ZnO is an Ⅱ-Ⅵ semiconductor with various interesting electrical,optical,acoustic and chemical properties due to its wide bandgap of 3.4 eV and a large exciton binding energy of 60 meV at room temperature.ZnO,like GaN,will be important for blue and ultra-violet devices.For development of ZnO based optoelectrical devices,the fabrication of p-type ZnO is of important significance.In this paper,the p-type ZnO thin films were prepared by thermal oxidation of Zn3N2∶Al,which was deposited on glass slice by reactive RF magnetron sputtering of zinc and Al in Ar/N2 atmosphere.The effects of sputtering power and oxidation temperature on the structural,electrical and optical properties of the samples were investigated by using X-ray diffraction (XRD),scanning electron microscopy (SEM),Hall-effect measurements and photoluminescence spectra.After the thermal oxidation,the diffraction peaks of Zn3N2 disappeared with the presence of the diffraction peaks of ZnO,which indicates that Zn3N2 films should have transformed to the ZnO thin films after oxidation.A p-type ZnO film could be obtained by oxidizing Zn3N2∶Al in oxygen atmosphere at 700℃ for 2 hours,which possesses relative good properties:low resistance (16.8 Ω·cm),moderate hole carrier concentration (1017cm-3),large Hall mobility (2.1 cm2/Vs),narrow full width at half maximum in the predominant excitonic ultraviolet emission peaks and weak deep-level visible emission.This suggests that thermal oxidization of Zn3N2 is an very effective method to fabricate low-resistivity p-type ZnO with high hole concentration.This work is of important significance to the development of ZnO based optoelectronic devices.