title: Thermal effect on the morphology and performance of organic photovoltaics.
abstract: The morphology of organic photovoltaics (OPVs) is a significant factor in improving performance, and establishing a method for controlling morphology is necessary. In this study, we propose a device-size simulation model, combining reptation and the dynamic Monte Carlo (DMC) algorithm, to investigate the relationship between the manufacturing process, morphology, and OPV performance. The reptation reproduces morphologies under thermal annealing, and DMC showed morphology-dependence of performance: not only short-circuit current density but also open-circuit voltage had optimal interfacial areas due to competition between exciton dissociation and charge collection. Besides, we performed transient absorption spectroscopy of various BHJ morphologies under realistic conditions, which revealed prompt and delayed dynamics of charge generation-the majority of the charges were from excitons that were generated on interfaces and dissociated within a few picoseconds, and the others from excitons that migrated to interfaces and dissociated on the order of sub-nanoseconds.
authors.affiliation: Department of Chemical System Engineering, Graduate School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan. yamasita@chemsys.t.u-tokyo.ac.jp and CREST, Japan Science and Technology Agency (JST), Tokyo 113-8656, Japan.
authors.forename: Eisuke
authors.identifier: http://orcid.org/0000-0002-6252-5414
authors.initials: E
authors.lastname: Kawashima
authors.affiliation: Department of Chemical System Engineering, Graduate School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan. yamasita@chemsys.t.u-tokyo.ac.jp and CREST, Japan Science and Technology Agency (JST), Tokyo 113-8656, Japan.
authors.forename: Mikiya
authors.initials: M
authors.lastname: Fujii
authors.affiliation: Department of Chemical System Engineering, Graduate School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan. yamasita@chemsys.t.u-tokyo.ac.jp and CREST, Japan Science and Technology Agency (JST), Tokyo 113-8656, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Yamashita