High stability self-powered Bi2O3 based ultraviolet photodetector with p-i-n heterojunction

The ultraviolet photodetectors find wide application in both military and civilian fields. Numerous wide bandgap semiconductors have been successfully developed and Bi₂O₃ attracted much attention in recent years due to its high photoconductivity, air stability, eco-friendly, and low cost. In this study, a self-powered transparent ultraviolet photodetector with a p-i-n structure was developed, the performance of which is greatly enhanced compared to that of p-n structure. The photodetector with the structure of AgNWs/NiO/Bi₂O₃/TiO₂/ITO achieved a responsivity of 145 mA W⁻¹, a detectivity of 5.5 * 10¹⁰ Jones, and a high EQE of 71 % under 254 nm light illumination with 10 μW cm⁻² of light intensity, also coupled with fast rise time of ∼20.8 ms and decay time of ∼21.1 ms. The responsivity of the photodetectors exhibits less than 3 dB attenuation within 200 Hz, and less than 10 % deterioration in 30 days under an ambient environment. The effects of solution concentration, phase structure, morphology, and band alignment of the films on the detection properties, as well as the mechanism of Bi₂O₃ enhancing the photodetection properties are discussed. The photodetectors possessing p-i-n structure with Bi₂O₃ are self-powered, high reliable, which are beneficial for long service life in applications.