The II-VI materials lattice matched to GaSb substrates are desirable for ultrahigh-efficiency multijunction solar cells. This paper reports the growth of ZnTe and ZnCdTe/ZnTe quantum wells on undoped GaSb (1 0 0) substrates using molecular beam epitaxy. During growth, in situ reflection high-energy electron diffraction shows fast and smooth transition from GaSb surface to ZnTe surface. Post-growth structural characterization using X-ray diffraction and high-resolution transmission electron microscopy reveals very low-defect density, i.e. high crystalline quality. Visible photoluminescence is observed from 10 to 300 K. (C) 2008 Elsevier B.V. All rights reserved.