采用溶胶-凝胶法制备出Y_(2-2 x)MgTiO_(6)∶2 x Eu^(3+)(YMT∶2 x Eu^(3+),0≤x≤0.11)新型红色荧光粉。通过X射线衍射仪(XRD)检测样品的纯度,结果显示YMT∶Eu^(3+)样品属于单斜晶系,空间群为P21/n,无其他杂相。扫描电子显微镜(SEM)照...采用溶胶-凝胶法制备出Y_(2-2 x)MgTiO_(6)∶2 x Eu^(3+)(YMT∶2 x Eu^(3+),0≤x≤0.11)新型红色荧光粉。通过X射线衍射仪(XRD)检测样品的纯度,结果显示YMT∶Eu^(3+)样品属于单斜晶系,空间群为P21/n,无其他杂相。扫描电子显微镜(SEM)照片显示荧光粉为2μm的不规则颗粒。当激发波长为264 nm时,发射光谱出现四个尖锐的发射峰,分别位于591(^(5)D_(0)→^(7)F_(1))、619(^(5)D_(0)→^(7)F_(2))、657(^(5)D_(0)→^(7)F_(3))和693 nm(^(5)D_(0)→^(7)F_(4))。Eu^(3+)离子之间能量传递为电偶极子-电偶极子(d-d)相互作用。YMT∶0.14Eu^(3+)荧光粉的CIE色度坐标为(0.645,0.332),与红光标准色坐标(0.67,0.33)非常接近。变温PL光谱及热激活能计算结果显示荧光粉具有一定的热稳定性,因此YMT∶Eu^(3+)是一种具有潜在应用价值的LED红色荧光粉。展开更多
开发高量子效率、高热稳定性和高化学稳定性的窄带蓝色荧光粉是广色域背光显示技术领域急需解决的难题.然而,最近报道的Eu^(2+)激活的窄带蓝色荧光粉主要集中在UCr_(4)C_(4)构型的基质材料中,而且化学稳定性往往较差.本工作采用高温固...开发高量子效率、高热稳定性和高化学稳定性的窄带蓝色荧光粉是广色域背光显示技术领域急需解决的难题.然而,最近报道的Eu^(2+)激活的窄带蓝色荧光粉主要集中在UCr_(4)C_(4)构型的基质材料中,而且化学稳定性往往较差.本工作采用高温固相法合成了一种硼磷酸盐Li_(3)Cs_(2)Sr_(2-x)B_(3)P_(6)O2_(4:x)Eu^(2+)(0.005≤x≤0.03,下文简写成LCSBPO:_(x)Eu^(2+))窄带蓝色(半峰宽FWHM=34 nm,λem=432 nm)荧光粉.Eu^(2+)离子的最佳掺杂量为0.02.LCSBPO:x Eu^(2+)荧光粉中存在两个Eu^(2+)离子荧光中心,分别对应占据在Sr(1)和Sr(2)两个格位的Eu2+离子.此外,LCSBPO:0.02Eu^(2+)荧光粉还具有较高的内/外量子效率(62.9%/16.8%)、出众的热稳定性(86.6%@150℃)、超高的色纯度(99%)和优异的化学稳定性(在去离子水中浸泡1个月后其发射强度能维持在93%).在25~250℃温度范围内,LCSBPO:0.02Eu^(2+)荧光粉还表现出优异的色度稳定性(Δx=0.0014,Δy=0.0024;4×10^(-4)≤ΔC≤9.7×10^(-3)).由LCSBPO:0.02Eu^(2+)蓝光荧光粉、商用β-Si Al ON:Eu^(2+)绿色荧光粉、商用K_(2)SiF_(6):Mn^(4+)红色荧光粉和365 nm的LED芯片封装的白光发光二极管(WLED)能发射出明亮的白光,且该WLED在CIE 1931色坐标中的色域面积可以达到NTSC(National Television System Committee)标准色域面积的83%.上述发现证明本工作报道的LCSBPO:0.02Eu^(2+)窄带蓝色荧光粉在WLED技术中有良好的潜在应用前景.展开更多
Eu^(2+) and Mn^(2+) co-activated CaAlSiN_(3) red phosphors were produced using the solid-state reaction tech⁃nique in a N2 environment.Excitation spectra,emission spectra,and diffuse reflection spectra were used to st...Eu^(2+) and Mn^(2+) co-activated CaAlSiN_(3) red phosphors were produced using the solid-state reaction tech⁃nique in a N2 environment.Excitation spectra,emission spectra,and diffuse reflection spectra were used to study the luminescence characteristics,energy gap,and thermal stability in detail.CaAlSiN_(3)∶Eu^(2+) exhibits an extended emission band when stimulated with 450 nm blue light,which is caused by the 4f65d to 4f7 transition of Eu^(2+).Similar⁃ly,CaAlSiN_(3)∶Mn^(2+) displays a wide emission band centered at 628 nm,which results from Mn^(2+)’s transition from 4T1(4G) to 6A1(6S).When the ions of Mn^(2+)were combined into CaAlSiN_(3)∶Eu^(2+),the photoluminescence intensity of Eu^(2+ )was greatly boosted because there was energy transfer and co-emission between Mn^(2+) and Eu^(2+).Beyond that,CaAlSiN_(3)∶Eu^(2+),Mn^(2+) emerges with splendid thermostability and high quantum efficiency,the quenching temperature surpasses 300℃,and the internal quantum efficiency is determined to be around 84.9%.The white LED was pack⁃aged with a combination of CaAlSiN_(3)∶Eu^(2+),Mn^(2+),LuAG∶Ce3+ and a blue chip.At a warm white-light corresponding color temperature(3009 K) with CIE coordinates(0.4223,0.3748),the color rendering index Ra has reached 93.2.CaAlSiN_(3)∶Eu^(2+),Mn^(2+) would have great application potential as a red-emitting phosphor for white LEDs.展开更多
(Gd,Lu)_(2)O_(3)∶Eu scintillation ceramics have promising applications in the high-energy X-ray imaging.Eu0.1Gd0.6Lu1.3O3 nano-powders with pure phase were prepared from the precursor calcined at 1050℃for 4 h by the...(Gd,Lu)_(2)O_(3)∶Eu scintillation ceramics have promising applications in the high-energy X-ray imaging.Eu0.1Gd0.6Lu1.3O3 nano-powders with pure phase were prepared from the precursor calcined at 1050℃for 4 h by the co-precipitation method.Using the synthesized nano-powders as initial material,Eu_(0.1)Gd_(0.6)Lu_(1.3)O_(3)ceramics were fabri-cated by vacuum pre-sintering at different temperatures for 2 h and hot isostatic pressing(HIP)at 1750℃for 3 h in ar-gon.The influence of pre-sintering temperature on the microstructure,optical and luminescence properties was investi-gated.The Eu_(0.1)Gd_(0.6)Lu_(1.3)O_(3)ceramics pre-sintered at 1625℃for 2 h combined with HIP post-treatment show the high-est in-line transmittance of 75.2%at 611 nm.The photoluminescence(PL)and X-ray excited luminescence(XEL)spectra of the Eu_(0.1)Gd_(0.6)Lu_(1.3)O_(3)transparent ceramics demonstrate a strong red emission peak at 611 nm due to the^(5)D_(0)→^(7)F_(2) transition of Eu^(3+).The PL,PLE and XEL intensities of the HIP post-treated Eu_(0.1)Gd_(0.6)Lu_(1.3)O_(3)ceramics show a trend of first ascending and then descending with the increase of pre-sintering temperature.The thermally stimulated lumines-cence(TSL)curve of the HIP post-treated Eu_(0.1)Gd_(0.6)Lu_(1.3)O_(3)ceramics presents one high peak at 178 K and two peaks with lower intensities at 253 K and 320 K.The peak at 320 K may be related to oxygen vacancies,and the lumines-cence peak at 178 K is related to defects caused by the valence state changes of Eu^(3+)ions.展开更多
γ-LiAlO2：Eu3＋（Eu3＋：LAO） phosphor was obtained by gel combustion method using LiNO3,Al（NO3）3·9H2O,Eu（NO3）3·6H2O and citric acid as raw materials.The structure,morphology and luminescence were chara...γ-LiAlO2：Eu3＋（Eu3＋：LAO） phosphor was obtained by gel combustion method using LiNO3,Al（NO3）3·9H2O,Eu（NO3）3·6H2O and citric acid as raw materials.The structure,morphology and luminescence were characterized by means of X-ray diffraction （XRD）,scanning electron microscopy （SEM）,photoluminescence （PL）.The results demonstrated that the phosphor was pure-phase of flaky tetragonal crystal system with a mean size of around 1 μm.The strongest excitation peak was at 254 nm,belonging to the broadband excitation and the maximum emission peak was at 613 nm,corresponding to the 5D0→7F2 transition of Eu3＋.Luminous intensity is closely related to the calcination temperature and doping concentration of Eu3＋.展开更多
文摘采用溶胶-凝胶法制备出Y_(2-2 x)MgTiO_(6)∶2 x Eu^(3+)(YMT∶2 x Eu^(3+),0≤x≤0.11)新型红色荧光粉。通过X射线衍射仪(XRD)检测样品的纯度,结果显示YMT∶Eu^(3+)样品属于单斜晶系,空间群为P21/n,无其他杂相。扫描电子显微镜(SEM)照片显示荧光粉为2μm的不规则颗粒。当激发波长为264 nm时,发射光谱出现四个尖锐的发射峰,分别位于591(^(5)D_(0)→^(7)F_(1))、619(^(5)D_(0)→^(7)F_(2))、657(^(5)D_(0)→^(7)F_(3))和693 nm(^(5)D_(0)→^(7)F_(4))。Eu^(3+)离子之间能量传递为电偶极子-电偶极子(d-d)相互作用。YMT∶0.14Eu^(3+)荧光粉的CIE色度坐标为(0.645,0.332),与红光标准色坐标(0.67,0.33)非常接近。变温PL光谱及热激活能计算结果显示荧光粉具有一定的热稳定性,因此YMT∶Eu^(3+)是一种具有潜在应用价值的LED红色荧光粉。
文摘开发高量子效率、高热稳定性和高化学稳定性的窄带蓝色荧光粉是广色域背光显示技术领域急需解决的难题.然而,最近报道的Eu^(2+)激活的窄带蓝色荧光粉主要集中在UCr_(4)C_(4)构型的基质材料中,而且化学稳定性往往较差.本工作采用高温固相法合成了一种硼磷酸盐Li_(3)Cs_(2)Sr_(2-x)B_(3)P_(6)O2_(4:x)Eu^(2+)(0.005≤x≤0.03,下文简写成LCSBPO:_(x)Eu^(2+))窄带蓝色(半峰宽FWHM=34 nm,λem=432 nm)荧光粉.Eu^(2+)离子的最佳掺杂量为0.02.LCSBPO:x Eu^(2+)荧光粉中存在两个Eu^(2+)离子荧光中心,分别对应占据在Sr(1)和Sr(2)两个格位的Eu2+离子.此外,LCSBPO:0.02Eu^(2+)荧光粉还具有较高的内/外量子效率(62.9%/16.8%)、出众的热稳定性(86.6%@150℃)、超高的色纯度(99%)和优异的化学稳定性(在去离子水中浸泡1个月后其发射强度能维持在93%).在25~250℃温度范围内,LCSBPO:0.02Eu^(2+)荧光粉还表现出优异的色度稳定性(Δx=0.0014,Δy=0.0024;4×10^(-4)≤ΔC≤9.7×10^(-3)).由LCSBPO:0.02Eu^(2+)蓝光荧光粉、商用β-Si Al ON:Eu^(2+)绿色荧光粉、商用K_(2)SiF_(6):Mn^(4+)红色荧光粉和365 nm的LED芯片封装的白光发光二极管(WLED)能发射出明亮的白光,且该WLED在CIE 1931色坐标中的色域面积可以达到NTSC(National Television System Committee)标准色域面积的83%.上述发现证明本工作报道的LCSBPO:0.02Eu^(2+)窄带蓝色荧光粉在WLED技术中有良好的潜在应用前景.
文摘Eu^(2+) and Mn^(2+) co-activated CaAlSiN_(3) red phosphors were produced using the solid-state reaction tech⁃nique in a N2 environment.Excitation spectra,emission spectra,and diffuse reflection spectra were used to study the luminescence characteristics,energy gap,and thermal stability in detail.CaAlSiN_(3)∶Eu^(2+) exhibits an extended emission band when stimulated with 450 nm blue light,which is caused by the 4f65d to 4f7 transition of Eu^(2+).Similar⁃ly,CaAlSiN_(3)∶Mn^(2+) displays a wide emission band centered at 628 nm,which results from Mn^(2+)’s transition from 4T1(4G) to 6A1(6S).When the ions of Mn^(2+)were combined into CaAlSiN_(3)∶Eu^(2+),the photoluminescence intensity of Eu^(2+ )was greatly boosted because there was energy transfer and co-emission between Mn^(2+) and Eu^(2+).Beyond that,CaAlSiN_(3)∶Eu^(2+),Mn^(2+) emerges with splendid thermostability and high quantum efficiency,the quenching temperature surpasses 300℃,and the internal quantum efficiency is determined to be around 84.9%.The white LED was pack⁃aged with a combination of CaAlSiN_(3)∶Eu^(2+),Mn^(2+),LuAG∶Ce3+ and a blue chip.At a warm white-light corresponding color temperature(3009 K) with CIE coordinates(0.4223,0.3748),the color rendering index Ra has reached 93.2.CaAlSiN_(3)∶Eu^(2+),Mn^(2+) would have great application potential as a red-emitting phosphor for white LEDs.
文摘(Gd,Lu)_(2)O_(3)∶Eu scintillation ceramics have promising applications in the high-energy X-ray imaging.Eu0.1Gd0.6Lu1.3O3 nano-powders with pure phase were prepared from the precursor calcined at 1050℃for 4 h by the co-precipitation method.Using the synthesized nano-powders as initial material,Eu_(0.1)Gd_(0.6)Lu_(1.3)O_(3)ceramics were fabri-cated by vacuum pre-sintering at different temperatures for 2 h and hot isostatic pressing(HIP)at 1750℃for 3 h in ar-gon.The influence of pre-sintering temperature on the microstructure,optical and luminescence properties was investi-gated.The Eu_(0.1)Gd_(0.6)Lu_(1.3)O_(3)ceramics pre-sintered at 1625℃for 2 h combined with HIP post-treatment show the high-est in-line transmittance of 75.2%at 611 nm.The photoluminescence(PL)and X-ray excited luminescence(XEL)spectra of the Eu_(0.1)Gd_(0.6)Lu_(1.3)O_(3)transparent ceramics demonstrate a strong red emission peak at 611 nm due to the^(5)D_(0)→^(7)F_(2) transition of Eu^(3+).The PL,PLE and XEL intensities of the HIP post-treated Eu_(0.1)Gd_(0.6)Lu_(1.3)O_(3)ceramics show a trend of first ascending and then descending with the increase of pre-sintering temperature.The thermally stimulated lumines-cence(TSL)curve of the HIP post-treated Eu_(0.1)Gd_(0.6)Lu_(1.3)O_(3)ceramics presents one high peak at 178 K and two peaks with lower intensities at 253 K and 320 K.The peak at 320 K may be related to oxygen vacancies,and the lumines-cence peak at 178 K is related to defects caused by the valence state changes of Eu^(3+)ions.
基金Funded by Southwest University of Technology (No.08zx0103)
文摘γ-LiAlO2：Eu3＋（Eu3＋：LAO） phosphor was obtained by gel combustion method using LiNO3,Al（NO3）3·9H2O,Eu（NO3）3·6H2O and citric acid as raw materials.The structure,morphology and luminescence were characterized by means of X-ray diffraction （XRD）,scanning electron microscopy （SEM）,photoluminescence （PL）.The results demonstrated that the phosphor was pure-phase of flaky tetragonal crystal system with a mean size of around 1 μm.The strongest excitation peak was at 254 nm,belonging to the broadband excitation and the maximum emission peak was at 613 nm,corresponding to the 5D0→7F2 transition of Eu3＋.Luminous intensity is closely related to the calcination temperature and doping concentration of Eu3＋.
