Color-tunable luminescence in Y7(1-m-n-z)Bi7mDy7nEU7zO6F9 (m=0.001-0.05, n=0-0.1, z=0.005, 0.01) phosphors

Luminescent materials composed of Y7(1-m-n-z)Bi7mDY7nEu7zO6F9 (m = 0.001-0.05, n = 0-0.1, z = 0.005, 0.01) were prepared using a flux-assisted solid-state reaction method. The X-ray diffraction patterns of the resultant phosphors were examined to index the peak positions. The excitation and emission spectra of Y7(1-m-n)Bi7mDy7nO6F9 (m = 0.01, n = 0; m = 0, n = 0.01; m = 0.01, n = 0.01) were investigated using photoluminescence (PL) spectroscopy. Critical emission quenching, as a function of B3+ or Dy3+ contents in Y7O6F9, was similarly observed at relatively low concentrations of both the activators. The dependence of the luminescent intensity of the Dy3+ co-doped (n = 0-0.1) host lattices on the Bi3+ content (m = 0.01) was also studied. Co-doping Dy3+ into the Bi3+-doped host structure enabled high energy transfer from Bi3+ to Dy3+; this energy transfer mechanism is discussed. Furthermore, the Y3+ ions in the lattice were replaced by Eu3+ ions in Y7(1-m-n)Bi7mDy7nO6F9 (m = 0.01, n = 0.01), and the diverse emission spectra by the energy-transfer and cooperation of Bi3+, Dy3+, and Eu3+ transitions and color Commission Internationale de l'Eclairage (CIE) coordinates were obtained. With these phosphors, the desired CIE values including emissions throughout blue, green, white, and red color regions of the spectra were achieved. (C) 2018 Elsevier B.V. All rights reserved.