• • The AZnO-F3N hybrid cathode interlayer achieves a PCE of 20.6% in binary PM6:L8-BO devices, surpassing conventional ZnO-based interlayers by >1% absolute, attributed to enhanced electron extraction and reduced trap-assisted recombination.
• • Incorporating BTP-eC9 as a third component in a ternary blend elevates PCE to 21.0% (certified 20.8%), with a fill factor of ~82.5%, representing the highest certified efficiency for single-junction OSCs to date.
• • The ternary OSCs exhibit good operational stability, maintaining >80% of initial PCE after 1000 hours of continuous illumination under 1-sun equivalent, addressing the chronic stability bottleneck of OSCs.
• • The AZnO-F3N CIL is universally effective across multiple donor–acceptor systems, thick-film (>300 nm) active layers, and flexible substrates, demonstrating compatibility with roll-to-roll manufacturing and mechanical flexibility requirements.