Roll-to-roll micro-gravure printed P3HT:PCBM organic solar cells

Roll-to-roll (R2R) micro-gravure printing is an attractive technology for fabricating organic solar cells (OSCs) at low cost with high throughput. The nanoscale morphology and phase separation of R2R micro-gravure printed active layers have a large influence on the photovoltaic performance of OSCs. Herein, we demonstrate that the photovoltaic performance of R2R micro-gravure printed P3HT:PCBM OSCs can be enhanced by optimizing phase separation using solvent engineering. R2R micro-gravure printed P3HT:PCBM blend film with chlorobenzene solvent enabled optimized phase separation and formation of a fine-tuned interpenetrating network in a bulk heterojunction (BHJ) layer compared with a film with 1,2-dicholorobenzene solvent. This creates an optimal transport pathway and therefore effectively enhances charge transport in the BHJ blend film and boosts device performance. This research shows that high-performance OSCs could be fabricated by large-scale, R2R micro-gravure printing with solvent engineering, which would accelerate the development of fully R2R micro-gravure printed flexible OSCs.