Hydrothermally synthesized β-NaGdF4:Eu3+@β-NaGdF4:Ce3+,Dy3+ phosphors with multicolor luminescence properties via dual-channel excitation and energy migration procedure

A collection of β-NaGdF4 core-shell structured (CSS) phosphors were synthesized by Hydrothermal method, both the core and shell regions of which are hexagonal phase. The as-prepared core particles have the microrods shape, and the shell was formed upon them via epitaxial growth. After thermal annealing treatment of the core phosphors at 600 °C, the corresponding core-shell structure can still be effectively constructed. The photoluminescence (PL) spectra reveal that the CSS phosphors grown upon the as-prepared core particles own superior luminescent properties; for the annealed CSS phosphor β-NaGdF4:Eu3+@β-NaGdF4, a large amount of defects existed on the interfaces between the core and shell regions severely quenched the emission intensity of the core region; on co-doped Ce3+ and Dy3+ ions into the null shell layer of the annealed CSS phosphor, the obtained phosphor shows excellent multicolor luminescence performance due to quenching phenomenon effectively suppressed by dual-channel excitation and energy migration procedure of Gd3+ ions. The prepared CSS phosphors in this work are excellent candidates for applications in solid-state lighting.