Optical properties of ZnO/(Zn, Mg)O quantum wells
Résumé
This paper reviews the optical properties of ZnO/(Zn, Mg)O single quantum wells grown by molecular
beam epitaxy. Both heteroepitaxial quantum well growth along the polar c-direction and homoepitaxial quantum well
growth on the nonpolar M plane cases are considered. The optical properties of these quantum wells are investigated
by using re ectance, continuous wave photoluminescence, and time-resolved photoluminescence spectroscopies. The
quantum-con ned Stark e ect dominates the properties of the excitons for polar quantum wells. The magnitude of the
internal electric eld that is induced by both spontaneous and piezoelectric polarizations is determined by comparing
the experimental results with a variational calculation of excitonic energies and lifetimes. For nonpolar quantum wells,
the optical spectra reveal strong in-plane optical anisotropies, as predicted by the group theory. Moreover, the radiative
recombination of free excitons is dominating the quantum well photoluminescence even at room temperature.