New way to enhance the uniformity of self-organized InAs quantum dots

Growth interruption was introduced after the deposition of GaAs cap layer, which is thinner than the mean height of Quantum dots. Uniformity of quantum dots has been enhanced because the full width of half maximum of photoluminescence decrease from 80meV to 27meV in these samples as the interruption time increasing from 0 to 120 second. Meanwhile, we have observed that the peak position of photoluminescence is a function of interruption time. This effect can be used to control the energy level of quantum dots. The phenomena mentioned above can be attributed to the diffusion of In atoms from the top of InAs islands to the top of GaAs cap layer caused by the difference of surface energies between InAs and GaAs.