Organic dyes that consist of an anthracene moiety between a triphenylamine donor group and a cyanoacrylic acid acceptor group displayed remarkable solar-to-energy conversion efficiency in dyesensitized solar cells. The planar geometry of anthracene and its bulky substituents helped the dyes to form a high quality monolayer on the surface of TiO2. A typical device made with the dye AN-Bu displayed a maximal photon-to-current conversion efficiency (IPCE) 65% in the region of 350-510 nm, a short-circuit photocurrent density (J(sc)) 12.78 mA cm(-2), an open-circuit photovoltage (V-oc) 0.73 V, and a fill factor (FF) 0.67, corresponding to an overall conversion efficiency 6.23%. In an experiment of using deoxycholic acid (DCA) as a co-absorbent, the values of Vo, stayed in a similar range, yet the values offs were reduced in ca. 11% due to a decrease of loading amounts. This result indicated that the quality of the dye films cannot be further improved by the adding of DCA. The photophysical properties were analyzed with the aid of a time-dependent density functional theory (TDDFT) model with the B3LYP functional. (C) 2013 Elsevier Ltd. All rights reserved.
