Cyclic thiourea/urea functionalized triphenylamine-based dyes for high-performance dye-sensitized solar cells.

Six cyclic thiourea/urea functionalized triphenylamine-based dyes (AZ1-AZ6) containing 2-cyanoacrylic acid as an acceptor and various linkers (phenyl, biphenyl, and bithiophene) were synthesized. They exhibited high photovoltaic performance owing to an improved short-circuit photocurrent density (J(sc)) and open-circuit voltage (V(oc)). Among them, AZ6 bearing a cyclic thiourea group and bithiophene linker showed the highest power conversion efficiency (PCE) up to 7.29%, which was comparable to that of N719 (PCE = 7.36%).