title: Linear and nonlinear photoexcitation dynamics in pi-conjugated polymers.
abstract: Linear and nonlinear recombination kinetics with various lifetime distributions were identified for long-lived photoexcitations in a series of pi-conjugated polymer films using modulation frequency and excitation intensity dependencies of the photoinduced absorption. This includes monomolecular, bimolecular, and defect-limited recombination processes that lead to saturation. Using generalized kinetics parameters, we found characteristic plots for all recombination processes. Specifically, the bimolecular recombination process shows superlinear intensity dependence away from the steady state; on the contrary, dispersive bimolecular recombination leads to sublinear dependence.
authors.affiliation: Department of Physics and Solid State Institute, Technion, Israel Institute of Technology, Haifa 32000, Israel.
authors.forename: O
authors.initials: O
authors.lastname: Epshtein
authors.forename: Y
authors.initials: Y
authors.lastname: Eichen
authors.forename: E
authors.initials: E
authors.lastname: Ehrenfreund
authors.forename: M
authors.initials: M
authors.lastname: Wohlgenannt
authors.forename: Z V
authors.initials: ZV
authors.lastname: Vardeny