title: Dynamics of Trion formation in InxGa1-xAs quantum wells.
abstract: We show a double path mechanism for the formation of charged excitons (trions); they are formed through bi- and trimolecular processes. This directly implies that both negatively and positively charged excitons coexist in a quantum well, even in the absence of excess carriers. The model is substantiated by time-resolved photoluminescence experiments performed on a very high quality InxGa1-xAs quantum well sample, in which the photoluminescence contributions at the energy of the trion and exciton and at the band edge can be clearly separated and traced over a broad range of times and densities. The unresolved discrepancy between the theoretical and experimental radiative decay time of the exciton in a doped semiconductor quantum well is explained by the same model.
authors.affiliation: Institut de Photonique et Electronique Quantiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH1015 Lausanne, Switzerland.
authors.forename: M T
authors.initials: MT
authors.lastname: Portella-Oberli
authors.forename: J
authors.initials: J
authors.lastname: Berney
authors.forename: L
authors.initials: L
authors.lastname: Kappei
authors.forename: F
authors.initials: F
authors.lastname: Morier-Genoud
authors.forename: J
authors.initials: J
authors.lastname: Szczytko
authors.forename: B
authors.initials: B
authors.lastname: Deveaud-Plédran