Bendable and foldable flexible organic solar cells based on Ag nanowire films with 10.30% efficiency

Abstract

For their wide applications in wearable devices, flexible organic solar cells (FOSCs) should have high power conversion efficiency (PCE), bendable and even foldable flexibility, and low fabrication cost. Herein, all-solution-processed FOSCs based on flexible hybrid transparent electrodes (FTE) of Ag nanowires (NWs) combined with PEDOT:PSS PH1000 doped with a small amount of ethylene glycol (EG) were fabricated. The photovoltaic performance of FOSCs is closely related to the substrate and the content of EG. The optimal content of 6 vol% EG doped in PH1000 has a positive effect on electrical conductivity, surface morphology and even flexibility. These FOSCs yield the best PCE of 10.30% with a short-circuit current density of 19.17 mA cm⁻² under optimal condition, which represent the highest efficiency reported to date for FOSCs with Ag NW electrodes. Furthermore, the optimal FOSCs demonstrate excellent mechanical flexibility, which can retain around 90% of the original PCE after 1000 bending cycles and exhibit over 75% of the original PCE even after complete folding. Our results demonstrate a new avenue to fabricate efficient and robust FOSCs with promising application potentials.