Positron annihilation spectroscopy is used to study point defects in Zn/1-x/Mn/x/GeAs/2/ crystals with low Mn content 0 < x < 0.042 with disordered zincblende and chalcopyrite structure. The role of negatively charged vacancies and non-open-volume defects is discussed with respect to the high p-type conductivity with carrier concentration 1E19 < n < 1E21 cm^-3 in our samples. Neutral As vacancies, together with negatively charged Zn vacancies and non-open-volume defects with concentrations around 1E16-1E18 cm^-3, increasing with the amount of Mn in the alloy, are observed. The observed concentrations of defects are not sufficient to be responsible for the strong p-type conductivity of our crystals. Therefore, we suggest that other types of defects, such as extended defects, have a strong influence on the conductivity of Zn1-xMnxGeAs2 crystals.
@article{arxiv.1404.1179,
title = {Point defects and p-type conductivity in Zn/1-x/Mn/x/GeAs/2/},
author = {L. Kilanski and C. Rauch and F. Tuomisto and A. Podgorni and E. Dynowska and W. Dobrowolski and I. V. Fedorchenko and S. F. Marenkin},
journal= {arXiv preprint arXiv:1404.1179},
year = {2015}
}