The interface properties of defective graphene on aluminium: A first-principles calculation

Abstract

The interfacial properties of graphene/Al composites are of critical important for exploring its high mechanical performance. To improve the mechanical properties, many experimental works have been done in past decades, however, the understanding of their physical mechanisms are limited. Here, the electronic structures and interfacial adhesion properties of pristine/virous deficient graphene(001)/Al(111) interfaces are calculated by first-principles method. Results show that single vacancy defective graphene (SVG)/Al interface has larger work of adhesion (Wad) of 5.62 J/m2 than the pristine (Wad of 1.03 J/m2) and other defective graphene/Al interfaces (Wad of 5.12 J/m2 for boron doped single vacancy defective graphene (BVG)/Al and Wad of 5.12 J/m2 for double vacancy defective graphene (DVG)/Al, respectively) due to the strong hybridization of Al-2p and C-2p orbits, which giving rise to the formation of polar covalent bonds with the bond populations of 0.62–0.72 at the deficient site The corresponding interface spacing decreasing from 2.72 Å (Pristine Gra/Al) to 2.17 Å (SVG/Al). And the defective graphene doped by B atoms could inhibit the interaction between Al and C atoms in the BVG/Al interface. Comparing with the SVG and BVG cases, the interface interaction strength of DVG/Al interface decreases due to the formation of octatomic ring, which could cape the carbon dangling bond and lead to a small structure deformation of graphene. However, it maintains a high Wad of 3.98 J/m2, indicating a better interface bonding strength than idea Gra/Al.