Enhanced photovoltaic performances of dye-sensitized solar cells sensitized with D-D-π-A phenothiazine-based dyes

Two new D-D-pi-A phenothiazine-based metal free organic dyes (WY5, WY6) were designed, synthesized, and applied in dye-sensitized solar cells (DSSCs) by introducing of benzil-based auxiliary electron donors into simple D-pi-A phenothiazine dye to improve the related photovoltaic performances. In the WY6-based solar cell, 4,4'-dimethoxybenzil acts as electron donor was used to improve the electron donating ability. So, the WY6-based solar cell finally obtains a better photovoltaic performance than that of WY5-based one. Furthermore, with the addition of benzil-based auxiliary donor, the absorption properties turn better, which directly results in the enhanced short-circuit photocurrent density (from 8.78 (T0) to 10.58 (WY5) and 11.50 mAcm(-2) (WY6)) and thus the enhanced power conversion efficiency (from 4.24 (T0) to 4.78 (WY5) and 5.52% (WY6)). In a word, the addition of benzil-based auxiliary electron donors effectively improved the performances of DSSCs. (C) 2016 Elsevier B.V. All rights reserved.