Zinc nitride films were prepared on quartz substrates by rf magnetron sputtering using pure zinc target in N-2-Ar plasma. X-ray diffraction (XRD) analysis indicates that the films just after deposition are polycrystalline with a cubic structure and a preferred orientation of (4 0 0). X-ray photoelectron spectroscopy (XPS) analysis also confirms the formation of N-Zn bonds and the substitution incorporation of oxygen for nitrogen on the surface of the films. The optical band gap is calculated from the transmittance spectra of films just after deposition, and a direct band gap of 1.01 +/- 0.02 eV is obtained. Room temperature PL measurement is also performed to investigate the effect of defect on the band gap and quality of the zinc nitride films. Crown Copyright (C) 2008 Published by Elsevier B.V. All rights reserved.