Synthesis of Two-Dimensional Hexagonal Boron Nitride and Mid-Infrared Nanophotonics

Two-dimensional hexagonal boron nitride (2D h-BN), a representative of 2D layered materials with unique structure and properties, is one of the most promising inorganic nanomaterials in recent years. The excellent properties of h-BN in the mid-infrared (MIR) region (∼2-20 μm) have also received much attention. At the same time, with the advancement of materials exploration and device-on-chip integrated systems, the synthesis of high-quality h-BN has encountered great challenges, which is a prerequisite for the application of h-BN in the MIR region. In this paper, we first review the recent advances in 2D h-BN synthesis by highlighting the research, advantages and disadvantages of various synthesis methods, and the critical issues encountered so far. Then, advances in the study and application of h-BN in the MIR region are explored, including perfect absorption, photodetectors, electro-optical modulators, phonon polaritons, and plasma excitons. Finally, we present our views on the challenges encountered in the synthesis and application of 2D h-BN in the MIR region in the near future in the context of the article's discussion and the potential of h-BN development, with the hope this review will be of some help to relevant researchers.