Akademik Veri Yönetim Sistemi
Gazi University Journal of Science, cilt.35, ss.1116-1127, 2022 (ESCI)
Undoped and cobalt (Co) doped tin oxide (SnO2) films were prepared onto glass slides via the
successive ionic layer adsorption and reaction (SILAR). Variable characterization methods were
applied to examine the effects of cobalt impurities on physical properties of SnO2 films. The
performed characterization measurements were X-ray diffraction, Ultraviolet–visible
spectrometer, Photoluminescence, and Raman. No peak ascribed to Co, SnO, or Sn was found in
the XRD spectrum which may indicate the integration of cobalt in SnO2 crystal lattices. And the
obtained XRD peaks may be related to the tetragonal rutile phase of pure SnO2. SEM images
exposed that the Co dopant atoms affectedthe sample morphologies. The optical analyses showed
that the transmittance and reflectance percentages dropped by the introduction of impurities to
the SnO2 system as the absorbance values of doped SnO2 samples increased. Thus,a red shift
(2.6–1.8 eV) occurred in the bandgapsas Co concentration changed in the films. The Raman
spectra of pure SnO2 and Co:SnO2 samples exhibited major peaksaround 481 cm−1
, 571 cm−1
and
602 cm−1
. In photoluminescence spectrum, it was noted that the emission intensity can both
increase or decrease due to the different cobalt doping ratios in the SnO2 nanostructures.
Resistance measurements displayed that the resistivity increased with the increment of doping
concentration. However, it was shown that the electrical conductivities could be increased after
the heat treatment of glass substrates up to 500 oC, a common behavior of semiconductor
materials.