Highly thermal-stable yellow-emitting tantalate phosphor Ca2YTaO6:Dy3+ for white-LEDs

Abstract

A series of luminescent Dy3+-doped Ca2YTaO6 phosphors were synthesized via the high temperature solid-state method firstly. They were characterized by X-ray diffraction (XRD) pattern, photoluminescence spectra, thermal quenching, and decay curves. The phosphors could be excited by near UV light 353 nm and emitted the luminescence consisting of blue (484 nm), yellow (576 nm), and red (669 nm) peaks, respectively. Furthermore, with the doping concentration of Dy3+ changed from 0.003 to 0.20, the maximum photoluminescence intensity for the Ca2YTaO6:xDy3+ phosphor was at xc = 0.05 mol. The corresponding critical transfer distance was around 17.20 Å and thermal quenching of Ca2YTaO6:0.05Dy3+ was over than 500 K. The color coordinates of all Ca2YTaO6:Dy3+ samples entered into the yellow-light region. The whited LED was fabricated from the yellow-emitting Ca2YTaO6:Dy3+ and blue-emitting BaMgAl10O17:Eu2+ phosphors with the near UV LED chip (385 nm). The above results presented the Ca2YTaO6:Dy3+ phosphor as a promising yellow-emitting candidate for white light emitting diodes (W-LEDs) applications.