Reversibility of Graphene‐Enhanced Raman Scattering with Fluorinated Graphene

Valeš, Václav; Melnikova, Zuzana; Verhagen, Tim; Vejpravová, J.; Kalbáč, Martin

doi:10.1002/pssb.201700177

Cited by 4 publications

(2 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The photoluminescence is quenched on both pristine and hydrogenated graphene layers and the Raman peaks are visible also in both cases. These results are consistent with those observed previously for fluorinated and 4-nitrophenyl functionalized graphene 37,38 .…”

Section: Resultssupporting

confidence: 93%

Graphene-enhanced Raman scattering on single layer and bilayers of pristine and hydrogenated graphene

Valeš

Drogowska-Horná

Guerra

et al. 2020

Sci Rep

Self Cite

View full text Add to dashboard Cite

Graphene-enhanced Raman scattering (GeRS) on isotopically labelled bilayer and a single layer of pristine and partially hydrogenated graphene has been studied. the hydrogenated graphene sample showed a change in relative intensities of Raman bands of Rhodamine 6 G (R6G) with different vibrational energies deposited on a single layer and bilayer graphene. the change corresponds qualitatively to different doping of graphene in both areas. Pristine graphene sample exhibited no difference in doping nor relative intensities of R6G Raman peaks in the single layer and bilayer areas. Therefore, it was concluded that strain and strain inhomogeneities do not affect the GERS. Because of analyzing relative intensities of selected peaks of the R6G probe molecules, it is possible to obtain these results without determining the enhancement factor and without assuming homogeneous coverage of the molecules. furthermore, we tested the approach on copper phtalocyanine molecules. Enhancement of the signal in spectroscopy has crucial importance for detection and study of a low amount of species. For Raman spectroscopy, the surface-enhanced Raman scattering (SERS) technique is widely used 1 enabling even single-molecule detection 2. One of the restrictions of this approach is the limited stability of the metals that are needed to achieve signal enhancement 3. Recently, it was observed that graphene itself can provide significant enhancement of the Raman signal and the so-called graphene-enhanced Raman scattering (GERS) 4-6 was established. Note that both SERS and GERS can contribute to the molecular Raman signal together 7. Apart from the relatively good chemical stability of graphene, it was also found that graphene quenches photoluminescence 8 , which is important for practical experiments. The GERS was observed for various molecules 9-11 and also for other 2D materials, which were employed as active substrate 12. Furthermore, it was shown that the enhancement can be tuned by changing the Fermi energy of graphene (modified by the electrical field effect) 13 , by substitutional doping with heteroatoms 14,15 , or by chemical functionalization 16,17. More detailed studies demonstrated that the enhancement is also a function of the phonon energy of the specific vibration and also laser excitation energy 10. The observed effects were rationalized by a simple theoretical approach taking into account several different resonance processes 18. It was already shown previously that different doping of graphene induced by functionalization leads to a change in the relative intensities of individual GERS peaks of the probe molecules 16. The overall GERS enhancement depends on the laser excitation energy, lowest unoccupied molecular orbital (LUMO), and highest occupied molecular orbital (HOMO) energies of the probe molecules, the vibrational energy of the actual molecular Raman mode, and on the Fermi energy of graphene 18. Specifically:

show abstract

Section: Resultssupporting

confidence: 93%

Graphene-enhanced Raman scattering on single layer and bilayers of pristine and hydrogenated graphene

Valeš

Drogowska-Horná

Guerra

et al. 2020

Sci Rep

Self Cite

View full text Add to dashboard Cite

show abstract

“…Fluorinated single-layered graphene (1-LG-F) represents a material with a wide range of applications. In particular, this material can be beneficial for electronic devices because its electronic properties can be tuned by the degree of fluorination from conductor to semiconductor to isolator [1][2][3]. Because 1-LG-F is only 1 nm thick and can be potentially ultra flat, one can consider applications to even include a tunnel barrier in spintronic devices [4] or for construction of BISFET etc.…”

Section: Introductionmentioning

confidence: 99%

Laser-ablation-assisted SF6 decomposition for extensive and controlled fluorination of graphene

Plšek

Drogowska

Fridrichová

et al. 2019

Carbon

Self Cite

View full text Add to dashboard Cite

We present a safe, clean, convenient, and easy-to-control method for extensive fluorination of graphene using laser-ablation-assisted decomposition of gaseous SF 6 molecules. The decomposition process is based on irradiation of a silicon target using a Nd:YAG laser (532 nm) in an SF 6 atmosphere. The reactive species produced in the plume above the silicon target are consequently responsible for fluorination of graphene placed in proximity to the plume.The applicability of the proposed method is demonstrated on fluorination of CVD-grown graphene on copper foil. Samples with different fluorination levels were evaluated using Xray photoelectron spectroscopy and Raman spectroscopy. The influence of the applied number of laser pulses on the nature of the C-F bonds, fluorine, and sulphur concentrations, as well as graphene damage, is discussed. The method enables control of fluorine content by simple counting of laser pulses. We show that a fluorination level corresponding to a stoichiometry up to CF1.4 can be achieved. The fluorination does not lead to the formation of Cu-F in contrast to previously published approaches.

show abstract

Evaluation of a cleaner de-icing production of bituminous material blending with graphene by electrothermal energy conversion

Xie

Guo

et al. 2020

Journal of Cleaner Production

View full text Add to dashboard Cite

Reversibility of Graphene‐Enhanced Raman Scattering with Fluorinated Graphene

Cited by 4 publications

References 21 publications

Graphene-enhanced Raman scattering on single layer and bilayers of pristine and hydrogenated graphene

Graphene-enhanced Raman scattering on single layer and bilayers of pristine and hydrogenated graphene

Laser-ablation-assisted SF6 decomposition for extensive and controlled fluorination of graphene

Evaluation of a cleaner de-icing production of bituminous material blending with graphene by electrothermal energy conversion

Contact Info

Product

Resources

About