A novel Tm^(3+)/Tb^(3+)/Sm^(3+)tri-doped Na_(5)Y_(9)F_(32)single crystal was synthesized by a modified Bridgman method for the propose of white light emitting diodes.The fluorescence spectra of various Sm^(3+)ion conc...A novel Tm^(3+)/Tb^(3+)/Sm^(3+)tri-doped Na_(5)Y_(9)F_(32)single crystal was synthesized by a modified Bridgman method for the propose of white light emitting diodes.The fluorescence spectra of various Sm^(3+)ion concentrations and fixed 0.4 mol%Tm^(3+)and 0.5 mol%Tb^(3+)were measured and studied systematically excited by near-ultraviolet light of 355 nm.The Sm3+ion concentration takes apparent effect on the relative intensity of peaks in the visible region and the color coordinate combining from these emission bands.A near pure white light emission with color coordinates(0.3295,0.3057)and color temperature(5657 K)can be obtained when the concentrations of Tm^(3+),Tb^(3+)and Sm^(3+)ions are 0.4 mol%,0.5 mol%and 0.8 mol%,respectively.Furthermore,the practical down-conversion internal quantum yield was measured by integrating spheres at about 14.39%.The tri-doped Na_(5)Y_(9)F_(32)single crystal shows a high thermal stability inferring from the temperature dependent emission in which the integrated emission intensities are reduced only by^3%with the increase of temperature from 280 to 450 K.The present results demonstrate that the Tm^(3+)/Tb^(3+)/Sm^(3+)tri-doped Na_(5)Y_(9)F_(32)single crystal may provide a promising candidate for white light-emitting diodes,luminescent materials and fluorescent display devices.展开更多
Na_(5)Y_(9)F_(32) single crystals doped with ~0.8-mol% Ho^(3+),~1-mol% Tm^(3+),and various Er^(3+) ion concentrations were prepared by a modified Bridgman method.The effects of Er^(3+)ion concentration on 2.0-μm emis...Na_(5)Y_(9)F_(32) single crystals doped with ~0.8-mol% Ho^(3+),~1-mol% Tm^(3+),and various Er^(3+) ion concentrations were prepared by a modified Bridgman method.The effects of Er^(3+)ion concentration on 2.0-μm emission excited by an800-nm laser diode were investigated with the help of their spectroscopic properties.The intensity of 2.0-μm emission reached to maximum when the Er^(3+) ion concentration was ~1 mol%.The energy transfer mechanisms between Er^(3+),Ho^(3+),and Tm^(3+) ions were identified from the change of the absorption spectra,the emission spectra,and the measured decay curves.The maximum 2.0-μm emission cross section of the Er^(3+)/Ho^(3+)/Tm^(3+)tri-doped Na_(5)Y_(9)F_(32) single crystal reached 5.26 × 10^(-21) cm^(2).The gain cross section spectra were calculated according to the absorption and emission cross section spectra.The cross section for ~2.0-μm emission became a positive gain once the inversion level of population was reached 30%.The energy transfer efficiency was further increased by 11.81% through the incorporation of Er^(3+) ion into Ho^(3+)/Tm^(3+) system estimated from the measured lifetimes of Ho^(3+)/Tm^(3+)-and Er^(3+)/Ho^(3+)/Tm^(3+)-doped Na_(5)Y_(9)F_(32)single crystals.The present results illustrated that the Er^(3+)/Ho^(3+)/Tm^(3+)tri-doped Na_(5)Y_(9)F_(32) single crystals can be used as promising candidate for 2.0-μm laser.展开更多
基金Project supported by the National Natural Science Foundation of China(51772159)the Natural Science Foundation of Zhejiang Province(LZ17E020001)The authors would like to acknowledge program of the K.C.Wong Magna Fund in Ningbo University.
文摘A novel Tm^(3+)/Tb^(3+)/Sm^(3+)tri-doped Na_(5)Y_(9)F_(32)single crystal was synthesized by a modified Bridgman method for the propose of white light emitting diodes.The fluorescence spectra of various Sm^(3+)ion concentrations and fixed 0.4 mol%Tm^(3+)and 0.5 mol%Tb^(3+)were measured and studied systematically excited by near-ultraviolet light of 355 nm.The Sm3+ion concentration takes apparent effect on the relative intensity of peaks in the visible region and the color coordinate combining from these emission bands.A near pure white light emission with color coordinates(0.3295,0.3057)and color temperature(5657 K)can be obtained when the concentrations of Tm^(3+),Tb^(3+)and Sm^(3+)ions are 0.4 mol%,0.5 mol%and 0.8 mol%,respectively.Furthermore,the practical down-conversion internal quantum yield was measured by integrating spheres at about 14.39%.The tri-doped Na_(5)Y_(9)F_(32)single crystal shows a high thermal stability inferring from the temperature dependent emission in which the integrated emission intensities are reduced only by^3%with the increase of temperature from 280 to 450 K.The present results demonstrate that the Tm^(3+)/Tb^(3+)/Sm^(3+)tri-doped Na_(5)Y_(9)F_(32)single crystal may provide a promising candidate for white light-emitting diodes,luminescent materials and fluorescent display devices.
基金Project supported by the National Natural Science Foundation of China(Grant No.51772159)the Natural Science Foundation of Zhejiang Province+2 种基金China(Grant No.LZ17E020001)the Natural Science Foundation of Ningbo City(Grant No.202003N4099)K C Wong Magna Fund in Ningbo University。
文摘Na_(5)Y_(9)F_(32) single crystals doped with ~0.8-mol% Ho^(3+),~1-mol% Tm^(3+),and various Er^(3+) ion concentrations were prepared by a modified Bridgman method.The effects of Er^(3+)ion concentration on 2.0-μm emission excited by an800-nm laser diode were investigated with the help of their spectroscopic properties.The intensity of 2.0-μm emission reached to maximum when the Er^(3+) ion concentration was ~1 mol%.The energy transfer mechanisms between Er^(3+),Ho^(3+),and Tm^(3+) ions were identified from the change of the absorption spectra,the emission spectra,and the measured decay curves.The maximum 2.0-μm emission cross section of the Er^(3+)/Ho^(3+)/Tm^(3+)tri-doped Na_(5)Y_(9)F_(32) single crystal reached 5.26 × 10^(-21) cm^(2).The gain cross section spectra were calculated according to the absorption and emission cross section spectra.The cross section for ~2.0-μm emission became a positive gain once the inversion level of population was reached 30%.The energy transfer efficiency was further increased by 11.81% through the incorporation of Er^(3+) ion into Ho^(3+)/Tm^(3+) system estimated from the measured lifetimes of Ho^(3+)/Tm^(3+)-and Er^(3+)/Ho^(3+)/Tm^(3+)-doped Na_(5)Y_(9)F_(32)single crystals.The present results illustrated that the Er^(3+)/Ho^(3+)/Tm^(3+)tri-doped Na_(5)Y_(9)F_(32) single crystals can be used as promising candidate for 2.0-μm laser.
