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

Abstract

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.