First-principles screening of dopants for high-conductivity graphene/copper interfaces

Chemical doping is one of the promising approaches for tailoring the electronic properties of graphene/copper (Gr/Cu) composites. However, the diversity of doping elements and their complex bonding configurations result in nuanced effects, such as the competition between increased carrier concentration and defect generation (lattice distortion). Therefore, it is essential to decouple such complex doping effects into the intrinsic contribution of the dopant atom and the extrinsic effects of defects like vacancies. In this work, first-principles calculations, deformation potential theory, and the parabolic band model are combined to investigate the intrinsic mechanisms of various dopants. This approach decouples their contributions to carrier concentration and mobility, enabling the effective selection of dopants with optimal carrier transport properties. The corresponding results reveal that dopants which significantly distort the Dirac cone structure, such as O, S, P, Br, and Si, lead to significant degradation of carrier mobility and are thus excluded. In contrast, N is identified as the optimal dopant of Gr/Cu composites, outperforming B by effectively enhancing carrier concentration while well maintaining high carrier mobility, thereby achieving a superior balance for enhanced conductivity. This work establishes a theoretical framework for dopant selection and provides key insights for the design of high-conductivity Gr/Cu composites.