A series connection architecture for large-area organic photovoltaic modules with a 7.5% module efficiency

The fabrication of organic photovoltaic modules via printing techniques has been the greatest challenge for their commercial manufacture. Current module architecture, which is based on a monolithic geometry consisting of serially interconnecting stripe-patterned subcells with finite widths, requires highly sophisticated patterning processes that significantly increase the complexity of printing production lines and cause serious reductions in module efficiency due to so-called aperture loss in series connection regions. Herein we demonstrate an innovative module structure that can simultaneously reduce both patterning processes and aperture loss. By using a charge recombination feature that occurs at contacts between electron- and hole-transport layers, we devise a series connection method that facilitates module fabrication without patterning the charge transport layers. With the successive deposition of component layers using slot-die and doctor-blade printing techniques, we achieve a high module efficiency reaching 7.5% with area of 4.15 cm 2 . The fabrication of organic photovoltaic modules usually relies on patterning techniques which limit their efficiencies. Here, the authors propose a module structure that avoids the patterning steps, and use doctor-blade printing and slot-die coating to fabricate large-area modules reaching 7.5% efficiencies.