Photodetectors based on 2D materials from UV to Thz

Abstract Two-dimensional (2D) material-based photodetectors have emerged as a core research hotspot in the optoelectronics community, attracting extensive investment from global research programs owing to their unique atomically thin structure and outstanding electronic and optoelectronic properties. The explored 2D material systems include graphene, black phosphorus, transition metal dichalcogenides, hexagonal boron nitride, and various van der Waals heterostructures derived from these materials, whose bandgap values span an ultra-wide range of 0–6 eV, enabling full-spectrum detection coverage from the ultraviolet to THz regime. To date, hundreds of 2D material-based photodetectors with diverse architectures and performance orientations have been reported. This work presents a systematic review of research progress in the field of 2D material-based photodetectors, adopting a mechanism-driven, problem-oriented analytical framework as its unique critical perspective to depart from conventional review narratives that catalog achievements merely by material categories. First, we briefly introduce five core photodetection mechanisms of 2D material devices, and clarify standardized evaluation benchmarks for fair performance comparison across different devices, including testing and calibration specifications for core parameters such as responsivity, specific detectivity, and response speed. Next, we review the latest research progress in the field: centered on the resolution of inherent performance bottlenecks that cannot be addressed by conventional bulk semiconductor photodetectors, we summarize key performance breakthroughs of state-of-the-art 2D photodetectors, including broadband spectral detection, high responsivity and detection sensitivity, fast response speed and high operation bandwidth, polarization-sensitive detection without external discrete optical components, and monolithic integration of light sensing and in-situ synaptic storage. We also sort out preliminary application explorations of 2D material-based photodetectors in typical scenarios such as uncooled infrared imaging, flexible wearable optoelectronic monitoring, and neuromorphic vision systems. Finally, we provide an outlook on future directions of this fast-growing field, critically discuss remaining open challenges including standardized performance calibration, compatibility with large-scale wafer manufacturing, and long-term operational stability, and propose general guidelines for the rational design of novel high-performance 2D photodetectors.