Structure and Photoluminescence Emission of Er2O3, CeO2, and Their Alloy Nanoparticles

We fabricated erbium, cerium, and their alloy oxide nanoparticles using the co-precipitation method. EDS analysis demonstrates the presence of oxygen, erbium, and cerium elements. FTIR and XRD analyses confirm the formation of Er₂O₃, CeO₂, and their alloy nanoparticles. XRD analysis revealed that the lattice parameters of CeO₂ nanoparticles increase with the addition of Er₂O₃. The photoluminescence spectrum, measured with a 532 nm green laser at room temperature, exhibited both green (540–570 nm) and red (650–700 nm) luminescence. The photoluminescence properties of Er₂O₃ nanoparticles originate from relaxation and emission corresponding to the ⁴S₃/₂→⁴I₁₅/₂ and ⁴F₉/₂→⁴I₁₅/₂ transitions, while the emission bands of CeO₂ nanoparticles arise from oxygen vacancies forming F-centers and Ce³⁺-related defects such as vacancies and interstitial atoms. The photoluminescence spectrum of Er:Ce:O alloy nanoparticles exhibit two intense bands in the region from 547 nm to 560 nm, with maxima at 2.266 eV and 2.214 eV, associated with f–f internal transitions ⁴F₉/₂→⁴I₁₅/₂ and ⁴S₃/₂→⁴I₁₅/₂ in the Er³⁺ ion, indicating the incorporation of Er³⁺ ions into the crystal lattice as substitutional ions