Two-Dimensional Graphene-Gold Interfaces Serve as Robust Templates for Dielectric Capacitors

Area of Science:

• Condensed Matter Physics
• Materials Science
• Surface Science

Background:

• Van der Waals (vdW) heterostructures are crucial for novel electronic devices.
• Graphene and gold interfaces are promising for advanced material applications.

Purpose of the Study:

• Investigate the electronic structure and stability of graphene-gold vdW interfaces.
• Explore the potential of these heterostructures as dielectric capacitors.

Main Methods:

• Density Functional Theory (DFT) with PBE-D2 functionals for electronic structure and binding energies.
• Ab initio molecular dynamics simulations to assess thermal stability.
• Fabrication and characterization of graphene-hexagonal boron nitride-gold dielectric capacitors.

Main Results:

• The graphene-gold vdW interface remains stable up to 1200 K.
• Above 1200 K, gold transforms from planar to a 3D cluster structure.
• Calculated gravimetric capacitances for h-BN bilayers are C1 = 7.6 μF/g and C2 = 3.2 μF/g.
• Observed deviations from classical charging models due to quantum phenomena at short contacts.

Conclusions:

• Graphene-gold vdW heterostructures exhibit unique electronic and thermal properties.
• These heterostructures demonstrate potential for dielectric capacitor applications.
• Quantum effects significantly impact capacitive behavior in nanoscale devices.