title: Magnetic-field dependence of the electroluminescence of organic light-emitting diodes: a competition between exciton formation and spin mixing.
abstract: We explore the magnetoelectroluminescence (MEL) of organic light-emitting diodes by evaluating the magnetic-field dependent fraction of singlet excitons formed. We use two- and multisite polaron-hopping models with spin mixing by hyperfine fields and different singlet and triplet exciton formation rates k(S) and k(T). A huge MEL is predicted when exciton formation is in competition with spin mixing and when k(T) is significantly larger than k(S). This competition also leads to a low-field structure in the MEL that is in agreement with recent experiments.
authors.affiliation: Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands. s.p.kersten@tue.nl
authors.forename: S P
authors.initials: SP
authors.lastname: Kersten
authors.forename: A J
authors.initials: AJ
authors.lastname: Schellekens
authors.forename: B
authors.initials: B
authors.lastname: Koopmans
authors.forename: P A
authors.initials: PA
authors.lastname: Bobbert