Effects of Inhibitor on PbS Thin Films Obtained by Chemical Bath Deposition

Thin films of polycrystalline lead sulfide (PbS) have been deposited on glass substrates by chemical bath deposition at 20 ± 1 °C in alkaline solutions. Aqueous solutions of lead nitrate (Pb(NO3)2), potassium hydroxide (NaOH), thiourea (CS(NH2)2) and sodium thiosulfate (Na2S2O3) were used together for the first time to obtain thin films of PbS. The chemical kinetics was investigated according to the amounts of Pb2+ concentrations measured by atomic absorption spectroscopy during the precipitation of PbS. It was found that sodium thiosulfate had an inhibitor effect for alkaline solutions. The structures of the films were characterized by X-ray diffractometer and showed that all the films had a galena-type cubic structure. The morphological characteristics of the PbS thin films were studied by scanning electron microscope and revealed that when the Na2S2O3 compound was used, the shape of the nanoparticles changed from the polymorphic form to the pyramidal form and pinhole-free PbS thin films could be produced.