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

摘要

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 (311 )B substrates by atomic hydrogen-assisted radio frequency (RF)-molecular beam epitaxy. A 40 nm-thick GaNo.007Aso.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 (311 )B can be controlled between 2 ×10~(10) and 1 × 10~(11) cm~（-2） by simply changing the growth temperature. Closely spaced In_(0.4)Ga_(0.6)As QDs on GaAs (311 )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.