Fabrication and characterization of P–N dual acceptor doped p-type ZnO thin films

P and N dual-acceptor doped p-type zinc oxide (ZnO:(P, N)) films have been realized by radio frequency (rf) magnetron sputtering and post-annealing techniques. The X-ray diffraction (XRD), secondary ion mass spectrometry (SIMS), X-ray photoelectron spectroscopy (XPS) and the Hall measurement techniques were employed to investigate the structural and the electrical properties in detail. Results indicated the electrical properties of the ZnO:(P, N) films were extremely sensitive to the annealing temperature and the conduction type could be changed dramatically from n-type to p-type, and finally changed to weak p-type in a range from 650 °C to 850 °C. The p-type ZnO:(P, N) film with the lower resistivity of 3.98 Ω cm, a hole concentration and Hall mobility of 1.16 × 1018 cm−3 and 1.35 cm2/Vs, respectively, was obtained at an optimal annealing temperature of 800 °C. The p-type conduction behavior of the ZnO:(P, N) film was confirmed by the rectifying I–V characteristics of the p-ZnO:(P, N)/n-ZnO homojunction. The chemical bonding states of P and N doped in ZnO:(P, N) film were examined by XPS analysis.