Repair of defects in photoactive layer of organic solar cells

• Published in: Solar energy materials and solar cells Vol. 134; pp. 334 - 339
• Main Authors: Oostra, A. Jolt, Blom, Paul W.M., Michels, Jasper J.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2015
• Subjects: Contact; Conversion; Damage; Defects; Hypochlorite; Lead (metal); Leakage current; OPV; Photovoltaic cells; Repair; Short circuit prevention; Solar cells; Surface area; OPV; Damage; Repair; Short circuit prevention; Hypochlorite
• ISSN: 0927-0248; 1879-3398
• DOI: 10.1016/j.solmat.2014.12.013

Defects occurring during printing of the photoactive layer in organic solar cells lead to short-circuits due to direct contact between the PEDOT:PSS anode and metallic cathode. We provide a highly effective repair method where the defected zone with bare PEDOT:PSS is treated with aqueous sodium hypochlorite to locally disrupt the conductivity of PEDOT:PSS by over-oxidation. We demonstrate that even macroscopically large defects with a surface area of 10mm2 can be repaired, restoring solar cell performance. In contrast, untreated defected solar cells exhibit a significantly increased leakage current and corresponding decrease in light-to-power conversion efficiency. [Display omitted] •We present a highly effective method to repair large-scale defects in organic solar cells.•Macroscopic defects covering 2.5% of the active region can be repaired.•The method is suitable for conventional cells with a Ba/Al or LiF/Al cathode.•The method is deemed compatible with large scale processing methods.