LPE growth and Characterization of Ga1-xInxAsySb1-y quaternary alloys

Band gap, solid phase composition and lattice mismatch data are presented characterising Ga1-xInxAsySb1-y layers grown by liquid phase epitaxy (LPE) on 100 oriented GaSb substrate. Nearly lattice-matched (a/a0.15%) Ga1-xInxAsySb1-y layers were grown over the range 0x0.20. The lattice-mismatch was estimated from X-ray diffraction measurements. The X-ray diffraction pattern of the lowest band gap (0.55 eV) Ga0.80In0.20As0.17Sb0.83 layer showed strong compositional grading, indicating the presence of a miscibility gap near this composition in this material system. The composition of the grown epitaxial layers was determined by electron probe microanalysis in the wavelength dispersive mode. Band gap energies down to 0.55 eV were obtained on different composition samples from infrared transmission measurements. The measured compositional dependence of the band gap exhibits smaller bowing than calculated using the correlated function expansion technique.