Synthesis and photoluminescence properties of Tb³⁺ Doped ZrO₂ hollow spheres

ZrO₂:Tb³⁺ hollow spheres were successfully fabricated with the resin microspheres as the template. The sample characterizations were carried out by means of X-ray diffraction (XRD), scanning electron microscope (SEM) and photoluminescence (PL) spectra. XRD results revealed Tb³⁺ doped samples were pure t-ZrO₂ phase after being calcined at 873 K. SEM results exhibited these Tb3+ doped ZrO₂ was hollow spheres, the diameter and thickness of which were about 450 nm and 50 nm, respectively. The PL spectra indicate that the ⁵D₄ →⁷F₅ (545 nm) electric dipole transition is the most intensive when excited at 235 nm. It is shown that the 2.0 mol% of doping concentration of Tb³⁺ ions in t-ZrO₂:Tb³⁺ is optimum. According to Dexter's theory, the critical distance between Tb³⁺ ions for energy transfer was determined to be 15 Å. It is found that the decay curves follow the single-exponential decay. The convenient synthetic procedure, excellent reproducibility, clean reactions, high yield, and fine quality of products in the work make the present route attractive and significant.