High performance photodetectors based on two-dimensional materials

Combing graphene and other two-dimentional materials in heterostructure or the hybridization of graphene with a gain material for photodetection offers the possiblity to expand the wavelength range of operation and improve performance. Here, we fabricated two novel photodetectors based on graphene-Bi₂Te₃ heterostructure and hybrid graphene-perovskite islands, respectively. Our results show that the graphene-Bi₂Te₃ photodetector has a photoresponsivity of 35 AW^-1 at a wavelength of 532 nm and an expanded detection wavelength range further to near-infrared (NIR) (980 nm) and telecommunication band (1550 nm). On the other hand, the hybrid graphene-perovskite phototransistros show a photoconductive gain of ~10⁹ electrons per photon and a responsivity of ~6.0×10⁵ AW^-1 with a broadband detection from ultraviolet (UV) to visible (250-700 nm).