Behavior of NiO thin films sprayed at different annealing time

Nickel oxide thin films were prepared by spray pyrolysis, using nickel chloride as precursor at the concentration of 0.05 M, deposited on ordinary glass substrates. The conditions of preparation were fixed except the annealing time, which is described through optical and electrical characterizations. The films exhibit a cubic structure, with a preferential orientation along (111) revealed by X-ray diffraction (XRD). The optical data measured by Lambda 900 UV/VIS/NIR spectrometer showing a transmission below 60 %. The refractive index n (lambda), extinction coefficient (k) and dielectric constants are calculated in the range of (300 and 1000 nm), besides Urbach and the gap energies. The electrical characterization using 4-point probe indicated that the sample with the highest annealing time is less resistive.