Long wavelength and narrow photoluminescence linewidth from InAs quantum dots with GaAs cap layer on GaAs (1Â 0Â 0) substrate

Growth interruption during the formation of InAs quantum dots (QDs) on a GaAs (1 0 0) substrate has been investigated in detail. A total of 1.9 mono layers (MLs) of an InAs QD nucleation layer was grown continuously to form a seed with high density. Further, the supply of up to 3 MLs of InAs with a growth interruption of 15 s for every 0.11 ML showed that photoluminescence intensity was improved by 23 times and red-shifted the photoluminescence emission nearly 42 nm. The continuous growth up to 1.9 MLs helped to double the dot density. 3.3 MLs of InAs embedded in a GaAs matrix, grown using interruption showed a strong RT photoluminescence peak at around 1272 nm with a very narrow FWHM of 27.1 meV.