Thin films of SnO2–CeO2 binary oxides obtained by pulsed laser deposition for sensing application (original) (raw)
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A series of SnO 2-CeO 2 powder mixed oxides (with 5, 10, and 20 % wt SnO 2) was prepared, characterized and used to study the sensing properties for CO, in absence of oxygen, using a CO-helium mixture. The results have shown that the SnO 2-CeO 2 powder has good response and recovery characteristics. This powder has better sensitivity to CO than pure SnO 2 at the working temperature of 400-450°C. A sensing mechanism was proposed and discussed in this paper. The results have indicated that the SnO 2-CeO 2 mixed oxides can be used as CO sensors, in absence of oxygen.
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In this work, the Ceria (CeO 2) was synthesized by co-precipitation method. The thick films of synthesized CeO 2 were prepared by screen printing technique. Films were fired at 350 °C, 400 °C, 450 °C for 2 h in muffle furnace. These films were characterized by XRD to investigate the structural properties of prepared material. The XRD confirmed the single phase cerium oxide nanoparticles. Scanning electron microscopy was utilized for the morphological parameters of prepared cerium oxide nanoparticles. The cubic shaped cerium nanoparticles with various diameters were observed from SEM images. The elemental composition of ceria was studied by EDS, where the perfect elemental composition of ceria was confirmed. The Fourier transform infra red spectroscopy was employed to find out metal-oxide vibrational bands in the cerium oxide nanoparticles. The effect of firing temperature was studied for cerium oxide calcined at 350 °C, 400 °C and 450 °C nanoparticles to study the various parameters such as Grain Size, Temperature Coefficient (T C), Stacking Fault Probability (α), Dislocation Density (ρ), Surface area, Activation Energy and RMS Microstrain (e).
Iraqi journal of science, 2023
This research deals with the effect of gallium oxide and cerium oxide as dopants on the structural and optical characteristics of tin oxide. Gallium and cerium oxide doped tin oxide was prepared with different doping concentrations (0, 0.03, 0.05 and 0.07) wt. pure and doped tin oxide thin films were prepared by the pulsed laser deposition technique. X-ray diffraction and UV-Visible spectrophotometer were employed to investigate both oxides doping effects. Results showed that all prepared samples have poly-crystalline structure with a preferred plane of crystal growth along (110), where the crystal size grew from 40.3 nm to 64.5 nm and to 43.5 nm for Ga 2 O 3 and CeO 2 doped tin oxide thin films, respectively. Transmittance decreased drastically by increasing the doping ratio of gallium oxide. In contrast, it increased by increasing the doping ratio of cerium oxide. The optical energy gap was found to change in nonsystematic sequence with the increase of Ga 2 O 3 doping concentration, while it decreased monotonically by increasing the CeO 2 doping concentration.
Optical Materials , 2024
This study investigated the synthesis and characterization of CeO 2 /SnO 2 composite powders and films by varying CeO 2 concentration ranging from 2 to 10 mol%. The sol-gel process was utilized to create composites. X-ray diffraction demonstrated that the resulting CeO 2 /SnO 2 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 CeO 2 concentration increases. The variation in the energy band gap and refractive index values indicate that CeO 2 /SnO 2 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 (H 2 S). CeO 2 /SnO 2 films demonstrated the highest sensitivity for hydrogen sulfide (H 2 S), with a sensitivity of 0.988 % and a response time of 40 s.