Probing the acoustic phonon dispersion and sound velocity of graphene by Raman spectroscopy
Probing the acoustic phonon dispersion and sound velocity of graphene by Raman spectroscopy
复制标题
用拉曼光谱探测石墨烯的声学声子色散和声速
DOI：
10.1016/j.carbon.2019.04.006
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发表时间：
2019-08-01
期刊：
影响因子：
10.9
通讯作者：
Tan, Ping-Heng
中科院分区：
文献类型：
--
作者：
Cong, Xin;Li, Qiao-Qiao;Tan, Ping-Heng
石墨烯在布里渊区Gamma点附近具有独特的声学声子分支，因而具有优异的热弹性性能，在基础研究和实际应用中引起了人们的极大关注。在这里，我们介绍了一种光学技术，以准确地探测纵向声学（LA）和横向声学（TA）声子分支的石墨烯在伽马点附近的双共振拉曼散射的组合声子模式在1650 - 2150 cm（-1）的范围内沿着与泛音2D'模式在类似于3200 cm（-1）。计算了石墨烯的声速（nu（TA）= 12：9 km/s，nu（LA）= 19.9km/s），比石墨的声速小10%左右。基于nu（TA）和nu（LA），可以估计二维（2d）弹性刚度（张力）系数c（11）和c（66）、杨氏模量Y-2d和泊松比σ（2d）。结果再次表明，双共振拉曼光谱是一个强大的工具，探测石墨烯的基本性质。(C)2019爱思唯尔有限公司版权所有。
The extraordinary thermal and elastic properties of graphene, mainly originating from its unique acoustic phonon branches near Gamma point in Brillouin zone, have attracted great attention in its fundamental researches and practical applications. Here, we introduce an optical technique to accurately probe longitudinal acoustic (LA) and transverse acoustic (TA) phonon branches of graphene near Gamma point by double resonant Raman scattering of the combination phonon modes in the range of 1650 - 2150 cm(-1) along with the overtone 2D' mode at similar to 3200 cm(-1). The corresponding sound velocities (nu(TA) = 12:9 km/s,nu(LA) = 19.9 km/s) of graphene have been accessed, which are about 10% smaller than those of graphite. Based on nu(TA) and nu(LA), the two-dimensional (2d) elastic stiffness (tension) coefficients c(11) and c(66), Young's modulus Y-2d and Poisson's ratio sigma(2d) can be estimated. The results demonstrate again that double resonant Raman spectroscopy is a powerful tool to probe the fundamental properties of graphene. (C) 2019 Elsevier Ltd. All rights reserved.