Working from Both Sides: Composite Metallic Semitransparent Top Electrode for High Performance Perovskite Solar Cells

We report herein perovskite solar cells using solution-processed silver nanowires (AgNWs) as transparent top electrode with markedly enhanced device performance, as well as stability by evaporating an ultrathin transparent Au (UTA) layer beneath the spin-coated AgNWs forming a composite transparent metallic electrode. The interlayer serves as a physical separation sandwiched in between the perovskite/hole transporting material (HTM) active layer and the halide-reactive AgNWs top-electrode to prevent undesired electrode degradation and simultaneously functions to significantly promote ohmic contact. The as-fabricated semitransparent PSCs feature a V_oc of 0.96 V, a J_sc of 20.47 mA cm^-2, with an overall PCE of over 11% when measured with front illumination and a V_oc of 0.92 V, a Jsc of 14.29 mA cm^-2, and an overall PCE of 7.53% with back illumination, corresponding to approximately 70% of the value under normal illumination conditions. The devices also demonstrate exceptional fabrication repeatability and air stability.