Roll-to-Roll Slot-Die Coated Organic Photovoltaic (OPV) Modules with High Geometrical Fill Factors

Flexible semi-transparent organic photovoltaic (OPV) modules were manufactured by roll-to-roll slot-die coating of three functional layers [ZnO, photoactive layer, and poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT: PSS)] and either the screen printing or inkjet printing of the top electrodes. A poly(3-hexylthiophene):[6,6] phenyl C61-butyric acid methyl ester (P3HT: PCBM) layer deposited from non-chlorinated solvents was used as the absorber layer. The modules were realized by slot-die coating of the layers onto a laser-patterned polyethylene terephthalate/ indium-tin oxide (PET/ITO) substrate, followed by laser structuring of all coated layers. The top electrodes were realized by high-resolution printing, which, combined with laser patterning of other layers, enables manufacturing of the modules with high geometrical fill factor (92.5%). The modules have an active area of 156 cm(2), and contain 13 serially interconnected cells. Two semitransparent electrodes (ITO from the bottom and PEDOT: PSS/Ag-grid from the top side) allow the absorption of photons incident from both sides. The performance of the modules was evaluated and compared among the modules by considering the following factors: (i) roll-to-roll slot-die coated vs. spin-coated layers, (ii) inkjet-printed vs. screen-printed top electrodes, (iii) top vs. bottom illumination. The demonstrated technology is one of the proven feasible ways towards industrial manufacturing of the OPV modules.