The InAs1-ySby epilayers with cutoff wavelength within 3-7 μm were grown on n-InAs substrates using liquid phase epitaxy(LPE).The energy band gap and lattice constant of the multi-layer as a function of the composition are investigated.The surface morphology and interface are observed using an optical microscopy.The optical properties of the epilayers are studied using Fourier transform infrared(FTIR) transmission spectra,photoluminescence(PL),and spectro-ellipsometry.The electrical properties are obtained by fitting the measured thickness dependence of the effective Hall parameters.The results show the potential applications of the materials for photovoltaic InAsSb detectors in mid-infrared wavelength range.