The influence of doping lead and annealing temperature on grown of nanostructures of TiO2 thin films prepared by a sol-gel method

Abstract

Pb+2-doped TiO2 thin films were prepared by a sol-gel dip-coating method on silicon substrate. The films were annealed at different temperatures (600–1000 °C) and at various thicknesses (68–120 nm). XRD, Raman and FTIR spectroscopy shows the crystallization of thin films on anatase, rutile and PbTiO3 phase, as annealing temperature increase from 600 °C to 1000 °C respectively. The SEM micrographs indicate that the morphology transform with increase of annealing temperature. At lower temperature we observed only anatase and rutile phase, with the increase of annealing temperature the formation of lead titanate (PbTiO3) take place. Photoluminescence and reflectance spectrum of Pb doped TiO2 thin films show absorption bands and a shift to higher wavelengths (lower energy). These results proved that doping lead in TiO2 modify the levels impurities and decreased the optical gap of TiO2 thin films which enhanced the optical properties.