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
Pr^（3＋）-doped transparent oxyfluoride glass-ceramic containing tetragonal LiYF_4 nanocrystals has been synthesized by melting-quenching method and subsequent thermal treatment and spectroscopic properties of Pr^（...Pr^（3＋）-doped transparent oxyfluoride glass-ceramic containing tetragonal LiYF_4 nanocrystals has been synthesized by melting-quenching method and subsequent thermal treatment and spectroscopic properties of Pr^（3＋） ions were investigated. The crystalline phase and microstructure of the LiYF_4 nanocrystals were studied by X-ray diffraction（XRD） and transmission electron microscopy（TEM）, respectively. Compared with those of Pr^（3＋）-doped glass（Pr^（3＋）：PG）, the sharp absorption and emission bands of Pr^（3＋）-doped glass-ceramic（Pr^（3＋）：GC） reveal parts of Pr^（3＋） ions are incorporated into LiYF_4 nanocrystals. The peak absorption cross-section at 443 nm（~3H_4 → ~3P_2） adds to 110% and the full width at half maximum（FWHM） for the band around 443 nm reduces from 22 to 14 nm after crystallization. The fluorescence lifetime of the ~3P_0 multiplet of Pr^（3＋） ions increases from 5.35 to 11.14 μs after crystallization. The results indicate that this glass-ceramic is promising to be a visible laser material.展开更多
Eye-safe 1.5～1.6 μm lasers have important applications in optical fiber communication, medicine, laser-range-finding, lidar, etc. Er^3＋ and Yb^3＋ co-doped crystal pumped by diode laser around 976 nm is an attracti...Eye-safe 1.5～1.6 μm lasers have important applications in optical fiber communication, medicine, laser-range-finding, lidar, etc. Er^3＋ and Yb^3＋ co-doped crystal pumped by diode laser around 976 nm is an attractive method for obtaining 1.5～1.6 μm laser in compact device with high output beam quality. In this paper, the recent research and progress of several important Er^3＋ and Yb^3＋ co-doped laser crystals at 1.5～1.6 μm in authors’ lab are reported.展开更多
A Sr3Yb2（BO3）4 single crystal was obtained by the Czochralski method. The structure of Sr3Yb2 （BO3）4 crystal was determined by single-crystal X-ray diffraction. The compound crystallizes in orthorhombic, space gro...A Sr3Yb2（BO3）4 single crystal was obtained by the Czochralski method. The structure of Sr3Yb2 （BO3）4 crystal was determined by single-crystal X-ray diffraction. The compound crystallizes in orthorhombic, space group Pnma with a=7.3750（8）, b=15.9265（14）, c=8.6776（9）, V=1019.25（18）3 , Mr=844.18, Z=4, Dc=5.501 g/cm3 , λ（MoKa）=0.71073, μ= 33.835 mm-1 , F（000）=1480, the final R=0.0339 and wR=0.0907 for 1090 observed reflections with I〉2σ（I）. The structure features a three-dimensional framework composed of isolated BO3 planar triangles bridged by YbO8 and SrO8 polyhedra. The Sr2＋ and Yb3＋ occupy statistically three independent sites with a Cm and two C1 local symmetries.展开更多
A series of near-infrared(NIR)down-conversion phosphors of La_(3)Ga_(5)SiO_(14)(LGS):Ce^(3+)/Yb^(3+)were synthesized via high-temperature solid-state reaction.Under excitation at 345 nm,the phosphors show strong NIR e...A series of near-infrared(NIR)down-conversion phosphors of La_(3)Ga_(5)SiO_(14)(LGS):Ce^(3+)/Yb^(3+)were synthesized via high-temperature solid-state reaction.Under excitation at 345 nm,the phosphors show strong NIR emission around 978 nm,which matches well with the optimal spectral response of crystalline silicon(c-Si)solar cells.The emission spectra and decay curves were used to demonstrate the energy transfer from Ce^(3+)to Yb^(3+).The energy transfer mechanism was discussed in detail,indicating that the energy transfer from Ce^(3+)to Yb^(3+)is dominated by a single photon process,and the energy transfer efficiency is up to 51%.In addition,La_(3)Ga_(5-z)Al_(2)SiO_(14)(z=0,1,2,3):Ce^(3+)/Yb^(3+)were also synthesized.The NIR emission intensity of La_(3)Ga_(2)Al_(3)SiO_(14):1%Ce^(3+)/5%Yb^(3+)is 4.6 times that of LGS:1%Ce^(3+)/5%Yb^(3+),and the thermal relaxation was used to explain this phenomenon.The results show that La_(3)Ga_(5-z)Al_(2)SiO_(14)(z=0,1,2,3):1%Ce^(3+)/5%Yb^(3+)phosphors have the potential to increase the conversion efficiency of c-Si solar cells.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supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB20000000)
文摘Pr^（3＋）-doped transparent oxyfluoride glass-ceramic containing tetragonal LiYF_4 nanocrystals has been synthesized by melting-quenching method and subsequent thermal treatment and spectroscopic properties of Pr^（3＋） ions were investigated. The crystalline phase and microstructure of the LiYF_4 nanocrystals were studied by X-ray diffraction（XRD） and transmission electron microscopy（TEM）, respectively. Compared with those of Pr^（3＋）-doped glass（Pr^（3＋）：PG）, the sharp absorption and emission bands of Pr^（3＋）-doped glass-ceramic（Pr^（3＋）：GC） reveal parts of Pr^（3＋） ions are incorporated into LiYF_4 nanocrystals. The peak absorption cross-section at 443 nm（~3H_4 → ~3P_2） adds to 110% and the full width at half maximum（FWHM） for the band around 443 nm reduces from 22 to 14 nm after crystallization. The fluorescence lifetime of the ~3P_0 multiplet of Pr^（3＋） ions increases from 5.35 to 11.14 μs after crystallization. The results indicate that this glass-ceramic is promising to be a visible laser material.
基金Supported by the National Natural Science Foundation of China (No. 50590405 and 50802094)the Major Programs of the Chinese Academy of Sciences (No. SZD08001-1)+1 种基金the Natural Science Foundation of Fujian Province (No. 2008J0173)the Knowledge Innovation Program of the Chinese Academy of Sciences
文摘Eye-safe 1.5～1.6 μm lasers have important applications in optical fiber communication, medicine, laser-range-finding, lidar, etc. Er^3＋ and Yb^3＋ co-doped crystal pumped by diode laser around 976 nm is an attractive method for obtaining 1.5～1.6 μm laser in compact device with high output beam quality. In this paper, the recent research and progress of several important Er^3＋ and Yb^3＋ co-doped laser crystals at 1.5～1.6 μm in authors’ lab are reported.
基金Supported by the National Natural Science Foundation of China (51002152)the Natural Science Foundation of Fujian Province (2010J05125)
文摘A Sr3Yb2（BO3）4 single crystal was obtained by the Czochralski method. The structure of Sr3Yb2 （BO3）4 crystal was determined by single-crystal X-ray diffraction. The compound crystallizes in orthorhombic, space group Pnma with a=7.3750（8）, b=15.9265（14）, c=8.6776（9）, V=1019.25（18）3 , Mr=844.18, Z=4, Dc=5.501 g/cm3 , λ（MoKa）=0.71073, μ= 33.835 mm-1 , F（000）=1480, the final R=0.0339 and wR=0.0907 for 1090 observed reflections with I〉2σ（I）. The structure features a three-dimensional framework composed of isolated BO3 planar triangles bridged by YbO8 and SrO8 polyhedra. The Sr2＋ and Yb3＋ occupy statistically three independent sites with a Cm and two C1 local symmetries.
基金the Ministry of Science and Technology of the People’s Republic of China(2016YFB0701002)Chinese Academy of Sciences(KFJ-STS-QYZX-069,XDB20000000)Natural Science Foundation of Fujian Province(2019J01127)。
文摘A series of near-infrared(NIR)down-conversion phosphors of La_(3)Ga_(5)SiO_(14)(LGS):Ce^(3+)/Yb^(3+)were synthesized via high-temperature solid-state reaction.Under excitation at 345 nm,the phosphors show strong NIR emission around 978 nm,which matches well with the optimal spectral response of crystalline silicon(c-Si)solar cells.The emission spectra and decay curves were used to demonstrate the energy transfer from Ce^(3+)to Yb^(3+).The energy transfer mechanism was discussed in detail,indicating that the energy transfer from Ce^(3+)to Yb^(3+)is dominated by a single photon process,and the energy transfer efficiency is up to 51%.In addition,La_(3)Ga_(5-z)Al_(2)SiO_(14)(z=0,1,2,3):Ce^(3+)/Yb^(3+)were also synthesized.The NIR emission intensity of La_(3)Ga_(2)Al_(3)SiO_(14):1%Ce^(3+)/5%Yb^(3+)is 4.6 times that of LGS:1%Ce^(3+)/5%Yb^(3+),and the thermal relaxation was used to explain this phenomenon.The results show that La_(3)Ga_(5-z)Al_(2)SiO_(14)(z=0,1,2,3):1%Ce^(3+)/5%Yb^(3+)phosphors have the potential to increase the conversion efficiency of c-Si solar cells.
