Probing Layer Number and Stacking Order of Few‐Layer Graphene by Raman Spectroscopy

Hao, Yong; Wang, Yingying; Wang, Lei; Ni, Zhenhua; Wang, Ziqian; Wang, Rui; Koo, Chee Keong; Shen, Zexiang; Thong, John T. L.

doi:10.1002/smll.200901173

Cited by 691 publications

(527 citation statements)

References 43 publications

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“…Examination of the quality of the graphene coating by micro-Raman spectroscopy allows determination of the number of graphene layers [on the basis of the intensity ratio of the 2D and G bands, i.e., the I(2D)/I(G) ratio] and also to estimate the defects in the graphene layer from the L D parameter, i.e., the distance between point defects [on the basis of the intensity ratio of the D and G bands, i.e., the I(D)/I(G) ratio]. [29][30][31] Spreading measurements were carried out on the prepared substrates. The first part of the spreading tests on the substrates made from pure copper and with graphene coating was carried out at 250°C with different annealing times (3 min, 8 min, 15 min, 30 min, and 60 min), without a protective atmosphere, and with use of Alu-33 flux (produced by Amasan).…”

Section: Methodsmentioning

confidence: 99%

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Effect of Graphene Layers on Phenomena Occurring at Interface of Sn-Zn-Cu Solder and Cu Substrate

Pstruś

Ozga

Gancarz

et al. 2017

Journal of Elec Materi

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Cu and graphene-coated Cu substrates spread with Sn-Zn eutectic-based alloy containing 0.5 wt.%, 1 wt.%, or 1.5 wt.% Cu have been studied at 250°C. Soldering experiments were performed for wetting time of 3 min, 8 min, 15 min, 30 min, and 60 min in (1) presence of flux without argon protective atmosphere and (2) fluxless in argon atmosphere. Solidified solder-pad couples were cross-sectioned and examined using scanning electron microscopy with energy-dispersive spectroscopy to study their interfacial microstructure. To assess the effect of graphene coating on solder, Cu pads were covered by graphene using chemical vapor deposition. The results revealed that the liquid solder did not wet the graphene-coated copper in the absence of flux. Wetting took place only with use of flux, because it destroyed the graphene layer and enabled contact of the liquid solder with the copper. Experiments were designed to demonstrate the effect of Cu addition and graphene coating on the kinetics of the formation and growth of Cu 5 Zn 8 and CuZn 4 phases identified by x-ray diffraction analysis, Raman spectroscopy, and energy-dispersive spectroscopy. A decrease of about 60% in the thickness of the intermetallic layer was observed when applying the graphene interlayer in presence of flux. Addition of copper to the Sn-Zn alloy improved the wettability as the copper content was increased.

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Section: Methodsmentioning

confidence: 99%

“…8 presents the dependence of the I(D)/I(G) ratio on the distance between point defects L D on the basis of Refs. [29][30][31]. Note that, with great damage to the graphene layer, a mixture of nanocrystalline graphene with amorphous carbon (Fig.…”

Section: Effect Of Graphene Layers On Phenomena Occurring At Interfacmentioning

confidence: 99%

Effect of Graphene Layers on Phenomena Occurring at Interface of Sn-Zn-Cu Solder and Cu Substrate

Pstruś

Ozga

Gancarz

et al. 2017

Journal of Elec Materi

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“…By examination of the location and shape of defect-activated D peak and the most two prominent features (G and G’ peaks) in the Raman spectra of graphenes with less than five layers, the number of graphene layers can be effectively identified without ambiguity [140,141]. However, the Raman spectrum of FLG thicker than five layers can be hardly distinguished from that of bulk graphite, as the stepwise broadened 2D band approaching that of bulk graphite due to continuous splitting of valence and conduction bands.…”

Section: The Structure Of Graphenementioning

confidence: 99%

Structure of graphene and its disorders: a review

Gao

Lee

et al. 2018

Science and Technology of Advanced Materials

494

187

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Monolayer graphene exhibits extraordinary properties owing to the unique, regular arrangement of atoms in it. However, graphene is usually modified for specific applications, which introduces disorder. This article presents details of graphene structure, including sp2 hybridization, critical parameters of the unit cell, formation of σ and π bonds, electronic band structure, edge orientations, and the number and stacking order of graphene layers. We also discuss topics related to the creation and configuration of disorders in graphene, such as corrugations, topological defects, vacancies, adatoms and sp3-defects. The effects of these disorders on the electrical, thermal, chemical and mechanical properties of graphene are analyzed subsequently. Finally, we review previous work on the modulation of structural defects in graphene for specific applications.

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“…It has been widely used in the identification of chemical compounds in areas ranging from basic research (e.g. graphene characterization 6) to quality control 7 and chemical identification (e.g. detection of impurities such as 2,4‐dinitrotoluene vapor to locate landmines 6, 8).…”

Section: Introductionmentioning

confidence: 99%

“…graphene characterization 6) to quality control 7 and chemical identification (e.g. detection of impurities such as 2,4‐dinitrotoluene vapor to locate landmines 6, 8). In CHO bioprocessing, Raman spectroscopy together with chemometrics 9, 10, 11 was proven useful for in situ monitoring of cell culture broth, in 2 to 5000 L bioprocesses 12, 13, 14.…”

Section: Introductionmentioning

confidence: 99%

Label‐free live cell imaging by Confocal Raman Microscopy identifies CHO host and producer cell lines

Mateu

Harreither

Schosserer

et al. 2016

Biotechnology Journal

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As a possible viable and non‐invasive method to identify high producing cells, Confocal Raman Microscopy was shown to be able to differentiate CHO host cell lines and derivative production clones. Cluster analysis of spectra and their derivatives was able to differentiate between different producer cell lines and a host, and also distinguished between an intracellular region of high lipid and protein content that in structure resembles the Endoplasmic Reticulum. This ability to identify the ER may be a major contributor to the identification of high producers. PCA enabled the discrimination even of host cell lines and their subclones with inherently higher production capacity. The method is thus a promising option that may contribute to early, non‐invasive identification of high potential candidates during cell line development and possibly could also be used for proof of identity of established production clones.

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Probing Layer Number and Stacking Order of Few‐Layer Graphene by Raman Spectroscopy

Cited by 691 publications

References 43 publications

Effect of Graphene Layers on Phenomena Occurring at Interface of Sn-Zn-Cu Solder and Cu Substrate

Effect of Graphene Layers on Phenomena Occurring at Interface of Sn-Zn-Cu Solder and Cu Substrate

Structure of graphene and its disorders: a review

Label‐free live cell imaging by Confocal Raman Microscopy identifies CHO host and producer cell lines

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