Point defects in two-dimensional hexagonal boron nitride: A perspective

Two-dimensional (2D) hexagonal boron nitride (h-BN) is one of the most promising materials for many technological applications ranging from optics to electronics. In past years, a property-tunable strategy that involves the construction of electronic structures of h-BN through an atomic-level design of point defects has been in vogue. The point defects imported during material synthesis or functionalization by defect engineering can endow h-BN with new physical characteristics and applications. In this Perspective, we survey the current state of the art in multifunction variations induced by point defects for 2D h-BN. We begin with an introduction of the band structure and electronic property of the pristine h-BN. Subsequently, the formation and characterization of the most obvious point defects and their modulation in electronic structures of h-BN nanomaterials are envisaged in theory. The experimental results obtained by atom-resolved transmission electron microscopy, magnetic measurement, and optical measurements have provided insights into the point defect engineered structures and their corresponding emerging properties. Finally, we highlight the perspectives of h-BN nanomaterials for heterostructures and devices. This Perspective provides a landscape of the point defect physics involved to demonstrate the modulation of the structure and functionalities in h-BN and identify the roadmap for heterostructure and device applications, which will make advances in electronics, spintronics, and nanophotonics.