Hybrid/Integrated Silicon Photonics Based on 2D Materials in Optical Communication Nanosystems

Silicon (Si) photonics have established as leading technologies in addressing the rapidly increasing demands of huge data transfer in optical communication systems with compact footprints, small power consumption, and ultradense bandwidth, which are driven by the next generation supercomputers and big data era. Particularly, Si photonics will penetrate into optical communication links at an ever-small scale, namely chip-to-chip and on-chip. However, the nanostructures made of Si with an indirect bandgap are not ideal candidates for on-chip light sources, modulators, and photodetectors, which most-frequently require optical materials with direct bandgap. Thanks to the advent of graphene, transition metal dichalcogenides and other two-dimensional (2D) materials, which can facilitate extraordinary progresses in improving device performance at the ultrathin scale, their integration with Si photonics furnishes a heterogeneous platform to construct fully functional and highly integrated photonic communication systems. In this work, the current advancements in the on-chip applications of Si photonics-2D materials heterostructures, inclusive of all essential chip-scale modules and integrated circuits, as well as the future prospective and challenges are reviewed and discussed. The present study sets out to objectively measure the feasibility of the hybrid integration between Si photonics and 2D materials in on-chip optical communications and the advanced applications beyond.