Properties of Cd doped PbS thin films: doping concentration effect

Highly crystalline cadmium doped lead sulphide (PbS:Cd) thin films with different Cd doping concentrations (0, 2, 4, 6 and 8 at-%) were fabricated on glass substrates using spray pyrolysis technique. The X-ray diffraction (XRD) studies revealed that all the films exhibit face centred cubic structure with a preferential orientation along the (2 0 0) plane irrespective of Cd doping concentration. Optical studies showed that the band gap of doped films vary between 1·96 and 2·12 eV with increasing Cd content and the film coated with 6 at-% Cd dopant has a maximum transmittance of nearly equal to 77%. Electrical studies revealed that the film coated with 6 at-%Cd dopant has a maximum conductivity of 12·67×10−1 Ω cm−1. The obtained results infer that the PbS:Cd film coated with 6 at-%Cd dopant has better structural, morphological, optical and electrical properties.