A series of Tm^3+/Dy^3+co-doped Ba3 LaNa(PO4)3 F(BLNPF) phosphors were synthesized successfully via a high-temperature solid-reaction,and luminescence properties were investigated.Upon near violet excitation,BLNPF:Tm^...A series of Tm^3+/Dy^3+co-doped Ba3 LaNa(PO4)3 F(BLNPF) phosphors were synthesized successfully via a high-temperature solid-reaction,and luminescence properties were investigated.Upon near violet excitation,BLNPF:Tm^3+,Dy^3+ phosphors exhibit Tm^3+:^1D2-^3 F4 and Dy^3+:^4 F(9/2)-^6 HJ(J=15/2,13/2,11/2)transitions with diffe rent luminescence intensity.The emitting color of the obtained products was found to shift from blue to white as a result of efficient energy transfer(ET) from Tm^3+to Dy^3+ions.According to photoluminescence emission intensity,the positive effect of activator on ET efficiency was calculated and the maximum ET efficiency was found around 72.6% with Dy^3+ concentration was 0.04.By means of Dexter's theoretical model,furthermore,dipole-dipole interaction was confirmed as the mechanism of energy transfer from Tm^3+ to Dy^3+ ions.The results suggested that BLNPF:Tm^3+,Dy^3+ phosphor might be a promising single-phased white-light-emitting phosphor for UV white-light LED.展开更多
A red emitting phosphor of Ba_3Eu(PO_4)_3:Tb^(3+) was synthesized by a solid state method. The energy transfer from Tb^(3+) to Eu3+ in Ba_3Eu(PO_4)_3:Tb^(3+) was proved by the spectral properties and decay curves. The...A red emitting phosphor of Ba_3Eu(PO_4)_3:Tb^(3+) was synthesized by a solid state method. The energy transfer from Tb^(3+) to Eu3+ in Ba_3Eu(PO_4)_3:Tb^(3+) was proved by the spectral properties and decay curves. The emission intensity of Ba_3Eu(PO_4)_3 is enhanced by doping Tb^(3+) as a sensitizer. For Ba_3Eu(PO_4)_3:Tb^(3+), the ~5D_3→~7F_J transition of Tb^(3+) occurs, and the corresponding emission intensities can be tuned when Tb^(3+) content increases, and the concentration quenching effect appears. However, for the ~5D_4→~7F_J transition of Tb^(3+), its intensity straight increases with increasing Tb^(3+) content. For Ba_3Eu(PO_4)_3:Tb^(3+), the values of CIE chromaticity coordinates are similar to those of commercial red phosphors of Sr_2Si_5N_8:Eu^(2+) and Y_2O_2S:Eu^(3+). The results indicate that this red emitting phosphor has a potential application for white LEDs.展开更多
基金The authors gratefully acknowledge the financial support of this project by the National Natural Science Foundation of China ( Grant No. 50021202, 50329201, and 60571035)；the Science and Technology Ministry of China (Grant No. 2003CB314701)；the Education Ministry of China, the Science and Technology Department of Guangdong Province；the Education Department of Guangdong Province；the Science and Technology Department of Guangzhou City.
文摘A series of Tm^3+/Dy^3+co-doped Ba3 LaNa(PO4)3 F(BLNPF) phosphors were synthesized successfully via a high-temperature solid-reaction,and luminescence properties were investigated.Upon near violet excitation,BLNPF:Tm^3+,Dy^3+ phosphors exhibit Tm^3+:^1D2-^3 F4 and Dy^3+:^4 F(9/2)-^6 HJ(J=15/2,13/2,11/2)transitions with diffe rent luminescence intensity.The emitting color of the obtained products was found to shift from blue to white as a result of efficient energy transfer(ET) from Tm^3+to Dy^3+ions.According to photoluminescence emission intensity,the positive effect of activator on ET efficiency was calculated and the maximum ET efficiency was found around 72.6% with Dy^3+ concentration was 0.04.By means of Dexter's theoretical model,furthermore,dipole-dipole interaction was confirmed as the mechanism of energy transfer from Tm^3+ to Dy^3+ ions.The results suggested that BLNPF:Tm^3+,Dy^3+ phosphor might be a promising single-phased white-light-emitting phosphor for UV white-light LED.
文摘A red emitting phosphor of Ba_3Eu(PO_4)_3:Tb^(3+) was synthesized by a solid state method. The energy transfer from Tb^(3+) to Eu3+ in Ba_3Eu(PO_4)_3:Tb^(3+) was proved by the spectral properties and decay curves. The emission intensity of Ba_3Eu(PO_4)_3 is enhanced by doping Tb^(3+) as a sensitizer. For Ba_3Eu(PO_4)_3:Tb^(3+), the ~5D_3→~7F_J transition of Tb^(3+) occurs, and the corresponding emission intensities can be tuned when Tb^(3+) content increases, and the concentration quenching effect appears. However, for the ~5D_4→~7F_J transition of Tb^(3+), its intensity straight increases with increasing Tb^(3+) content. For Ba_3Eu(PO_4)_3:Tb^(3+), the values of CIE chromaticity coordinates are similar to those of commercial red phosphors of Sr_2Si_5N_8:Eu^(2+) and Y_2O_2S:Eu^(3+). The results indicate that this red emitting phosphor has a potential application for white LEDs.
