Photodetector Based on Twisted Bilayer Graphene/Silicon Hybrid Slot Waveguide with High Responsivity and Large Bandwidth

Graphene/silicon hybrid photodetector operating at communication wavelength has attracted enormous attention recently due to its potential realize bandwidth larger than 100 GHz. However, the responsivity is intrinsically limited by low absorption from atomic-thick graphene monolayer, which imposes significant obstacles towards practical application. Although plasmonic structures been widely applied enhance responsivity, it may induce metallic thus limit lower 0.6 A/W. Twisted bilayer (TBG) reported hold ability dramatically optical unique twist-angle-dependent van Hove singularities. In this article, we present a design of silicon/TBG with higher 1 A/W and exceeding The enhanced achieved tuning twisted angle TBG increase within 1550 nm as well utilizing silicon slot waveguide boost mode overlap TBG. fabrication process proposed also discussed demonstrating advantages complexity. could not only exhibit superior performance compared previously silicon/monolayer photodetector, but pave way for application graphene-based optoelectronic devices.