High‐performance Self‐powered Ultraviolet‐visible‐near infrared Broadband Photodetectors Based on Sb<sub>2</sub>Se<sub>3</sub>/TiO<sub>2</sub> Heterojunctions and Multifunctional Applications
Songyao Gao, Jianping Xu, Jianping Xu, Shaobo Shi, Jing Chen, Jianghua Xu, Jianghua Xu, Lina Kong, Xiaosong Zhang, Lan Li
Abstract
Abstract High‐performance broadband photodetectors (PDs) are essential components in spectroscopy, remote sensing, imaging, and light communication applications. In this paper, Sb 2 Se 3 nanoparticles (NPs) are uniformly deposited on TiO 2 nanorod arrays (NRs) to construct a type II heterojunction with good interfacial contact by a simple two‐step potentiostatic electrochemical deposition method combined with N 2 atmosphere annealing at 280, 290 and 300 °C to control the amount of Se in Sb 2 Se 3 . A good interfacial contact between Sb 2 Se 3 and TiO 2 is conducive to the separation and transport of photogenerated carriers. Sb 2 Se 3 /TiO 2 PDs exhibit excellent self‐powered photoresponse in a broad spectral range from ultraviolet‐visible‐near infrared (UV‐VIS‐NIR) due to the combined effects of high light absorption, low defect density, and more suitable band alignment. The optimal parameters with a responsivity of 13.48 A W −1 , detectivity of 7.9 × 10 11 Jones, and response time of 18/20 µs are demonstrated for the PDs annealed at 290 °C. The excellent performance broadband Sb 2 Se 3 /TiO 2 PDs are used to construct the application models in the light communication for light encryption and flaw detection. This work opens up a new strategy for Sb 2 Se 3 /TiO 2 PDs in multifunctional applications.