title: Phase separation in bulk heterojunctions of semiconducting polymers and fullerenes for photovoltaics.
abstract: Thin-film solar cells are an important source of renewable energy. The most efficient thin-film solar cells made with organic materials are blends of semiconducting polymers and fullerenes called the bulk heterojunction (BHJ). Efficient BHJs have a nanoscale phase-separated morphology that is formed during solution casting. This article reviews recent work to understand the nature of the phase-separation process resulting in the formation of the domains in polymer-fullerene BHJs. The BHJ is now viewed as a mixture of polymer-rich, fullerene-rich, and mixed polymer-fullerene domains. The formation of this structure can be understood through fundamental knowledge of polymer physics. The implications of this structure for charge transport and charge generation are given.
authors.affiliation: Department of Materials and Centre for Plastic Electronics, Imperial College London, London SW7 2AZ, United Kingdom.
authors.forename: Neil D
authors.initials: ND
authors.lastname: Treat
authors.forename: Michael L
authors.initials: ML
authors.lastname: Chabinyc
mesh_terms: D037741:Fullerenes / Q000737:chemistry*; D044367:Phase Transition; D055668:Photochemical Processes; D011108:Polymers / Q000737:chemistry*; D012666:Semiconductors; D012993:Solar Energy
chemical_list: D037741:Fullerenes; D011108:Polymers