A novel Ba4Gd3K3(PO4)6F2:Eu2+ blue-white emitting phosphor for near-ultraviolet excited light-emitting diodes

Abstract

Abstract Exploring new phosphors with broadband emission could find potential applications in white light emitting diodes (w-LEDs). However, it is still a severe challenging to achieve a broadband emission in single activator doped phosphors. Herein, we reported a novel apatite-type Ba4Gd3K3(PO4)6F2:Eu2+ phosphor with broadband blue-white emission, which almost cover the whole visible light range. Differing from previous reports, we prove that the broadband emission is originated from the accommodation of Eu2+ ions in the M(1), Gd(2) and K(3) sites, respectively. Emission spectrum and luminescence decay curves further confirm the existence of three emission centers in Ba4Gd3K3(PO4)6F2:Eu2+ phosphor. White LED (Ra\u202f=\u202f81 and CCT\u202f=\u202f3780K) can be obtained by depositing Ba4Gd3K3(PO4)6F2:Eu2+ and red-emitting CaAlSiN3:Eu2+ phosphors on 395\u202fnm LED chip. Moreover, the as-obtained Ba4Gd3K3(PO4)6F2:Eu2+ phosphor can give an stable color output at high temperature, demonstrating that this novel phosphor could be an potential candidate for next-generation near ultraviolet excited white LEDs.