Understanding the blade coated to roll-to-roll coated performance gap in organic photovoltaics

The fabrication of efficient organic photovoltaic (OPV) modules via high throughput methods is a crucial milestone to facilitate their commercialization. The achievement of reliable printing and coating processes for large-scale modules has, however, been challenging thus far. Indeed, the performance gap is large between cells produced at lab-scale and those resulting from industrial methods. Therefore, understanding the critical steps in the upscaling process is decisive to address the research efforts towards decreasing the aforementioned gap. In this contribution, we analyze the efficiency losses associated with several of the main steps involved in the up-scaling pathway of the OPV devices, from lab-scale blade coating to pre-industrial slot die roll-to-roll coating. We show that when using materials in the active layer for which the performance is tolerant to thickness/microstructure variations, the critical steps are related to the charge carrier blocking layers, as well as potential losses due to parasitic absorption in the semitransparent electrodes.