In this peper we have synthesized powder crystal form (Y,Gd) BO3:Eu(3+)Phosphors by microwave heating method. ItS structure belongs to hexagonal system with lattice parameters a=0.3796,c=0. 8835. Its excitation spetra...In this peper we have synthesized powder crystal form (Y,Gd) BO3:Eu(3+)Phosphors by microwave heating method. ItS structure belongs to hexagonal system with lattice parameters a=0.3796,c=0. 8835. Its excitation spetra peaks at 239.0nm and 240. 0nm monitored at the emission of 589nm and 612nm respectively, the half peak width is 40nm. Under 240nm excitation the phosphors show a strons oranse-red luminescence, the fluorescent intensity ratio for I589/I612 is 1.9/1展开更多
The (Y,Gd)BO 3∶Eu phosphor was synthesized by solid state reaction. The UV spectra showed that in a certain range of Gd 3+ concentration, more Gd 3+ absorbed energy and transferred it to Eu 3+ with its increasing con...The (Y,Gd)BO 3∶Eu phosphor was synthesized by solid state reaction. The UV spectra showed that in a certain range of Gd 3+ concentration, more Gd 3+ absorbed energy and transferred it to Eu 3+ with its increasing concentration. From the spectra in VUV region, it was observed that both the doping and the concentrations of Gd 3+ , Eu 3+ greatly affected the absorption of the host lattice. The absorbances at 147 nm and 170 nm increased when the Gd 3+ was doped which can be explained as that Gd 3+ transferred energy to BO 4. The optical properties of (Y,Gd)BO 3∶Eu were the best when the concentration of Eu 3+ was about 0.04.展开更多
Highly efficient phosphors under vacuum ultraviolet excitation are still demanded for the development of plasma display panels and Hg-free fluorescent lamps. The phosphors of Eu3＋ doped （Y, Gd, Lu）BO3 were synthesi...Highly efficient phosphors under vacuum ultraviolet excitation are still demanded for the development of plasma display panels and Hg-free fluorescent lamps. The phosphors of Eu3＋ doped （Y, Gd, Lu）BO3 were synthesized with solid state reaction method and the contents of y3＋ Gd3＋, and Lu3＋ for plasma display panel red phosphor were optimized under vacuum ultraviolet excitation. Two new potential candidates, which were （Y1-S-TGdsLuT）BO3： Eu^3＋ （0〈S〈0.2, 0〈T〈0.1） and （GdlYJLuK）BO3： Eu3＋ （0.5〈I〈0.7, 0.2〈J〈0.4, 0〈K〈0.1）, were olgtained. The mechanism of luminescence improvement was discussed upon the analysis of crystal microstructure and excitation spectra.展开更多
Y, Gd)Al 3(BO 3) 4∶Eu 3+ samples were prepared by the conventional solid state reaction. The XRD results indicate that the crystal symmetry is low. The excitation spectrum is composed of two broad bands centered ...Y, Gd)Al 3(BO 3) 4∶Eu 3+ samples were prepared by the conventional solid state reaction. The XRD results indicate that the crystal symmetry is low. The excitation spectrum is composed of two broad bands centered at about 170 and 250 nm respectively. In the emission spectra, the peak wavelength is about 616 nm under 147 nm VUV excitation. The luminescent chromaticity coordinate and the relative intensity change along with Gd 3+ mole concentration in the range of 0.15 to 0.85 mol (and Eu 3+ mole concentration, 0.02 to 0.1 mol). The correlative data show that the concentration quenching occurs when the Eu 3+ mole concentration ranges from 0.02 to 0.1 mol, and the Gd 3+→Gd 3+, Gd 3+→Eu 3+ and host→Eu 3+, Gd 3+ energy transfers exist, and Gd 3+ mole concentration influences Eu 3+ emission.展开更多
(Y, Gd)BO_3∶Eu 3+ particles coated with nano-hematite were prepared by a facile method, for example (humid) solid phase reaction at room temperature. The resulted hematite-coated (Y,Gd)BO_3∶Eu 3+ particles were char...(Y, Gd)BO_3∶Eu 3+ particles coated with nano-hematite were prepared by a facile method, for example (humid) solid phase reaction at room temperature. The resulted hematite-coated (Y,Gd)BO_3∶Eu 3+ particles were characterized by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) analysis, X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), and photoluminescence spectra (PL). The SEM and EDS analyses indicate that the particles are coated with a very thin layer of iron oxide. XPS results further confirmed that the coating was hematite, and the coating thickness was in nanometer range. XRD patterns showed that either the hematite coating was too thin or the content of hematite was too small, so that the XRD cannot detect it. The emission spectra illustrate that the peak near 580 nm disappears due to the coating of iron oxide, and when the coating is very thin, the ratio of 5D_0→7F_2 to 5D_0→7F_1 of coated particles is higher than that of uncoated ones, which indicates that the color purity of the phosphor is increased by coating nano-hematite.展开更多
文摘In this peper we have synthesized powder crystal form (Y,Gd) BO3:Eu(3+)Phosphors by microwave heating method. ItS structure belongs to hexagonal system with lattice parameters a=0.3796,c=0. 8835. Its excitation spetra peaks at 239.0nm and 240. 0nm monitored at the emission of 589nm and 612nm respectively, the half peak width is 40nm. Under 240nm excitation the phosphors show a strons oranse-red luminescence, the fluorescent intensity ratio for I589/I612 is 1.9/1
文摘The (Y,Gd)BO 3∶Eu phosphor was synthesized by solid state reaction. The UV spectra showed that in a certain range of Gd 3+ concentration, more Gd 3+ absorbed energy and transferred it to Eu 3+ with its increasing concentration. From the spectra in VUV region, it was observed that both the doping and the concentrations of Gd 3+ , Eu 3+ greatly affected the absorption of the host lattice. The absorbances at 147 nm and 170 nm increased when the Gd 3+ was doped which can be explained as that Gd 3+ transferred energy to BO 4. The optical properties of (Y,Gd)BO 3∶Eu were the best when the concentration of Eu 3+ was about 0.04.
基金supported by the Special Foundation of Hefei University of Technology for Doctor Degree Staff (103-036402)the Postdoctoral Research Fellow of Materials Science and Engineering of Hefei University of Technology (103-035038)
文摘Highly efficient phosphors under vacuum ultraviolet excitation are still demanded for the development of plasma display panels and Hg-free fluorescent lamps. The phosphors of Eu3＋ doped （Y, Gd, Lu）BO3 were synthesized with solid state reaction method and the contents of y3＋ Gd3＋, and Lu3＋ for plasma display panel red phosphor were optimized under vacuum ultraviolet excitation. Two new potential candidates, which were （Y1-S-TGdsLuT）BO3： Eu^3＋ （0〈S〈0.2, 0〈T〈0.1） and （GdlYJLuK）BO3： Eu3＋ （0.5〈I〈0.7, 0.2〈J〈0.4, 0〈K〈0.1）, were olgtained. The mechanism of luminescence improvement was discussed upon the analysis of crystal microstructure and excitation spectra.
文摘Y, Gd)Al 3(BO 3) 4∶Eu 3+ samples were prepared by the conventional solid state reaction. The XRD results indicate that the crystal symmetry is low. The excitation spectrum is composed of two broad bands centered at about 170 and 250 nm respectively. In the emission spectra, the peak wavelength is about 616 nm under 147 nm VUV excitation. The luminescent chromaticity coordinate and the relative intensity change along with Gd 3+ mole concentration in the range of 0.15 to 0.85 mol (and Eu 3+ mole concentration, 0.02 to 0.1 mol). The correlative data show that the concentration quenching occurs when the Eu 3+ mole concentration ranges from 0.02 to 0.1 mol, and the Gd 3+→Gd 3+, Gd 3+→Eu 3+ and host→Eu 3+, Gd 3+ energy transfers exist, and Gd 3+ mole concentration influences Eu 3+ emission.
文摘(Y, Gd)BO_3∶Eu 3+ particles coated with nano-hematite were prepared by a facile method, for example (humid) solid phase reaction at room temperature. The resulted hematite-coated (Y,Gd)BO_3∶Eu 3+ particles were characterized by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) analysis, X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), and photoluminescence spectra (PL). The SEM and EDS analyses indicate that the particles are coated with a very thin layer of iron oxide. XPS results further confirmed that the coating was hematite, and the coating thickness was in nanometer range. XRD patterns showed that either the hematite coating was too thin or the content of hematite was too small, so that the XRD cannot detect it. The emission spectra illustrate that the peak near 580 nm disappears due to the coating of iron oxide, and when the coating is very thin, the ratio of 5D_0→7F_2 to 5D_0→7F_1 of coated particles is higher than that of uncoated ones, which indicates that the color purity of the phosphor is increased by coating nano-hematite.
