Carrier transfer and photoluminescence quenching in InAs/GaAs multilayer quantum dots

A detailed study of the carrier transfer and photoluminescence (PL) quenching in stacked InAs/ GaAs quantum dots (QDs) is presented. Vertically aligned QD structures, grown by atomic layer molecular beam epitaxy, with different numbers N of dot planes and different spacer thicknesses (d) were prepared and studied. The dependencies of carrier transfer from the GaAs barriers to the InAs QDs and of the PL quenching channels on the design parameters N and d have been identified by performing continuous wave and time-resolved PL measurements. We have found that both the radiative recombination and capture efficiency into the QDs are reduced by increasing N and by decreasing d, as a consequence of the deterioration of the interdot GaAs spacers induced by stacking. © 2000 American Institute of Physics.