Phenylenevinylene copolymers of dihexylthienylbenzothiadiazole and triphenylamine or tetraphenylbenzidine: synthesis, characterization and photovoltaic properties

Abstract

Three novel low-band gap phenylenevinylene copolymers (P1, P2, and P3), containing dihexylthienylbenzothiadiazole (DTBT) and triphenylamine (TPA) or tetraphenylbenzidine (TPD) were synthesized via the Wittig-Horner reaction. The effects of TPA and TPD on the thermal, optical, electrochemical and photovoltaic properties were investigated. The UV-Vis spectrum of P3, which contains TPD in the polymer backbone, exhibits a broader and stronger absorption in the film than those of P1 and P2. The bulk heterojunction solar cells were fabricated with the as-synthesized polymers as the donors and [6,6]-phenyl-C 61 -butyric acid methyl ester as the acceptor in a 1:4 weight ratio. The device based on P3 exhibits the maximum power conversion efficiency of 1.11 % under simulated AM 1.5 G solar irradiation (100 mW/cm 2 ).

Exploring Structure-Property Relationships in a Bio-Inspired Family of Bipodal and Electronically-Coupled Bistriphenylamine Dyes for Dye-Sensitized Solar Cell Applications

“…Our synthesized family of bichromic-bipodal D-π-D-A dyes are presented in Figure 2 and organized into three groups. The full synthetic procedures and characterization of these dyes and 16 novel precursors inspired from previously reported building blocks [46][47][48][49][50] can be found in the Supporting Information. Dyes in Group 1 do not have any thiophene π-spacers, whereas, dyes in Group 2 contain one thiophene π-spacer between the two TPA units, and dyes in Group 3 contain two thiophene π-spacers between the two TPA units.…”