We have grown nitrogen-doped ZnO films by two kinds of epitaxial methods on lattice-matched ScAlMgO4 substrates. We measured the photoluminescence (PL) of the two kinds of ZnO:N layers in the donor-acceptor-pair transition region. The analysis of the excitation-intensity dependence of the PL peak shift with a fluctuation model has proven that our observed growth-technique dependence can be explained in terms of the inhomogeneity of charged impurity distribution. It was found that the inhomogeneity in the sample prepared with the process that provides showing better electrical properties was significantly smaller in spite of the similar nitrogen concentration. The activation energy of acceptors has been evaluated to be ≈170 meV, which is independent of the nitrogen concentration.
- Zinc oxide