Charge-Transfer Mechanism in Graphene-Enhanced Raman Scattering
Charge-Transfer Mechanism in Graphene-Enhanced Raman Scattering
复制标题
石墨烯增强拉曼散射中的电荷转移机制
DOI：
10.1021/jp3088447
复制
发表时间：
2012-11-29
影响因子：
3.7
通讯作者：
Zhang, Jin
中科院分区：
文献类型：
--
作者：
Ling, Xi;Moura, L. G.;Zhang, Jin
在拉曼散射的化学增强机理中，讨论了两种电荷转移模型。激发态和基态的电荷转移机制，表现出增强的拉曼信号对激发的不同依赖性。波长研究石墨烯增强拉曼散射中的电荷转移机制，研究酞菁铜的拉曼激发光谱。（CuPc）分子在545-660 nm范围内得到。用普通共振拉曼散射公式拟合了GERS系统中的谱线，其中入射和散射共振峰很好地区分开来，能量差等于分子振动的能量。这一结果符合基态电荷转移的预测，在该模型中，增强的拉曼信号对激发的依赖性：波长与普通的拉曼散射的波长相同，并且由于观察到可能的电荷转移共振峰，排除了激发态电荷转移的预测：因此，GERS被证明是基态电荷转移：同时，由于GEM系统可以很容易地获得分子的拉曼激发谱，而这通常是很难获得的。GERS为抑制这种效应开辟了一条新的途径：这项工作有助于更深入地理解石墨烯增强的拉曼散射。
In the chemical enhancement Mechanism for Raman scattering the two types of charge transfer models,. the excited state and the ground state charge transfer mechanisms, present the different dependence of the enhanced Raman signals on the excitation. wavelength. To investigate the type of charge transfer mechanism in graphene-enhanced Raman scattering (GERS); the Raman excitation profiles of the copper phthalocyanine.(CuPc) molecule were obtained in the range of 545-660 nm. The profiles in the GERS system were fitted Well with the function of the ordinary resonant Raman scattering expression, Where the incident and scattered resonance peaks Were well-distinguished with the energy difference equaling the energy of the Molecular vibrations. This result meets the prediction of ground-state charge transfer, in which model the dependence of the enhanced Raman signals on the excitation :Wavelength is the same as that of the ordinary;Raman scattering, and rules out the prediction of the excited-state charge transfer because of the possible charge-transfer resonance peak observed: Therefore, the GERS was proved to be a ground-state charge-transfer:Mechanism:Meanwhile,because the Raman excitation profiles of molecule can be obtained in the GEM system easily, Which is usually difficult to obtain due. to the absorption of the molecules, GERS opens up a new way to suppress this effect: This work contributes the deeper understanding, : of the graphene-enhanced Raman scattering.