Highly asymmetrical porphyrins with enhanced push-pull character for dye-sensitized solar cells.
A porphyrin π-system has been modulated by enhancing the push-pull character with highly asymmetrical substitution for dye-sensitized solar cells for the first time. Namely, both two diarylamino moieties as a strong electron-donating group and one carboxyphenylethynyl moiety as a strong electron-withdrawing, anchoring group were introduced into the meso-positions of the porphyrin core in a lower symmetrical manner. As a result of the improved light-harvesting property as well as high electron distribution in the anchoring group of LUMO, a push-pull-enhanced, porphyrin-sensitized solar cell exhibited more than 10% power conversion efficiency, which exceeded that of a representative highly efficient porphyrin (i.e., YD2)-sensitized solar cell under optimized conditions. The rational molecular design concept based on highly asymmetric, push-pull substitution will open the possibilities of further improving cell performance in organic solar cells.
Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Nishikyo-ku, Kyoto 615-8510 (Japan), Fax: (+81) 75-383-2571.
Kei
K
Kurotobi
Yuuki
Y
Toude
Kyosuke
K
Kawamoto
Yamato
Y
Fujimori
Seigo
S
Ito
Pavel
P
Chabera
Villy
V
Sundström
Hiroshi
H
Imahori
absorption spectroscopy; electron transfer; porphyrinoids; solar cells; titanium oxide