染料敏化TiO2纳晶体系激发态振动相干效应对光致电子转移速率的影响

Effects of Excited State Vibrational Coherence on Photo-Induced Electron Transfer Rates in Dye-Sensitized Nanocrystalline TiO_2

基于激发态电子占有率表达式和Frank-Condon因子唯象公式,当染料激发态振动能级单模振动频率为0.2eV和TiO2纳晶半导体导带宽为1.4eV时,从理论上研究了取不同重组能、注入能级位置和初始振动波包时激发态振动能级间振动相干效应对光致电子转移速率的影响.与文献的理论结果比较,证实了唯象公式的合理性,其相关修正参数分别为A=16,B=0.4735,C=0.1.本文的工作将为进行光致电子转移速率的实验研究和染料敏化太阳能电池的应用研究提供理论基础和指导.

Based on the expression for the electron occupation probability of the excited state, and the empirical formula of the Franck-Condon factor, theoretical investigations of the effects of excited state vibrational coherence on photo-induced electron transfer rates of a nanocrystalline TiO2 semiconductor were carried out. The calculations were performed at different values of reorganization energy, various energetic positions for the injecting level and several initial vibrational wave packets, using a single vibrational spacing mode of 0.2 eV and a conductor bandwidth of 1.4 eV. Comparing the results to the published literature confirmed that the empirical formula should be rationalized with modified parameters of A=16, B=0.4735, and C=0.1. This work will provide a theoretical basis and guidance for future experimental work concerning photo-induced electron transfer rates as well as research into applications of dyesensitized solar cells.