TEMPERATURE-DEPENDENT TIME-RESOLVED EXCITON LUMINESCENCE IN GAAS ALGAAS QUANTUM WIRES AND DOTS/

Transient photoluminescence of GaAs/AlGaAs quantum wires and quantum d ots formed by strain confinement is studied as a function of temperatu re. At low temperature, luminescent decay times of the wires and dots correspond to the radiative decay times of localized excitons. The rad iative decay time can be either longer or shorter than that of the hos t quantum well, depending on the size of the wires and dots. For small wires and dots (similar to 100 nm stressor), the exciton radiative re combination rate increases due to lateral confinement. Exciton localiz ation due to the fluctuation of quantum well thickness plays an import ant role in the temperature dependence of luminescent decay time and e xciton transfer in quantum wire and dot structures up to at least simi lar to 80 K. Lateral exciton transfer in quantum wire and dot structur es formed by laterally patterning quantum wells strongly affects the d ynamics of wire and dot luminescence. The relaxation time of hot excit ons increases with the depth of strain confinement, but we find no con vincing evidence that it is significantly slower in quasi 1-D or 0-D s ystems than in quantum wells.