Van der Waals MoS2/PdSe2 Heterostructures Grown by Chemical Vapor Deposition for Broadband and Polarized Photodetection

Abstract

AbstractRecently, group‐X transition metal dichalcogenides with tunable distinct optical and superior electrical properties have displayed profound potential in various optoelectronic devices. In this work, novel van der Waals (vdWs) heterostructures composed of monolayer MoS2 and few‐layer PdSe2 grown by chemical vapor deposition are employed in photodetectors for broadband and polarized photodetection. Excitingly, optoelectronic measurements show that the MoS2/PdSe2 photodetector is sensitive to near‐infrared light with responsivity as high as 6.9 A W−1, specific detectivity up to 6.3 × 1010 Jones, and a rapid response speed of 0.378/0.708 s at 830 nm. This is mainly attributed to the enhanced light absorption and the type‐II band alignment of the heterostructure. Under illumination, not only the intralayer excitations but also the interlayer excitations contribute to the carrier's generation in relevant layers, which enables the broadband photoresponse. In addition, this photodetector also exhibits a good polarization sensitivity with dichroic ratio about 1.34. All these results demonstrate that the MoS2/PdSe2 vdWs heterostructures are suitable for the realization of next‐generation high‐performance broad and polarized photodetectors.