Photodetection and Infrared Imaging Based on Cd 3 As 2 Epitaxial Vertical Heterostructures.

Due to the nontrivial electronic structure, Cd 3 As 2 is predicted to possess various transport properties and outstanding photoresponses. Photodetectors based on topological materials are mostly made up of nanoplates, yet monolithic in situ heteroepitaxial Cd 3 As 2 photodetectors are rarely reported to date owing to the crystal mismatch between Cd 3 As 2 and semiconductors. Here, we demonstrate Cd 3 As 2 /Zn x Cd 1- x Te/GaSb vertical heteroepitaxial photodetectors via molecule beam epitaxy. By constructing dual-Schottky junctions, these photodetectors show high responsivity and external quantum efficiency in a broadband spectrum. Based on the strong and fast photoresponse, we achieved visible light to near-infrared imaging using a one-pixel imaging system with a galvo. Our results illustrate that the integration of three-dimensional Dirac semimetal Cd 3 As 2 with semiconductors has potential applications in broadband photodetection and infrared cameras.