Energy Band-Gap Engineering of Graphene Nanoribbons

TLDR

The study investigates electronic transport in lithographically patterned graphene ribbons, where lateral confinement induces an energy gap near the charge neutrality point. The authors patterned graphene layers into ribbons of varying widths and orientations, contacted them with metal electrodes, and measured conductance in the non‑linear regime at low temperatures to determine energy gap sizes. Temperature‑dependent conductance measurements reveal that narrower ribbons exhibit larger energy gaps, which scale inversely with ribbon width, demonstrating lithographic control of graphene band gaps.

Abstract

We investigate electronic transport in lithographically patterned graphene ribbon structures where the lateral confinement of charge carriers creates an energy gap near the charge neutrality point. Individual graphene layers are contacted with metal electrodes and patterned into ribbons of varying widths and different crystallographic orientations. The temperature dependent conductance measurements show larger energy gaps opening for narrower ribbons. The sizes of these energy gaps are investigated by measuring the conductance in the non-linear response regime at low temperatures. We find that the energy gap scales inversely with the ribbon width, thus demonstrating the ability to engineer the band gap of graphene nanostructures by lithographic processes.