Synthesis and Luminescence Properties of ZnO: Eu3+ Nanopowders

The effect of Eu³⁺ doping on the structural and photoluminescence properties of zinc oxide (ZnO) nanopowders synthesized via the sol–gel method was investigated. The samples were characterized using powder X-ray diffraction (XRD), Raman spectroscopy, photoluminescence (PL), and photoluminescence excitation (PLE) spectroscopy. XRD results revealed that samples with low Eu³⁺ concentration exhibited a single hexagonal wurtzite phase, whereas higher Eu³⁺ concentrations consisted of ZnO and Eu₂O₃ phases. The results calculated from XRD indicate that a small amount of Eu3+ ions has been successfully doped into the ZnO host lattice. The Raman spectra of Eu3+ doped ZnO reveal significant modifications in vibrational behavior arising from Eu3+ incorporation. PL spectrum of the undoped ZnO sample exhibits peaks in both the ultraviolet (UV) and visible regions. The UV emission peaks arise from electron recombination near the band gap, while the visible emission peaks are attributed to oxygen vacancies (). The sharp direct 4f–4f excitation and emission lines of Eu³⁺ were observed in the PLE and PL spectra, respectively. The energy transfer from the ZnO host to Eu³⁺ ions is found.