Effects of spatial confinement and layer disorder in photoluminescence of GaAs sub(1-x)Bi sub(x)/GaAs heterostructures

The structural and optical properties of a set of high-quality GaAs sub(1-x)Bi sub(x)/GaAs quantum well (QW) heterostructures with Bi concentrations ranging from 3.5% to 6.7% are studied. The energies of the excitonic ground state transitions are determined as a function of Bi concentration and spatial confinement. The influence of material disorder on the optical properties of QWs is investigated. It is determined that trap-related luminescence responds differently to temperature changes depending on whether the Bi concentration is more or less than 5%. Below 5% it contributes significantly to the overall photoluminescence line shape whereas above 5%, it is insignificant.