Effect of grain size and temperature on DC electrical conductivity of tin oxide nanoparticles synthesized by gel combustion method

Abstract

Tin oxide (SnO 2 ) nanomaterials of different grain size have been prepared using gel combustion method by varying the fuel (C 6 H 8 O 7 ) to oxidizer (HNO 3 ) molar ratio as a process parameter. The prepared samples were characterized by using X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Energy Dispersive Analysis X-ray Spectroscope (EDAX). The XRD patterns showed the formation of single phase Tetragonal rutile structure. The average particle size is found to be in the range of 19-34 nm. SEM images show high porosity in the material. The DC electrical conductivity of SnO 2 thick film increases with the temperature significantly from 308K to 670K.The DC electrical conductivity of SnO 2 thick film decreases with decrease in grain size due to the effect of surface to volume ratio while activation energy increases with decrease of grain size .

Deep vs shallow nature of oxygen vacancies and consequentn-type carrier concentrations in transparent conducting oxides

“…If, instead, this level can be attributed to V O , which becomes more dominant once the hydrogen donors are removed, then our calculated value is also in good agreement with this result. We note that a level at 0.28-0.35 eV has been observed in many n-type samples [75,[164][165][166] (as has the ∼0.15 eV level) [73][74][75]167], and that, in a study on SnO 2 nanoparticles [168], a switching of activation energy from 0.11 to 0.35 eV was observed in the largest nanoparticle when changing from low to high temperature.…”