For graphene/copper (Gr/Cu) composites,
achieving high-quality
interfaces between Gr and Cu (strong interfacial bonding strength
and excellent electron transport performance) is crucial for enabling
their widespread applications in electronic devices. This study employs
first-principles calculations and the nonequilibrium Green’s
function method to systematically investigate the mechanical and electrical
conductivity properties of Cu(111)/Gr/Cu(111) interfaces with various
stacking sequences and different forms of Gr. For these interface
systems, the binding energy, separation work, charge transfer, and
electrical conductivity across the interface were obtained. The results
show that the top-fcc interface exhibits superior interfacial properties,
characterized by relatively high binding energy (−3.00 eV/C
atom) and separation work (≥0.78 J/m2), a small
interfacial distance (2.85 Å), and enhanced electron transport
capacity (2.12 G0/nm2). A bilayer form of Gr
significantly reduces electronic conductance across the Gr/Cu interface
by nearly 2.46 orders of magnitude. Furthermore, point defects in
Gr, especially single-vacancy defects, disrupt the traditional trade-offs
between mechanical and electrical performance, simultaneously enhancing
mechanical performance by 7.50–124.36% and electrical performance
by 33.02%. Additionally, stress mechanisms have been proposed to further
enhance the interfacial electrical conductivity of Gr/Cu composites.
The present study provides a theoretical basis for exploring the engineering
applications of Gr/Cu composite materials.