Li Yuanzuo, Sun Chaofan, Song Peng, Ma Fengcai, Yang Yanhui
College of Science, Northeast Forestry University, Harbin, 150040, Heilongjiang, China.
Department of Physics, Liaoning University, Shenyang, 110036, Liaoning, China.
Chemphyschem. 2017 Feb 17;18(4):366-383. doi: 10.1002/cphc.201601101. Epub 2017 Jan 19.
A series of dyes, containing thiophene and thieno[3,2-b]thiophene as π-conjugated bridging units and six kinds of groups as electron acceptors, were designed for dye-sensitized solar cells (DSSCs). The ground- and excited-state properties of the designed dyes were investigated by using density functional theory (DFT) and time-dependent DFT, respectively. Moreover, the parameters affecting the short-circuit current density and open-circuit voltage were calculated to predict the photoelectrical performance of each dye. In addition, the charge difference density was presented through a three-dimensional (3D) real-space analysis method to investigate the electron-injection mechanism in the complexes. Our results show that the longer conjugated bridge would inhibit the intramolecular charge transfer, thereby affecting the photoelectrical properties of DSSCs. Similarly, owing to the lowest chemical hardness, largest electron-accepting ability, dipole moment (μnormal ) and the change in the energy of the TiO conduction band (ΔECB ), the dye with a (E)-3-(4-(benzo[c][1,2,5]thiadiazol-4-yl)phenyl)-2-cyanoacrylic acid (TCA) acceptor group would exhibit the most significant photoelectrical properties among the designed dyes.
设计了一系列以噻吩和噻吩并[3,2 - b]噻吩作为π共轭桥连单元、六种基团作为电子受体的染料，用于染料敏化太阳能电池（DSSC）。分别采用密度泛函理论（DFT）和含时密度泛函理论研究了所设计染料的基态和激发态性质。此外，计算了影响短路电流密度和开路电压的参数，以预测每种染料的光电性能。另外，通过三维（3D）实空间分析方法给出了电荷差分密度，以研究配合物中的电子注入机制。我们的结果表明，较长的共轭桥会抑制分子内电荷转移，从而影响染料敏化太阳能电池的光电性能。同样，由于具有最低的化学硬度、最大的电子接受能力、偶极矩（μ）以及二氧化钛导带能量变化（ΔECB），含有（E）-3-（4-（苯并[c][1,2,5]噻二唑-4-基）苯基）-2-氰基丙烯酸（TCA）受体基团的染料在所设计的染料中表现出最显著的光电性能。
