Photoreflectance and Photoluminescence of Strained InxGal−xAs/GaAs Single Quantum Wells

Molecular Beam Epitaxy (MBE) grown single strained layer quantum wells composed of GaAs/InxGa1−x As/GaAs have been characterized at room temperature by photoreflectance and at 6K and 77K by photoluminescence. Excellent agreement between experimentally determined quantum transitions and theory is achieved utilizing a band offset ratio of 85:15 (conduction band:valence band) and a contribution of the hydrostatic compression to the valence band movement corresponding to the pressure sensitivity of the spin orbit band. Analysis of low temperature data indicate that strain induced band changes are not temperature dependent and data obtained at 77K leads to an empirical equation describing the non-strained band gap energy as a function of In fraction, and which differs slightly from that for bulk InGaAs crystals.