Recent advances in two-dimensional graphdiyne for nanophotonic applications

Graphdiyne (GDY), an atom-thick sp- and sp2-hybridized all-carbon material, is an emerging carbon allotrope which holds great potentials in many fields, such as gas separation, solar cells, catalysis, energy storage and conversion, nonlinear optics, etc. Since its successful synthesis in 2010, a large quantity of theoretical and experimental studies has already exhibited its excellent properties, including eco-friendly character, higher chemical stability, large specific surface area, narrow band gap, and high carrier mobility. Among them, the interaction between 2D GDY nanosheets (NSs) and photons has presented unprecedented potentials in the nanophotonic devices over the past decade. In this review, the controlled synthesis of the well-defined 2D GDY NSs is first briefly introduced. Subsequently, the fundamental properties (band structure, Raman spectroscopy and optical property) and latest nanophotonic applications (photodetectors, photocatalysis, nonlinear photonics, solar cells, surface plasmon resonance sensors, and biophotonics) are comprehensively summarized. Finally, some personal insights on the development prospects and constraints of nanophotonic devices based on 2D GDY are presented. It is anticipated that this review can provide an in-depth understanding between 2D GDY and photons, and further inspire more efforts toward new designs of functional 2D GDY-based nanophotonic devices to promote the advancement of next-generation nanophotonic systems.