Turak, A., Hanisch, J., Barrena, E., Welzel, U., Widmaier, F., Ahlswede, E., et al. (2010). Systematic analysis of processing parameters on the ordering and performance of working poly(3-hexyl-thiopene): (6,6)-pheyl C61-butyric acid methy ester solar cells. Journal of Renewable and Sustainable Energy, 2(5): 053103. doi:10.1063/1.3488381.