Synthesis and luminescence properties of CaGd2(MoO4)(4):Dy3+, Eu (3+), Tm3+ phosphors for warm white UV LEDs

A series of Dy3+, Eu3+, and Tm3+-activated CaGd2(MoO4)4 (CGM) ovoid-like microstructured phosphors have been successfully prepared using an ethylenediamine tetraacetic acid-assisted hydrothermal method at 200°C for 24 h. The crystal structure, phase, morphology, composition, and luminescence properties of the phosphors were characterized by x-ray diffraction analysis, energy-dispersive spectrometry, field-emission scanning electron microscopy, photoluminescence (PL) spectroscopy, and lifetime measurements. Under ultraviolet excitation, the rare-earth-ion activated CGM phosphors exhibited characteristic PL properties. Efficient and strong energy transfer processes from Eu3+ to Dy3+ and from Tm3+ to Dy3+ were demonstrated. The CGM:Dy3+, Eu3+, Tm3+ phosphors exhibited strong color-tunable emission and warm white light, having great potential for application in white light-emitting diodes