Recent Advances in the Functional 2D Photonic and Optoelectronic Devices

2D layered materials such as graphene, black phosphorus (BP), transition metal dichalcogenides (TMDCs), and their hybrid systems exhibit wide coverage of bandgaps, unique crystal structures, and the facile integration for potential applications in photonic and optoelectronic devices. In the recent two years, various 2D functional systems have been developed with novel optoelectronic properties, thereby expanding the functional applications. Beyond the speed, efficiency, or sensitivity, these 2D crystals can offer additional advantages and distinct applications in terms of spectrum range, polarization, intensity, and structural designs. The main contents here focus on optoelectronic and photonic devices with unique functional applications, especially mentioning areas as follows: long-wavelength photodetector, 2D polarization-sensitive photodetector, 2D optoelectronic memory, and 2D material-based optical modulator. For each section, the device design, performance, and operational principles are investigated and systematically discussed. Finally, the current research status is summarized and perspectives on possible applications in future are offered.