Stabilisation of hBN/SiC Heterostructures with Vacancies and Transition-Metal Atoms

TL;DR

This study explores how vacancies and transition-metal atoms can stabilize hBN/SiC heterostructures, enabling controlled metal functionalization for catalytic energy applications through computational and machine learning methods.

Contribution

It introduces a novel approach to stabilize hBN/SiC heterostructures using vacancies and transition metals, providing design guidelines for surface reactivity enhancement.

Findings

Boron vacancy induces covalent bonding with silicon and nitrogen.

Transition-metal adatoms can be stably anchored at finite temperatures.

hBN/SiC heterostructure is suitable for atomically precise metal functionalization.

Abstract

When two-dimensional atomic layers of different materials are brought into close proximity to form van der Waals (vdW) heterostructures, interactions between adjacent layers significantly influence their physicochemical properties. These effects seem particularly pronounced when the interface exhibits local order and near-perfect structural alignment, leading to the emergence of Moir\'e patterns. Using quantum mechanical density functional theory calculations, we propose a prototypical bilayer heterostructure composed of hexagonal boron nitride (hBN) and silicon carbide (SiC), characterized by a lattice mismatch of 18.77\% between their primitive unit cells. We find that the removal of boron atoms from specific lattice sites can convert the interlayer interaction from weak vdW coupling to robust localized silicon-nitrogen covalent bonding. Motivated by this, we study the binding of transition-metal adatoms and formulate design guidelines to enhance surface reactivity, thereby enabling the controlled isolation of single-metal atoms. Our machine-learning-assisted molecular dynamics simulations confirm both dynamical stability and metal anchoring feasibility at finite temperatures. Our results suggest the hBN/SiC heterostructure as a versatile platform for atomically precise transition-metal functionalization, having potential for next-generation catalytic energy-conversion technologies.