6 - Defect in 2D materials beyond graphene

Abstract

In this chapter, we focus on defect structures in two-dimensional (2D) atomic crystals beyond graphene, with emphasis on 2D semiconducting transition-metal dichalcogenides and insulating hexagonal boron nitride. Structural defects, ranging from zero-dimensional point defects to one-dimensional grain boundaries, lateral interfaces, and edges are systematically discussed. Specifically, the atomic configurations of these various structural defects are revealed using atomic-resolution electron microscopy imaging, and their dynamical evolution under electron beam irradiation are also reviewed. When further combined with first-principle calculations and local property measurements, the atomic structure information of defects revealed by electron microscopy, as discussed in this chapter, can help to understand the structure–property correlations in 2D materials and to develop new methods of defect engineering for tuning the local properties of 2D materials.