Effect of Temperature on the Properties of Nickel Sulfide Films Performed by Spray Pyrolysis Technique

In this work, we have prepared new materials of the nickel sulfide thin films by using the spray pyrolysis technique for promising co-catalyst to improve the photocatalytic performance or superconductivity. The effect of deposition temperature (523, 573 and 623 K) on structural, optical and electrical properties was investigated. The XRD diffraction shows that the prepared nickel sulfide at 523, 573 and 623 K having an orthorhombic, hexagonal and hexagonal structure, which were Ni₃S₂, Ni₁₇S₁₈ and NiS₂, respectively. The minimum value of crystallite size (45,9 nm) was measured of deposited film at 573K. The thin films prepared at 523 and 573 K have an average transmittance is about 20 %. The prepared Ni₁S₂ thin film at T=623 K has the lowest calculated optical band gap and Urbach energy. The Ni₁S₂ thin film also has the best calculated of the refractive index and the extinction coefficient. The FTIR spectrums of the nickel sulfide have various bands such as Ni-S, C-H, O-H, N–H and C-S. The maximum electrical conductivity is 4,29x10⁵ (Ω.cm)⁻¹ was obtained at 573K of the Ni₁₇S₁₈. The nickel sulfide thin films sprayed at 573K have good structural, optical and electrical properties.