We present the first comparative in situ small and wide angle X-ray scattering study of two polymers that are relevant for organic photovoltaics, during coating on a flexible substrate. From the obtained measurements we identified several differences between the drying of the two polymers. The polymer optimized for roll-to-roll coating attained its final morphological packing nearly instantly after deposition, and had the shortest drying profile. We therefore conclude that fast-drying polymers which are influenced less by drying temperature or substrate inhomogeneities are better suited for roll-to-roll coating, and that fundamentally, the kinetics of drying dominate the process in the case of roll-to-roll slot-die coating.
Rossander, L. H., Dam, H. F., Carlé, J. E., Helgesen, M., Rajkovic, I., Corazza, M., Krebs, F. C., & Andreasen, J. W. (2017). In-line, roll-to-roll morphology analysis of organic solar cell active layers. Energy & Environmental Science, November(11), 2411-2419. https://doi.org/10.1039/C7EE01900A