Probing Interfacial Electron Transfer in Coumarin 343 Sensitized TiO2 Nanoparticles with Femtosecond Stimulated Raman
Probing Interfacial Electron Transfer in Coumarin 343 Sensitized TiO2 Nanoparticles with Femtosecond Stimulated Raman
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DOI：
10.1021/ja907188b
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发表时间：
2009-11-04
影响因子：
15
通讯作者：
Mathies, Richard A.
中科院分区：
文献类型：
--
作者：
Frontiera, Renee R.;Dasgupta, Jyotishman;Mathies, Richard A.
利用飞秒受激拉曼光谱(FSRs)作为结构探针，研究了太阳能电池增敏剂香豆素343与纳米二氧化钛之间的界面电子转移。电荷转移络合物的共振拉曼光谱显示了多种振动运动，主要由碳主链和钛氧结合模式组成，这些振动将分子引导出激发态势能面上的Franck-Condon区。还报道了自由基阳离子的振动光谱和衰变动力学。这些光谱表明，空穴位于共轭碳环上，施主机制涉及多个振动运动。最后，我们对香豆素343通过结构修饰改善太阳能电池敏化性能的前景进行了讨论。
Femtosecond Stimulated Raman Spectroscopy (FSRS) is used as a structural probe of the interfacial electron transfer between Coumarin 343, a solar cell sensitizer, and TiO2 nanoparticles. Resonance Raman spectra of the charge-transfer complex reveals multiple vibrational motions, consisting primarily of carbon backbone and Ti-O binding modes, that direct the molecule out of the Franck-Condon region on the excited state potential energy surface. The vibrational spectrum and decay dynamics of the radical cation are also reported. These spectra indicate that the hole is localized on the conjugated carbon rings and that the donation mechanism involves multiple vibrational motions. We conclude with a discussion of prospects for improving the solar cell sensitization properties of Coumarin 343 through structural modification.