Realization of p-type In1.75Sb0.25Se3 alloys for short-wave infrared photodetectors

Abstract

The narrow-gap semiconductors (NGSs) with two-dimensional (2D) layered structures provide fundamental advantages, such as low noise and high quantum efficiency, for short-wave infrared (SWIR) optoelectronic devices. However, realizing high-performance photodetectors based on 2D NGSs with high photoresponsivity, low noise, and fast response speed remains a challenge. Here, we present the design, preparation, and characterization of an In2(1− x)Sb2 xSe3 SWIR photodetector. Trivalent antimony (Sb3+) substitutional doping not only induced the β′-β phase transition at room temperature but also made the alloy a good candidate for the p-type semiconductor. Moreover, the individual In1.75Sb0.25Se3 nanoflake realized an excellent photoresponse in a broadband range from visible (405 nm) to SWIR (1550 nm) light with a photoresponsivity of 134 A W−1 and a detectivity of 1.82 × 107 Jones. These performances were superior to the reported In2Se3, Sb2Se3, and other In or Sb selenide photodetectors, which indicated that the β-In2(1− x)Sb2 xSe3 alloy may provide a potential building block for short-wave infrared photodetectors.