High responsivity and broadband polarized photodetectors based on InSe/ReSe2 van der Waals heterostructures

Van der Waals (vdWs) heterostructures constructed by different two dimensional materials provides excellent platforms to fulfill superior capabilities and multiple functionalities in high-performance optoelectronic devices. Herein, a novel InSe/ReSe2 vdWs p-n junction heterostructure for broadband linear-polarized photodetection ranging from ultraviolet (UV) to infrared (IR) spectrum is demonstrated. Owing to the enhanced light absorption and the intralayer transition of electron-hole pairs companied with interlayer transition in the InSe/ReSe2 vdW heterostructures with type-II band alignment, the photodetector exhibits extraordinary photoresponsivity about 53.29 A/W at 300 nm, 16.01 A/W at 638 nm, and 3.54 A/W at 980 nm, which is beyond the photoresponse cutoff of the corresponding individual InSe and ReSe2 devices. Meanwhile, the maximum detectivity D* reaches up to 1.33 × 1011 Jones, 4.00 × 1010 Jones, and 8.87 × 109 Jones at 300 nm, 638 nm, and 980 nm, respectively. Moreover, the response speed of rise/decay times reaches to 0.36/0.39 ms, which are two orders of magnitude faster than the currently reported values. These results suggest that the ReSe2 related vdW heterostructures offer an opportunity to develop next-generation high performance broadband ultra-fast polarized photodetectors.