Characterization of Non-Polar ZnO Layers with Positron Annihilation Spectroscopy

• Authors: A. Zubiaga , F. Tuomisto , J. Zúñiga-Pérez , V. Muñoz-San José
• Languages of publication: EN

Abstracts

EN

We applied positron annihilation spectroscopy to study the effect of growth polarity on the vacancy defects in ZnO grown by metal-organic vapor phase deposition on sapphire. Both c-plane and a-plane ZnO layers were measured, and Zn vacancies were identified as the dominant defects detected by positrons. The results are qualitatively similar to those of earlier experiments in GaN. The Zn vacancy concentration decreases in c-plane ZnO by almost one order of magnitude (from high 10^{17} cm^{-3} to low 10^{17} cm^{-3}) when the layer thickness is increased from 0.5 to 2 μm. Interestingly, in a-plane ZnO the Zn vacancy concentration is constant at a level of about 2×10^{17} cm^{-3} in all the samples with thicknesses varying from 0.6 to 2.4 μm. The anisotropy of the Doppler broadening of the annihilation radiation parallel and perpendicular to the hexagonal c-axis was also measured.

Keywords

EN

61.72.uj; 68.55.Ln; 68.37.-d; 78.70.Bj

Discipline

• 78.70.Bj: Positron annihilation(for positron states, see 71.60.+z in electronic structure of bulk materials; for positronium chemistry, see 82.30.Gg in physical chemistry and chemical physics)
• 61.72.uj: III-V and II-VI semiconductors
• 68.37.-d: Microscopy of surfaces, interfaces, and thin films
• 68.55.Ln: Defects and impurities: doping, implantation, distribution, concentration, etc.(for diffusion of impurities, see 66.30.J-)

• Publisher: Institute of Physics, Polish Academy of Sciences
• Journal: Acta Physica Polonica A
• Year: 2008
• Volume: 114
• Issue: 5
• Pages: 1257-1264

Dates

published

2008-11

received

2008-06-07

Contributors

author

A. Zubiaga

• Department of Engineering Physics, Helsinki University of Technology, P.O. Box 1100, 02015 TKK Espoo, Finland

author

F. Tuomisto

• Department of Engineering Physics, Helsinki University of Technology, P.O. Box 1100, 02015 TKK Espoo, Finland

author

J. Zúñiga-Pérez

• Centre de Recherche sur l'Hétéro-Epitaxie et ses Applications (CRHEA), Centre National de la Recherche Scientifique (CNRS), 06560 Valbonne, France

author

V. Muñoz-San José

• Universitat de Valncia, Departamento de Fisica Aplicada i Electromagnetisme, Dr. Moliner 50, 46100 Burjassot, Valencia, Spain

References

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Identifiers

DOI

10.12693/APhysPolA.114.1257