Advances in 2D Materials Research with Atomic Resolution TEM/STEM*

Atomic resolution TEM/STEM enables in-depth studies of the defects, structure, and growth of 2D materials. As such examples of recent advances in 2D materials research with atomic-resolution TEM/STEM, I present some of the recent findings and achievements on 2D materials and their materials science. Studies on the growth of ZnO monolayer on graphene and graphene oxide substrate will be presented. In situ TEM observation demonstrates atom-by-atom growth of ZnO monolayer on graphene. Among the unique growth mechanisms for 2D h-BN, which is different from graphene, the formation of intertwined double-spiral few-layer h-BN is driven by screw dislocations located at antiphase boundaries. We discovered atomically sharp twin boundaries composed of a 6′6′ configuration in CVD–synthesized few-layer h-BN, which show conducting feature with a zero bandgap. Additionally, we demonstrate anisotropic angstrom-wide Cu intercalation in black phosphorus, where Cu atoms are intercalated along a zigzag direction of black phosphorus. The Cu intercalation induces transition of angstrom-wide electronic channels from semiconductor to semimetal in black phosphorus.