Structural and optical properties of undoped and antimony-doped lead telluride thin films

Undoped and antimony-doped lead telluride (Sb-doped PbTe) thin films were deposited onto borosilicate and fluorine-doped tin oxide (FTO) glass substrates by a spray pyrolysis method. The structural and optical properties were investigated. The X-ray diffraction (XRD) patterns indicate that PbTe and PbTe:Sb on both substrates had a cubic structure. Sb doping yields a decrease in lattice constant and crystallite size of PbTe. The onset (E-g(onset)) and direct (E-g(di)) optical band gap increases with Sb incorporation into the PbTe lattice. The E-g(onset) and E-g(di) values were in the range of 1.17-1.22 eV and 1.40-1.53 eV for each condition, respectively. Defects and disorders in the PbTe lattice were also performed due to Sb incorporation into both neighboring vacancies of the Pb and Te atoms. (c) 2020 Elsevier B.V. All rights reserved.