Atomically Thin Hexagonal Boron Nitride and Its Heterostructures

Abstract Atomically thin hexagonal boron nitride (h‐BN) is an emerging star of 2D materials. It is taken as an optimal substrate for other 2D‐material‐based devices owing to its atomical flatness, absence of dangling bonds, and excellent stability. Specifically, h‐BN is found to be a natural hyperbolic material in the mid‐infrared range, as well as a piezoelectric material. All the unique properties are beneficial for novel applications in optoelectronics and electronics. Currently, most of these applications are merely based on exfoliated h‐BN flakes at their proof‐of‐concept stages. Chemical vapor deposition (CVD) is considered as the most promising approach for producing large‐scale, high‐quality, atomically thin h‐BN films and heterostructures. Herein, CVD synthesis of atomically thin h‐BN is the focus. Also, the growth kinetics are systematically investigated to point out general strategies for controllable and scalable preparation of single‐crystal h‐BN film. Meanwhile, epitaxial growth of 2D materials onto h‐BN and at its edge to construct heterostructures is summarized, emphasizing that the specific orientation of constituent parts in heterostructures can introduce novel properties. Finally, recent applications of atomically thin h‐BN and its heterostructures in optoelectronics and electronics are summarized.