Improving the optoelectronic properties of single-crystalline antimony sulfide rods through simultaneous defect suppression and surface cleaning

Abstract

Low-dimensional semiconductors can be used for the fabrication of various optoelectronic devices due to their fascinating structures and physical properties. Herein, one-dimensional single-crystalline antimony sulfide (Sb₂S₃) rods with tunable lengths/diameters were synthesized via a hydrothermal approach followed by thermal treatment. Comprehensive structural characterizations and theoretical simulations revealed that annealing in H₂/Ar can further remove the sulfur residue on the pristine Sb₂S₃ surface and improve the crystallinity of the rods with a reduced number of structural defects. The resultant high-quality Sb₂S₃ rods manifested impressive optoelectronic properties. As a proof-of-concept, a single Sb₂S₃ rod photodetector was fabricated and tested. The device manifested good response rate (5.10 A W⁻¹), high external quantum efficiency (1130.7%), fast rise/decay time during on/off switching (4.03/4.08 ms), and a good detection rate (2.16 × 10¹⁰ Jones, herein “Jones” are the unit of detection rate by default). The photodetector also displayed a high switching ratio of 109.8 under 560 nm monochromatic light. The photodetection performance is superior or comparable to recently reported systems. Our results highlight the importance of the fine control of crystallinity, purity and defects (density) of semiconductors through rational post treatment for optoelectronic applications. The Sb₂S₃ rods may also find potential applications in other optoelectronic devices.