Modify Cd₃As₂ nanowires with sulfur to fabricate self-powered NIR photodetectors with enhanced performance

Cd₃As₂ nanowires (NWs) have great potential in the near-infrared (NIR) photodetection field due to their excellent optoelectronic properties as a typical Dirac semimetal. However, the existence of surface oxidization limits their photoresponse performance for practical applications. Here, we modified the surface of Cd₃As₂ NWs with sulfur to prevent surface oxidizing and optimize the bandgap structure to improve the photoresponse performance. The S-modified Cd₃As₂ samples existed as core/shell Cd₃As₂/CdS NWs and the corresponding single NW device showed a responsivity of 0.95 A/W in the NIR band at a 0 V bias, which is three orders of magnitude higher than that of an unmodified NW. This study provides an efficient and universally applicable way to prevent semimetals nanostructures from oxidizing and promote their optoelectronic properties.