Customizing the reduction of individual graphene oxide flakes for precise work function tuning with meV precision.

Yuefeng Huang,William R Hendren,Joel M Katzen,Robert M Bowman,Lifa Zhang,J Marty Gregg,Gang Zhang,Fumin Huang,Dengke Ma,Patrick Turner,Gavin E Donnelly

doi:10.1039/d0na00321b

Abstract

Being able to precisely control the reduction of two-dimensional graphene oxide films will open exciting opportunities for tailor-making the functionality of nanodevices with on-demand properties. Here we report the meticulously controlled reduction of individual graphene oxide flakes ranging from single to seven layers through controlled laser irradiation. It is found that the reduction can be customized in such a precise way that the film thickness can be accurately thinned with sub-nanometer resolution, facilitated by extraordinary temperature gradients >102 K nm−1 across the interlayers of graphene oxide films. Such precisely controlled reduction provides important pathways towards precision nanotechnology with custom-designed electrical, thermal, optical and chemical properties. We demonstrate that this can be exploited to fine tune the work function of graphene oxide films with unprecedented precision of only a few milli electronvolts.

Highlights

Customizing the reduction of individual graphene oxide flakes for precise work function tuning with meV precision†
It is found that the reduction can be customized in such a precise way that the film thickness can be accurately thinned with sub-nanometer resolution, facilitated by extraordinary temperature gradients >102 K nmÀ1 across the interlayers of graphene oxide films
Such precisely controlled reduction provides important pathways towards precision nanotechnology with custom-designed electrical, thermal, optical and chemical properties. We demonstrate that this can be exploited to fine tune the work function of graphene oxide films with unprecedented precision of only a few milli electronvolts

Summary

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Customizing the reduction of individual graphene oxide flakes for precise work function tuning with meV precision†. It is found that the reduction can be customized in such a precise way that the film thickness can be accurately thinned with sub-nanometer resolution, facilitated by extraordinary temperature gradients >102 K nmÀ1 across the interlayers of graphene oxide films. Such precisely controlled reduction provides important pathways towards precision nanotechnology with custom-designed electrical, thermal, optical and chemical properties. We demonstrate that this can be exploited to fine tune the work function of graphene oxide films with unprecedented precision of only a few milli electronvolts. As WF is a fundamental metric of optoelectronic devices, central to the performance of photovoltaics, photodetectors, and light emitting diodes etc, being able to accurately tune the WF will have signi cant implications in device performance

Results

Theoretical simulation

Sample preparation

Raman and optical measurement