Preparation and characterization of undoped and antimony doped tin oxide thin films synthesized by spray pyrolysis


Undoped and antimony doped tin oxide thin films (SnO2 :Sb) have been deposited by the spray pyrolysis method on glass substrates heated at 350°C, with various doping concentrations 0 (undoped), 1 at.%, 3 at.%, and 5 at.%. The influence of annealing temperature and various Sb doping rates on the structural, morphological and optical properties have been investigated, using grazing incidence X-ray diffraction (GIXRD), profilometry, atomic force microscopy (AFM), UV-Visible spectrophotometry and photoluminescence measurements (PL). GIXRD diagrams show that the films deposited atvarious Sb concentrations are polycrystalline with a tetragonal rutile type structure and preferred orientation direction along [110]. It has been also noted that the grain size changes between 11 nm and 25 nm. Atomic force microscopy (AFM) visualization revealed that surface morphology was found to be influenced by the incorporation of Sb and average roughness was varied between 4.580 nm and 10.793 nm. The optical characterization shows that the maximum value of transmittance of 82 % was found for SnO2: 1 at.% Sb thin films were annealed at 400°C for 4 hours and the optical band gap values range from 3.668 eV to 4.224 eV of SnO2 films. Room-temperature photoluminescence measurements under excitation at 325 nm show broad emission peak, Photoluminescence (PL) properties influenced by antimony doping for the SnO2 films are investigated.