Main content area

Systematic Study of the Effect of Auxiliary Acceptors in D–A′−π–A Sensitizers Used on Dye-Sensitized Solar Cells C

Li, Ping, Zhang, Houyu, Troisi, Alessandro
Journal of physical chemistry 2018 v.122 no.42 pp. 23890-23898
dyes, energy, physical chemistry, quantum mechanics, solar cells
We perform a systematic quantum chemical investigation to elucidate the effect of auxiliary acceptors (A′) on the electronic properties of D–A′−π–A dyes used in dye-sensitized solar cells. A large set of dyes (380) are considered to achieve robust conclusions. Our calculations indicate that the auxiliary acceptor modulates, as expected, the lowest unoccupied molecular orbital level of the dye, except for very poor acceptors. More surprisingly, some auxiliary acceptors also modify the highest occupied molecular orbital level of the dye and its excited states effectively act as auxiliary donors as well. The study of the data set reveals that the effect of changing the π-bridges is highly systematic and predictable. Despite the variability in the geometry between the connected fragments, the frontier molecular orbital energy levels of dyes are very closely related to the energy levels of the component fragments, e.g., it is easy to predict the change in the electronic structure of a dye due to the change of one of its constituents.