The effects of growth interruption on interfacial quality of GaInAsSb/AlGaAsSb heterostructures grown by organometallic vapor-phase epitaxy are reported. In Situ reflectance monitoring and ex situ characterization by high-resolution X-ray diffraction, 4 K photoluminescence (PL), and time-resolved PL indicate that GaInAsSb is extremely sensitive to growth interruption time as well as the ambient atmosphere during interruption. By optimizing the growth switching sequence, surface recombination velocity as low as 30 cm/s was achieved for GaInAsSb/AlGaAsSb double heterostructures. (C) 2004 Elsevier B.V. All rights reserved.