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).
