Promising pyridinium ylide based anchors towards high-efficiency dyes for dye-sensitized solar cells applications: Insights from theoretical investigations

We theoretically examine a series of anchors for dye-sensitized solar cells application, with particular attention was paid to the potential of novel pyridinium ylide based anchors. The geometrical structure, electronic property, and optical spectrum of the isolated dyes and its interface with TiO2 are analyzed by using quantum chemistry calculations. Quantum dynamics simulation is performed to investigate the interface electron transfer process across the dye/TiO2 interface. The key parameters influencing the short-circuit current and open-circuit voltage are calculated to quantify the performance of different dyes. Our results show that the pyridinium ylide based anchors benefit light-harvesting and improve intramolecular charge transfer character as well as shift up the conduction band edge of TiO2 semi-conductor which further increase short-circuit current and open-circuit voltage. Conjugated rhodanime-3-acetic anchor exhibits the enhanced electron injection than the non-conjugated structure due to the more significant donor-acceptor interaction. The simulation performed in this work demonstrates the potential of novel pyridinium ylide based anchors with respect to the traditional carboxylic acid and rhodanime-3-acetic based anchors, reveals the crucial role of local structure variation in the interface electron transfer, and finally guides the design of high-efficiency sensitizer for dye-sensitized solar cells application. (C) 2018 Elsevier Ltd. All rights reserved.