Low temperature reflectivity study of ZnO/(Zn,Mg)O quantum wells grown   on M-plane ZnO substrates
  We report growth of high quality ZnO/Zn0.8Mg0.2O quantum well on M-plane oriented ZnO substrates. The optical properties of these quantum wells are studied by using reflectance spectroscopy. The optical spectra reveal strong in-plane optical anisotropies, as predicted by group theory, and marked reflectance structures, as an evidence of good interface morphologies. Signatures ofc onfined excitons built from the spin-orbit split-off valence band, the analog of exciton C in bulk ZnO are detected in normal incidence reflectivity experiments using a photon polarized along the c axis of the wurtzite lattice. Experiments performed in the context of an orthogonal photon polarization, at 90^{\circ}; of this axis, reveal confined states analogs of A and B bulk excitons. Envelope function calculations which include excitonic interaction nicely account for the experimental report. 
Luc Beaur (L2C), Thierry Bretagnon (L2C), Christelle Brimont (L2C),   Thierry Guillet (L2C), Bernard Gil (L2C), Dimitri Tain...
cond-mat.mtrl-sci cond-mat.other