Studies on Structural and Optical Properties of Lead Sulfide (PbS) Thin Films by Dip Coating Techniques

PbS, or lead sulfide, is deposited as thin films on glass surfaces using the straightforward and controllable dip coating method. Lead nitrate, sodium hydroxide, thiourea, and water were the reactive materials employed to create the PbS thin films under constant lead nitrate concentrations, constant dipping periods, and variable bath temperatures. The film thickness measured by a digital micrometer increases as the temperature of the PbS thin film decreases. X-ray diffraction investigations were used to characterize the films’ structural properties. The films have excellent substrate adherence and are well crystallized in the favored orientation (1 1 1) of the face-centered cubic structure. A UV-VIS spectrophotometer was used to assess the films’ transmission and reflectance spectra in order to ascertain their optical properties. The infrared spectrum has low transmittance and reflection, whereas neither is present in the ultraviolet or visible spectrum. Its intensity increases in the ultraviolet and ultraviolet-VIS area and then diminishes, according to absorption spectra. The visible and ultraviolet regions of the spectrum exhibit the highest levels of absorption, which proves the film being created is nanocrystalline. It was determined that the predicted band gap was between 2.00 eV and 2.2 eV.