中文摘要：

为了研究四硫富瓦烯（TTF）基团对有机染料敏化剂光电性能的影响，以咔唑染料Dye 1 为原型，引入TTF基团作为电子给体，设计了咔唑染料Dye 2. 采用密度泛函理论（DFT）和含时密度泛函理论（TD-DFT）分别计算模拟了纯染料分子和吸附团簇（TiO2）9后的形貌、分子轨道能级以及紫外-可见吸收光谱，采用周期性密度泛函理论计算模拟染料分子在二氧化钛（101）面吸附的表面形貌. 结果发现：在有机染料中引入TTF基团有助于有机染料敏化剂在二氧化钛表面的抗团聚作用和分子内的电荷转移；最为重要的是，TTF 基团的强给电子能力极大地增强了有机染料敏化剂的光捕获能力. 所有的计算结果表明，TTF基团是一种非常有潜力改善染料敏化剂光电性能的给电子基团.

英文摘要：

To investigate the effect of a tetrathiafulvalene （TTF） unit on the photovoltaic properties of the corresponding dye sensitizer, a TTF-carbazole-based sensitizer, Dye 2, was designed; it was based on the framework of Dye 1. The geometries, electronic structures, and optical properties of Dye 1 and Dye 2 before and after binding to （TiO2）9 clusters were investigated using density functional theory （DFT） and time- dependent DFT. The surface morphologies of the dyes on TiO2 （101） surfaces were simulated by periodic DFT calculations using the DMol^3 program. The calculated results showed that the introduction of TTF units into dyes could help to inhibit dye aggregation on the TiO2 surface; this is conducive to intramolecular charge-transfer transitions and significantly improves the light-harvesting ability. The calculated results demonstrate that the TTF unit is a very promising electron donor for improving the photovoltaic properties of organic dye sensitizers.