Self-Powered Near-Infrared photodetector based on Graphyne/Hexagonal boron phosphide heterostructure with high responsivity and Robustness: A theoretical study

Abstract Two-dimensional van der Waals (vdW) heterostructures provide an ideal platform for various optoelectronic applications. However, a weak self-powered near-infrared photoresponsivity limits their applications. Here, a novel self-powered near-infrared photodetector with ultra-broadband, high responsivity, and high robustness based on graphyne/hexagonal boron phosphide (Gyne/BP) heterostructure is proposed by using the first-principles calculation and quantum transport simulations. The self-powered near-infrared Gyne/BP photodetector displays a wideband photoresponsivity from 750 nm to 1500 nm and the maximum photoresponsivity can reach up to 120 mA/W. Revealed by the interfacial properties of Gyne/BP heterostructure, the type-II band alignment, large CBO and VBO, and built-in electric field contribute to the superior photoresponsivity. Surprisingly, such broadband and high self-powered photoresponsivity are robust against external elastic strain by virtue of the robust type-II band alignment, large band offset, and intrinsic built-in electric field in strained Gyne/BP heterostructure. Nonetheless, the compressive strained Gyne/BP photodetector generates superior photoresponsivity compared with unstrained one on account of the enhanced light absorption and smaller effective mass. Our study demonstrates that Gyne/BP vdW heterostructure is a promising candidate for self-powered near-infrared photodetector, and the robustness of the photoelectric properties provides enormous convenience in experimental fabrication.