Confined excitons in GaN-AlGaN quantum wells

We calculate the original properties of excitons in GaN-AlGaN quantum wells by a variational approach in the envelope function formalism. The separati on of electrons and holes by huge internal electric fields induces an enhan ced dependence of exciton binding energy and oscillator strength on the wel l width. We demonstrate the necessity,to perform excitonic calculations for obtaining, in particular, reliable values of oscillator strengths (thus ra diative lifetimes), which are extremely sensitive to the well width.