Iron complex/graphene oxide hybrid modification of ZnO surface for achieving stable inverted organic photovoltaics

We synthesized a four-coordinated semi-cyclic iron complex and composited it with graphene oxide (GO) to form a hybrid iron complex/GO-based material for organic solar cells (OSC). X-ray diffraction (XRD) analysis showed increased spacing between the GO sheets, indicating that the iron complex successfully intercalated or exfoliated the GO and deposited it on the surface. The as-prepared functionalized graphene oxide (FGO) also exhibits superior dispersion, which can avoid severe aggregation during fabrication. We demonstrated the impact of utilizing FGO as an interlayer to modify the ZnO-based OSC. Through X-ray Photoelectron Spectroscopy (XPS) and Photoluminescence (PL) analysis, we confirmed that FGO effectively reduces oxygen defects on the ZnO surface, leading to a reduction in the rate of carrier recombination and promoting the efficiency (up to 17.04 %) and ambient-stability of PM6:Y6-based OSCs. This discovery holds tremendous potential for advancing the development of high-performance OSCs with exceptional long-term stability.