Organic photovoltaic modules fabricated by an industrial gravure printing proofer

Large-area, flexible organic photovoltaic (OPV) modules are fabricated successfully by gravure printing in air, using an industrial-scale printing proofer of similar performance to commercial roll-to-roll printing processes. Both the hole transport layer, poly-3,4-ethylenedioxy-thiophene:poly(styrene sulfonic-acid) (PEDOT:PSS), and the active layer, poly(3-hexylthiophene):[6,6]-phenyl C61 butyric acid methyl ester (P3HT:PCBM), are successively printed on indium tin oxide (ITO) coated polyethylene terephthalate (ITO/PET) substrates with evaporated aluminum (Al) top electrodes. The 45 cm2 modules, composed of 5 cells connected in series, show power conversion efficiency (PCE) of over 1.0%, in which the short-circuit current (Jsc) and open-circuit voltage (Voc) are as high as 7.14 mA/cm2 and 2.74 V (0.55 V per cell), respectively. The PCEs could be potentially improved by the further optimization of the layer interface, layer morphology and flexible substrate properties. The results suggest that gravure printing may be a suitable technique for fast commercial processing of large-area, flexible OPVs with high output.

► We successfully use an industrial-scale gravure printing proofer to process OPV modules. ► The 45 cm2 P3HT:PCBM modules fabricated by gravure printing could give a PCE of over 1.0%. ► The PCEs of OPV modules by gravure printing could be potentially improved through further optimization.