Designing nanoscale capacitors based on twin-graphene.

Abstract

A 'twin-graphene' bilayer-based nanoscale capacitor and nanoscale dielectric capacitor are designed using a density functional theory approach including van der Waals dispersion correction. A strong effect on electronic properties is observed for different stacking modes. The AB stacking mode is the most stable one among the considered stacking modes with a band gap of 0.553 eV. Our predicted energy and charge-storage capacities are higher than those of other nanoscale capacitors designed using other two-dimensional carbon allotropes. We designed a nanoscale dielectric capacitor by placing a 'twin-graphene like BN sheet' (n = 1-3) sandwiched between 'twin-graphene' layers. The capacitance decreases significantly in the nanoscale dielectric capacitor model compared to the nanoscale capacitor model. However, the measured capacitance is higher than that of the previously studied nanoscale dielectric capacitor models. The significant capacitance of our proposed models ensures their promising applications for designing next-generation nanoscale capacitors.