Recent progress and remaining challenges of 2D material-based terahertz detectors

Abstract Two-dimensional(2D) materials have attracted enormous interests owing to their unique band structures as well as extraordinary electronic and optical properties. Atomic thickness combined with the weak van der Waals interaction between layers provides exceptional advantages in wafer-scale production and integration. The versatility of 2D materials makes it possible to achieve ultra-fast and ultra-sensitive terahertz (THz) detection at room temperature. Therefore, since graphene was discovered in 2004, 2D material-based THz detectors have rapidly become a hot research topic. Here, a review of the latest progress in THz detection based on the emerging 2D materials is presented. Firstly, the excellent optoelectronic properties of 2D materials, including graphene, transition-metal dichalcogenides (TMDCs) and black phosphorus (BP), are introduced. Then, an insight into different photodetection mechanisms as well as the key factors for the comparison between different detectors are introduced. State-of-art photodetectors classified by different detection mechanisms are summarized systematically. Finally, the remaining challenge and perspective of 2D material-based THz detectors are discussed briefly.