The stable interfaces between various edges of hBN and step edges of Cu surface in hBN epitaxial growth: a comprehensive theoretical exploration

Abstract

High-index Cu surfaces were broadly shown to be substrates capable for templating the epitaxial growth of uniformly aligned hexagonal boron nitride (hBN) islands whereas the mechanism of hBN growth on high-index Cu surfaces is still missing. Since hBN nucleation prefers step edges on a high-index Cu surface, the understanding of the interfaces between the hBN edges and the step edges of Cu substrates is critical for revealing the mechanism of hBN epitaxial growth on high-index Cu surfaces. Our extensive theoretical study reveals that both types of zigzag edges and armchair edge tend to retain their pristine structures on a Cu surface due to the effective passivation of the dangling bonds of hBN edges. This study paves a way to explore the growth kinetics of hBN on high-index Cu surfaces and also sheds light on the growth mechanisms of various two-dimensional materials on active metal substrates.