title: Modification of D-A-π-A configuration toward a high-performance triphenylamine-based sensitizer for dye-sensitized solar cells: a theoretical investigation.
abstract: In an attempt to shed light on how the addition of a benzothiadiazole (BTD) moiety influences the properties of dyes, a series of newly designed triphenylamine-based sensitizers incorporating a BTD unit as an additional electron-withdrawing group in a specific donor-acceptor-π-acceptor architecture has been investigated. We found that different positions of the BTD unit provided significantly different responses for light absorption. Among these, it was established that the further the BTD unit is away from the donor part, the broader the absorption spectra, which is an observation that can be applied to improve light-harvesting ability. However, when the BTD unit is connected to the anchoring group a faster, unfavorable charge recombination takes place; therefore, a thiophene unit was inserted between these two acceptors, providing redshifted absorption spectra as well as blocking unfavorable charge recombination. The results of our calculations provide valuable information and illustrate the potential benefits of using computation-aided sensitizer design prior to further experimental synthesis.
authors.affiliation: Center for Organic Electronic and Alternative Energy, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190 (Thailand).
authors.forename: Ruangchai
authors.initials: R
authors.lastname: Tarsang
authors.forename: Vinich
authors.initials: V
authors.lastname: Promarak
authors.forename: Taweesak
authors.initials: T
authors.lastname: Sudyoadsuk
authors.forename: Supawadee
authors.initials: S
authors.lastname: Namuangruk
authors.forename: Nawee
authors.initials: N
authors.lastname: Kungwan
authors.forename: Siriporn
authors.initials: S
authors.lastname: Jungsuttiwong
keywords: density functional calculations; donor-acceptor systems; electron transfer; energy conversion; sensitizers