High-performance Self-powered Ultraviolet-visible-near infrared Broadband Photodetectors Based on Sb₂Se₃/TiO₂ Heterojunctions and Multifunctional Applications

High-performance broadband photodetectors (PDs) are essential components in spectroscopy, remote sensing, imaging, and light communication applications. In this paper, Sb2Se3 nanoparticles (NPs) are uniformly deposited on TiO2 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 degrees C to control the amount of Se in Sb2Se3. A good interfacial contact between Sb2Se3 and TiO2 is conducive to the separation and transport of photogenerated carriers. Sb2Se3/TiO2 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 x 10(11) Jones, and response time of 18/20 mu s are demonstrated for the PDs annealed at 290 degrees C. The excellent performance broadband Sb2Se3/TiO2 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 Sb2Se3/TiO2 PDs in multifunctional applications.