Over 14% Efficiency Folding-Flexible ITO-free Organic Solar Cells Enabled by Eco-friendly Acid-Processed Electrodes.

ABSTRACT

Environment-friendly manufacturing and mechanical robustness are imperative for commercialization of flexible OSCs as green-energy source, especially in portable and wearable self-powered flexible electronics. Although, the commonly adopted PEDOTPSS electrodes that are treated with severely corrosive and harmful acid lack foldability. Herein, efficient folding-flexible OSCs with highly conductive and foldable PEDOTPSS electrodes processed with eco-friendly cost-effective acid and polyhydroxy compound are demonstrated. The acid treatment endows PEDOTPSS electrodes with high conductivity. Meanwhile, polyhydroxy compound doping contributes to excellent bending flexibility and foldability due to the better film adhesion between PEDOTPSS and PET substrate. Accordingly, folding-flexible OSCs with high efficiency of 14.17% were achieved. After 1,000 bending or folding cycles, the device retained over 90% or 80% of its initial efficiency, respectively. These results represent one of the best performances for ITO-free flexible OSC reported so far and demonstrate a novel approach toward commercialized efficient and foldable green-processed OSCs.