Influence of Ligand on the Morphological, Electrical, Optical and Solid State Properties of Chemical Bath Deposited Lead Sulphide Thin Film

Abstract

Lead sulfide (PbS) thin films with different concentrations of ligand have been deposited on the glass substrate at room temperature using Chemical Bath Deposition (CBD) technique. The influence of ligand on the Optical, Solid State, Morphological and Electrical properties of the deposited thin films has been investigated. The results show that, the absorption coefficient of the films was found to increase as the concentration of Ligand decreases towards longer wavelength region and the energy band gap was observed to increase from 1.61eV to 3.71eV as the concentration of Ligand increases. Surface morphology shows that the deposited thin films are of polycrystalline and the particle grains are evenly distributed across the substrates’ surface. The electrical properties of the films as deduced using Four-Point Probe (FPP) technique also shows that there is a consistent increase in the electrical conductivity ≥ 1043 ( Ωm) -1 and sheet resistance (∼1024Ω) as the concentration of Ligand increases.