Enhancing photoelectronic properties of ZnX (X = S, Se)/AlN hetero-bilayers via interlayer twisting

Twist-angle engineering serves as a powerful strategy for tailoring the physical properties of two-dimensional (2D) semiconductors. In this work, we systematically investigate ZnX (X = S, Se)/AlN hetero-bilayers using density functional theory (DFT) and non-adiabatic molecular dynamics (NAMD) simulations. Our findings reveal that interlayer twisting exerts a significant regulatory effect on the band structure and photogenerated carrier dynamics. We demonstrate that these hetero-bilayers possess an intrinsic type-II band alignment, providing a robust driving force for interfacial charge separation and enhanced ultraviolet (UV) absorption. Furthermore, our results highlight a pronounced disparity in relaxation rates, where hot holes cool significantly faster than hot electrons. This cooling process is sensitive to the specific twist angle, offering a mechanism to prolong hot carrier lifetimes through structural modulation. This study demonstrates that ZnX/AlN bilayers are promising candidates for UV-range optoelectronic applications and establishes twist-angle modulation as a core paradigm for designing next-generation high-energy photon conversion devices.