Nucleation of CVD-prepared hexagonal boron nitride on Ni(100), Ni(110) and Ni(111) surfaces: A theoretical study

To understand the initial nucleation of hexagonal boron nitride (h-BN) prepared by chemical vapor deposition (CVD) on different surfaces, the stability of (BN)(n) (n = 1-12) clusters on Ni(100), Ni(110) and Ni(111) was systematically explored by density functional theory (DFT) calculations. Our results show that a geometry crossover from chain-like to honeycomb-like occurs on all three metal surfaces except that the critical dimension is different. The low index surface (100) is more suitable for BN nucleation in the initial stage, while Ni(111) becomes the preferred surface as BN grows. This difference is mainly attributed to the metal atomic packing density, the symmetry of the substrate, the deformation of the BN clusters, and the lattice mismatch between BN clusters and different metal surfaces. The synergistic effect ensures efficient charge transfer between the BN cluster and the underlying metal, which determines the nucleation of the BN cluster. In addition, the nucleation barrier and critical size of BN clusters can also be tuned by adjusting the ratio of B to N in the feedstock. These results should provide useful information for rational design of experimental conditions to obtain high-quality h-BN.

Automated summary

Density functional theory calculations were performed to investigate the nucleation process of hexagonal boron nitride (h-BN) on different metal surfaces. The results showed a geometry crossover from chain-like to honeycomb-like structures on all surfaces. The low index surface (100) was found to be more favorable for BN nucleation in the initial stage, while Ni(111) became the preferred surface as BN grew. The differences were mainly attributed to the metal atomic packing density, substrate symmetry, deformation of the BN clusters, and lattice mismatch between BN clusters and metal surfaces.