Characterization of SiC-grown epitaxial graphene microislands using tip-enhanced Raman spectroscopy

Vantasin, Sanpon; Tanaka, Yoshito; Uemura, Sei; Suzuki, Toshiaki; Kutsuma, Yasunori; Doujima, Daichi; Kaneko, Tadaaki; Ozaki, Yukihiro

doi:10.1039/c5cp05014f

Cited by 15 publications

(28 citation statements)

References 65 publications

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“…Although both charge and strain could affect the positions of G and 2D bands, the unintentional electron doping of epitaxial graphene on SiC substrate was found previously to be only about 1 × 10 13 cm −2 [35]. Such order of magnitude shows negligible influence on the 2D-band frequency [29,36].…”

Section: Resultsmentioning

confidence: 99%

Raman Study of Strain Relaxation from Grain Boundaries in Epitaxial Graphene Grown by Chemical Vapor Deposition on SiC

et al. 2019

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Strains in graphene play a significant role in graphene-based electronics, but many aspects of the grain boundary effects on strained graphene remain unclear. Here, the relationship between grain boundary and strain property of graphene grown by chemical vapor deposition (CVD) on the C-face of SiC substrate has been investigated by Raman spectroscopy. It is shown that abundant boundary-like defects exist in the graphene film and the blue-shifted 2D-band frequency, which results from compressive strain in graphene film, shifts downward linearly as 1/La increases. Strain relaxation caused by grain boundary diffusion is considered to be the reason and the mechanism is analyzed in detail.

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Section: Resultsmentioning

confidence: 99%

Raman Study of Strain Relaxation from Grain Boundaries in Epitaxial Graphene Grown by Chemical Vapor Deposition on SiC

et al. 2019

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“…Tip-enhanced Raman spectroscopy (TERS) is a powerful technique resulting in strongly increasing Raman signals from molecules attached to a metallic nanostructure. It is of great significance in many fields such as chemistry, biology, medicine, pharmacology, and environmental science [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. TERS is one of the useful tools for detecting single molecule with high sensitivity and molecular specificity.…”

Section: Introductionmentioning

confidence: 99%

Selective Excitation on Tip-Enhanced Raman Spectroscopy by Pulse Shaping Femtosecond Laser

et al. 2018

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In this paper, we propose a scheme for achieving ultrafast coherent control of the selective excitation among three excited states in stimulated Raman scattering process on a tip-enhanced Raman spectroscopy (TERS). The center frequencies of the pump and Stokes laser pulses are 14,000 cm −1 and 12,500 cm −1 , and their spectral bandwidths are both 700 cm −1. By properly modulating the spectral phase distribution and cutting the frequency components, the stimulated Raman transition probabilities of two excited state keep maximal, while the other one can be suppressed to zero. The shaped pump and Stokes pulse irradiate obliquely into the TERS nanostructure containing a single layer molecule. The impulse response in temporal and frequency domain is calculated by using finite-difference time-domain (FDTD) simulation followed by Fourier transform. The frequency components and the relative phase are same with the corresponding input pulses, but the intensities are enhanced by more than 10 times. Compared with the case without the TERS nanostructure, the probability of selective excited Raman transition increases by more than 4 orders of magnitude, and the selective depressed Raman peak keeps at 0.

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“…Both of these limitations can be overcome with tip‐enhanced Raman spectroscopy (TERS), which allows for high spatial resolution imaging by locally enhancing the excitation and scattered fields. For graphene, TERS has allowed for nanoscale imaging of twisted bilayer graphene, characterization of the number of graphene layers, surface contamination, defects and edges, strain, doping, and plasmonic effects …”

Section: Introductionmentioning

confidence: 99%

Tip‐enhanced Raman scattering of graphene

Beams

2017

J Raman Spectroscopy

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This article reviews the mechanism of tip-enhanced Raman spectroscopy (TERS) and its importance for characterizing graphene. The theoretical foundation of TERS and experimental implementation are discussed. Conventionally, Raman scattering is treated as a spatially incoherent process where the total signal is proportional to the scattering volume. However, in the near-field regime, the scattered fields can add coherently because the TERS interaction volume is on the same length scale as the phonon correlation length. These coherence effects are significant for two-dimensional materials as will be discussed theoretically and experimentally. Therefore, TERS provides an optical method to probe phonon correlations at the nanoscale. In addition, this article will review the TERS applications for characterizing defects, edges, and nanoscale strain in graphene. Finally, the outlook and future applications are discussed. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

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Characterization of SiC-grown epitaxial graphene microislands using tip-enhanced Raman spectroscopy

Cited by 15 publications

References 65 publications

Raman Study of Strain Relaxation from Grain Boundaries in Epitaxial Graphene Grown by Chemical Vapor Deposition on SiC

Raman Study of Strain Relaxation from Grain Boundaries in Epitaxial Graphene Grown by Chemical Vapor Deposition on SiC

Selective Excitation on Tip-Enhanced Raman Spectroscopy by Pulse Shaping Femtosecond Laser

Tip‐enhanced Raman scattering of graphene

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