Ultraviolet Raman Spectroscopy of Single and Multi-layer Graphene
TLDR
In this paper, the authors investigated the Raman spectra of single-layer and multi-layer graphene under ultraviolet laser excitation at the wavelength of 325 nm and found that while the G peak of graphene remains pronounced in UV Raman, the 2D band intensity undergoes severe quenching.Abstract:
We investigated Raman spectra of single-layer and multi-layer graphene under ultraviolet laser excitation at the wavelength of 325 nm. It was found that while the G peak of graphene remains pronounced in UV Raman spectra, the 2D band intensity undergoes severe quenching. The evolution of the ratio of the intensities of the G and 2D peaks, I(G)/I(2D), as the number of graphene layers n changes from n=1 to n=5, is different in UV Raman spectra from that in conventional visible Raman spectra excited at the 488 nm and 633 nm wavelengths. The 2D band under UV excitation shifts to larger wave numbers and is found near 2825 1/cm. The observed UV Raman features of graphene were explained by invoking the resonant scattering model. The obtained results contribute to the Raman nanometrology of graphene by providing an additional metric for determining the number of graphene layers and assessing its quality.read more
Citations
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Graphene–Multilayer Graphene Nanocomposites as Highly Efficient Thermal Interface Materials
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Two-dimensional gallium nitride realized via graphene encapsulation
Zakaria Y. Al Balushi,Ke Wang,Ram Krishna Ghosh,Rafael A. Vilá,Sarah M. Eichfeld,Joshua D. Caldwell,Xiaoye Qin,Yu-Chuan Lin,Paul A. DeSario,Greg Stone,Shruti Subramanian,Dennis F. Paul,Robert M. Wallace,Suman Datta,Joan M. Redwing,Joshua A. Robinson +15 more
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Strongly Anisotropic Thermal Conductivity of Free‐Standing Reduced Graphene Oxide Films Annealed at High Temperature
Jackie D. Renteria,S. Ramirez,Hoda Malekpour,Beatriz Alonso,Alba Centeno,Amaia Zurutuza,Alexandr I. Cocemasov,Alexandr I. Cocemasov,Denis L. Nika,Denis L. Nika,Alexander A. Balandin +10 more
TL;DR: In this article, the in-plane and cross-plane thermal conductivity of reduced graphene oxide films subjected to a high-temperature treatment of up to 1000 °C was investigated.
References
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Journal ArticleDOI
Electric Field Effect in Atomically Thin Carbon Films
Kostya S. Novoselov,Andre K. Geim,Sergey V. Morozov,Da Jiang,Y. Zhang,S. V. Dubonos,Irina V. Grigorieva,A. A. Firsov +7 more
TL;DR: Monocrystalline graphitic films are found to be a two-dimensional semimetal with a tiny overlap between valence and conductance bands and they exhibit a strong ambipolar electric field effect.
Journal ArticleDOI
Two-dimensional gas of massless Dirac fermions in graphene
Kostya S. Novoselov,A. K. Geim,Sergey V. Morozov,Da Jiang,Mikhail I. Katsnelson,Irina V. Grigorieva,S. V. Dubonos,A. A. Firsov +7 more
TL;DR: This study reports an experimental study of a condensed-matter system (graphene, a single atomic layer of carbon) in which electron transport is essentially governed by Dirac's (relativistic) equation and reveals a variety of unusual phenomena that are characteristic of two-dimensional Dirac fermions.
Journal ArticleDOI
Raman spectrum of graphene and graphene layers.
Andrea C. Ferrari,Jannik C. Meyer,Vittorio Scardaci,Cinzia Casiraghi,Michele Lazzeri,Francesco Mauri,S. Piscanec,Da Jiang,K. S. Novoselov,S. Roth,A. K. Geim +10 more
TL;DR: This work shows that graphene's electronic structure is captured in its Raman spectrum that clearly evolves with the number of layers, and allows unambiguous, high-throughput, nondestructive identification of graphene layers, which is critically lacking in this emerging research area.
Journal ArticleDOI
Superior Thermal Conductivity of Single-Layer Graphene
Alexander A. Balandin,Suchismita Ghosh,Wenzhong Bao,Irene Calizo,Desalegne Teweldebrhan,Feng Miao,Chun Ning Lau +6 more
TL;DR: The extremely high value of the thermal conductivity suggests that graphene can outperform carbon nanotubes in heat conduction and establishes graphene as an excellent material for thermal management.
Journal ArticleDOI
Graphene-based composite materials
Sasha Stankovich,Dmitriy A. Dikin,Geoffrey Dommett,K. Kohlhaas,Eric Zimney,Eric A. Stach,Richard D. Piner,SonBinh T. Nguyen,Rodney S. Ruoff +8 more
TL;DR: The bottom-up chemical approach of tuning the graphene sheet properties provides a path to a broad new class of graphene-based materials and their use in a variety of applications.