The influence of shell parameters on phonons in core-shell nanoparticles: a resonant Raman study
The influence of shell parameters on phonons in core-shell nanoparticles: a resonant Raman study
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DOI：
10.1088/0957-4484/20/36/365704
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发表时间：
2009-09-09
期刊：
影响因子：
3.5
通讯作者：
Zahn, D. R. T.
中科院分区：
文献类型：
--
作者：
Dzhagan, V. M.;Valakh, M. Ya;Zahn, D. R. T.
研究了不同壳层厚度对CdSe/ZnS核壳纳米粒子振动共振拉曼光谱的影响。壳沉积的方法的核-壳结构的依赖性来自纳米粒子的振动和光致发光光谱的比较。沿着壳层峰的出现，核的声子谱在壳层生长后发生了显著的变化。在核壳纳米粒子的CdSe LO峰线形的变化进行了讨论，相对于壳形成时的光学和声学声子的光谱可能发生的变化。基于观察到的CdSe 2LO/LO峰强度比的下降，激子耦合到CdSe LO声子的ZnS壳层沉积后，假设减弱。壳形成后的载体本地化体积的变化进行了讨论，作为一个可能的原因减少耦合。
The effect of shells of various thicknesses on the vibrational resonant Raman spectra of CdSe/ZnS core-shell nanoparticles is studied. The dependence of the core-shell structure on the method of shell deposition is derived from a comparison of the vibrational and photoluminescence spectra of nanoparticles. Along with the appearance of peaks attributed to the shell, the phonon spectrum of the core undergoes significant changes upon shell growth. The change of the CdSe LO peak lineshape in core-shell nanoparticles is discussed with respect to possible changes in the spectrum of both optical and acoustical phonons upon shell formation. Based on the observed decrease of the CdSe 2LO/LO peak intensity ratio, a weakening of exciton coupling to the CdSe LO phonon upon ZnS shell deposition is supposed. The change in the carrier localization volumes upon shell formation is discussed as a possible reason for the reduced coupling.