Beijing University of Chemical Technology, and the University of Massachusetts Amherst have reported advancements in zinc oxide (ZnO) electron transport layer modification for organic solar cells. The researchers synthesized two naphthalene diimide-based zwitterionic polymers, incorporating benzene rings (BZ) and C=C double bonds (CZ), which were designed to passivate surface defects, lower the work function, and improve charge extraction efficiency. When integrated into inverted organic solar cells using PM6:Y6 and PM6:BTP-eC9 active layers, devices with BZ-modified ZnO achieved power conversion efficiencies of 16.36%–16.50%, while those with CZ-modified ZnO reached nearly 18%. The modified layers improved conductivity, inhibited electron recombination, extended carrier lifetimes, and decreased interfacial resistance when compared to pristine ZnO. The devices exhibited 90% of the initial efficiency after 800 hours of operation. Microscopy and spectroscopy confirmed a decrease in defect density, a smoothed and more uniform morphology, and improved ultraviolet light absorption to enhance device stability and compatibility.