The identification and nature of bound exciton I-line PL systems in ZnO

The chemical identification of donor bound excitons in ZnO has been studied using radioactive ions. Implantations of $117Ag$ - which decays to radioactive Cd and In - have enabled the identification of the $I2$ optical feature as being the ionized donor counterpart of $I9$⁠, one of the most prominent optical features in the photoluminescence spectrum of ZnO. Both of these lines are consistent with In occupying a Zn site.