Structural and morphological evolution studies of CdS thin films prepared by chemical bath deposition by different agitation methods

Chemical badi deposition was one of the most important methods to prepare CdS films. The properties of CdS films could be substantially influenced by the solution agitation methods. CdS films were prepared by chemical bath deposition; stirring, without solution agitation, ultrasonication and vibration, respectively. The growth rate, structural and morphological properties of CdS films prepared by different solution agitation methods were investigated by profilometer, X-ray diffraction (XRD), scanning electron microscope (SEM) and atomic force microscope(AFM), respectively. As the deposition time increased, the film thickness increased correspondingly and finally came to saturation. The CdS films prepared by stirring and vibration had higher growth rate, larger grain size and rougher surface morphologies. When the CdS films were prepared by without solution agitation at short deposition time, large area of the region consisted of small grains with size of 12 nm. As the deposition time increased, the area of this region decreased and finally disappeared. According to the morphological evolution of CdS films with deposition time, it could be inferred that the growth of CdS films was dominated by ion-by-ion mechanism at certain reactant concentration. The influence of different solution agitation methods on the CdS films morphologies was analyzed by the comparison of the CdS thin films prepared by different solution agitation methods.