الفهرس 
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Abstract
Thin films of black nickel on copper substrate for solar collector applications are prepared using electrochemical deposition technique. The electrodeposition parameters such as current density, temperature, concentration, additives, duration are optimized in order to improve the properties of the prepared films. Due to the amorphous structure of black nickel film, the oxygen and sulpher ligands have different interactions with the 3d energy levels of nickel and zinc cations. In this case, the prepared black nickel film can absorb almost all the wavelengths in solar range. The oxygen is added by two techniques: the first technique, the oxygen gas is injected into the electrolyte solution. The electrolyte solution is saturated by oxygen gas for five minutes. In the second technique, the oxygen is added through the addition of hydrogen peroxide. The electrodeposited films have been physically characterized using X-ray diffraction, energy dispersive X-ray, scanning electron microscope. Also these films have been optically characterized using color analysis tool and emissivity, absorptivity and reflectivity spectroscopic measurements. It is found that increasing the current density during the electrodeposition of the black nickel films will prevent the formation of crystalline structure as revealed from x-ray diffraction data. Also increasing the current density during the electrodeposition decreases the percentage of anions (O and S) and increases the percentage of cations (Ni and Zn).Increasing the time and the current density of electrodeposition enhance the emissivity due to increasing the thickness of the deposited films. The addition of hydrogen peroxide as a source of oxygen enhances both the absorptivity of the black nickel films in the solar range and the reflectivity in the infrared range.