Coherent phonon and surface-enhanced Raman scattering dynamics in solids
Coherent phonon and surface-enhanced Raman scattering dynamics in solids
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DOI：
10.1016/j.jlumin.2014.01.058
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发表时间：
2014-08
影响因子：
3.6
通讯作者：
J. Takeda;I. Katayama;K. Shudo;M. Kitajima
中科院分区：
文献类型：
--
作者：
J. Takeda;I. Katayama;K. Shudo;M. Kitajima
研究了金(Au)沉积石墨和苯硫醇(BT)自组装单分子膜(SAM)吸附在Au膜上的相干声子和表面增强拉曼散射(SERS)动力学。利用超快泵浦-探测光谱技术，通过Au半球体或纳米级粗糙金薄膜，灵敏地探测到位于表面/界面的高频声子的暂态行为。在Au沉积的石墨中，Au纳米粒子周围的石墨表面附近的电场得到了强烈的增强，Au纳米粒子的典型直径约为10 nm。结果清楚地观察到了表面附近的无序诱导模(D模)。在BT-SAM中，Au膜的纳米级粗糙度可能有助于相干振动的幅度增强，直到检测到的能级。根据这些结果，我们相信相干SERS光谱将为未来在单分子层和单分子水平上观察相干声子动力学打开大门。
We have demonstrated coherent phonon and surface-enhanced Raman scattering (SERS) dynamics of carbon-related materials: gold (Au) deposited graphite and benzenethiol (BT) self-assembled monolayer (SAM) adsorbed on Au film with roughness. Using ultrafast pump-probe spectroscopy with the enhanced electric field via Au hemispheres or Au film with nanoscale roughness, transient behaviors of high frequency phonons located at surface/interface were sensitively detected. In Au deposited graphite, the electric field near graphite surface around Au nanoparticles, whose typical diameter is ~10 nm, is strongly enhanced. As a result, the disorder-induced mode (D-mode) near the surface was clearly observed. In BT-SAM, the nanoscale roughness of the Au film might contribute to the amplitude enhancement of coherent vibrations up to the detected level. From these results, we believe that coherent SERS spectroscopy will open the door to observe coherent phonon dynamics even at the level of monolayer and single molecules for future.