Preparation, photoluminescence and thermally stable luminescence of high brightness red LiY5P2O13:Eu3+ phosphor for white LEDs

A new red-emitting phosphor LiY5(1−x)P2O13:xEu3+ has been prepared using a conventional high-temperature solid-state method. The phosphors were characterized by X-ray powder diffraction (XRD). The characteristic photoluminescence properties were studied in detail by ultraviolet-visible diffuse reflection, photoluminescence excitation (PLE), emission (PL) spectra and decay times. The concentration quenching mechanism has been investigated, and demonstrated to involve a dipole-quadrupole interaction. Under excitation at 394 and 467 nm, sharp red light can be observed due to the 5D0 → 7F2 transition of the Eu3+ ions. The intensity of the emission from 5D0 to 7F2 is 3.9 times higher than that of commercial phosphors, Y2O2S:Eu3+ when the Eu3+ concentration is x = 0.1. Judd-Ofelt parameters of Eu3+ in the LiY5P2O13 phosphors were calculated, and the refractive index of LiY5P2O13 was deduced to be about 2.22. Finally, LiY5P2O13:Eu3+ exhibited excellent thermal stability compared with Y2O2S:Eu3+. The above results suggest that LiY5P2O13:Eu3+ can be a potential red emitting phosphor for NUV/blue pumped white LEDs.