Authors: Yihao Wang, Zaichun Sun, Bingchu Mei
Published: 2025-03-17
Source: Full article
AbstractBismuth chalcohalides demonstrate tunable optical and electronic properties, offering new orientations for the material design and properties exploration. Recently, bismuth sulfide halides (Bi13S18X2, X═Cl, Br, I) have been regarded as a kind of potential infrared (IR) photoelectrical materials, owing to the narrow bandgap, small effective mass, and low toxicity. In this work, (310)‐orientated Bi13S18Br2 thin films are synthesized on the α‐Al2O3 (0001) single crystal via mist chemical vapor deposition at atmospheric pressure. Bi13S18Br2 thin films possessed a narrow bandgap of ≈0.85 eV, suitable for harvesting the light from ultraviolet to the near‐IR range. The conduction mechanism of Bi13S18Br2 is discussed from 2 to 300 K. The Bi13S18Br2‐based photodetector exhibited interesting near‐IR photodetection performance, which is comparable and even superior to the well‐investigated IR photodetectors. The responsivity reached up to 10.0 and 7.3 A W−1 under the illumination of 808 and 1064 nm light, respectively. This study is expected to contribute to the development of “mixed‐anion electronics” and advance photodetection techniques.