Realization of tunable emission via efficient Tb3+-Eu3+ energy transfer in K3Gd(PO4)2 for UV-excited white light-emitting-diodes

A n-UV convertible phosphor K3Gd(PO4)(2):Tb3+, Eu3+ with tunable-emitting color has been synthesized by the solid state reaction. Under the Tb3+ excitation (373 nm), the Eu3+ emissions increase dramatically with increasing the Eu3+ content due to the efficient energy transfer from Tb3+ to Eu3+, which has been justified through the luminescence spectra and fluorescence decay curves. K3Gd(PO4)(2):0.5Tb(3+), yEu(3+) can achieve tunable color emissions from yellowish-green through orange-yellow and ultimately to reddish-orange by simply adjusting the Eu3+ content. In addition, the energy transfer mechanism was demonstrated to be the dipole-dipole interaction and the energy transfer efficiency was calculated. The present results indicate that this novel orange-yellow emitting phosphor can be as a potential candidate for the application in white LEDs. (C) 2013 Elsevier B.V. All rights reserved.