ABSTRACT

Thin solid films of PbS along with some varying concentrations of impurity ions (Cd, Ni and Co), were grown on glass substrates at room temperature using chemical bath deposition technique. Spectral absorbaiice of the thin films was measured with a spectropholomeler in the UV-VIS-NIR regions of the electromagnetic spectrum. Other optical and solid state properties of the films such as; transmittance (T), reflectance (ft), ifl(lCX of refraction (ii), real dielectric constant (cr), imaginary dielectric constant (ci ). optical conductivity (c), indirect allowed transition band gap (Ng') and direct allowed transition band gap (E), were evaluated using mathematical relations, and quantitative values obtained with Excel package. The surface microstructure obtained for the films showed that the films are polycrystalline with varying crystal arrangement X-ray diffraction (XRD) crystallographic atialysis revealed that the thin films are nanocrystall inc in nature with varying crystallite sizes. Sonic variations in the material • properties of PbS thin films were mainly due to thermal annealing of the films at different temperatures, while the variations in properties of the films deposited with impurity ions were attributed to the impurity ion conceni ia1ions. The results provide an impetus for producing PbS thin films of varying material properties R'r various applications. Identified areas of applications include solar cell collection, microelectronics, ant ire Ii ection and protective coat i rigs.