A new self-activated vanadate phosphor of Na2YMg2(VO4)3 and luminescence properties in Eu3+ doped Na2YMg2(VO4)3

A novel self-activated vanadate phosphor of Na2YMg2(VO4)3 was prepared using a sol-gel method. Phase formation was verified through X-ray diffraction studies. Luminescence characteristics such as photoluminescence excitation, emission spectra and decay curves were investigated. This host can be efficiently excited by ultraviolet (UV) light, and exhibits an intense green emission band in the regions from 400 nm to 750 nm with maximum at about 521 nm, originating from VO43- groups. The band gap energy of Na2YMg2(VO4)3 is estimated to be an approximate value of 2.95 eV by UV-visible absorption spectra. Intensities of host and Eu3+ emissions and their decay curves depend on Eu3+ doping concentration. Various luminescent colors, including warm white, can be easily tuned by adjusting concentrations. Spectrum analysis showed that energy transfer from host to Eu3+ ions occurred with low efficiency. Luminescence properties of as-prepared materials indicate to be as a potential candidate for application in near-UV exciting white LEDs.