High responsivity and fast UV–vis–short-wavelength IR photodetector based on Cd ₃ As ₂ /MoS ₂ heterojunction

Abstract

High responsivity, fast response time, ultra-wide detection spectrum are pursuing goals for state-of-art photodetectors. Cd₃As₂, as a three-dimensional (3D) Dirac semimetal, has a zero bandgap, high light absorption rate in broad spectral region, and higher mobility than graphene at room temperature. However, photoconductive detectors based Cd₃As₂ suffer low quantum efficiency due to the absence of high built-in field. Here, a Cd₃As₂ nanoplate/multilayer MoS₂ heterojunction photodetector was fabricated which achieved a quite high responsivity of 2.7 × 10³ A W^-1 at room temperature. The photodetector exhibits a short response time of in broad spectra region from ultraviolet (365 nm) to short-wavelength-infrared (1550 nm) and reached 65 μs at 650 nm. This work provides a great potential solution for high-performance photodetector and broadband imaging by combining 3D Dirac semi-metal materials with semiconductor materials.