Photodetection and Infrared Imaging Based on Cd<sub>3</sub>As<sub>2</sub> Epitaxial Vertical Heterostructures.

Yang, Yunkun; Zhou, Junchen; Xie, Xiaoyi; Zhang, Xingchao; Li, Zihan; Liu, Shanshan; Ai, Linfeng; Ma, Qiang et al. · ACS Nano · 2022

basic_science · Level V

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Abstract

Due to the nontrivial electronic structure, Cd<sub>3</sub>As<sub>2</sub> 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<sub>3</sub>As<sub>2</sub> photodetectors are rarely reported to date owing to the crystal mismatch between Cd<sub>3</sub>As<sub>2</sub> and semiconductors. Here, we demonstrate Cd<sub>3</sub>As<sub>2</sub>/Zn<sub><i>x</i></sub>Cd<sub>1-<i>x</i></sub>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<sub>3</sub>As<sub>2</sub> with semiconductors has potential applications in broadband photodetection and infrared cameras.