Low temperature based PDINO cathode interlayer for high operational photostable inverted non-fullerene organic solar cells

The performance and industrial visibility of organic solar cells (OSCs) are greatly impacted by the functionality and stability of the interfacial layers. Many reported interface materials exhibited limitations in their fabrication temperature along with the operational stability toward the industrial up-scalability. In this work, a systematic analysis was conducted on the fresh and photo-aged-inverted non-fullerene organic solar cells (iNF-OSCs) with different structures of the electron transporting layers (ZnO, ZnO/PDINO, and PDINO), through studying their optical and electronic properties using external quantum efficiency measurements and impedance spectroscopy. Consequently, we presented PDINO as an efficient low temperature operation cathode interlayer for iNF-OSCs. Compared to the benchmark interface layers for i-OSCs such as ZnO, the PDINO interlayer used to replace the ZnO film, exhibiting a remarkable operational photostability. Where PDINO based iNF-OSCs demonstrated an extremely photostable behavior that is almost three times higher than the ZnO based devices under AM 1.5G (100 mW cm−2) continuous illumination conditions. This behavior might be attributed to the PDINO interlayer properties, which undergoes with no photochemical reaction with the contacted PM6:Y7 photo-active layer, avoiding the inescapable photocatalytic effect that is commonly obtained by the ZnO interlayer.