摘要
报道了一种新型的Mn^(4+)掺杂水合六氟钛酸钙CaTiF_(6)·2H_(2)O:Mn^(4+)红色荧光粉,详细研究了基质的结构转变和荧光粉的发光性能及高显色指数(显指)暖白光LED应用。CaTiF_(6)·2H_(2)O:Mn^(4+)在130~200℃间脱水转化为CaTiF_(6):Mn^(4+),荧光光谱发生改变,重新吸附水分子可恢复到CaTiF_(6)·2H_(2)O:Mn^(4+),发光性能不可逆。重要的是,该荧光粉在较长波626 nm和635 nm处分别发射锐线极强的零声子线(ZPL)和ν6振动峰,色坐标为(0.701,0.299),更接近人眼敏感的红光边界650 nm(色坐标x~0.72,y~0.28),有助于提高暖白光LED的显色指数、拓宽背光源的色域。晶体结构和晶体场强度计算指出,Mn^(4+)在CaTiF_(6)·2H_(2)O:Mn^(4+)中占据低对称性的格位,所受到的晶体场强度较弱,Mn—F键的共价性较强。另外,通过表面疏水化显著提升了荧光粉耐湿性能,共掺小离子半径的Si^(4+)增强了荧光粉发光热稳定性。以CaTiF_(6)·2H_(2)O:Mn^(4+)作为红光成分,获得了高显色指数(R_(a)=90,R_(9)=68)的暖白光LED,在高品质的暖白光照明中具有潜在的应用。
Herein, a new Mn^(4+)-doped hydrate calcium hexafluorotitanic CaTiF_(6)·2H_(2)O:Mn^(4+)red phosphor is reported. Physical properties of host, luminescence properties and warm white LED application of this phosphor are studied carefully. CaTiF_(6)·2H_(2)O:Mn^(4+)removes H_(2)O to be CaTiF_(6):Mn^(4+)with changed emission spectrum. CaTiF_(6):Mn^(4+)could adsorb H_(2)O and recover to CaTiF_(6)·2H_(2)O:Mn^(4+)except emission intensity. Importantly, it emits extremely strong zero phonon line(ZPL) and ν6vibration peaking at longer wavelength of 626 nm and 635 nm in sequence. This unique emission gives color coordinates of(0. 701, 0. 299), more closing to the red-light boundary of human eyes sensibility(650 nm, chromaticity coordinate x~0. 72, y~0. 28), which could enhance the color rendering index(Ra) of WLED and widen the color gamut of backlight display. The combination of crystal structure and crystal field strength calculation demonstrates that Mn^(4+)ion locates at a highly unsymmetric lattice and experiences weak crystal field strength with strongly covalent Mn—F bond in CaTiF_(6)·2H_(2)O:Mn^(4+). Moreover, coating with hydrophobic layer enhances the moisture resistant of CaTiF_(6)·2H_(2)O:Mn^(4+). Codoping small ionic radius Si^(4+)improves its thermal stability. Using CaTiF_(6)·2H_(2)O:Mn^(4+)as red-light component, a warm white LED with high R_(a)~90 and R_(9)~ 68 was achieved, showing potential in high color quality warm white lighting applications.
作者
陈孔岚
张学亮
宋恩海
周亚运
袁健
樊婷
邓婷婷
CHEN Konglan;ZHANG Xueliang;SONG Enhai;ZHOU Yayun;YUAN Jian;FAN Ting;DENG Tingting(Guangdong-Hong Kong-Macao Joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology,School of Physics and Optoelectronic Engineering,Foshan University,Foshan 528225,China;Guangdong Provincial Key Laboratory of Fiber Laser Materials and Applied Techniques,State Key Laboratory of Luminescent Materials and Devices,South China University of Technology,Guangzhou 510641,China)
出处
《发光学报》
EI
CAS
CSCD
北大核心
2023年第2期259-270,共12页
Chinese Journal of Luminescence
基金
国家自然科学基金(51902053)
广东省自然科学基金(2019A1515011988)
广东省教育厅项目(2021KTSCX119)
智能微纳光电技术粤港澳联合实验室研究基金(2020B1212030010)
广东省光纤激光材料与应用技术重点实验室开放基金(华南理工大学2021-07)。
