Graphene-Supported Thin Metal Films for Nanophotonics and Optoelectronics.

Dmitry I Yakubovsky,Aleksey V Arsenin,Kirill V Voronin,Yury V Stebunov,Roman V Kirtaev,Valentyn S Volkov,Artem A Voronov

doi:10.3390/nano8121058

Abstract

Graphene-metal hybrid nanostructures have attracted considerable attention due to their potential applications in nanophotonics and optoelectronics. The output characteristics of devices based on such nanostructures largely depend on the properties of the metals. Here, we study the optical, electrical and structural properties of continuous thin gold and copper films grown by electron beam evaporation on monolayer graphene transferred onto silicon dioxide substrates. We find that the presence of graphene has a significant effect on optical losses and electrical resistance, both for thin gold and copper films. Furthermore, the growth kinetics of gold and copper films vary greatly; in particular, we found here a significant dependence of the properties of thin copper films on the deposition rate, unlike gold films. Our work provides new data on the optical properties of gold and copper, which should be considered in modeling and designing devices with graphene-metal nanolayers.

Highlights

In recent years, a great deal of interest has been directed toward the use of graphene/metal hybrid nanostructures in the development of high-efficiency photonic, plasmonic, optoelectronic and nanoscale electronic devices [1,2,3]
Metal/graphene hybrid structures allow one to obtain a significant improvement in the strength and fatigue limit in bending compared to conventional metal structures without graphene [25,26], which allows an increase in the functionality of thin-film metal structures in relation to their use in flexible electronics applications
We have investigated the influence of a graphene underlayer on Au and Cu films properties in continuous thin films at thicknesses of 25 and 50 nm

Summary

Introduction

A great deal of interest has been directed toward the use of graphene/metal hybrid nanostructures in the development of high-efficiency photonic, plasmonic, optoelectronic and nanoscale electronic devices [1,2,3]. Nanometric composite hybrid structures consisting of alternating thin layers of metal deposited onto a sublayer of graphene have been used to demonstrate room temperature operation of novel ultrasensitive broadband photodetectors [21,24,27], photovoltaic solar cells [19,28], hybrid graphene/metasurface systems at terahertz and infrared frequencies [24,29,30,31,32] and highly sensitive surface-enhanced Raman scattering (SERS) biosensors with the fluorescence quenching effect [33,34,35] Such novel composites can be potentially used as transparent graphene-based neural interfaces for electrophysiology, in vivo neural imaging, optogenetic applications [36,37] and brain-computer interfaces [38]. The results of the experimental study are demonstrated in detail below

Sample Fabrication

Structural Characterization

Optical and Electrical Characterization

Results and Discussion

Thin Copper Films

Conclusions