Asymmetric double donor-π-acceptor dyes based on phenothiazine and carbazole donors for dye-sensitized solar cells

Four organic dyes with asymmetric double donor-π-acceptors system based on phenothiazine and carbazole donors were designed, synthesized and utilized in dye-sensitized solar cells (DSSCs). Among four dyes, dye with octyl chain and cyanoacetic acid acceptor exhibits the highest short-circuit photocurrent density (9.64 mA cm−2) and open-circuit photovoltage (720 mV), leading to the best overall power conversion efficiency of 4.76%.231