采用传统的高温固相法制备一种新型的红色荧光粉Ba_(6)Gd_(2)Ti_(4)O_(17):Sm^(3+),并通过X射线衍射(X-ray diffraction,XRD)、扫描电子显微镜(scanning electron microscope,SEM)、荧光(photoluminescence,PL)光谱及色坐标表征系列样...采用传统的高温固相法制备一种新型的红色荧光粉Ba_(6)Gd_(2)Ti_(4)O_(17):Sm^(3+),并通过X射线衍射(X-ray diffraction,XRD)、扫描电子显微镜(scanning electron microscope,SEM)、荧光(photoluminescence,PL)光谱及色坐标表征系列样品的物相、形貌和发光性能.PL光谱表明该荧光粉可以被近紫外光有效激发,在407 nm近紫外光激发下,发射光谱由四个发射峰组成,最强发射峰位于616 nm处,归结为Sm^(3+)的^(4)G_(5/2)→^(6)H_(7/2)跃迁.随着Sm^(3+)掺杂量的增加,荧光粉的发光强度先增大后减小,最佳掺杂比例(物质的量分数)为3%.系列掺杂比例荧光粉的色坐标基本不变,均位于红光区.研究结果表明,该荧光粉是一种具有应用前景的新型白光发光二极管(light-emitting diode,LED)用红色荧光粉.展开更多
A novel red-emitting phosphor tantalate Ca_(2)YTaO_(6):Eu^(3+)was synthesized by a solid-state reaction.The purity and surface morphology of the phosphors were characterized.The Ca_(2)YTaO_(6):Eu^(3+)phosphors show a ...A novel red-emitting phosphor tantalate Ca_(2)YTaO_(6):Eu^(3+)was synthesized by a solid-state reaction.The purity and surface morphology of the phosphors were characterized.The Ca_(2)YTaO_(6):Eu^(3+)phosphors show a sharp emission peak at 612 nm under near-ultraviolet(n-UV) at 395 nm because of the ^(5)D0→^(7)F_(2) transition of Eu^(3+).The optimal Eu^(3+)doping concentration in Ca_(2)YTaO_(6) is 40 mol% and the critical energy-transfer distance of Eu^(3+)ions was calculated to be 0.9 nm.The emission spectra of Ca_(2)YTaO_(6):Eu_(3+)from 300 to 480 K were investigated.The thermal-quenching temperature(T_(0.5)) of Ca_(2)YTaO_(6):Eu^(3+)is above 480 K.The color purity of Ca_(2)YTaO_(6):40 mol%Eu^(3+)is as high as 99.8%.The luminescence lifetime of Ca_(2)YTaO_(6):40 mol%Eu^(3+)was also discussed.The high color purity and high thermal stability of Eu^(3+)-doped Ca_(2)YTaO_(6) phosphors contribute to its application value in white lightemitting diodes(w-LEDs).展开更多
Hydrothermal treatment of calcium oxide and boric acid mixtures at temperaturesbetween 234 ℃ and 300 ℃ has produced a colorless, transparent, orthorhombic compound Ca2B6O11 · H2O. Of the seven known members of ...Hydrothermal treatment of calcium oxide and boric acid mixtures at temperaturesbetween 234 ℃ and 300 ℃ has produced a colorless, transparent, orthorhombic compound Ca2B6O11 · H2O. Of the seven known members of the series of hydrated dicalcium hexaborate containing boron-oxygen six-membered ring anionic group (B3O8)7, only the title compound has been found to have the nonlinear optical effect. The second harmanic generation (SHG) effect of its crystal is larger than that of KH2PO4 (KDP). The reflection spectrum has shown that this compound has no absorption in the experimental wavelength range (800-240 nm). Its crystal structure is favorable for generating the nonlinear optical effect.展开更多
基金financially supported by the National Natural Science Foundation of China (Grant No. 51862012)the Natural Science Foundation of Jiangxi Province (Grants No. 20202BAB204008, 20165ABC28010)the Innovation Leadership Program of Ganzhou。
基金The work was supported by Undergraduate Innovation Fund of Northwest A&F UniversityChina(201910712069)+3 种基金Hunan Provincial Key Laboratory of Xiangnan Rare-Precious Metals Compounds and Applications(2019XGJSKFJJ01)the Construction Program of the key discipline in Hunan Provincethe Projects of the Education Department of Hunan Province(No.18A465)Science and Technology Plan Project of Chenzhou City(jsyf2017014)。
文摘A novel red-emitting phosphor tantalate Ca_(2)YTaO_(6):Eu^(3+)was synthesized by a solid-state reaction.The purity and surface morphology of the phosphors were characterized.The Ca_(2)YTaO_(6):Eu^(3+)phosphors show a sharp emission peak at 612 nm under near-ultraviolet(n-UV) at 395 nm because of the ^(5)D0→^(7)F_(2) transition of Eu^(3+).The optimal Eu^(3+)doping concentration in Ca_(2)YTaO_(6) is 40 mol% and the critical energy-transfer distance of Eu^(3+)ions was calculated to be 0.9 nm.The emission spectra of Ca_(2)YTaO_(6):Eu_(3+)from 300 to 480 K were investigated.The thermal-quenching temperature(T_(0.5)) of Ca_(2)YTaO_(6):Eu^(3+)is above 480 K.The color purity of Ca_(2)YTaO_(6):40 mol%Eu^(3+)is as high as 99.8%.The luminescence lifetime of Ca_(2)YTaO_(6):40 mol%Eu^(3+)was also discussed.The high color purity and high thermal stability of Eu^(3+)-doped Ca_(2)YTaO_(6) phosphors contribute to its application value in white lightemitting diodes(w-LEDs).
文摘Hydrothermal treatment of calcium oxide and boric acid mixtures at temperaturesbetween 234 ℃ and 300 ℃ has produced a colorless, transparent, orthorhombic compound Ca2B6O11 · H2O. Of the seven known members of the series of hydrated dicalcium hexaborate containing boron-oxygen six-membered ring anionic group (B3O8)7, only the title compound has been found to have the nonlinear optical effect. The second harmanic generation (SHG) effect of its crystal is larger than that of KH2PO4 (KDP). The reflection spectrum has shown that this compound has no absorption in the experimental wavelength range (800-240 nm). Its crystal structure is favorable for generating the nonlinear optical effect.
