Heterostructures with a compressively strained single InAs1-xSbx/AlSb1-yAsy quantum well (QW) have been grown by molecular beam epitaxy on GaSb(0 0 1) substrates and studied by X-ray diffraction, transmission electron microscopy and photoliumnescence (PL) spectroscopy. An intense PL with the peak wavelength ranging from 2 to 4.5 mum (FWHM is of 30-50 meV) has been observed at 80 K as the QW width varies from 4 to 20 nm, respectively. The band gap energies of the InAsSb/AlSbAs QWs calculated for a wide range of x and y alloy compositions at the effective mass approximation, taking account of stresses accumulated in the QW and barriers, are in good agreement with the experimental values. (C) 2002 Elsevier Science B.V. All rights reserved.