We present results of magneto-optical measurements and theoretical analysis of shallow bound exciton complexes in bulk ZnO. Polarization and angular dependencies of magneto-photoluminescence spectra at 5 T suggest that the upper valence band has Γ7 symmetry. Nitrogen doping leads to the formation of an acceptor center that compensates shallow donors. This is confirmed by the observation of excitons bound to ionized donors in nitrogen doped ZnO. The strongest transition in the ZnO:N (I9 transition) is associated with a donor bound exciton. This conclusion is based on its thermalization behavior in temperature-dependent magneto-transmission measurements and is supported by comparison of the thermalization properties of the I9 and I4 emission lines in temperature-dependent magneto-photoluminescence investigations.
@article{arxiv.cond-mat/0308315,
title = {Magneto-Optical Properties of Bound Excitons in ZnO},
author = {A. V. Rodina and M. Strassburg and M. Dworzak and U. Haboeck and A. Hoffmann and A. Zeuner and H. R. Alves and D. M. Hofmann and B. K. Meyer},
journal= {arXiv preprint arXiv:cond-mat/0308315},
year = {2009}
}