Efficient large-area flexible organic photovoltaic modules on transparent thin silver electrodes

Abstract

Large-area flexible organic photovoltaic (OPV) modules are challenging to achieve high power conversion efficiency (PCE). Electrical shunts or shortages generally occur in large-area OPV modules due to the ultrathin (100–200 nm) and soft active layers. Improving the surface smoothness of bottom transparent electrode will be able to suppress the shunts and shortages. In this work, we report a method to fabricate smooth and flexible transparent electrodes based on thin silver film, and further to fabricate efficient large-area flexible OPV modules. The fabricated thin silver transparent electrodes simultaneously have high conductivity, high optical transmittance, good mechanical flexibility and low surface roughness. Humidity exposure (h.e.) treatment on MoO₃ effectively facilitates the continuous growth of the thin transparent silver electrode. 6 nm silver film on MoO₃ (h.e.) on plastic substrate shows a transmittance up to 89%, a sheet resistance of 15 Ω/sq, and a low surface roughness with a root-mean-square value of 0.276 nm. Furthermore, 52-cm² flexible organic solar modules (15 subcells) showed a certified PCE of 12.66%. Furthermore, a 1350 cm² flexible component assembled by 25 pieces of 52–55 cm² modules showed certified PCE of 12.10% with an open-circuit voltage of 62.85 V.