Nonparabolic behavior of GaSb-AlSb quantum wells under hydrostatic pressure

Abstract

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 (${R}^{\mathrm{*}}$) versus pressure. We find 1/${R}^{\mathrm{*}}$(${\mathrm{dR}}^{\mathrm{*}}$/dP)=\ensuremath{\sim}1%/kbar. We estimate a valence-band offset \ensuremath{\Delta}${E}_{v}$\ensuremath{\sim}40 meV.