First-principle calculations of adsorption of Ga (Al, N) adatoms on the graphene for the van-der-Waals epitaxy

Abstract

III-nitride compound semiconductors attract a lot of attention for practical applications because of their excellent physical properties. However, transfer of GaN-based epitaxial films grown on single-crystalline substrates (e.g., sapphire) are difficult without GaN film damage. Thus, it is challenging to scale-up GaN film production to electronic applications, such as wearable and foldable devices. Two-dimensional (2D) layered materials, such as graphene, have in-plane lattice arrangements similar to III-nitride compounds. Thus, detachable nitride films can be grown by van-der-Waals epitaxy (vdWE) on these 2D non-single-crystalline substrates, especially if the substrate is appropriately orientated. To demonstrate the feasibility of this approach, this work theoretically analyzed the adsorption energies of Ga (Al, N) adatoms on the single- and multi-layered graphene using first-principle calculations. Graphene with three and more layers can be pre-oriented during the vdWE-based growth of III-nitride compounds. Feasibility of pre-treatment of pre-oriented graphene layer by N2 plasma and other modeling results related to plasma-assisted molecular beam epitaxy were confirmed experimentally.