The role of high Mg level as a dopant on the PbS nanostructures grown by the CBD method

This paper reports influence of high level magnesium doping on lead sulfide (PbS) thin films. PbS films were deposited by chemical bath deposition (CBD) method. We investigated optical, structural and morphological properties of the films with respect to Mg doping concentration. Characteristic film properties such as crystal quality, elemental composition, band gap and surface morphology were examined using x-ray diffractometer (XRD), energy dispersive spectroscopy (EDS), UV-vis spectrophotometer and scanning electron microscope (SEM). XRD analysis showed that crystallite size of PbS: Mg thin films decreased from 17.89 to 10.47 nm by increasing Mg doping level from 0% to 15%. EDS analysis confirmed incorporation of Mg in PbS films. SEM measurements showed that film morphology was influenced by the magnesium doping level. UV-vis spectrophotometer measurements demonstrated that the optical transmittance of magnesium doped films increases up to 25% as compared to pure PbS film. Band gap energy of the coated samples was found to be increasing in the range of 1.67-2.43 eV according to Mg doping level.