Towards achieving improved efficiency using newly designed dye-sensitized solar cell devices engineered with dye-anchored counter electrodes

Abstract Partial absorption of the solar spectrum is one of the key limitations of dye-sensitized solar cells (DSSCs). In an attempt to address this issue, we have developed co-sensitized working electrode based dye anchored counter electrode (DACE) DSSC strategy to achieve panchromatic absorption using multiple dyes. Herein, we have synthesized a dithionopyrrole based TP–DTP dye and a porphyrin-based Y351-S dye and explored to a new type of DSSCs modified with DACE. To realize the effect of DACE electrode on the DSSC efficiency, we have fabricated five different DSSCs devices namely, S-DSSC1, S-DSSC2, S-DACE, CO-DSSC, and CO-DACE using these synthesized dyes and compared their performances systematically. In addition, the detailed impedance and stepped light-induced transient measurements of the photocurrent and voltage (SLIM-PCV) experiments are also performed to assess the charge transfer resistance and charge collection efficiency of these devices. The highest efficiency of 8.72 ± 0.15 % is observed for the CO-DACE-based devices, which is higher than the traditional DSSCs made of single dye-sensitized (S-DSSC1 and S-DSSC2), and co-sensitized DSSC (CO-DSSC). It can be attributed to the enhanced incident photon to current conversion efficiency (IPCE) and short circuit current (Jsc) which clearly portray the advantage of DACE electrode in harvesting maximum incident light.