Beyond Vibrationally Mediated Electron Transfer: Coherent Phenomena Induced by Ultrafast Charge Separation
Robert Huber, Lars Dworak, Jacques E. Moser, Michael Grätzel, Josef Wachtveitl
备注：
This work was supported by the German Research Foundation (DFG) (Hu 1006/6-1, WA 1850/6-1) and European Union projects FDML-Raman (FP7 ERC StG, contract no. 259158) and ENCOMOLE-2i (Horizon 2020, ERC CoG no. 646669)
发表信息：
The Journal of Physical Chemistry C 2016 120 (16), 8534-8539
Wave packet propagation succeeding electron transfer (ET) from alizarin dye molecules into the nanocrystalline TiO2 semiconductor has been studied by ultrafast transient absorption spectroscopy. Due to the ultrafast time scale of the ET reaction of about 6 fs the system shows substantial differences to molecular ET systems. We show that the ET process is not mediated by molecular vibrations and therefore classical ET theories lose their applicability. Here the ET reaction itself prepares a vibrational wave packet and not the electromagnetic excitation by the laser pulse. Furthermore, the generation of phonons during polaron formation in the TiO2 lattice is observed in real time for this system. The presented investigations enable an unambiguous assignment of the involved photoinduced mechanisms and can contribute to a corresponding extension of molecular ET theories to ultrafast ET systems like alizarin/TiO2.
Elucidating Norrish Type-I reactive pathways by ultrafast X-ray absorption spectroscopy
Stanford PULSE Institute, SLAC National Accelerator Laboratory（斯坦福PULSE研究所，SLAC国家加速器实验室）；Department of Physics, Ludwig-Maximilians-Universität München（慕尼黑路德维希-马克西米利安大学物理系）；Department of Chemistry, Stanford University（斯坦福大学化学系）；Linac Coherent Light Source, SLAC National Accelerator Laboratory（SLAC国家加速器实验室直线相干光源）；Department of Chemistry, Columbia University（哥伦比亚大学化学系）；Initiative for Computational Catalysis, Flatiron Institute（平井研究所计算催化倡议）
XMCQDPT2-Fidelity Transfer-Learning Potentials and a Wavepacket Oscillation Model with Power-Law Decay for Ultrafast Photodynamics
Department of Chemistry, Lomonosov Moscow State University（莫斯科大学化学系）；MSU Institute for Artificial Intelligence, Lomonosov Moscow State University（莫斯科大学人工智能研究所）；Institute of Quantum Physics, Irkutsk National Research Technical University（伊尔库茨克国立研究技术大学量子物理研究所）
