2D materials integrated with metallic nanostructures: Fundamentals and optoelectronic applications

Due to their novel electronic and optical properties, atomically thin layered two-dimensional (2D) materials are becoming promising to realize novel functional optoelectronic devices including photodetectors, modulators, and lasers. However, light-matter interactions in 2D materials are often weak because of the atomic-scale thickness, thus limiting the performances of these devices. Metallic nanostructures supporting surface plasmon polaritons show strong ability to concentrate light within subwavelength region, opening thereby new avenues for strengthening the light-matter interactions and miniaturizing the devices. This review starts to present how to use metallic nanostructures to enhance light-matter interactions in 2D materials, mainly focusing on photoluminescence, Raman scattering, and nonlinearities of 2D materials. In addition, an overview of ultraconfined acoustic-like plasmons in hybrid graphene-metal structures is given, discussing the nonlocal response and quantum mechanical features of the graphene plasmons and metals. Then, the review summarizes the latest development of 2D material-based optoelectronic devices integrated with plasmonic nanostructures. Both off-chip and on-chip devices including modulators and photodetectors are discussed. The potentials of hybrid 2D materials plasmonic optoelectronic devices are finally summarized, giving the future research directions for applications in optical interconnects and optical communications.