Nitrogen-doped ZnO/Al2O3 films grown at elevating temperatures (300-800 degrees C) have been investigated by plasma-assisted molecular beam epitaxy (P-MBE). High nitrogen concentration (-10(2)(2) cm(-)(3)) is achieved in the films grown at relatively low growth temperature (<500 degrees C) range. High nitrogen concentration accompanies considerable degradation of crystallinity and residual tensile strain, which was evaluated by high resolution X-ray diffraction (HRXRD). The structural evolution is discussed in terms of the increase of complex defect density in films. The ionization energy of acceptor was estimated as -140 meV from the excitation power dependence of donor-acceptor pair emission line by using low temperature (10K) photoluminescence spectroscopy.