The Influence of CeO2 Concentration on Some Physical Properties of Y2O3 Thin Films

Abstract

       Thin films of pure yttrium oxide (Y₂O₃) and doped with cerium oxide (CeO₂) were prepared by the chemical spray pyrolysis(CSP)method. The structural, optical and electrical properties of the prepared films were investigated. The analysis of X-ray diffraction (XRD) thin films revealed that the undoped and doped Y₂O₃  were amorphous with a broad hump around 27^o and narrow humps around 48^o and 62^o for all samples. Except for the Y₂O₃:6wt.%CeO₂ thin film, all had signal preferential orientation along the (100) plane at 2θ=12.71^o which belongs to CeO₂, Field emission scanning electron microscopic (FE-SEM) images confirmed the formation of the nanosized particles which resembles circles and others revealed rods and balls shape. UV-Vis spectra study showed peak absorption at a wavelength of 305 nm, with blue shift due to quantum confinement, and this also happened for the doped films, with direct energy band gaps. The photoluminescence spectra (PL) of undoped Y₂O₃ and doped thin films showed an emission peak at 365 nm at the same wavelength of all the prepared samples with a slight difference. All prepared films show three activation energies except Y₂O₃:6wt.%CeO₂ film has two activation energies. From I-V characteristic curves, the prepared films have Schottky behavior except  Y₂O₃:6wt.%CeO₂ film, which displayed ohmic behavior. Y₂O₃:6wt.%CeO₂ fabricated device revealed good photosensitivity for VIS and IR wavelength.