Reflectance study of Al0.4Ga0.6Sb/GaSb single quantum wells

We report a reflectance study from 0.6 to 1.5 eV and at temperatures from 6 to 300 K on a series of Al0.4Ga0.6Sb/GaSb single quantum wells with differ ent well thicknesses (t(w) = 4, 6, 8 and 11.7 nm), grown by Molecular beam Epitaxy on (001) GaSb substrates R spectra show clear evidence of the struc tures associated to the allowed transitions from the n-th heavy- and light- hole to the rt-th conduction subband level for n = 1,2. The comparison betw een the experimental transition energies and those calculated in the framew ork of the envelope-function scheme showed a good agreement, thus confirmin g the reliability of the values for relevant QW parameters as band-offset, effective masses and band non-parabolicity.