Exploring the influence of CeO2 incorporation on the physicochemical characteristics of SnO2 nanocomposites

Abstract

In the present manuscript, polycrystalline (1-x)SnO₂-xCeO₂ nanocomposites (NCs), where x = 0, 0.05, and 0.10, were synthesized using sol–gel reaction route and their structural, microstructural, and electrical characteristics were investigated. Rietveld refined X-ray diffractogram (XRD) of the compositions [x = 0.05 and 0.10] revealed the co-existence of polymorphs of tetragonal crystalline phase [\(P{4}_{/2}mnm\)] for SnO₂ and cubic phase [\(Fm\overline{3 }m\)] for CeO₂. Selected area electron diffraction (SAED) pattern of pristine SnO₂ [x = 0] depicted 2-dimensional lattice plane analogous to rutile type symmetry as observed in XRD studies and high-resolution transmission electron microscopic (HRTEM) image for x = 0.10 depicted lattice planes [110] belonging to SnO₂ with d-spacing of 0.34 nm and [111] with d-spacing of 0.31 nm. Hall Effect studies displayed that the carrier concentration increased from 2.66 to 7.67 cm⁻³ and mobility decreased from 5.09 to 1.49 cm²/Vs with CeO₂ addition in SnO₂. The optical energy band gap decreased from 3.38 to 3.13 eV with the addition of CeO₂ content in SnO₂. The enhancement in the dielectric constant was observed as the concentration of CeO₂ increased the dielectric constant increased from 28 to 79. The coexistence of polymorphs of tetragonal SnO₂ and cubic CeO₂ effectively shifted its semiconductor properties from n-type (donor) to p-type (acceptor type).