We demonstrated that tridoping with F- ions is an effective way to improve the fluorescence quantum efficiency of CaWO4:Eu3+,Na+ nanocrystals. F--tridoped samples with different F- concentrations were synthesized b...We demonstrated that tridoping with F- ions is an effective way to improve the fluorescence quantum efficiency of CaWO4:Eu3+,Na+ nanocrystals. F--tridoped samples with different F- concentrations were synthesized by a hydrothermal process. The fluorescence spectra and decay curves were measured at room temperature. The fluorescence intensity of F--tridoped samples is about 3 times that for the non F--doped sample. The fluorescence quantum efficiency can be enhanced by 21% when the atomic ratio of F to W was 0.7.展开更多
Eu3+ doped CaWO4 with tetragonal system were prepared at comparatively low temperature (125 ℃) in ethylene glycol medium. The phosphor was further investigated by X-ray difffactometer (XRD), photoluminescence sp...Eu3+ doped CaWO4 with tetragonal system were prepared at comparatively low temperature (125 ℃) in ethylene glycol medium. The phosphor was further investigated by X-ray difffactometer (XRD), photoluminescence spectrophotometer (PL), Fourier transform infra red (FT-IR) spectroscopy and transmission electron microscopy (TEM). XRD analysis indicated a decrease in the unit cell volume of CaWO4 with increasing Eu3+ ion concentration. It indicated the homogeneous substitution of Ca2+ ions in CaWO4 by the Eu3+ ions. TEM images showed that the particle size ranged from 20 to 200 nm and it could extend the application of the nanoparticles. The photoluminescence study showed that the intensity of electric dipole transition (SD0→TF2) at 614 nm dominated over the magnetic dipole transition (SD0→TFx) at 592 nm. The optimum concentration of Eu3+ for the highest luminescence was found to be 20 at.%. The as prepared samples were found to be dispersible in water and methanol.展开更多
基金Supported by the National Natural Science Foundation of China(No.51002152)the Natural Science Foundation of Fujian Province(No.2010J05125)
文摘We demonstrated that tridoping with F- ions is an effective way to improve the fluorescence quantum efficiency of CaWO4:Eu3+,Na+ nanocrystals. F--tridoped samples with different F- concentrations were synthesized by a hydrothermal process. The fluorescence spectra and decay curves were measured at room temperature. The fluorescence intensity of F--tridoped samples is about 3 times that for the non F--doped sample. The fluorescence quantum efficiency can be enhanced by 21% when the atomic ratio of F to W was 0.7.
基金Project supported by the Department of Science and Technology (DST), New Delhi, Govt. of India
文摘Eu3+ doped CaWO4 with tetragonal system were prepared at comparatively low temperature (125 ℃) in ethylene glycol medium. The phosphor was further investigated by X-ray difffactometer (XRD), photoluminescence spectrophotometer (PL), Fourier transform infra red (FT-IR) spectroscopy and transmission electron microscopy (TEM). XRD analysis indicated a decrease in the unit cell volume of CaWO4 with increasing Eu3+ ion concentration. It indicated the homogeneous substitution of Ca2+ ions in CaWO4 by the Eu3+ ions. TEM images showed that the particle size ranged from 20 to 200 nm and it could extend the application of the nanoparticles. The photoluminescence study showed that the intensity of electric dipole transition (SD0→TF2) at 614 nm dominated over the magnetic dipole transition (SD0→TFx) at 592 nm. The optimum concentration of Eu3+ for the highest luminescence was found to be 20 at.%. The as prepared samples were found to be dispersible in water and methanol.