الفهرس 
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Abstract
Copper sulfide (Cu2S) thin films were deposited by chemical spray pyrolysis technique using aqueous solutions containing Copper chloride dehydrate (CuCl2.2H2O) and Thiourea (SC(NH2)2), as sources of copper and sulfur; respectively. The deposited film was observed to be blackish brown in color, well adherent to the substrate, pin-hole free and uniform. The films were prepared at different deposition temperatures to reach the optimal temperature where single phase of Cu2S thin films is formed. The effect of deposition time was studied for the films prepared at deposition temperature 370oC and 400 oC and deposited on two different types of substrate: glass and polyimide (PI) substrates. characterizations of these films were carried out to understand how the change in time of spray and type of substrate influenced the structural, optical and electrical properties of the films formed. Two series for Cu2S thin films at different deposition time were prepared; one on glass substrates and the other on polyimide substrates. For laser treatment, the samples prepared at fixed deposition time (60 min) were selected. The effect of NIR continuous wave (CW) diode laser irradiation was performed at wavelength of 805 nm, which collimated and passed through 1 cm x1 cm aperture. The laser output intensity was fixed at 50 watt/cm2 and exposed for 10 minute. The structural, compositional, morphological, optical and electrical properties were investigated for both as deposited and treated samples. The XRD studies revealed that the sprayed Cu2S films were polycrystalline with cubic structure. The crystallite size of the prepared films on glass substrates decreased with increasing the deposition time whereas in case of deposition on polyimide substrates a wavy behavior was observed. The decrease in crystallite size was attributed to the formation of new crystallites over the older ones in agreement with literature. The laser treated films showed increase in crystallite size compared to as-deposited films on both deposition cases on glass and polyimide substrates. Chemical composition ratio of Cu to S was affected by laser treatment processes which consequently affect the properties of prepared films. It was found that the Cu ratio increased and sulfur decreased with laser treatment in deposited films on glass and polyimide substrates. The laser treatment influenced the microstructure and surface morphology of the films. SEM studies of the film surface before and after laser treatment indicated that the surface morphology was improved with laser treatment and became more spherical with uniform shape. Absorption coefficient (α) of sprayed Cu2S films on glass substrates were found to be in order of 105 cm-1. The energy band gap (Eg) decreased either with increasing deposition time or with laser irradiation of both substrates. The deposited films showed p-type conductivity with electrical conductivity dependence on films’ stoichiometry.