Synthesis of high transparency of F doped NiO monocrystalline thin films by spray deposition

The main objective of this work is to investigate a new material based on fluorine doped NiO thin films by spray deposition technique. Nickel nitrate hexahydrate Ni(NO3)2.6H2O and ammonium fluoride (NHF4) with a ratio of F/Ni = 0.04 were used to prepare F doped NiO. The structural, optical and electrical properties of F doped NiO thin films were investigated with different NiO:F solution volumes of 5, 10, 15 and 20 ml using the spray technique. The prepared F doped NiO thin films have a monocrystalline nature with a cubic structure; the (111) diffraction peak is the preferred orientation; the maximum crystallite size is 19.21 nm obtained for 20 ml. The optical property shows that the all the prepared F doped NiO thin films have a good transmittance of about 80 % in the visible region. The F doped NiO thin films deposited with 20 ml have a minimum optical gap energy of 3.51 eV and the highest value of Urbach energy of 0,689 meV. However, the thin film prepared with 5 ml has a minimum electrical resistivity of 231 Ω.cm, which can be used as a gas sensing.