Effects of annealing temperature on morphology and Crystallinity of nitrogen doped zinc oxide (ZnO:N) nano films

Abstract

Semiconductor of ZnO has been extensively researched in recent years for its extraordinary properties. ZnO is naturally an n-type semiconductor and due to asymmetric doping limitations, it is difficult to obtain p-type ZnO. In this work the deposited nitrogen doped zinc oxide nano films by reactive magnetron sputtering technique, were treated using conventional thermal annealing, while, the annealing temperature were varied from 300°C to 800°C in a mixture of nitrogen and oxygen ambient. The surface morphology, Crystallinity and electrical characteristics of prepared films have been investigated with respect to the temperature of annealing process. The XRD spectra of samples before and after annealing processes confirmed the deposition of wurtzite crystalline structures of ZnO. However, the annealed samples exhibited smaller FWHM compared to un-annealed ones, which confirms better crystalline structure of annealed films. Moreover, un-annealed specimens showed n-type conductivity with an electron concentration of 2.5×1016 cm-3, while the annealed samples exhibited p-type behavior with a hole concentration of 8.2×1015 cm-3.