Highly efficient and stable organic solar cell modules processed by blade coating with 5.6% module efficiency and active area of 216 cm2

In this study, an efficient and stable large‐area blade‐coated organic solar cell (OSC) module with an active area of 216 cm2 (16 elementary cells connected in series) is demonstrated by combining appropriate thermal annealing treatment with the use of 4,4′‐(((methyl(4‐sulphonatobutyl)ammonio)bis(propane‐3,1‐diyl))bis(dimethyl‐ammoniumdiyl))bis‐(butane‐1‐sulfonate) (MSAPBS) as the cathode interfacial layer. For the opaque device using poly[4,8‐bis(5‐(2‐ethylhexyl)thiophen‐2‐yl)benzo[1,2‐b;4,5‐b′]dithiophene‐2,6‐diyl‐alt‐(4‐(2‐ethylhexyl)‐3‐fluorothieno[3,4‐b]thiophene‐)‐2‐carboxylate‐2‐6‐diyl)] (PBDTTT‐EFT (PTB7‐Th)):[6,6]‐phenyl C71‐butyric acid methyl ester (PC71BM) blend film as the active layer, the power conversion efficiency (PCE) of 5.6% is achieved under AM 1.5G solar light illumination. Very encouragingly, our strategy can be applicable for semitransparent OSCs, and a remarkable PCE up to 4.5% is observed. To the best of our knowledge, the PCE of 5.6% for opaque device and 4.5% for semitransparent device represent the highest PCE ever reported for OSCs with the active area exceeding 100 cm2. The devices also show an impressive stability under outdoor environment, where the efficiency decay is less than 30% for 60 days. Our findings can pave the way toward the development of organic solar cell modules with high performance and long‐term stability.