Growth interruption during the formation of InAs quantum dots (QDs) on a GaAs (100) 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 rim. 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. (c) 2005 Elsevier B.V. All rights reserved.