Electronic conduction in copper-graphene composites with functional impurities

TL;DR

This study uses ab initio DFT calculations to analyze how functional impurities and ring disorder in coal-derived graphene affect electronic conduction in copper-graphene composites, revealing the impact of structure and purity on electrical properties.

Contribution

It provides new insights into how impurities and structural disorder influence electronic conduction in copper-graphene composites, highlighting the importance of purity and orientation.

Findings

Functional groups contribute to states below the Fermi level.

Ring disorder disrupts electron flow and induces charge localization.

Crystal orientation and graphene purity significantly affect conductivity.

Abstract

Coal-derived graphene-like material and its addition to FCC copper are investigated using ab initio plane wave density functional theory (DFT). We explore ring disorder in the sp2 carbon, and functional impurities such as oxides (-O), and hydroxides (-OH) that are common in coal-derived graphene. The electronic density of states analysis revealed localized states near the Fermi level, with functional groups contributing predominantly to states below the Fermi level, while carbon atoms in non-hexagonal rings contributed mainly to states above it. The functionalization of graphene induces charge localization while ring disorder disrupts the continuous flow of electrons. By projecting the electronic conductivity along specific spatial directions, we find that both the crystal orientation and the graphene purity significantly influence the anisotropy and magnitude of electronic transport in the composites. This study implicitly highlights the importance of structural stress to obtain improved electrical conductivity in such composites.