Temperature-dependent Raman investigation on suspended graphene: Contribution from thermal expansion coefficient mismatch between graphene and substrate

Tian, Shuang; Yang, Yang; Liu, Zhe; Wang, Chao; Pan, Ruhao; Gu, Changzhi; Li, Junjie

doi:10.1016/j.carbon.2016.03.046

Cited by 67 publications

(62 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indeed, some effects on the Gr properties can be related to stress induced by differences of thermal expansion coefficient with respect to the substrate. Moreover, it has also been hypothesized that some peculiarities arise from the Van der Waals interaction characterizing Gr and the other 2D materials and also differences in Gr substrate distance . In this context, interfacial defects of SiO 2 , one of the most used dielectrics in electronic devices, were found to be relevant as well as the potentialities to intercalate molecules between Gr and substrate …”

Section: Introductionmentioning

confidence: 99%

“…In the study of these features, in general, a prominent role has been recognized to Raman spectroscopy, a technique able to non‐invasively investigate the properties of Gr as well as its interaction with neighboring materials . In addition, the presence of strain has been highlighted by this kind of measurements and the possibility to evaluate the effects induced by the substrate, a major concern too in characterizing, and solving those criticisms that could arise in devices based on Gr …”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Graphene‐SiO₂ Interaction from Composites to Doping

Armano

Buscarino

Cannas

et al. 2019

Physica Status Solidi (a)

View full text Add to dashboard Cite

An overview of the interaction between monolayer graphene and SiO2 dielectric substrate is reported focusing on the effect this latter has on doping and strain induced by thermal treatments in controlled atmosphere. The disentanglement of strain and doping is highlighted and the comparison with another dielectric substrate of Al2O3 evidences the critical role that the substrate has in the electronic properties of graphene. The reported results pave the way for microelectronic devices based on graphene on dielectrics and for Fermi level tuning in composites of graphene and nanoparticles.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Graphene‐SiO₂ Interaction from Composites to Doping

Armano

Buscarino

Cannas

et al. 2019

Physica Status Solidi (a)

View full text Add to dashboard Cite

show abstract

“…Peaks D and G are overlapped by a combination of sp2 and sp3 bonds, corresponding to the presence of structural disorder or defects [47]. Thus, these spectroscopic results and those obtained by using the microscopic technique indicate that 800 ∘ C is not an adequate temperature for the synthesis of graphene since different carbon species are obtained.…”

Section: Raman Spectroscopymentioning

confidence: 83%

“…The G peak originates from the first-order scattering process due to the double degenerate phonon mode vibrations at the center of Brillouin zone and is related to sp 2 bonded carbon [45]. Measurement of D / G ratio is a well-known method for characterization of disorder [46,47]. Ferrari et al [48] showed that it is possible to use the second-order 2D (or G ) band in the graphene Raman spectra to learn about the number of layers in a graphene sample by using the 2D / G ratio [49].…”

Section: Raman Spectroscopymentioning

confidence: 99%

Graphene Synthesis Using a CVD Reactor and a Discontinuous Feed of Gas Precursor at Atmospheric Pressure

Moreno-Bárcenas

Pérez-Robles

Vorobiev

et al. 2018

Journal of Nanomaterials

View full text Add to dashboard Cite

The present work shows a new method in order to cost-effectively achieve the synthesis of graphene by Chemical Vapor Deposition (CVD). Unlike most usual processes, where precursors such as argon, H 2 , CH 4 , and high purity copper foil are used, the proposed method has replaced the previous ones by N 2 , N 2 (90%) : H 2 (10%), C 2 H 2 , and electrolytic copper (technical grade) since the use of industrialized precursors helps reduce production costs. On the other hand, the process was modified from a continuous flow system with vacuum to a discontinuous one at atmospheric pressure, eliminating the use of vacuum pump. In addition, this modification optimized the consumption of gases, which reduced the waste and the emission of pollutant gases into the atmosphere. Graphene films were grown under different gas flowrates and temperatures. Then, the obtained material was characterized by TEM, Raman spectroscopy, and AFM, confirming the presence of few graphene layers. In brief, the growth time was reduced to six minutes with acetylene as a carbon precursor at 1000 ∘ C and at atmospheric pressure, with a flow rate of 30 sccm. Finally, the reported conditions can be used for the synthesis of good quality graphene films in industrial applications.

show abstract

“…The estimated temperature of the sample at the highest laser powers was found to be ~200°C. Temperature coefficients of the G and 2D bands were reported to be χ G = −0.016 cm −1 /K and χ 2D = −0.034 cm −1 /K for supported single‐layer graphene and χ G = −0.015 cm −1 /K and χ 2D = −0.066 cm −1 /K for supported bilayer graphene, or χ G = −0.01517 cm −1 /K and χ 2D = −0.03915 cm −1 /K for suspended single‐layer graphene . Significantly higher coefficients of χ G = −0.0468 cm −1 /K and χ 2D = −0.0946 cm −1 /K for single‐layer graphene were explained by oxygen‐induced hole doping taking place after temperature‐dependent Raman measurements .…”

Section: Resultsmentioning

confidence: 99%

In situ Raman study of laser‐induced stabilization of reduced nanoceria (CeO_2−x) supported on graphene

Nikolenko

Strelchuk

Gnatyuk

et al. 2018

J Raman Spectroscopy

View full text Add to dashboard Cite

This work demonstrates a novel approach to application of in situ Raman spectroscopy to study laser‐induced stabilization of reduced nanoceria (CeO2−x) supported on graphene—a promising nanocomposite for future development of nanomaterial‐enabled gas sensors or vital catalysts for hydrogenation of alcohols under anaerobic conditions. Structural stabilization of CeO2−x nanoparticles (NPs) on a graphene surface is evidenced by significant modification of Raman spectra—the appearance, increase in relative intensity, and low‐wavenumber shift of CeO2 F2g band at excitation laser powers higher than ~5 mW. The effect is related to the reduction in a number of oxygen vacancies in CeO2−x NPs. Analysis of the graphene 2D and G band wavenumbers through ω2D(ωG) correlation indicated a decrease in p‐type graphene doping attributed to the charge transfer between the stabilizing CeO2−x NPs and the graphene that occurs due to trapping of graphene mobile holes by oxygen vacancies in CeO2−x. High‐resolution transmission electron microscopy analysis supported this idea by showing the increased lattice constant of fluorite‐type hexagonal‐shaped CeO2−x NPs as compared with bulk CeO2 and which could be related to partial reduction of CeO2−x NPs as a result of the Ce4+ transformation to Ce3+ with formation of corresponding oxygen vacancies. X‐ray photoelectron spectroscopy data confirmed the mixed Ce4+/Ce3+ valence state of the CeO2−x NPs. Thus, by combining the structure conversion of nanoceria induced by electromagnetic radiation and its stabilization by the graphene support, this work provides a foundation for advanced concepts in the development of the next‐generation catalysts and sensors.

show abstract

Temperature-dependent Raman investigation on suspended graphene: Contribution from thermal expansion coefficient mismatch between graphene and substrate

Cited by 67 publications

References 36 publications

Graphene‐SiO₂ Interaction from Composites to Doping

Graphene‐SiO₂ Interaction from Composites to Doping

Graphene Synthesis Using a CVD Reactor and a Discontinuous Feed of Gas Precursor at Atmospheric Pressure

In situ Raman study of laser‐induced stabilization of reduced nanoceria (CeO_2−x) supported on graphene

Contact Info

Product

Resources

About

Temperature-dependent Raman investigation on suspended graphene: Contribution from thermal expansion coefficient mismatch between graphene and substrate

Cited by 67 publications

References 36 publications

Graphene‐SiO2 Interaction from Composites to Doping

Graphene‐SiO2 Interaction from Composites to Doping

Graphene Synthesis Using a CVD Reactor and a Discontinuous Feed of Gas Precursor at Atmospheric Pressure

In situ Raman study of laser‐induced stabilization of reduced nanoceria (CeO2−x) supported on graphene

Contact Info

Product

Resources

About

Graphene‐SiO₂ Interaction from Composites to Doping

Graphene‐SiO₂ Interaction from Composites to Doping

In situ Raman study of laser‐induced stabilization of reduced nanoceria (CeO_2−x) supported on graphene