Optical studies of In<i>x</i>Ga1−<i>x</i>As/GaAs strained-layer quantum wells

Abstract

Intense single-peak photoluminescences of free-exciton origin were observed in InxGa1−x As/GaAs strained-layer quantum wells with x ranging from 0.09 to 0.20. Band lineups in these strained-layer heterostructures were determined by the dependence of luminescence energy on the well thickness. The heterojunction discontinuity in the heavy hole valence bands was found to be about 30% of the gap difference and independent of x. Exciton-phonon coupling was determined by temperature-dependent absorption measurements and the coupling strength was found to be similar to that of unstrained GaAs/AlxGa1−x As quantum wells.