title: Manifestation of carrier relaxation through the manifold of localized states in PCDTBT:PC60BM bulk heterojunction material: the role of PC84BM traps on the carrier transport.
abstract: The transport and relaxation of photogenerated carriers in a bulk heterojunction (BHJ) material made of a blend of PCDTBT and PC(60) BM are studied as a function of the concentration of PC(84)BM impurities. For low concentrations of PC(84)BM, the increasing activation energy with delay time indicates transport dominated by trap-limited carrier drift while the photocarriers relax through a manifold of disorder-induced localized states near the band edge. In the BHJ material with high concentration of PC(84)BM, transport is dominated by carrier hopping within the PC(84)BM impurity band.
authors.affiliation: Center for Polymers and Organic Solids, University of California, Santa Barbara, California 93106, USA.
authors.forename: Wei Lin
authors.initials: WL
authors.lastname: Leong
authors.forename: Gerardo
authors.initials: G
authors.lastname: Hernandez-Sosa
authors.forename: Sarah R
authors.initials: SR
authors.lastname: Cowan
authors.forename: Daniel
authors.initials: D
authors.lastname: Moses
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Heeger
mesh_terms: D037741:Fullerenes / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D011789:Quantum Theory; D012993:Solar Energy; D013830:Thiadiazoles / Q000737:chemistry
chemical_list: D037741:Fullerenes; D011108:Polymers; D013830:Thiadiazoles; C015700:benzo-1,2,3-thiadiazole