Bifacial quasi-solid-state dye-sensitized solar cells with Poly (vinyl pyrrolidone)/polyaniline transparent counter electrode

We synthesized Poly (vinyl pyrrolidone) (PVP)/polyaniline (PANI) nanocomposites and applied them as transparent counter electrode (CE) for bifacial quasi-solid-state dye-sensitized solar cells (DSSCs). PVP surrounded with aniline acted as efficient steric stabilizer in the polymerization process. Moreover, the present of PVP in PANI CE facilitated the generation of active reaction-sites in the interface between counter electrode and electrolyte and further reduced the electron recombination. The DSSC fabricated with PVP (4 wt%)/PANI CE exhibited improved power conversion efficiency up to 5.45%, which was comparable to that of DSSC assembled with Pt CE (5.57%). In the case of rear-illumination, the PVP (4 wt%)/PANI based DSSC showed an efficiency of 4.66%, which was 85.5% of the efficiency obtained from front illumination and much higher than that of DSSC with Pt CE (1.14%). The bifacial DSSC with PVP/PANI counter electrode showed an optimal power efficiency of 5.81% under illumination from both front and rear sides, which is higher than that of Pt based DSSC (5.70%) under the same condition. Long-term stability tests indicated that the photovoltaic device with PVP/PANI counter electrode exhibited an enhanced durability than that of DSSC assembled with Pt CE.