NIR-absorbing heptamethine dyes with tailor-made counterions for application in light to energy conversion.
A method to exchange the counterion of cyanine dyes to Δ-TRISPHAT(-) and PF6(-) is presented. The influence of these counterions on the photophysical and electrochemical properties of the cyanine dye in solution is discussed, and tendencies in the solid packing are highlighted by X-ray crystal structures. The compounds were applied in semitransparent bilayer organic solar cells together with C60, and a power conversion efficiency of 2.2% was achieved while maintaining a high transparency level in the visible region of 66%.
Laboratory for Functional Polymers, Swiss Federal Laboratories for Materials Science and Technology (Empa) , 8600 Dübendorf, Switzerland.
Anna C
AC
Véron
Hui
H
Zhang
Anthony
A
Linden
Frank
F
Nüesch
Jakob
J
Heier
Roland
R
Hany
Thomas
T
Geiger