Mechanical and Electrical Conductivity Properties of Graphene/Cu Interfaces: A Theoretical Insight

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• High-quality interfaces in graphene/copper (Gr/Cu) composites are critical for advanced electronic applications.
• Optimizing interfacial bonding strength and electron transport is essential for Gr/Cu composite performance.

Purpose of the Study:

• To systematically investigate the mechanical and electrical conductivity properties of Cu(111)/Gr/Cu(111) interfaces.
• To explore the impact of stacking sequences, graphene forms, and defects on interface characteristics.

Main Methods:

• Utilizing first-principles calculations.
• Employing the nonequilibrium Green's function method.
• Analyzing binding energy, separation work, charge transfer, and electrical conductivity.

Main Results:

• The top-fcc interface demonstrated superior properties: high binding energy (-3.00 eV/C atom), significant separation work (≥0.78 J/m²), small interfacial distance (2.85 Å), and enhanced electron transport (2.12 G₀/nm²).
• Bilayer graphene reduced electronic conductance by nearly 2.46 orders of magnitude.
• Graphene point defects, particularly single vacancies, improved mechanical performance (7.50-124.36%) and electrical performance (33.02%).

Conclusions:

• The top-fcc interface is optimal for Gr/Cu composites.
• Graphene defects can overcome traditional mechanical-electrical trade-offs.
• Proposed stress mechanisms can further enhance interfacial electrical conductivity, providing a theoretical basis for Gr/Cu engineering applications.