Research on the Mechanism of Diamond Heteroepitaxial Growth Based on First-principles Calculations

Although single-crystal diamond is successfully grown on some other substrate materials, the heteroepitaxial mechanism is still not fully understood. In this research, by analyzing the density of states curve of surface atoms in heterostructures and comparing them with atoms in the bulk material, the electronic properties of the surface atoms can be revealed. Monolayer carbon (C) atoms on cubic boron nitride (c-BN) surface exhibit some properties of diamond-like carbon. Conversely, the monolayer C atoms covering the Iridium (Ir) surface demonstrate distinct metallic properties. The C atoms on the surface of the 8-layer heterostructure exhibit some properties of diamond-like carbon. This explains why single-crystal diamond heteroepitaxy growth on Ir film requires the bias-enhanced nucleation process. However, on the c-BN surface, single-crystal diamonds can be grown directly. The method is also used to analyze the heteroepitaxy of indium phosphide (InP) on gallium arsenide (GaAs) and gallium nitride (GaN) on aluminum nitride (AlN), and the results have further confirmed the effectiveness. Therefore, this approach offers a new perspective for identifying suitable substrate materials based on their electronic properties, rather than solely relying on the matching of lattice constants and surface energies.