The maximum response of the devices is observed at 260 nm with a responsivity of 4.5 mA/W at a zero bias voltage. A comparable detectivity of 3.4 × 10 11 Jones was also calculated. Moreover, the rise time and fall time were found to be 1.1 and 0.1 s, respectively. The obtained results of CeO 2 /TiO 2 TF devices render them highly suitable for applications demanding high response and self-sufficient functionality.