Two-dimensional antimony selenide (Sb2Se3) nanosheets prepared by hydrothermal method for visible-light photodetectors

Two-dimensional Sb2Se3 is a p-type semiconductor material, a prominent member of VA-VIA group, which has drawn widespread attention due to stable structure, excellent optoelectronic and photoelectric properties as compared to its bulk counterpart. In current work, Sb2Se3 nanosheets are synthesized for the first time by highly facile hydrothermal method. The antimony triselenide nanosheets morphology is investigated by XRD, SEM, Raman, TEM and AFM analysis. Majority of 2D nanosheets are rectangles and parallelograms, having length, width, and thickness from 2 to 16 mu m, 1 to 8 mu m, and 17 to 40 nm respectively. The phonon dispersion reveals that Sb2Se3 nanosheets are thermodynamically stable. The bandgap of as-synthesize nanosheets, by analysis of absorption spectra, is calculated to be similar to 1.55 eV which is well consistent with our first principles calculations (1.58 eV). The photoelectric characteristics of fabricated nanosheets are explored by developing a film-based photodetector, which shows a better response to visible-light with an "ON/OFF" ratio of 10.8 with short response/recovery times (0.40/0.12 s) and long-term durability. The electric current of Sb2Se3 nanosheets based photodetector has shown significant improvement in both dark and under light illumination. Current study could be a crucial move in promoting Sb2Se3 nanosheets based semiconductors for high performance optoelectronic applications.