Synthesis and luminescence properties of Eu3+/Dy3+ ions co-doped Ca2La8(GeO4)6O2 phosphors for white-light applications

Eu3+/Dy3+ ions co-doped Ca2La8(GeO4)(6)O-2 (CLGO) phosphors were prepared by a pechini-type sol-gel method. The structural and morphological studies of the CLGO phosphors were carried out by measuring X-ray diffraction patterns and scanning electron microscope images. The photoluminescence (PL) spectra of the CLGO: Eu3+ phosphor exhibited the intense red emission due to the electric-dipole transition while the CLGO: Dy3+ phosphor showed the blue (F-4(9/2)-> H-6(15/2)) and yellow (F-4(9/2)-> H-6(13/2)) emissions with almost equal intensities. The Eu3+/Dy3+ ions co-doped CLGO phosphor showed the improved white light by shifting towards the warm white region. The energy transfer from Dy3+ to Eu3+ ions was investigated by means of PL intensities. The lifetime measurements were also performed for single-doped and co-doped samples. The calculated chromaticity coordinates indicated that these phosphors may be suitable for the fabrication of near-UV excitation-based white light-emitting diodes. (C) 2014 Elsevier B.V. All rights reserved.