Inorganic Chemistry, Center of Molecular Devices, Royal Institute of Technology, Teknikringen 30, 10044 Stockholm, Sweden.
Langmuir. 2010 Feb 16;26(4):2592-8. doi: 10.1021/la902897z.
Three donor-linker-acceptor triphenylamine-based cyanoacrylic acid organic dyes used for dye-sensitized solar cells (DSCs) have been examined with respect to their effect on the open-circuit voltage (V(oc)). Our previous study showed a decrease in V(oc) for DSCs based on dyes with increased molecular size (increased linker conjugation). In the present study, we investigate the origin of V(oc) with respect to (i) conduction band (E(CB)) positions of TiO(2) and (ii) degree of recombination between electrons in TiO(2) and electrolyte acceptor species at the interface. These parameters were studied as a function of dye structure, dye load, and I(2) concentration. Two types of behavior were identified: the smaller polyene dyes show a surface-protecting effect preventing recombination upon increased dye loading, whereas the larger dyes enhance the recombination. How the different dye structures affect the recombination is discussed in terms of dye surface blocking and intermolecular interactions between dyes and electrolyte acceptor species.
三种供体-连接体-受体三苯胺基氰基丙烯酸有机染料已被用于染料敏化太阳能电池 (DSC)，以研究它们对开路电压 (V(oc)) 的影响。我们之前的研究表明，基于分子尺寸增大的染料 (增加连接体共轭) 的 DSCs 的 V(oc) 降低。在本研究中，我们研究了开路电压与 (i) TiO(2) 的导带 (E(CB)) 位置和 (ii) TiO(2) 中的电子与界面处电解质受体物种之间的复合程度的关系。这些参数作为染料结构、染料负载和 I(2) 浓度的函数进行了研究。确定了两种类型的行为：较小的多烯染料表现出表面保护效应，可防止在增加染料负载时发生复合，而较大的染料则增强了复合。不同染料结构如何影响复合是根据染料表面阻塞和染料与电解质受体物种之间的分子间相互作用来讨论的。
