Edge-Dependent Capacitive Response and Geometry-Tunable Metallization Field in Same-Lattice Graphene/Graphane/Graphene Nanoribbon Nanocapacitors

Increasing either lateral width generally lowers the metallization field in both edge geometries. Notably, fixed-graphene-width, variable-spacer-width calculations show that this reduction can occur even when the zero-field band gap remains nearly unchanged, demonstrating that the metallization field reflects the combined influence of the low-energy electronic structure and lateral electrostatic geometry rather than the zero-field band gap alone.

At a common postclosure reference field, wider structures store more total charge and energy but exhibit lower gravimetric capacitance, revealing a trade-off between the field required to access the electrode-like regime and the mass-normalized capacitive response. Zigzag systems additionally undergo pronounced reconstruction of pre-existing edge magnetism, whereas armchair systems develop only weak spin polarization and generally higher gravimetric capacitance.

These results identify edge geometry and both lateral widths as complementary design variables for controlling the metallization field and capacitive response.