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Indexed by:期刊论文

Date of Publication:2016-09-01

Journal:NANOSCIENCE AND NANOTECHNOLOGY LETTERS

Included Journals:SCIE、EI、Scopus

Volume:8

Issue:9

Page Number:764-769

ISSN No.:1941-4900

Key Words:Nanostructure; Fluorides; Luminescence; Judd-Ofelt analysis; Solvothermal

Abstract:Eu3+-doped BaAlF5 nanophosphors were synthesized by a mild hydrothermal method. The final products were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and photoluminescence spectroscopy. The XRD results indicate that the prepared samples have a single phase. The FE-SEM and TEM images show that the prepared BaAlF5:Eu3+ nanophosphors contain many rice-shaped particles with an average length of 50 nm and an average width of 30 nm. When excited at 394 nm, BaAlF5:Eu3+ nanophosphors exhibit characteristic emissions of Eu3+. The transitions of D-5(0) -> F-7(J) (J = 1, 2, 4) show intense emission; however, the transitions of D-5(0) -> F-7(3) and D-5(1) -> F-7(1) of Eu3+ are weak. Moreover, the crystal-field splitting of both the MD and ED transitions into two main lines was also observed. The Judd-Ofelt (J-O) intensity parameters Omega(lambda) (lambda = 2, 4) and radiative transition rate of the D-5(0) level was calculated from the emission spectra. The room temperature decay curves of the D-5(0) -> F-7(1) transitions of BaAlF5:Eu3+ were measured, and an average luminescence lifetime of 1.50 ms was obtained by single exponential fitting. The emission quantum efficiency eta for 5, 10, 15, 20, 25, 30, and 40 mol% doped BaAlF5 nanophosphors was calculated to be 12%, 16%, 20%, 14%, 14%, and 15%, respectively.