Dependence of the optical properties on the GaAs spacer thickness for vertically stacked InAs/GaAs quantum dots

Temperature-dependent photoluminescence (PL) measurements have been carried out to investigate the dependence of the optical properties on the GaAs spacer thickness for vertically stacked InAs/GaAs quantum dots (QDs). The PL spectra showed that the peak corresponding to the interband transitions form the ground electronic subband to the ground heavy-hole band (E0-HH1) of the InAs QDs shifted to a higher energy side with increasing the GaAs spacer thickness and that the full width at maximum (FWHM) of the (E0-HH1) peak rapidly decreased with increasing a spacer thickness. The position energy and the FWHM of the (E0-HH1) peak for the InAs/GaAs QDs at several temperatures were observed. The present observations can help improve understanding of the dependence of the optical properties on the GaAs spacer thickness for vertically stacked InAs/GaAs QDs.