Photoluminescence properties and energy transfer of KY1-x Lnx (MoO4)2 (Ln=Sm3+, Eu3+) red phosphors

Eu3+ and Sm3+ activated double molybdates, KY(1-x)Ln(x)(MoO4)(2) (Ln=Sm3+, Eu3+), were synthesized by a convenient solid-state method. The photoluminescence properties, energy transfer and concentration quenching were investigated in the excitation and emission spectra. The results exhibit that with Sm3+ and Eu3+ ions co-doped into the host, the excitations around 394 nm and 465 nm become broader and their intensities are prominently enhanced compared to that of the single Eu3+ doped sample. The effective energy transfer from Sm3+ to Eu3+ is found to exist for Sm3+ and Eu3+ co-doped KY(MoO4)(2) phosphors. Besides, with increasing Eu3+ doping concentration, the chromaticity coordinates of KY(1-x)Ln(x)(MoO4)(2) (Ln=Sm3+, Eu3+) approach to the NTSC standard values in a systematic way. The KY(MoO4)(2):Sm3+, Eu3+ phosphors may be potentially used as red phosphors for white light-emitting diodes. (C) 2014 Elsevier B.V. All rights reserved.