Solar‐Blind Ultraviolet Photodetectors Based on Two‐Dimensional Materials and Their Heterostructures

ABSTRACT Solar‐blind ultraviolet (UV) photodetectors operating within the wavelength range of 200–280 nm have attracted considerable interest owing to their vital applications in missile warning, flame sensing, space communication, and environmental monitoring. Conventional solar‐blind photodetectors based on three‐dimensional (3D) wide‐bandgap semiconductors are often limited by complex fabrication processes, high cost, and intrinsic rigidity. The emergence of two‐dimensional (2D) materials offers a promising alternative, capitalizing on their distinctive properties such as strong light‐matter interactions, tunable bandgaps, excellent flexibility, and the ability to construct van der Waals heterostructures free from lattice‐matching constraints. This review provides a comprehensive summary of recent advances in solar‐blind UV photodetectors based on 2D materials and their heterostructures. First, the fundamental mechanisms and performance metrics of photodetectors are described. Subsequently, a detailed overview of recent progress in devices fabricated from various 2D materials is presented, including layered materials (e.g., hexagonal boron nitride, transition metal dichalcogenides, metal thio/selenophosphates, bismuth oxyhalides), novel materials (e.g., metal oxides and perovskites), and mixed‐dimensional heterostructures (2D/3D heterostructures). Finally, the review addresses the remaining challenges and suggests prospective research directions, highlighting the potential of 2D materials in enabling the next generation of high‐performance, flexible, and miniaturized solar‐blind.