Interfacial exciplex formation in bilayers of conjugated polymers

• Published in: The Journal of chemical physics Vol. 139; no. 16; p. 164908
• Main Authors: Nobuyasu, R S, Araujo, K A S, Cury, L A, Jarrosson, T, Serein-Spirau, F, Lère-Porte, J-P, Dias, F B, Monkman, A P
• Format: Journal Article
• Language: English
• Published: United States 28.10.2013
• ISSN: 1089-7690
• DOI: 10.1063/1.4827097

The donor-acceptor interactions in sequential bilayer and blend films are investigated. Steady-state and time-resolved photoluminescence (PL) were measured to characterize the samples at different geometries of photoluminescence collection. At standard excitation, with the laser incidence at 45° of the normal direction of the sample surface, a band related to the aggregate states of donor molecules appears for both blend and bilayer at around 540 nm. For the PL spectra acquired from the edge of the bilayer, with the laser incidence made at normal direction of the sample surface (90° geometry), a new featureless band emission, red-shifted from donor and acceptor emission regions was observed and assigned as the emission from interfacial exciplex states. The conformational complexity coming from donor/acceptor interactions at the heterojunction interface of the bilayer is at the origin of this interfacial exciplex emission.