Surfactant-assisted hydrothermal synthesis of octahedral structured NaGd(MoO4)2:Eu3+/Tb3+ and tunable photoluminescent properties

Abstract

NaGd(MoO4)2:Eu3+/Tb3+ phosphors were synthesized via a facile hydrothermal method with a surfactant-assisted environment. The properties were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and photoluminescence (PL). The XRD patterns and FESEM image indicate that NaGd(MoO4)2:Eu3+/Tb3+ phosphors crystallize well with the scheelite structure and the morphology of the sample is octahedral. The octahedral morphology of the phosphors is found to be manipulated by the glutamic acid. The luminescent properties reveal that under 277nm excitation, Eu3+ and Tb3+ doped NaGd(MoO4)2 phosphors show strong red and green emission. Moreover, Eu3+ and Tb3+ co-doped NaGd(MoO4)2 phosphors display the multicolor luminescence when excited by a single excitation wavelength or different excitation wavelengths, and the luminescence colors of the samples can be tuned from red, yellow, yellow–green, to green when adjusting the doping concentration of the activator ions. Furthermore, the possible energy transfer mechanism in Tb3+ and Eu3+ co-doped NaGd(MoO4)2 was proposed in term of the experimental results and analysis. The as-prepared phosphors may find potential applications in the field such as color displays.