Coulomb Blockade and Hopping Conduction in Graphene Quantum Dots Array

TL;DR

This paper investigates electron transport in chemically functionalized graphene, revealing Coulomb blockade effects and hopping conduction in a two-dimensional array of graphene quantum dots at low temperatures.

Contribution

It demonstrates Coulomb blockade and hopping conduction in graphene quantum dot arrays, linking quantum dot size and disorder to transport properties.

Findings

Suppression of current below 15 K due to Coulomb blockade

Coulomb oscillations with energy scales of 6.2-10 meV

Efros-Shklovskii variable range hopping observed

Abstract

We show that the low temperature electron transport properties of chemically functionalized graphene can be explained as sequential tunneling of charges through a two dimensional array of graphene quantum dots (GQD). Below 15 K, a total suppression of current due to Coulomb blockade through GQD array was observed. Temperature dependent current-gate voltage characteristics show Coulomb oscillations with energy scales of 6.2-10 meV corresponding to GQD sizes of 5-8 nm while resistance data exhibit an Efros-Shklovskii variable range hopping arising from structural and size induced disorder.