Controlled growth of high-quality Bi₂S₃ nanowires and their application in near-infrared photodetection

A study on the chemical vapor deposition growth of monocrystalline Bi₂S₃ nanowires and their applications in near-infrared polarized photodetectors are reported. High-quality Bi₂S₃ nanowires were obtained with a maximum length of 14 μm and a minimum diameter of 35 nm. A growth model was also developed to explain the morphology change with respect to growth parameters which including precursor temperature, growth time, carrier gas flow rate, and inner tube pressure, leading to a better understanding of their growth mechanism. Photodetectors based on Bi₂S₃ single nanowires presented remarkable device performance with a responsivity of 4.21 A/W, a specific detectivity of 1.64 × 10¹⁰ Jones, an external quantum efficiency of 981.76%, and a photoresponse rate of 12.25 ms under the illumination of an 830 nm laser at room temperature (300 K). Under room temperature conditions, the Bi₂S₃ single nanowire photodetector also showed high polarization sensitivity to near-infrared light signals with a high dichroic ratio of 1.79. Based on these results, it indicates that Bi₂S₃ nanowires have a substantial portion of promise for near-infrared polarized photodetectors.