Song Yanlin, Lu Xiaofang, Sheng Yang, Geng Zhiyuan
Gansu Key Laboratory of Polymer Materials, College of Chemistry and Chemical Engineering, Key Laboratory of Eco-environment-related Polymer Materials; Ministry of Education, Northwest Normal University, Lanzhou, 730070, Gansu, People's Republic of China.
J Mol Model. 2018 Nov 15;24(12):339. doi: 10.1007/s00894-018-3871-9.
In light of the performance of the SD2 pigments in DSSC, in order to expand the absorption spectral scope, decrease the energy difference between the highest occupied and the lowest unoccupied molecular orbitals, with SD2 dye molecular electron donor and electron acceptor as the fundamental framework, the indole fragment and thiophene derivative in the prototype dye molecule were replaced by the two π-bridges (labeled PA, PB, respectively) and the four auxiliary electron acceptors (labeled A1, A2, A3, A4, respectively). For the sake of characterizing dye molecules as thoroughly as possible in DSSC, the frontier orbital energy levels, ultraviolet absorption spectra, natural bond orbital analysis, intramolecular charge transfer, charge and hole reorganization energies, parameters influencing the short-circuit current density and the open-circuit photovoltage for these eight individual dye molecules are carried out to try to fully characterize the properties of these dye molecules. According to these computational results of physical quantities and based on the performance of these dye molecules in the above aspects, in this paper, six free molecular models were picked out to combine with titanium dioxide cluster to calculate their geometrical structures, frontier orbital distributions, electron excitation energies, ultraviolet absorption spectra and the composition of the electronic transitions in chloroform solvent with polarizable continuum model. The results of these calculations show that the PA-A2 and PB-A4 dye molecule has better properties in electron transfer and spectral absorption range before and after the adsorption on the titanium dioxide.
鉴于SD2颜料在染料敏化太阳能电池（DSSC）中的性能，为了扩大吸收光谱范围，减小最高占据分子轨道和最低未占据分子轨道之间的能量差，以SD2染料分子的电子供体和电子受体为基本框架，将原型染料分子中的吲哚片段和噻吩衍生物分别用两个π桥（分别标记为PA、PB）和四个辅助电子受体（分别标记为A1、A2、A3、A4）取代。为了在DSSC中尽可能全面地表征染料分子，对这八个单独的染料分子进行了前沿轨道能级、紫外吸收光谱、自然键轨道分析、分子内电荷转移、电荷和空穴重组能、影响短路电流密度和开路光电压的参数等研究，试图充分表征这些染料分子的性质。根据这些物理量的计算结果，并基于这些染料分子在上述方面的性能，本文挑选出六个自由分子模型与二氧化钛簇结合，在极化连续介质模型下计算它们在氯仿溶剂中的几何结构、前沿轨道分布、电子激发能、紫外吸收光谱以及电子跃迁组成。这些计算结果表明，PA - A2和PB - A4染料分子在吸附于二氧化钛前后的电子转移和光谱吸收范围方面具有更好的性能。
