Physical origin of enhanced electrical conduction in aluminum-graphene composites

The electronic and transport properties of aluminum-graphene compositematerials were investigated using ab initio plane wave density functionaltheory. The interfacial structure is reported for several configurations. Insome cases, the face-centered aluminum (111) surface relaxes in a nearly idealregistry with graphene, resulting in a remarkably continuous interfacestructure. The Kubo-Greenwood formula and space-projected conductivity wereemployed to study electronic conduction in aluminum single- and double-layergraphene-aluminum composite models. The electronic density of states at theFermi level is enhanced by the graphene for certain aluminum-grapheneinterfaces, thus, improving electronic conductivity. In double-layer graphenecomposites, conductivity varies non-monotonically with temperature, showing anincrease between 300-400 K at short aluminum-graphene distances, unlike theconsistent decrease in single-layer composites.