X, l, and γ lines in low temperature photoluminescence spectra ofal0.47Ga0.53As0.035Sb0.965 alloys

In Al 0.47 Ga 0.53 As 0.035 Sb 0.965 layers nearly lattice-matched to GaSb (100) substrates, the X, L, and Γ optical transitions have energies close to each other. By varying the temperature of the samples and the power of the laser beam, one can separate the contribution of every tran,sition ion the photoluminescence spectra and measure the different transition energies versus temperature. The experiments provide very accurate measurements of the difference between the above transition energies and, together with X-ray double diffraction measurements, show the existence of fluctuations of composition within the alloy.