Résumé
Nonpolar (11-20) (Ga,In)N multi-quantum wells have been studied by polarized, temperature dependent photoluminescence (PL). A non monotonic temperature dependence of the difference in PL peak energies recorded for E parallel to c or E perpendicular to c, and of the polarization ratio is observed. We interpret these effects by first an orthorhombic distortion of the crystal and an increased electron-hole exchange energy relative to GaN. This increase is in agreement with calculations on the effect of confinement on the exciton exchange splitting.