Isolated Ni atoms induced edge stabilities and equilibrium shapes of CVD-prepared hexagonal boron nitride on the Ni(111) surface

Abstract

Hexagonal boron nitride (h-BN) has received extensive attention due to its potential applications in electronic devices, but the growth mechanism of h-BN remains unclear. Here, the stability of various h-BN edges terminated by isolated Ni atoms on the Ni(111) surface was investigated by density functional theory (DFT) calculations. Our results show that most edges terminated by isolated Ni atoms have lower energies than those passivated by the Ni(111) surface, and that the zigzag edge terminated with nitrogen atoms (ZZN) is the most stable one. Combined with Wulff construction theory, we predict that the equilibrium morphology of h-BN domains is likely to be triangles enclosed by ZZN edges in N-rich environments, while the triangles are enclosed by ZZB edges in B-rich environments. An in-depth understanding of the stability of h-BN edges terminated by isolated Ni atoms on the Ni(111) surface is crucial to reveal the growth mechanism. Therefore, it should provide valuable information for controlling the morphology of h-BN domains in experiments and provide useful perspectives for the synthesis of other two-dimensional binary materials.