Nonparabolic behavior of GaSb-AlSb quantum wells under hydrostatic pressure.
Résumé
We present a photoluminescence investigation of the electronic properties of a strained GaSb-AlSb quantum well under hydrostatic pressure. Our experiment, performed at liquid-helium temperature, permits us to measure a pressure shift of the quantized exciton smaller than the GaSb band-gap shift. Such an effect is analyzed in the framework of a model calculation which takes account of the nonparabolicity and of the change of the quantized Rydberg (R*) versus pressure. We find 1/R*(dR*/dP)=∼1%/kbar. We estimate a valence-band offset ΔEv∼40 meV.