Sol gel fabrication of CeO2/SnO2 nanocomposite films for habilitation in optoelectronic and sensing properties

Abstract

This study investigated the synthesis and characterization of CeO2/SnO2 composite powders and films by varying CeO2 concentration ranging from 2 to 10 mol%. The sol-gel process was utilized to create composites. X-ray diffraction demonstrated that the resulting CeO2/SnO2 powders were polycrystalline, whereas the composite films had amorphous structures. The morphology of the produced samples was studied with SEM and TEM. Also the specific surface area was measured using the Brunauer-Emmett-Teller (BET) technique and the optical characteristics were assessed using a UV–Vis spectrophotometer. The absorption coefficients, energy gaps, and refractive indices of the composite films were determined. Direct and indirect energy gaps were from 3.71 to 3.27 eV and 2.70 to 2.26 eV, respectively. The refractive index increases from 1.61 to 1.7 as the CeO2 concentration increases. The variation in the energy band gap and refractive index values indicate that CeO2/SnO2 nanocomposite films are a viable composite film for optoelectronic devices. The investigated films have electrical conductivity values ranging from 10−2 to 10−8 Ω−1 cm−1. The gas sensing test was studied using different gases as liquid petroleum gas (LPG), carbon monoxide (CO), and Hydrogen sulfide (H2S). CeO2/SnO2 films demonstrated the highest sensitivity for hydrogen sulfide (H2S), with a sensitivity of 0.988 % and a response time of 40 s.