Dynamics of Trion formation in InxGa1-xAs quantum wells.
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.
Portella-Oberli
M T
MT
Institut de Photonique et Electronique Quantiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH1015 Lausanne, Switzerland.
Berney
J
J
Kappei
L
L
Morier-Genoud
F
F
Szczytko
J
J
Deveaud-Plédran
B
B