Effects of relatively low pH on chemically deposited PbS thin films

Abstract

This study probed, through an experimental process, the structural and morphological properties of polycrystalline thin films of lead (II) sulfide (PbS) produced by using the chemical bath deposition technique. The effects of pH were examined within the scale of 7-11 in detail. The atomic absorption data showed that the reaction rate decreased when the pH of the solutions was reduced. A structural analysis was carried out by using the X-ray diffraction (XRD) pattern. The preferred orientation of the films shifted from the (111) plane to the (002) plane, according to the XRD pattern, when the pH of the solutions was reduced. A significant changing was formed in crystallite sizes. When pH of the solution was not changed, the crystallite size was calculated as to be 84 nm. On the other hand, when pH was decreased, the crystallite size was decreased up to 30 nm. Surface morphologies were analyzed through scanning electron microscopy. The lowered pH showed that lead (II) sulfide can be produced in cubic forms.