title: Factors Affecting the Performance of Champion Silyl-Anchor Carbazole Dye Revealed in the Femtosecond to Second Studies of Complete ADEKA-1 Sensitized Solar Cells.
abstract: Record laboratory efficiencies of dye-sensitized solar cells have been recently reported using an alkoxysilyl-anchor dye, ADEKA-1 (over 14 %). In this work we use time-resolved techniques to study the impact of key preparation factors (dye synthesis route, addition of co-adsorbent, use of cobalt-based electrolytes of different redox potential, creation of insulating Al2O3layers and molecule capping passivation of the electrode) on the partial charge separation efficiencies in ADEKA-1 solar cells. We have observed that unwanted fast recombination of electrons from titania to the dye, probably associated with the orientation of the dyes on the titania surface, plays a crucial role in the performance of the cells. This recombination, taking place on the sub-ns and ns time scales, is suppressed in the optimized dye synthesis methods and upon addition of the co-adsorbent. Capping treatment significantly reduces the charge recombination between titania and electrolyte, improving the electron lifetime from tens of ms to hundreds of ms, or even to single seconds. Similar increase in electron lifetime is observed for homogenous Al2O3over-layers on titania nanoparticles, however, in this case the total solar cells photocurrent is decreased due to smaller electron injection yield from the dye. Our studies should be important for a broader use of very promising silyl-anchor dyes and the further optimization and development of dye-sensitized solar cells.
authors.affiliation: NanoBioMedical Centre, Adam Mickiewicz University in Poznań, Umultowska 85, 61-614, Poznań, Poland.|Quantum Electronics Laboratory, Faculty of Physics, Adam Mickiewicz University in Poznań, Umultowska 85, 61-614, Poznań, Poland.
authors.forename: Jan
authors.initials: J
authors.lastname: Sobuś
authors.affiliation: Faculty of Chemistry, Adam Mickiewicz University in Poznań, Umultowska 89b, 61-614, Poznań, Poland.
authors.forename: Błażej
authors.initials: B
authors.lastname: Gierczyk
authors.affiliation: Quantum Electronics Laboratory, Faculty of Physics, Adam Mickiewicz University in Poznań, Umultowska 85, 61-614, Poznań, Poland.
authors.forename: Gotard
authors.initials: G
authors.lastname: Burdziński
authors.affiliation: NanoBioMedical Centre, Adam Mickiewicz University in Poznań, Umultowska 85, 61-614, Poznań, Poland.
authors.forename: Mariusz
authors.initials: M
authors.lastname: Jancelewicz
authors.affiliation: Laboratory of Photomolecular Science, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland.|Department of Physical Chemistry, University of Tor Vergata-Rome, Via della Ricerca Scientifica 1, 00133, Rome, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Polanski
authors.affiliation: Laboratory of Photomolecular Science, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland.
authors.forename: Anders
authors.initials: A
authors.lastname: Hagfeldt
authors.affiliation: Quantum Electronics Laboratory, Faculty of Physics, Adam Mickiewicz University in Poznań, Umultowska 85, 61-614, Poznań, Poland. marziol@amu.edu.pl.
authors.forename: Marcin
authors.identifier: http://orcid.org/0000-0003-1882-6022
authors.initials: M
authors.lastname: Ziółek
keywords: cobalt-based electrolytes; dye-sensitized solar cells; dyes/pigments; time-resolved laser spectroscopy