PHOTOLUMINESCENCE OF ALAS GAAS SUPERLATTICE QUANTUM-WELLS/

We report the results of low-temperature photoluminescence (PL) studie s of AlAs/GaAs superlattice quantum wells (SLQWs), obtained by placing various periods of short-period AlAs/GaAs superlattices (SLs) between two Al0.45Ga0.55As confining layers. Structures with a constant well width and various combinations of AlAs and GaAs layer thicknesses in t he SLs are synthesized by molecular beam epitaxy. Two distinct peaks a re resolved in the PL spectra, which can be attributed to transitions involving heavy-hole and light-hole bands. Comparison of 4 and 77 K PL spectra reveal evidence of type-II band alignment in SLQWs with thin GaAs layers.