Up-Conversion Luminescence of the NaRF4-NaR'F-4 (R: Y, Yb, Er) Core-Shell Nanomaterials

: Hyppanen I, Holsa J, Kankare J, Lastusaari M, Pihlgren L, Soukka T

Publisher: SPRINGER/PLENUM PUBLISHERS

: 2011

: Journal of Fluorescence

: JOURNAL OF FLUORESCENCE

: J FLUORESC

: 3

: 21

: 3

: 963

: 969

: 7

: 1053-0509

DOI: https://doi.org/10.1007/s10895-010-0655-8

Up-converting NaRF4-NaR'F-4 (R: Y, Yb, Er) nanomaterials with different core-shell combinations were prepared with the co-precipitation method. The X-ray powder diffraction (XPD) measurements revealed the presence of both the cubic and hexagonal NaRF4 phases. The crystallite sizes calculated with the Scherrer formula were 100 and 150 nm for the cubic and hexagonal phases, respectively. The FT-IR spectra showed water impurities. The up-conversion luminescence and luminescence decays were studied with NIR laser excitation at 970 nm. The up-conversion luminescence spectra showed strong red (640-685 nm) (F-4(9/2) -> I-4(15/2)) and moderate green (515-560 nm) (H-2(11/2,) S-4(3/2) -> I-4(15/2)) Er3+ luminescence. The strongest up-conversion luminescence and longest red luminescence decay was obtained from the Na(Y,Yb)F-4-NaErF4 core-shell combination.