Effects of Na2CO3 flux addition on the structure and photoluminescence properties for Eu3+-doped YVO4 phosphor

The luminescence properties of (Y0.9Eu0.1)VO4 phosphor with Na2CO3 flux prepared using the solid-state reaction were investigated. The XRD patterns show that all of the peaks are attributed to the YVO4 phase. The best crystallinity was obtained with 2 wt% Na2CO3 flux addition. The surface morphology of (Y0.9Eu0.1)VO4 phosphor changed from fluffy to a bar shape structure after Na2CO3 flux addition due to the tetragonal crystal system of YVO4. The calcined powders emit bright red luminescence centered at 618 nm due to the 5D0→7F2 electric dipole transition under an excitation wavelength of 318 nm; its intensity was increased about 15% with 2 wt% Na2CO3 flux addition. Red shift behavior was observed for the charge transfer state (CTS) absorption, which was due to the grain size of (Y0.9Eu0.1)VO4 phosphor increasing with increasing flux content. For 2 wt% Na2CO3 flux addition, the red emission of the (Y0.9Eu0.1)VO4 phosphor had CIE chromaticity coordinates of (0.66, 0.34), which are very close to the NTSC system standard red chromaticity coordinates of (0.67, 0.33).

► The 5D0→7F2 intensity was increased about 15 % by 2 wt% Na2CO3 addition.
► CIE coordinates of (Y0.9Eu0.1)VO4 were (0.66, 0.34) for 2 wt% Na2CO3 addition.
► Particle shape of (Y0.9Eu0.1)VO4 become a bar shape for 2 wt% Na2CO3 addition.