Inkjet Technology for Large-Area OPV Applications

The roll-to-roll manufacturing process is believed to significantly reduce the cost-price of large area organic photovoltaic systems. Therefore, we build up knowledge base concerning the influence of process conditions on the performance of polymer solar cells. Inkjet printing has been a major research in processing photoactive materials because of its advantage of non-contact deposition and the ease for patterning for various industrial processes. A large area solar cell module, with inkjet printed PEDOT:PSS Orgacon (TM) (Agfa-Gevaert, Belgium)and photoactive layers (based on P3HT:[C60]PCBM blend) on a flexible substrate, has been demonstrated. Both the PEDOT:PSS and photoactive layer were deposited by inkjet printing. A non-chlorinated solvent was used for the deposition of the photoactive blend. In this contribution, some of the fundamental aspects of inkjet ink and substrate interaction, and the resulting layer homogeneity of the active layer in relation to OPV-device performance are investigated. Combining both theoretical and experimental approaches, we studied the layer formation on a moisture barrier. We have enabled to deposit homogenous PEDOT and OPV using commercially available inkjet heads. Furthermore, we would like to demonstrate the ability of using inkjet printing for fabrication of OPV devices, with Agfa high conductive PEDOT:PSS and Merck and Plextronics P3HT polymers dissolved in solution. The inkjet ink properties and the substrate pretreatment have been optimized in order to ensure a stable and robust printing and drying process. The flexible solar cell module illustrated a power conversion efficiency of 3.2% under AM 1.5 conditions.