DFT and experimental investigations on structural, electronic, thermoelectric, and optical properties of Zn doped PbS

Abstract

Pure PbS and Zn-doped thin films have been synthesized with chemical derived spin coating approach. The prepared films were explored by the combination of first principle based investigations and experimental findings. The simulations were executed by Weink2 computational code. The well crystallinized and pure cubic phase thin films were examined by the X-ray diffraction analysis. The scanning electron micrgraphs indicated uneven aggregated granular morphology of pure PbS films. However, the Zn doping effectively influenced the morphology with compact rods-like geometry leading to the formation of uniform thin rods in highly Zn-doped composition. Zn-doped PbS films revealed the main contribution of Pb–s, Pb-f, S-p, and Zn-d orbitals in the density of states spectra. A considerable reduction was observed in PbS band gap (≈ 1.17 eV) with an increase in the integration of Zn contents into PbS lattice. The thermoelectric characteristics were expressively changed with a rise in temperature and Zn doping contents. The maximum Zn-doped composition displayed the highest values of refractive index (≈ 3.24) and real epsilon (≈ 10.15) in experimental outcomes. The optical parameters were modulated with Zn doping demonstrating their suitability for optoelectronic applications.