ITO-free organic solar cells with oxide/metal/oxide multilayer structure cathode

High-performance gallium-doped zinc oxide (GZO)/Ag/GZO multilayer structured transparent conductive electrodes were deposited on glass substrates by magnetron sputtering technique through optimizing oxygen flow, thickness of GZO and thermal annealing treatment. In a comparative study of optical and electric properties with the most commonly used indium tin oxide (ITO)electrode, the resultant GZO/Ag/GZO electrodes show lower sheet resistance of 10.66 Ωsq−1, higher average visible transmittance of 90.04% and superior figure of merit (FoM) of 328 Ω−1. When used as ITO-free transparent conductive electrode (TCE) for both classical fullerene and non-fullerene organic solar cells, comparable device performance or even better than that of those fabricated from ITO electrode is obtained. Given its low-cost, large-scale production accessibility, the GZO/Ag/GZO based electrode could be a good candidate for application in a wide range of organic electronics.