Semiconducting properties of Ge-doped BaSnO3 ceramic

The electrical and optical properties of Ge-doped BaSnO3 ceramics sintered at various temperatures have been investigated to determine their semiconductor behavior. The electrical conductivity of Ge-doped BaSnO3 samples increases with increase in temperature, confirming that the samples exhibit a semiconductor behavior. A maximum conductivity value of 6.31 × 10−9 S/cm was observed for the sample sintered at 1200 °C. The optical band gaps of the Ge-doped BaSnO3 samples were determined by means of reflectance spectra. The variation of optical band gap with temperature was analyzed using Eg(T) = Ego + βT relation. The rate of change of the band gap β of BaSn0.99Ge0.01O3 was found to be 7.6 × 10−4 (eV/°C). A minimum optical band gap value of 2.95 eV was observed for the sample sintered at 1400 °C. It is evaluated that BaSn0.99Ge0.01O3 is a wide band gap semiconductor and its semiconducting properties change with sintering temperature.