Interdisziplinäres Zentrum für Materialwissenschaften
  Publications [search]   
Offers for students
Interdisziplinäres Zentrum für Materialwissenschaften
Nanotechnikum Weinberg
Heinrich-Damerow-Str. 4,
D-06120 Halle, Germany
Phone: +49 345 55 28471
Telefax:+49 345 55 27390 e-mail:
[Papers] [Theses] [Reports] [Posters]

J. Gebauer, R. Krause-Rehberg, M. Prokesch, K. Irmscher
Identification and quantitative evaluation of compensating Zn-vacancy-donor complexes in ZnSe by positron annihilation
Phys. Rev. B 66 (2002), 115206

We investigate defects in n-type ZnSe bulk crystals by positron annihilation. With positron lifetime spectroscopy, vacancies with a positron lifetime of (28061) and (275610) ps were found in ZnS:I and ZnSe:Al, respectively. The positron bulk lifetime was 241 ps at 300 K, determined in an undoped semi-insulating reference. The vacancies were identified to be Zn-vacancy donor complexes by combining the positron lifetime measurements with that of the positron-electron annihilation momentum distribution. This finding is supported by previous electron-paramagnetic-resonance measurements. The samples exhibited different degrees of electrical compensation, adjustable by thermal treatment under defined Zn vapor pressure. The vacancy concentration measured by positron annihilation could explain the deactivation of donors quantitatively. Thus, compensation of n-type conductivity in ZnSe is due to self-compensation through native Zn-vacancy donor complexes.

Keywords: positron annihilation; lifetime; vacancies; complexes; zinc selenide; density; compensation
View/download pdf

Impressum Copyright © Center of Materials Science, Halle, Germany. All rights reserved.