Hybrid Photodetection Mechanisms Tuned with Tunneling

Abstract

In this paper, we report two strategies for realizing the hybrid photodetection mechanisms for high-performance broadband photodetectors built with tunable van der Waals (vdW) heterojunction interfaces. All electrically-controlled photoresponse tuned by the atomically-thin tunneling barrier and bandgap contrast across the vdW heterojunction interfaces can be used to adjust the tunneling resistance and suppress the dark current. Adjusting the hybrid photodetection through the switching operation can lead to an optimized optical switching ratio covering from the ultra-violet to the mid-infrared ranges. The representative device structures suitable for each strategy (1) naturally formed oxidation layer (2) energy band alignment, and their characterization exhibit how the hybrid gauge of the photodetection mechanisms can be tuned by quantum tunneling and charge trapping at the vdW heterointerfaces.