Annealing Temperatures Effect on Nickel Oxide Thin Films

In the present paper, NiO thin films were prepared on glass substrates using a spin coating method with 0.7 M. There the NiO thin films were heated at different crystallization temperatures of 25, 450, 500, 550 and 600 degreesC for 2 hours. XRD spectra of prepared NiO thin films indicate that the films have a polycrystalline structure; it is the cubic type of NiO. We have obtained that the crystallite size was increased to the maximum value of 50.32 nm of (200) plane was obtained at 600 degreesC. We conclude that the crystallinity of NiO thin films was improved with increasing crystallization temperature, it depends too few defects. Spectrophotometer (UV-vis) of NiO films shows an average optical transmission of about 85%. The optical bandgap energy was increased after crystallized from 3.101 for without crystallization to 3.855 eV for a crystallized film at 500 degreesC. At high crystallization temperature, we found that the NiO thin films have the lowest disorder, the minimum Urbach energy was obtained at a temperature of 600 degreesC is 180 meV. The NiO thin films have a good electrical property with the minimum of the sheet resistance was found at a lower temperature.