Native Point Defects at ZnO Surfaces, Interfaces and Bulk Films

The impact of electronically-active native point defects on ZnO optoelectronic technologies at the nanoscale is only now being explored. We are able to address the impact of these defects on Schottky barrier formation and doping using a combination of depth-resolved and scanned probe techniques. We clearly identify the optical transitions and energies of VZn and VZn clusters, Ga on Zn site donors, Li on Zn sites, the effects of different annealing methods on their spatial distributions in ion-implanted as well as Ga grown-in ZnO, and how VZn, VZn clusters, and VO complexes contribute to near- and sub-surface carrier density. These results reveal the interplay between ZnO electronic defects, polarity, and surface nanostructure. Overall, the influence of native point defects on doping, Schottky barriers, and transport point to new ways for controlling these properties (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim