Abstract
By understanding the synergetic effects of the PEDOT:PSS additives on the performance of solution based inverted OPVs we proposed an optimised additive mixture as an effective route to further increase the hole selectivity of the inverted OPV structure. The proposed additive mixture of (Zonyl 0.5%:Dynol 0.2%) result to improved reliability and around 12% improvement on the PCE of inverted OPVs. [Display omitted]
•A method for improving the PCE of solution processed inverted solar cells.•The origin of the improvement is the enhanced hole selectivity of inverted OPVs.•Different boiling points wetting agents in PEDOT:PSS improve the device fill factor.•The proposed additive mixture in PEDOT:PSS improves reliability of the results.•The proposed PEDOT:PSS treatment improves 12% the PCE of the inverted OPVs.
Solution based inverted Organic Photovoltaic (OPVs) usually use Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) derivatives combined with pristine processing additives as hole selective contact on top of the hydrophobic conjugated polymer:fullerene active layer. In this study, PEDOT:PSS based hole selective contact is treated with two different boiling point additives, 2,5,8,11-tetramethyl-6-dodecyn-5,8-diol ethoxylate (Dynol) and Zonyl FS-300 fluorosurfactant (Zonyl). Although corresponding inverted OPVs using the above PEDOT:PSS:Additives show similar power conversion efficiency (PCE) values, the mechanisms of their implementation on inverted OPV operation are not identical. By understanding the synergistic effects of PEDOT:PSS processing additives on the hole selectivity of inverted OPVs we demonstrate a novel combination of PEDOT:PSS additives mixture as an effective route to further increase the hole selectivity, reliability andpower conversion efficiency of inverted OPVs.