Photonics and Optoelectronics of 2D Materials

Here we would like to review our recent progresses on the photonic and optoelectronic applications of graphene and other two-dimensional (2D) layered materials. Firstly, we develop a serials of new saturable absorbers based on graphene heterostructures and other 2D materials, including graphene/Bi2Te3, black phosphorus and self-doped plasmonic 2D Cu3-xP nanosheets as well as 2D halide perovskite. Depending on their nonlinear optical properties, both high energy Q-switched laser and ultrafast mode-locked pulse generation were demonstrated. Secondly, in order to fabricate improved graphene photodetectors, we combine graphene with other 2D materials with high optical gain and achieve highly responsive photodetection in different wavelength ranges, e.g., graphene/perovskite for visible light detection, graphene/MoTe2 for near infrared light detection and graphene-Bi2Te3 for broadband infrared light detection. Furthermore, we developed new methods to grow and transfer large area single crystal WS2, large area MoS2/WS2 heterojunction, and monolayer-bilayer WSe2 heterojunction, and demonstrated their applications for highly responsive photoelectric devices. Thirdly, we investigated plasmonic excitation and THz modulation in graphene Bi2Te3, graphene nanoribbon and 3D graphene using either spectroscopic or real space imaging techniques. Last, we report our recent progress on the synthesis of 2D organic-inorganic hybrid perovskite nanosheets as well as their optoelectronic applications.