Growth of unrelaxed and unstrained Al(z)ln(1-z)As(y)Sb(1-y) with a lattice constant=6.23 angstrom was demonstrated lnAs(1-x)Sb(x), with this lattice constant produces a bandgap corresponding to absorption in the long-wavelength infrared range. The structures were grown on GaSb substrates, using a lattice constant shifting buffer layer. Good photoluminescence intensity was shown, ranging from 2.0 to 4.5 mu m, demonstrating the potential for development of multi-color infrared detectors that can cover both the mid- and long-wavelength infrared bands. Published by Elsevier B.V.