Stacking of InAs/GaAs QDs with less strain by using growth interruption

InAs quantum dots (QDs) with less size fluctuations were obtained on GaAs (100) substrate by using the growth interruption of 15 seconds for every 0.11 ML after depositing 1.9 MLs of InAs continuously. Light emission with a wavelength of 1242 nm at room temperature from InAs QDs has been obtained. Atomic force microscopy images show that the initial continuous growth up to 1.9 MLs acted as a "seed" and helped to double the dot density. The subsequent supply of In with interruptions resulted in a large dot size while maintaining a high dot density. The six layer stacked (d = 22 nm) QDs grown with interruptions showed nearly 7 times stronger photoluminescence at room temperature than the continuously grown structure