Influence of the benzo[d]thiazole-derived π-bridges on the optical and photovoltaic performance of D-π-A dyes

New metal-free organic sensitizers containing a benzo[d]thiazole or phenyl unit as the pi-conjugated system, a triphenylamine as an electron donor, and a cyanoacrylic acid moiety as an electron acceptor were synthesized and used for dye-sensitized solar cells. Photophysical and electrochemical properties of these dyes were investigated, and their performances as sensitizers in solar cells were measured. The introduction of a benzo[d]thiazole unit into the molecular structure resulted in a high incident photon-to-current conversion efficiency (more than 70%) from 340 nm to 600 nm. One solar cell containing a benzo[d]thiazole unit, produced a eta of 5.85% (J(SC) = 10.63 mA cm(-2), V-OC = 0.72 V, and ff = 0.77) under 100 mW cm(-2) simulated AM 1.5 G solar irradiation. (C) 2012 Elsevier Ltd. All rights reserved.