Scalable fabrication of the graphitic substrates for graphene-enhanced Raman spectroscopy

Tommi Kaplas,Pasi Vahimaa,Yuri Svirko,Sari Suvanto,Antti Matikainen,Tarmo Nuutinen

doi:10.1038/s41598-017-09308-9

Tommi Kaplas, Pasi Vahimaa + Show 4 more

Open Access

https://doi.org/10.1038/s41598-017-09308-9

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Journal: Scientific Reports	Publication Date: Aug 17, 2017
Citations: 9	License type: open-access

Affiliation: University of Eastern Finland, Aalto University

Abstract

We propose direct synthesis of ultra-thin graphitic films on a dielectric substrate using sacrificial Ni catalyst layer, which significantly increases the crystallinity of the photoresist pyrolyzed at the temperature of 800 °C and above. A considerable amount of multilayer graphene in the photoresist film pyrolyzed in the presence of the Ni catalyst gives rise to an enhancement of the Raman signal of dye Sudan III molecules deposited on the substrate. We demonstrate comparable enhancement of the Raman signal from Sudan III molecules deposited on the fabricated graphitic substrate and those deposited on graphene, which was conventionally transferred to the silica substrate.

Highlights

Ever since graphene isolation 15 years ago, a variety of applications have been proposed and demonstrated for both single and multilayered graphene[1,2,3]
In contrast to the conventional surface-enhanced Raman spectroscopy (SERS), which exploits local field enhancement in the vicinity of metal nanoparticles deposited on the dielectric substrate, Graphene enhanced Raman spectroscopy (GERS) is driven by the charge transfer between the analyte and graphene[9]
Between 700 and 800 °C, the pyrolyzed photoresist film (PPF) synthesized in presence of the Ni film underwent remarkable transformation and at the process temperature of 800 °C, the melted Ni film receded to an array of micron- and submicron sized nickel particles (See Fig. 2), which remained nearly unchanged when the process temperature was increased up to 900 °C

Summary

Introduction

Ever since graphene isolation 15 years ago, a variety of applications have been proposed and demonstrated for both single and multilayered graphene[1,2,3]. The direct synthesis of these highly ordered atomically thin graphitic films on dielectric and semiconductor substrates remains a difficult task This is partially because the chemical vapor deposition (CVD), a conventional graphene synthesis technique, relies on a metal (e.g. Cu and Ni) catalyst[3], while applications usually require graphene deposited on a dielectric/semiconductor substrate. In the framework of such an approach, one needs just to remove the remains of the metal film from the substrate in order to obtain graphene deposited on the dielectric substrate This technique is relatively simple and straightforward, the electronic properties of the obtained polycrystalline single- and multilayer graphene are usually poorer than those of the transferred one[5]. In contrast to the conventional surface-enhanced Raman spectroscopy (SERS), which exploits local field enhancement in the vicinity of metal nanoparticles deposited on the dielectric substrate, GERS is driven by the charge transfer between the analyte and graphene[9]. Enhancement of the Sudan III Raman lines comparable to that can be obtained by using graphene conventionally grown on a copper foil and transferred onto a dielectric substrate

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Results

Conclusion