Preparation and characterizations of monocrystalline Na doped NiO thin films

Abstract

In the present work, the effect of Na doping on optical, structural and electrical properties of Na doped NiO thin films were studied. The spray pneumatic method was used to deposit the Na doped NiO thin films in the range 0 to 5 wt.%, it are investigated at a substrate temperature of 420 °C with NiO solution 0.1 M. Firstly in the XRD specra, as found that a only (111) peak was observed for Na doped NiO thin film indicate that the Na doped NiO thin films a monocrystalline in nature with cubic structure. The maximum crystallite size of Na doped NiO thin films was 18.90 nm at 3 wt.%. Secondary, the optical transmissions spectra Na doped NiO thin films having a high transparency with comparing to undoped film in visible region. The band gap energy was decreased after doping by Na and reaching a minimum value is 3.53 eV at 2 wt.%. The minimum value of Urbach energy was 0.312 eV, it is obtained at 3 wt.%. In the end, the minimum electrical resistance of the Na doped NiO films was located at 5 wt.%. The optimum Na doping amount is achieved at 3 at %.