Evidence of exciton complexes in non polar ZnO/(Zn,Mg)O A-plane quantum well

Excitons complexes in ZnO/(Zn, Mg)O non-polar quantum well have been studied by using continuous-wave photoluminescence according to temperature and to the density of excitation. The spectrum of photoluminescence of the quantum well consists of three different lines. The ratio between the intensities of these lines depends of the temperature but also of the density of excitation. The lines are attributed to the free exciton, the negatively charged trion and the biexciton. The binding energy of trion and biexciton are found to be respectively 19.5 ± 2 meV and 45 ± 5 meV.