Concentration of Spraying Solution Effect on the Structural, Morphological and Optical Properties of NiO Thin Films

In the present study nickel oxide NiO thin fi lms of thickness ranging about 250 e 350 nm which were prepared on glass substrates by using chemical spray pyrolysis as a simple and low cost method. The impact of thickness and aqueous solution molarity concentration on the crystal structure and optical characteristics were investigated. The results showed that the deposited fi lms is homogenous and have a good adherent to the glass substrates. The crystal structure results showed that all fi lms have polycrystalline in nature, of rock salt phase, and the preferential orientation is an along (111) plane. The diffraction intensity was increased with the increase in spray solution concentration, leading to the enhancement of the crystallinity and an increase in the crystallite size from 9.7 nm to 28.5 nm and reducing the dislocation density from (104.3 e 12.2) £ 10 16 line/m 2 . While the results of AFM results show that the grain size (D) enlarges with increasing molarities concentration. Transmittance spectra con fi rm that the optical transmittance is of the direct allowed type, while the value of transparency ranged from moderate to weak value and decrease when the spray so-lution molar concentration and fi lm thickness increases. Whereas the forbidden energy gap was decremented with the increment of molarity concentration of spray solution and fi lm thickness from 3.85 to 3.15 eV.