Resonant Field Emission from Noble-Metal/Graphene Heterostructures

Field emission from metals underpinned early vacuum-tube technology, and recent nanoscale engineering made field-emission devices compatible with modern silicon platforms. However, the limited tunability of electron transport in metals has restricted their applicability. Here, we show that noble metals coated with graphene exhibit clean nonmonotonic <i>I</i>-<i>V</i> characteristics arising from resonant tunneling through the electronic states of graphene, enabled by the atomic thinness and weak electronic hybridization of graphene with noble metals. Our approach combines ab initio interface parameters with exact solutions of the Schrödinger equation for electron transmission across the interface. We analyze two experimentally relevant geometries: a vertical configuration with a flat suspended emitter and a coplanar configuration with sharp electrodes allowing for strong field enhancement and gating. These results establish a practical route to tunable electron transport in metal heterostructures, positioning them as competitive components for air-channel field-emission nanoelectronics.