Tuning the electronic transport properties of graphene through functionalisation with fluorine

TL;DR

This study demonstrates how fluorine functionalisation can be used to tune the electronic transport properties of graphene, enabling transitions between different conduction regimes and opening possibilities for electronic applications.

Contribution

It provides a systematic analysis of how varying fluorine content affects the electronic transport regimes in graphene monolayers and multilayers, revealing controllable property modulation.

Findings

Transition from Mott to Efros-Shklovskii hopping with increased fluorination

Multilayer fluorinated graphene exhibits 2D Mott variable range hopping

High fluorine concentration induces a band gap of 0.25 eV with thermally activated transport

Abstract

Engineering the electronic properties of graphene has triggered great interest for potential applications in electronics and opto-electronics. Here we demonstrate the possibility to tune the electronic transport properties of graphene monolayers and multilayers by functionalisation with fluorine. We show that by adjusting the fluorine content different electronic transport regimes can be accessed. For monolayer samples, with increasing the fluorine content, we observe a transition from electronic transport through Mott variable range hopping in two dimensions to Efros - Shklovskii variable range hopping. Multilayer fluorinated graphene with high concentration of fluorine show two-dimensional Mott variable range hopping transport, whereas CF0.28 multilayer flakes have a band gap of 0.25eV and exhibit thermally activated transport. Our experimental findings demonstrate that the ability to control the degree of functionalisation of graphene is instrumental to engineer different electronic properties in graphene materials.