N-Al codoped p-type ZnO thin films have been realized by dc reactive magnetron sputtering in N2O ambient. Hall measurement, X-ray photoelectron spectroscopy, X-ray diffraction and optical transmission were carried out to investigate the effect of growth temperature on the properties of codoped films. Results indicated that N-Al codoped p-type ZnO films with good structural, electrical and optical properties can only be obtained at an intermediate temperature region (e.g., 500 ° C. The codoped p-type ZnO had the lowest resistivity of 57.3 &UOmega; cm, and a carrier concentration up to 2.52 x 10(17) cm(-3). In addition, the N-Al codoped p-type ZnO film deposited at 500 ° C was of good crystallinity with a (0 0 2) preferential orientation, and high transmittance about 90% in the visible region. © 2004 Elsevier B.V. All rights reserved.