Investigation of the structural, optical, electrical, and photovoltaic characteristics of nanostructured Ce-doped BaTiO3 by a modified combustion method

A modified solution combustion approach was used to prepare barium titanate doped with 0.5%, 1%, and 2% cerium. XRD analysis was used to estimate the crystallite size. The doped samples of barium titanate were in the cubic phase and pure barium titanate was in the tetragonal phase. As cerium limits grain growth, it was found that the crystallite size of the compounds decreased from 24 nm to 18.31 nm with an increase in cerium concentration. The irregular shape of the sample and the observation that cerium prevents crystallite size growth were both confirmed by TEM analysis of the samples. The band gap of the samples lowered from 3.15 eV to 2.98 eV by cerium doping according to UV-visible spectroscopic investigation. With an increase in cerium content, the Urbach energy increased from 0.35 eV to 0.59 eV. FTIR spectra were used to calculate the vibrational constant and bond length of the samples. The length of the bond between Ti and O atoms shortened to 1.9981 & Aring; from 2.1121 & Aring; and the bond intensifies when Ce is doped in barium titanate. The value of the force constant increased from 1.79 N cm(-1) to 2.11 N cm(-1) with cerium doping. The cerium doped compounds showed a drop in PL signal strength, which suggests that the photogenerated charge carrier recombination rate has decreased in the doped sample. The bulk electrical conductivity of the ceramic samples decreased due to the increase in activation energy. For the construction of dye-sensitized solar cells, titanium dioxide was also synthesized by the same method. The as-prepared titanium dioxide consists of rutile and anatase mixed phases. Pure BaTiO3 and BaCe0.02 Ti0.98O3 were mixed separately with titanium dioxide in different weight proportions. They were used for the preparation of photoanodes in the construction of dye-sensitized solar cells. An increase in current density to 0.402 mA cm(-2) from 0.261 mA cm(-2) and an improvement in efficiency from 0.019% to 0.022% were both achieved through this process.