This paper reports on the growth using a modified physical vapour transport technique of good epitaxial CdTe layers on GaAs(l 0 0), (1 1 1)A and (2 1 1)B substrates. FWHM values as low as 250 arcsec with growth rates of 10-20 mu m/h were recorded for 20-mu m-thick CdTe layers grown epitaxially on (1 1 1)A GaAs. The surface morphology of all the films was examined to measure the potential growth of high-quality thick films. Interfacial strain relaxation is studied by a combination of high-resolution X-ray diffraction (XRD) and etch profiling, which indicates that at a film thickness of similar to 0.65 pm, there is an abrupt change in the mechanism. It implies that above this thickness, the strain energy has fallen below the threshold for dislocation formation. (C) 2007 Elsevier B.V. All rights reserved.