Localized States and Resultant Band Bending in Graphene Antidot Superlattices

TL;DR

This study investigates how localized edge states in graphene antidot superlattices influence band bending and electric fields, affecting fluorescence and doping, with implications for light-harvesting technologies.

Contribution

It provides experimental insights into the role of localized edge states and built-in electric fields in graphene antidot superlattices, highlighting their impact on optical and electronic properties.

Findings

Fluorescence quenching increases with antidot filling fraction.

Unpatterned samples show fluorescence enhancement under back-gating.

Built-in lateral electric fields cause p-type doping and fluorescence effects.

Abstract

We fabricated dye sensitized graphene antidot superlattices with the purpose of elucidating the role of the localized edge state density. The fluorescence from deposited dye molecules was found to strongly quench as a function of increasing antidot filling fraction, whereas it was enhanced in unpatterned but electrically back-gated samples. This contrasting behavior is strongly indicative of a built-in lateral electric field that accounts for fluorescence quenching as well as p-type doping. These findings are of great interest for light-harvesting applications that require field separation of electron-hole pairs.