Fabrication of Sb2Se3-based high-performance self-powered Visible-NIR broadband photodetector

Antimony selenide (Sb2Se3) is a narrow-band gap semiconductor with tuneable optoelectronic properties. It has recently gained significant attention due to its unique crystal structure, high carrier transport, stability, ease of processing, and inexpensiveness. Further, Sb2Se3 thin films have been successfully utilized in photovoltaics; however, their application in photodetectors is still unexplored. Herein, we report the fabrication of a Sb2Se3- based self-powered, broad-band photodetector using Sb2Se3 thin film deposited by a simple thermal evaporation technique. The fabricated photodetector (PD) exhibited exceptional performance, featuring a broad absorption band covering the visible to the infrared wavelength region and high responsivity of 3.37AW-1. The Vis-IR PD demonstrates outstanding figure-of-merit performance parameters such as specific detectivity of 1.0x1011 Jones, external quantum efficiency of 369.3%, with noise equivalent power of 2.95x10-13 WHz-1/2. In addition, the device displays excellent photodetection performance under self-power (at zero applied bias) conditions with a responsivity of 3.02 mAW-1 with long-term stability. The performance of Sb2Se3 photodetectors is attributed to the excellent crystallinity of the Sb2Se3 thin film and the strong electric field established at the interface between Sb2Se3 and Au, which facilitates the efficient separation of photogenerated electron-hole pairs. These findings open up new avenues for Sb2Se3-based photodetectors in optoelectronics.