Near UV-pumped yellow-emitting Ca3TeO6:Dy3+ phosphor for white light-emitting diodes

A series of Ca3TeO6:xDy(3+) (x = 0.01, 0.02, 0.05, 0.10, 0.15, 020, and 0.25) tellurate yellow-emitting phosphors were synthesized via the high-temperature solid-state method. The X-ray diffraction patterns of these phosphors revealed that all the samples have a double-perovskite type with monoclinic structure. The Ca3TeO6:Dy3+ phosphor exhibit characteristic emission transitions, F-4(9/2)-H-6(15/2) transition and F-4(9/2)-H-6(13/2) transition, respectively. The intense yellow light indicates that Dy3+ ion occupies the interstitial Ca site in the Ca3TeO6 host. The optimal Dy3+ ion concentration was determined as 10 mol%. The critical energy transfer distance was calculated as 14 angstrom. The concentration quenching mechanism of Dy3+ was investigated in details. The temperature effect on photoluminescence was discussed in order to evaluate the thermal stability. The obtained results illustrate Ca3TeO6Dy3+ was a new kind of yellow-emitting potential phosphor for WLEDs. (C) 2019 Published by Elsevier B.V.