Localized excitons in InxGa1-xN/GaN quantum well structure

Photoluminescence (PL) and photoreflectance (PR) have been employed to stud y the optical transitions of InxGa1-xN/GaN quantum well (QW) structures gro wn by metal-organic chemical vapor deposition (MOCVD). The main PL peak at 2.895 eV is attributed to the excitons localized at trap centers, which ori ginate from the In-rich region within the well. Several emission bands on b oth sides of the main peak are attributed to the interference fringe effect s and the recombination of excitons localized at several levels in the In0. 183Ga0.817 N well. The PL peak at 3.040 eV is ascribed to the lowest n=1 qu antized transition which agrees well with the calculated result.