Synthesis, photochromic adjustment and energy transfer of Tb 3+ , Sm 3+ -doped Bi-based fluoride luminescent materials

A series of Terbium ions and Samarium ions doped NaBiF 4 phosphors were synthesized by precipitation method at room temperature. Under ultraviolet light excitation, the phosphors possess multicolor emissions including green, yellow-green as well as white. Furthermore, in NaBiF 4 : Tb 3+ , Sm 3+ system, there are energy transfer processes from Bi 3+ to Tb 3+ and from Tb 3+ to Sm 3+ ions, and the energy transfer mechanism between Tb 3+ and Sm 3+ ion is quadrupole–quadrupole (q-q) interaction. Multicolor luminescence including white light emission can be acquired via varying the content of Tb 3+ or Sm 3+ . The CIE chromaticity diagram directly displays the hue variability of the as-synthesized samples. This type of color-tunable luminescence phosphors is potential in the fields of photoelectronic devices and biomedical science.