Effects of simultaneous change of Mg2+ and Ti4+ contents on the luminescence properties of Y2O2S:Eu3+, Mg2+, Ti4+ nanotubes

Red long-lasting phosphor Y2O2S:Eu3+, Mg2+, Ti4+ nanotubes were synthetized by the hydrothermal method. The effects of simultaneous change of Mg2+ and Ti4+ contents on the luminescence properties were investigated. The samples were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL), and thermoluminescence spectra (TL). XRD investigation revealed that the precursors was a pure phase of Y(OH)3 and the sulfuretted samples was a pure phase Y2O2S. SEM observation showed that the sulfuretted phosphors inherited the tube-like shape from the precursors. Under 325 nm UV excitation, the samples exhibited the strongest red emission at 627 nm, which corresponded to the transition from 5D0 to 7F2 level of Eu3+ ion. When the content of (Mg2+, Ti4+) multiple-ion dopant was 3.0%, the trap depth of sample was 0.9 eV and the decay time could last for over 450 s (≥1 mcd/m2) after 365 nm UV radiation for 10 min.