Tunability of Photoluminescence of InAs/GaAs Quantum Dots by Growth Pause Introduced Ripening

The effect of dot ripening pause on self organized InAs/GaAs QD's grown by MBE at two different growth rates and the resulting tunability of emission properties were studied with the help of PL and AFM experiments. We found the evolution of larger coherent islands with dot-pause due to high surface mobility of the In adatoms at the growth temperature resulting in a redshift in the PL spectra. A small blue shift in the emission is observed in case of the islands grown at higher growth rate and being allowed to ripen for sufficient time due to In desorption at high growth temperature