Evaluation of Built‐In Potential and Loss Mechanisms at Contacts in Organic Solar Cells: Device Model Parameterization, Validation, and Prediction

摘要: Maximizing the power conversion effi ciency of organic solar cells requires simultaneous optimization its short-circuit current density, fi ll factor, and open-circuit voltage V oc . Several key parameters device model needed to understand these quantities have not been reliably determined, even for prototypical poly(3-hexylthiophene):phenyl-C 61 -methylbutyric ester (P3HT:PCBM) photoactive layer (PAL). Detailed analysis loss mechanisms at contacts their rational possible. Here, using crosslinked P3HT network:PCBM with predefi ned ultrafi ne donor–acceptor morphology very high internal quantum ciencies, built-in potential bi is measured decouple extract other cells. Using refi parameters, general evaluated following established: i) The PAL composition rst optical absorption optimum displaced towards more strongly absorbing component due thin lm effects. ii) optimal cell confi guration one in which slower carrier travels on average shorter distance collection contact, a consequence asymmetric photogeneration profi le. iii) thickness optima follows simple λ p / n scaling law, where center wavelength corresponding refractive index.