DSSCs based on aniline derivatives functionalized with a tert-butyldimethylsilyl group and the effect of the π-spacer

We have developed four new dyes for DSSCs with a tert-butyldimethylsilylether in order to test their physical and photovoltaic properties. These dyes consist of a novel donor based on a functionalized N,N-dialkylaniline, a heteroaromatic pi-conjugated spacer, such as thiophene or benzothiadiazole ring, and cyanoacetic acid as acceptor group. DFT theoretical studies predict, on the one hand, higher molar extinction coefficient for dyes with thiophene spacers than for those with benzothiadiazole groups while, on the other hand, the use of benzothiadiazole ring would give rise to the reduction of the back electron transfer (BET). The experimental studies have confirmed the predicted higher absorption of thiophene dyes and the better photovoltaic performance of the DSSCs prepared with these dyes. Finally, the stability of the response would support further studies of dyes with anilines functionalized with a tertbutyldimethylsilyl group to perform long-term devices. (C) 2017 Elsevier Ltd. All rights reserved.