Preparation And Luminescent Properties Of Rare Earth Doped Yttrium Phosphate-Vanadate Nano Materials

The basic principle of photoluminescence was described in this paper. The characteristics, photoluminescence theory and preparation methods of rare earth luminescent materials were also described. The progress and the application of rare earth luminescent materials were also summarized.Y_xEu_1-xP_yV_1-yO₄ (x=0.98, 0.96, 0.94, 0.92, 0.90; y=0, 0.25, 0.50, 0.75) nanoparticles were synthesised by hydrothermal method. The phase structure of phorphors, TEM morphology and luminescent properties were investigated, respectively. The influence of the reaction time on the experimental results is also discussed. The results show that the samples belong to tetragonal phase, and that the particle size is about 40 nm. And the nanoparticles are oval in shape, and they have polycrystalline structure. In the excitation spectra of Y_xEu_1-xP_yV_1-yO₄, the broad excitation band at 225³50 nm is a charge transfer transition band of O^2--V⁵⁺. Blue shift of the peak is observed with the increase of y value. Narrow excitation peak at 396 nm is attributed to the characteristic 7F0â†'5L6 transition of Eu³⁺. The excitation intensities increase with the increase of Eu-doped concentration or the value of P: V. By analyzing the emission spectra of Y_xEu_1-xP_yV_1-yO₄, we can conclude: the characteristic emission intensities of Eu³⁺ increase with the increase of the Eu-doped concertration or the value of P: V. When the value of P: V is 3: 1, a strong blue emission at 350⁵25 nm is observed. The peak intensities decrease with the increase of the Eu-doped concertration. The reaction time has little effect on the luminescent properties.The Y_xDy_1-xP_yV_1-yO₄ (x=0.98, 0.96, 0.94, 0.92, 0.90; y=0, 0.25, 0.50, 0.75) nanoparticles were also synthesized. The results show that the Y_xDy_1-xP_yV_1-yO₄ samples belong to tetragonal phase, and that the particle size is about 30 nm. And the nanoparticles are oval in shape, and they have polycrystalline structure. In the excitation spectra of Y_xDy_1-xP_yV_1-yO₄, the broad excitation band at 225³50 nm is a charge transfer transition band of O2-?V5+. Blue shift of the peak is observed with the increase of y value. The excitation band at 368 nm is the characteristic 4f-4f transition absorption of Dy³⁺. The change of reaction time has little effect on the wide excitation band at 225³50 nm. Two strong emission bands at 485 nm and 576 nm can be found in the emission spectra of Y_xDy_1-xP_yV_1-yO₄ samples. The emission band at 485 nm is attributed to the magnetic dipole transition of 4F9/2-6H15/2, and the emission band at 576 nm is ascribed to the electric dipole transition of 4F9/2-6H13/2. In the range of 350⁵25 nm, there is a wide weak emission band at 450 nm, which is attributed to the emission band of VO43-. With the decrease of the Dy-doped concentration or the increase of the P: V value, the emission intensity of VO43- increases. The reaction time had little effect on the luminescent intensity.