Selective control of self-organized In0.5Ga0.5As/GaAs quantum dot properties: Quantum dot intermixing

Selective postgrowth control of the photoluminescence (PL) wavelength has b een demonstrated for a single layer self-organized In0.5Ga0.5As/GaAs quantu m dot (QD) structure. This was achieved by rapid thermal processing of dots using different dielectric caps. Selective band gap shifts of over 100 meV were obtained between samples capped with sputtered and plasma enhanced si lica deposition, with the band gap shift under regions covered with plasma enhanced chemical vapor deposition SiO2 less than 70 meV. The effects of di fferent caps on the PL linewidth were also observed. The differential band gap shift will enable the integration of passive and active devices in QD s ystems. (C) 2000 American Institute of Physics. [S0021- 8979(00)01721-7].