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Zinc vacancy and oxygen interstitial in ZnO revealed by sequential annealing and electron irradiation

2012; American Physical Society; Volume: 86; Issue: 12 Linguagem: Inglês

10.1103/physrevb.86.121203

1550-235X

Knut Erik Knutsen, Augustinas Galeckas, A. Zubiaga, F. Tuomisto, G. C. Farlow, Bengt Svensson, Andrej Kuznetsov,

Copper-based nanomaterials and applications

By combining results from positron annihilation and photoluminescence spectroscopy with data from Hall effect measurements, the characteristic deep level emission centered at $\ensuremath{\sim}$1.75 eV and exhibiting an activation energy of thermal quenching of 11.5 meV is associated with the zinc vacancy. Further, a strong indication that oxygen interstitials act as a dominating acceptor is derived from the analysis of charge carrier losses induced by electron irradiation with variable energy below and above the threshold for Zn-atom displacement. We also demonstrate that the commonly observed green emission is related to an extrinsic acceptorlike impurity, which may be readily passivated by oxygen vacancies.