title: Peripheral Hole Acceptor Moieties on an Organic Dye Improve Dye-Sensitized Solar Cell Performance.
abstract: Investigation of charge transfer dynamics in dye-sensitized solar cells is of fundamental interest and the control of these dynamics is a key factor for developing more efficient solar cell devices. One possibility for attenuating losses through recombination between injected electrons and oxidized dye molecules is to move the positive charge further away from the metal oxide surface. For this purpose, a metal-free dye named E6 is developed, in which the chromophore core is tethered to two external triphenylamine (TPA) units. After photoinduced electron injection into TiO2, the remaining hole is rapidly transferred to a peripheral TPA unit. Electron-hole recombination is slowed down by 30% compared to a reference dye without peripheral TPA units. Furthermore, it is found that the added TPA moieties improve the electron blocking effect of the dye, retarding recombination of electrons from TiO2to the cobalt-based electrolyte.
authors.affiliation: Department of Chemistry-Ångström Laboratory Center of Molecular Devices Uppsala University Box 523 751 20 Uppsala Sweden.
authors.forename: Yan
authors.initials: Y
authors.lastname: Hao
authors.affiliation: Organic Chemistry Centre of Molecular Devices Department of Chemistry Chemical Science and Engineering Royal Institute of Technology (KTH) SE-10044 Stockholm Sweden.
authors.forename: Erik
authors.initials: E
authors.lastname: Gabrielsson
authors.affiliation: Department of Chemistry-Ångström Laboratory Center of Molecular Devices Uppsala University Box 523 751 20 Uppsala Sweden.
authors.forename: Peter William
authors.initials: PW
authors.lastname: Lohse
authors.affiliation: Department of Chemistry-Ångström Laboratory Center of Molecular Devices Uppsala University Box 523 751 20 Uppsala Sweden.
authors.forename: Wenxing
authors.initials: W
authors.lastname: Yang
authors.affiliation: Department of Chemistry-Ångström Laboratory Center of Molecular Devices Uppsala University Box 523 751 20 Uppsala Sweden.
authors.forename: Erik M J
authors.initials: EM
authors.lastname: Johansson
authors.affiliation: Department of Chemistry-Ångström Laboratory Center of Molecular Devices Uppsala University Box 523 751 20 Uppsala Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Hagfeldt
authors.affiliation: Organic Chemistry Centre of Molecular Devices Department of Chemistry Chemical Science and Engineering Royal Institute of Technology (KTH)SE-10044 Stockholm Sweden; State Key Laboratory of Fine Chemicals DUT-KTH Joint Research Centre on Molecular Devices Dalian University of Technology (DUT) 116024 Dalian China.
authors.forename: Licheng
authors.initials: L
authors.lastname: Sun
authors.affiliation: Department of Chemistry-Ångström Laboratory Center of Molecular Devices Uppsala University Box 523 751 20 Uppsala Sweden.
authors.forename: Gerrit
authors.initials: G
authors.lastname: Boschloo
keywords: cobalt electrolytes; dye‐sensitized solar cells; hole transport; interfacial charge transfer; recombination dynamics