Large-area organic solar cells by accelerated blade coating

Abstract

Abstract Large-area photovoltaic devices have been fabricated using the blade coating technique. In this study, the use of accelerated blade motion in this technique significantly improved the thickness uniformity of blade-coated layers of polymer solar cells on an A4 glass substrate. Two types of active layers, P3HT:PC61BM and POD2T-DTBT:PC71BM, were studied. For the P3HT:PC61BM film, a thickness of 221 ± 14 nm was realised in a 12 × 15 cm2 active region with a coating blade acceleration of 8 mm/s2. For the POD2T-DTBT:PC71BM film, a thickness of 98 ± 6 nm was realised with a coating blade acceleration of 10 mm/s2. Ten cells, each measuring 0.9 cm × 12 cm and monolithically fabricated, were connected in series, yielding a total active area of 108 cm2. The power conversion efficiency of the resulting 10-cell module was 2.66% and 3.64% for P3HT:PC61BM and POD2T-DTBT:PC71BM, respectively. The blade coating technique involving the accelerated blade motion is therefore useful for fabricating low-cost large-area organic solar cells, and it may be a promising alternative for the commercialisation of organic solar cells.