title: Influence of copolymer interface orientation on the optical emission of polymeric semiconductor heterojunctions.
abstract: We have examined the Coulombic interactions at the interface in a blend of two copolymers with intramolecular charge-transfer character and optimized band offsets for photoinduced charge generation. The combination of both time-resolved measurements of photoluminescence, and quantum-chemical modeling of the heterojunction allows us to show that relative orientation across the heterojunction can lead to either a repulsive barrier ( approximately 65 meV) or an attractive interaction which can enhance the charge-transfer processes. We conclude that polymer orientation at the heterojunction can be as important as energy-band offsets in determining the dynamics of charge separation and optical emission.
authors.affiliation: Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 0HE, United Kingdom.
authors.forename: P
authors.initials: P
authors.lastname: Sreearunothai
authors.forename: A C
authors.initials: AC
authors.lastname: Morteani
authors.forename: I
authors.initials: I
authors.lastname: Avilov
authors.forename: J
authors.initials: J
authors.lastname: Cornil
authors.forename: D
authors.initials: D
authors.lastname: Beljonne
authors.forename: R H
authors.initials: RH
authors.lastname: Friend
authors.forename: R T
authors.initials: RT
authors.lastname: Phillips
authors.forename: C
authors.initials: C
authors.lastname: Silva
authors.forename: L M
authors.initials: LM
authors.lastname: Herz