Surfactant Effect of Sb on GaInAs Quantum Dots Grown by Molecular Beam Epitaxy

Abstract
A surfactant effect of antimony (Sb) was investigated for self-assembled GaInAs quantum dots (QDs). The introduction of Sb into the QDs cause a large blue shift of the photoluminescence (PL) wavelength with a decrease in the full width at half maximum (FWHM) and an increase in intensity in comparison with QDs without Sb. Atomic force microscope (AFM) measurement showed a marked reduction in QD density from 1.0×1010 cm-2 to 7.0×107 cm-2. This indicates that Sb suppresses the formation of QDs and that the wetting layer remains to be a quantum well (QW) structure. The PL wavelength of the GaInAsSb wetting layer was elongated by increasing the amount of Sb supply. This result indicates the expansion of the critical thickness of the growth mode change from 2D to 3D.