Optical Studies of In sub x Ga sub (1-x) As/GaAs Strained Layer Quantum Wells.

Intense single-peak photoluminescences of free exciton origin were observed in In sub x Ga sub (1-x) As/GaAs strained layer quantum wells with x ranging from 0.09 to 0.20. Band line-ups 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/Al sub x Ga sub (1-x) As quantum wells.