Realizing record efficiencies for ultra‐thin organic photovoltaics through step‐by‐step optimizations of silver nanowire transparent electrodes

Abstract

AbstractUltra‐thin (also known as ultra‐flexible) organic photovoltaics (OPVs) represent a strong contender among emerging photovoltaic technologies. However, due to the imbalance between the optical and electrical properties of indium tin oxide (ITO)‐free transparent electrodes, the ultra‐thin OPVs often exhibit lower efficiency compared to the brittle yet more balanced rigid ITO counterparts. Here, we design and fabricate an advanced ultra‐thin OPV, which involves a thoroughly optimized silver nanowires (AgNWs) transparent electrode (named AZAT) with excellent optical, electrical and mechanical properties. Specifically, the high‐kinetic energy spray‐coating method successfully yields a curve‐shaped, tightly connected and uniformly distributed AgNWs film, complemented by a capping layer of zinc oxide:aluminum‐doped zinc oxide (ZnO:AZO) to improve charge collection capability. Simultaneously, the transparency of the electrode is enhanced through precise optical optimization. Thus, we implant the AZAT‐based devices on 1.3 μm polyimide substrates and demonstrate ultra‐thin OPVs with a record efficiency of 18.46% and a power density of 40.31 W g−1, which is the highest value for PV technologies. Encouragingly, the AZAT electrode also enables the 10.0 cm2 device to exhibit a high efficiency of 15.67%. These results provide valuable insights for the development of ultra‐thin OPVs with high efficiency, low cost, superior flexibility, and up‐scaling capacity.