Structural, optical and electrical properties of N-doped ZnO thin films prepared by thermal oxidation of pulsed filtered cathodic vacuum arc deposited ZnxNy films

Abstract

In this study, N-doped ZnO thin films were fabricated by oxidation of ZnxNy films. The ZnxNy thin films were deposited on glass substrates by pulsed filtered cathodic vacuum arc deposition (PFCVAD) using metallic zinc wire (99.999%) as a cathode target in pure nitrogen plasma. The influence of oxidation temperature, on the electrical, structural and optical properties of N-doped ZnO films was investigated. P-type conduction was achieved for the N-doped ZnO obtained at 450 degrees C by oxidation of ZnxNy, with a resistivity of 16.1 Omega cm, hole concentration of 2.03 x 10(16) cm(-3) and Hall mobility of 19 cm(2)/Vs. X-ray photoelectron spectroscopy (XPS) analysis confirmed the incorporation of N into the ZnO films. X-ray diffraction (XRD) pattern showed that the films as-deposited and oxidized at 350 degrees C were amorphous. However, the oxidized films in air atmosphere at 450-550 degrees C were polycrystalline without preferential orientation. In room temperature photoluminescence (PL) spectra, an ultraviolet (UV) peak was seen for all the samples. In addition, a broad deep level emission was observed. (C) 2011 Elsevier B. V. All rights reserved.