A novel orange-red emitting Ba3 Y4 O9：Sm^（3＋） phosphors were prepared by a high temperature solidstate reaction in air. X-ray diffraction（XRD）, photoluminescence spectra, fluorescence decay and temperature-depen...A novel orange-red emitting Ba3 Y4 O9：Sm^（3＋） phosphors were prepared by a high temperature solidstate reaction in air. X-ray diffraction（XRD）, photoluminescence spectra, fluorescence decay and temperature-dependent emission spectra were utilized to characterize the structure and luminescence properties. The results show that the excitation spectrum includes a series of linear peaks at350, 367, 382, 410, 424, 445, 470 and 495 nm, respectively. Under 410 nm excitation, the emission peaks were located at 574 nm（~4 G（5/2）-~6 H（5/2））, 608 nm（~4 G（5/2）-~6 H（7/2））,659 nm（~4 G（5/2）-~6 H（9/2）） and722 nm（~4 G（5/2）-~6 H（11/2））, respectively. The concentration quenching occurs when x equals 0.08 for Ba3 Y（4-x）O9：xSm^（3＋） phosphor and its mechanism is ascribed to the dipole-dipole interaction. The chromaticity coordinates of Ba3 Y（3.92）O9：0.08 Sm^（3＋） phosphor are in the orange-red region. The temperature-dependent study shows that this phosphor has excellent luminescence thermal-stability.And the luminescence intensity of Ba3 Y（3.92）O9：0.08 Sm^（3＋） phosphor at 473 K only declines by about25.75% of its initial intensity. The experimental data indicate that Ba3 Y4 O9：Sm^（3＋） phosphor may be promising as an orange-red emitting phosphor for white light emitting diodes.展开更多
A series of reddish orange phosphors Ba3Gd1-x（PO4）3：xSm^3＋ （x = 0.02, 0.04 0.12） were prepared by the high-temperature solid-state reaction. X-ray powder diffraction （XRD） and diffuse reflectance and photolumi...A series of reddish orange phosphors Ba3Gd1-x（PO4）3：xSm^3＋ （x = 0.02, 0.04 0.12） were prepared by the high-temperature solid-state reaction. X-ray powder diffraction （XRD） and diffuse reflectance and photoluminescence spectra were utilized to characterize the structure and spectral properties of the phosphors. The phosphors have strong absorption in the near-UV region. CIE chromaticity coordinates of the phosphors are located in the reddish orange region since the strongest emission band is around 598 nm and related to the 4G5/2 - 6H7/2 transition of Sm^3＋. Optimal concentration of Sm^3＋ in the phosphors is about 6.0 at%. The quantum yield of the Ba3Gdo.94（PO4）3：0.06Sm^3＋ under excitation at 403 nm is about 52.07%. Temperature dependent photoluminescence spectra of the Ba3Gdo.94（PO4）3：0.06Sm^3＋ were measured and the phosphor exhibits high thermal stability of emission. All the results show that the Ba3Gd（PO4）3：Sm^3＋ phosphor may be a potential red phosphor for near-UV based white LEDs.展开更多
A novel fluoro-apatite-type compound, Ba3TbK（PO4）3F was developed via a high-temperature solid-state reaction route for the first time. X-ray photoelectron spectroscopy（XPS）, scanning electron microscopy（SEM）, a...A novel fluoro-apatite-type compound, Ba3TbK（PO4）3F was developed via a high-temperature solid-state reaction route for the first time. X-ray photoelectron spectroscopy（XPS）, scanning electron microscopy（SEM）, and high-resolution TEM（HRTEM） were used to investigate the component element and microstructure of the phosphor was systematically investigated. The luminescence properties of Ba3TbK（PO4）3F：Sm3＋ were investigated systemically. The results revealed that the Ba3TbK（PO4）3F：Sm3＋ phosphor could be efficiently excited in a broad wavelength region ranging from 200 to 400 nm, which matched perfectly with the ultraviolet（UV） light-emitting diode（LED） chips. Based on the energy transfer（ET） between Tb3＋ and Sm3＋, the color hue of Ba3Tb1–nK（PO4）3F：n Sm3＋（n=0–0.03） was modulated from green（0.305, 0.591） to yellow（0.486, 0.437） area by controlling the Sm3＋doping concentration. The critical distance between Tb3＋ and Sm3＋ ions in Ba3TbK（PO4）3F：Sm3＋ was calculated and the corresponding energy quenching mechanism was identified. Fascinatingly, both the Ba3TbK（PO4）3F and Ba3Tb0.995K（PO4）3F： 0.005Sm3＋ phosphors exhibited very high thermal stability from room temperature（25 oC） to 300 oC, which is extremely important for practical application. In addition, the activation energy for thermal quenching of the Ba3Tb0.995K（PO4）3F：0.005Sm3＋ sample was estimated to be as high as 0.312 eV. These findings demonstrated that as-prepared phosphor may serve as a high-performance candidate for the application in w-LEDs.展开更多
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
基金supported by the National Key Research and Development Program of China(2016YFB0701003)Key Program of the Frontier Science of the Chinese Academy of Sciences(YZDY-SSW-JSC018)+1 种基金National Natural Science Foundation of China(51402288)Natural Science Foundation of Liaoning Province(201602674)
文摘A novel orange-red emitting Ba3 Y4 O9：Sm^（3＋） phosphors were prepared by a high temperature solidstate reaction in air. X-ray diffraction（XRD）, photoluminescence spectra, fluorescence decay and temperature-dependent emission spectra were utilized to characterize the structure and luminescence properties. The results show that the excitation spectrum includes a series of linear peaks at350, 367, 382, 410, 424, 445, 470 and 495 nm, respectively. Under 410 nm excitation, the emission peaks were located at 574 nm（~4 G（5/2）-~6 H（5/2））, 608 nm（~4 G（5/2）-~6 H（7/2））,659 nm（~4 G（5/2）-~6 H（9/2）） and722 nm（~4 G（5/2）-~6 H（11/2））, respectively. The concentration quenching occurs when x equals 0.08 for Ba3 Y（4-x）O9：xSm^（3＋） phosphor and its mechanism is ascribed to the dipole-dipole interaction. The chromaticity coordinates of Ba3 Y（3.92）O9：0.08 Sm^（3＋） phosphor are in the orange-red region. The temperature-dependent study shows that this phosphor has excellent luminescence thermal-stability.And the luminescence intensity of Ba3 Y（3.92）O9：0.08 Sm^（3＋） phosphor at 473 K only declines by about25.75% of its initial intensity. The experimental data indicate that Ba3 Y4 O9：Sm^（3＋） phosphor may be promising as an orange-red emitting phosphor for white light emitting diodes.
基金Project supported by the National Key Research and Development Program of China(2016YFB0701002)
文摘A series of reddish orange phosphors Ba3Gd1-x（PO4）3：xSm^3＋ （x = 0.02, 0.04 0.12） were prepared by the high-temperature solid-state reaction. X-ray powder diffraction （XRD） and diffuse reflectance and photoluminescence spectra were utilized to characterize the structure and spectral properties of the phosphors. The phosphors have strong absorption in the near-UV region. CIE chromaticity coordinates of the phosphors are located in the reddish orange region since the strongest emission band is around 598 nm and related to the 4G5/2 - 6H7/2 transition of Sm^3＋. Optimal concentration of Sm^3＋ in the phosphors is about 6.0 at%. The quantum yield of the Ba3Gdo.94（PO4）3：0.06Sm^3＋ under excitation at 403 nm is about 52.07%. Temperature dependent photoluminescence spectra of the Ba3Gdo.94（PO4）3：0.06Sm^3＋ were measured and the phosphor exhibits high thermal stability of emission. All the results show that the Ba3Gd（PO4）3：Sm^3＋ phosphor may be a potential red phosphor for near-UV based white LEDs.
基金supported by the National Natural Science Foundations of China(51672258 and 51572246)the Fundamental Research Funds for the Central Universities(2652015296)
文摘A novel fluoro-apatite-type compound, Ba3TbK（PO4）3F was developed via a high-temperature solid-state reaction route for the first time. X-ray photoelectron spectroscopy（XPS）, scanning electron microscopy（SEM）, and high-resolution TEM（HRTEM） were used to investigate the component element and microstructure of the phosphor was systematically investigated. The luminescence properties of Ba3TbK（PO4）3F：Sm3＋ were investigated systemically. The results revealed that the Ba3TbK（PO4）3F：Sm3＋ phosphor could be efficiently excited in a broad wavelength region ranging from 200 to 400 nm, which matched perfectly with the ultraviolet（UV） light-emitting diode（LED） chips. Based on the energy transfer（ET） between Tb3＋ and Sm3＋, the color hue of Ba3Tb1–nK（PO4）3F：n Sm3＋（n=0–0.03） was modulated from green（0.305, 0.591） to yellow（0.486, 0.437） area by controlling the Sm3＋doping concentration. The critical distance between Tb3＋ and Sm3＋ ions in Ba3TbK（PO4）3F：Sm3＋ was calculated and the corresponding energy quenching mechanism was identified. Fascinatingly, both the Ba3TbK（PO4）3F and Ba3Tb0.995K（PO4）3F： 0.005Sm3＋ phosphors exhibited very high thermal stability from room temperature（25 oC） to 300 oC, which is extremely important for practical application. In addition, the activation energy for thermal quenching of the Ba3Tb0.995K（PO4）3F：0.005Sm3＋ sample was estimated to be as high as 0.312 eV. These findings demonstrated that as-prepared phosphor may serve as a high-performance candidate for the application in w-LEDs.
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.
