Spin coating method deposited nickel oxide thin films at various film thickness

The objective of this research is to study the influence of the film thickness on the optical and electrical characterizations of the prepared NiO thin films. For this, we used thin films such as nickel oxide, which has been prepared on the glass substrates by a spin-coating technique using nickel nitrate hexahydrate (Ni (NO3)2.6H2O) as source materials. The coating process was repeated for 13, 14-, 15-, 16- and 17-layer times to obtain a good NiO thin film. The optical and electrical characterizations were observed to be dependent on each film's thickness. For smaller film thickness the thin films have a high optical transmission (over 88 %) in the visible of the longer of the wavelength higher than 400 nm. The bandgap energy was found to be in the range of 3.94-4.06 eV depending on the film thickness. The lowest value of Urbach energy was 0.182 eV. In the end, the electrical measurements are investigated by the four-point method, the results show that the good electrical conductivity was found at 171 nm.