Color tunable CaZnM(PO) (M = Lu/Tb, Lu/Eu, Tb/Eu) phosphors: luminescence, energy transfer and thermal stability studies for n-UV white LEDs.

A series of Tb- and Eu-doped CaZnLu(PO) (CZLP:Tb and CZLP:Eu) as well as CaZnTb(PO):Eu (CZTP:Eu) phosphors have been prepared via the traditional high-temperature solid-state reaction. X-ray powder diffraction (XRD) patterns of the as-prepared phosphors indicate that the introduction of Tb or Eu affects neither the phase impurity nor the crystal structure of the CZLP host lattice. The concentration dependent photoluminescence (PL) spectra reveal that even if Lu was fully substituted by the dopants, Tb or Eu, the phenomenon of concentration quenching would not occur.