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
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
采用CaxSi合金前驱物和Eu B6常压氮化制备了Ca Al Si N3∶Eu2+氮化物红色荧光粉。研究了不同烧结温度、添加助熔剂及二次烧结对发光性能的影响。通过扫描电子显微镜(SEM)、X射线衍射(XRD)、荧光分光光度计对发光材料的形貌、晶体结构、...采用CaxSi合金前驱物和Eu B6常压氮化制备了Ca Al Si N3∶Eu2+氮化物红色荧光粉。研究了不同烧结温度、添加助熔剂及二次烧结对发光性能的影响。通过扫描电子显微镜(SEM)、X射线衍射(XRD)、荧光分光光度计对发光材料的形貌、晶体结构、发光性能与热稳定性进行了研究。分析结果表明:通过合金前驱物常压氮化法得到的氮化物荧光粉具有Ca Al Si N3结构,空间群为Cmc21。Ca Al Si N3∶Eu2+红色荧光粉的最佳烧结温度为1 550℃。添加质量分数为6%的Sr F2助熔剂后,荧光粉发光强度的提升效果最好。添加6%Sr F2助熔剂及二次烧结后得到的荧光粉的晶粒生长更加完整,颗粒度明显改善,发射光谱的相对强度也明显提高,比未加助熔剂单次烧结的荧光粉相对强度提高了近一倍。将发射峰位在640 nm的Ca0.98Al Si N3∶0.02Eu2+红色荧光粉应用在白光LED的封装中,获得了色温为3 109 K、显色指数为92.5以及色温为4 989K、显色指数为95.8的高显色白光LED,说明本文合成的氮化物红色荧光粉可以实现暖白光和正白光高显色的白LED发光器件。展开更多
A series of novel luminescent materials, SrZnO2:M (M=Eu3+, or Eu3+ + Li+) have been synthesized by high-temperature solid-state reaction. The structure and luminescence properties of SrZnO2:Eu3+ phosphor were studied ...A series of novel luminescent materials, SrZnO2:M (M=Eu3+, or Eu3+ + Li+) have been synthesized by high-temperature solid-state reaction. The structure and luminescence properties of SrZnO2:Eu3+ phosphor were studied through XRD, photoluminescence and Raman spectroscopy. The excitation spectra show a broad intense band and a number of small peaks corresponding to the inner 4f-shell excitations of Eu3+ (the strongest one is at 395 nm for 7F0-5L6). After SrZnO2:Eu3+ phosphor was co-doped with Li+ ions, its charge transfer band extended to longer wavelengths. This resulted in increase of luminescent quantum efficiency of the sample. SrZnO2:Eu3+,Li+ phosphor can be efficiently excited by longer UV. From the fluorescence spectrum of SrZnO2:Eu3+ phosphor, apart from transition emissions of 5D0 → 7FJ (J=0~4), the transition emissions from 5D1 → 7FJ (J=0~2) have been observed. For the SrZnO2:Eu3+ phosphor, under excitation of UV, the dominant emission is at about 612 nm, due to the 5D0 → 7F2 hypersensitive transition. The incorporation of Li+ ions greatly enhanced the luminescence intensity and made emission peak from 5D0 → 7F2 transition red-shifted.展开更多
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。
文摘采用CaxSi合金前驱物和Eu B6常压氮化制备了Ca Al Si N3∶Eu2+氮化物红色荧光粉。研究了不同烧结温度、添加助熔剂及二次烧结对发光性能的影响。通过扫描电子显微镜(SEM)、X射线衍射(XRD)、荧光分光光度计对发光材料的形貌、晶体结构、发光性能与热稳定性进行了研究。分析结果表明:通过合金前驱物常压氮化法得到的氮化物荧光粉具有Ca Al Si N3结构,空间群为Cmc21。Ca Al Si N3∶Eu2+红色荧光粉的最佳烧结温度为1 550℃。添加质量分数为6%的Sr F2助熔剂后,荧光粉发光强度的提升效果最好。添加6%Sr F2助熔剂及二次烧结后得到的荧光粉的晶粒生长更加完整,颗粒度明显改善,发射光谱的相对强度也明显提高,比未加助熔剂单次烧结的荧光粉相对强度提高了近一倍。将发射峰位在640 nm的Ca0.98Al Si N3∶0.02Eu2+红色荧光粉应用在白光LED的封装中,获得了色温为3 109 K、显色指数为92.5以及色温为4 989K、显色指数为95.8的高显色白光LED,说明本文合成的氮化物红色荧光粉可以实现暖白光和正白光高显色的白LED发光器件。
文摘A series of novel luminescent materials, SrZnO2:M (M=Eu3+, or Eu3+ + Li+) have been synthesized by high-temperature solid-state reaction. The structure and luminescence properties of SrZnO2:Eu3+ phosphor were studied through XRD, photoluminescence and Raman spectroscopy. The excitation spectra show a broad intense band and a number of small peaks corresponding to the inner 4f-shell excitations of Eu3+ (the strongest one is at 395 nm for 7F0-5L6). After SrZnO2:Eu3+ phosphor was co-doped with Li+ ions, its charge transfer band extended to longer wavelengths. This resulted in increase of luminescent quantum efficiency of the sample. SrZnO2:Eu3+,Li+ phosphor can be efficiently excited by longer UV. From the fluorescence spectrum of SrZnO2:Eu3+ phosphor, apart from transition emissions of 5D0 → 7FJ (J=0~4), the transition emissions from 5D1 → 7FJ (J=0~2) have been observed. For the SrZnO2:Eu3+ phosphor, under excitation of UV, the dominant emission is at about 612 nm, due to the 5D0 → 7F2 hypersensitive transition. The incorporation of Li+ ions greatly enhanced the luminescence intensity and made emission peak from 5D0 → 7F2 transition red-shifted.
