Structural, Electrical and Optical Properties of NiO Nanostructured Growth Using Thermal Wet Oxidation of Nickel Metal Thin Film

Abstract

The synthetic NiO nanostructures have been grown using thermal wet oxidation of metallic Ni thin films on ITO/glass by RF sputtering. The deposited Nickel thin films layer were oxidized in stream atmosphere at varying temperatures range of 400 °C to 700 °C inside furnace. Structural, surface morphology, electrical and the optical properties of NiO nanostructure were analysed by X-ray diffraction (XRD), Field effect scanning electron microscope (FESEM), energy dispersive X-ray (EDX), hall effects measurements and UV-Visible spectroscope measurements. XRD analysis proves that the NiO nanostructure has a cubic structure with orientation of the most intense peak at (200), and the film prepared 600 °C shows a better crystalline quality. FESEM and AFM results also prove that by increasing the oxidation temperature, the dimensions and roughness of the NiO nanoparticle thin layer increases. Also the oxidation rate appears higher. The optimum temperature for synthesizing high quality NiO with great stoichiometric and crystalline property was determined to be at 600 of wet oxidation. EDX results reveals only O and Ni present in the treated samples, indicating a pure NiO composition obtained. From UV-Vis absorption spectroscope of Tauc’s relationship, the bang gap was observed to increase with temperature at range of 3.29 – 4.09 eV. The effect of annealing was highlighted on the tunability of electrical property Ni thin films with both n-type and p-type behavior NiO as determine from hall measurement. The observed tunability of NiO thin film will ease way toward p-n homojunction realization for optoelectronic device applications of short wave length that involves photodetectors and LEDs