Growth of InGaAs/GaNAs strain-compensated quantum dot superlattice on GaAs (311)B by molecular beam epitaxy

We have studied the Structural and optical properties of 10 stacked layers of self-organized In(0.4)Ga(0.6)As quantum dots (QDs) grown on GaAs (31 1)B substrates by atomic hydrogen-assisted radio frequency (RF)-molecular beam epitaxy. A 40 nm-thick GaN(0.007)As(0.993) dilute nitride, which is used to cover each QD layer acts as a strain-compensation layer (SCL). The density of strain-compensated In(0.4)Ga(0.6)As QDs on GaAs (3 1 1)B can be controlled between 2 x 10(10) and 1 x 10(11) cm(-2) by simply changing the growth temperature. Closely spaced In(0.4)Ga(0.6)As QDs on GaAs (3 11)B shows an ordered structure, in which we observe clear peaks in the two-dimensional fast Fourier transformation image. The temperature dependence of photoluminescence (PL) spectra shows a narrower linewidth over the whole temperature range 30-300 K for strain-compensated QDs owing to better uniformity in the QD size. (C) 2008 Elsevier B.V. All rights reserved.