Resonant field emission from noble-metal/graphene heterostructures

TL;DR

This study demonstrates that noble-metal/graphene heterostructures exhibit tunable, resonant electron emission properties, enabling advanced nanoelectronic applications through precise control of electron tunneling.

Contribution

It introduces a novel approach combining ab-initio parameters and Schrödinger equation solutions to analyze resonant tunneling in metal/graphene interfaces.

Findings

Resonant tunneling causes non-monotonic I-V characteristics.

Graphene coating enables tunable electron transport in metals.

Vertical and coplanar geometries show practical field-emission control.

Abstract

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 non-monotonic $I-V$ characteristics arising from resonant tunneling through graphene's electronic states, enabled by graphene's atomic thinness and weak electronic hybridization with noble metals. Our approach combines ab-initio interface parameters with exact solutions of the Schr\"odinger 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.