(Ca1-xBax)2SiO4∶Eu荧光粉相变和光谱调控  

Cation Substitution-Dependent Phase Transition and Color-Tunable Emission in(Ca1-xBax)2SiO4∶Eu Phosphor Series

作　　者：汪雨 罗岚[1,2] 郭锐[1] 孙传耀 高明远 WANG Yu;LUO Lan;GUO Rui;SUN Chuan-yao;GAO Ming-yuan(School of Materials Science and Engineering,Nanchang University,Nanchang330001,China;Key Laboratory of Lightweight and High Strength Structural Materials of Jiangxi Province,Nanchang University,Nanchang 330001,China)

机构地区：[1]南昌大学材料科学与工程学院,江西南昌330001 [2]南昌大学江西省轻质高强结构材料重点实验室,江西南昌330001

出　　处：《光谱学与光谱分析》2020年第6期1895-1901,共7页Spectroscopy and Spectral Analysis

基　　金：国家重点研发计划项目(2016YFB0701203,2016YFB0701201,2017YFB1103701);国家自然科学基金项目(11564025,51671101,51062003,51701037);江西省教育厅重点计划项目(GJJ150010),南昌大学双创及科研训练项目基金项目(31080002);南昌大学大学生创新创业训练项目基金项目(20190402352);南昌大学科研训练项目基金项目(11564025)资助。

摘　　要：采用高温固相法在1170℃还原气氛下保温3.5 h制备了(Ca1-xBax)1.95SiO4∶0.05Eu(x=0,0.1,0.3,0.5,0.6,0.7,0.8,0.9,1.0)系列新型荧光粉,并研究了其基体晶相、Eu离子价态、光谱性能。随着x值增大,粉末物相组成发生如下改变:γ-Ca2SiO4(x=0)→T相和γ-Ca2SiO4混合物(0≤x<0.7)→T相(0.7≤x<0.9)→Ba2SiO4相(x≥0.9),即(Ca1-xBax)2SiO4粉末只在富Ba端形成有限置换型固溶体,即T相和Ba2SiO4相粉末。点阵参数精确分析表明:随着Ba离子增加,T相荧光粉(0.7≤x<0.9)处于M1,M2,M5点位碱土离子配位数增大进而晶格参数增大较为明显,而Ba2SiO4相荧光粉(x≥0.9)中碱土离子配位数无变化晶格参数变化也较小;Eu离子以取代碱土离子方式进入晶格,对晶格影响较小。T相和Ba2SiO4相荧光粉XPS全谱分析结果类似,均出现Ba(3p3/2),Ba(3d3/2),Ba(3d5/2),O(1s),Eu(4d),Si(2p3/2)电子结合特征峰;其O(1s)核心电子结合能精细谱也类似,有2个光电子峰组成,分别对应晶格氧、间隙氧缺陷(Eu^3+取代+2碱土离子造成);进一步Eu(4d)高分辨XPS分析表明,随着x值增大,T相粉末Eu^2+/Eu^3+比值增大(Eu离子形成+2可能性增大),而Ba2SiO4相粉末Eu^2+/Eu^3+比值变化不明显。在254和365 nm紫外激发下Ca1.95SiO4∶0.05Eu(γ-Ca2SiO4相荧光粉)可用作红色荧光粉,而(Ca1-xBax)1.95SiO4∶0.05Eu(x≥0.7,即T相(其绿光宽谱发射峰中心在455 nm附近)或Ba2SiO4相荧光粉(其绿光宽谱发射峰中心在510 nm附近))可用作绿色荧光粉;T相荧光粉绿光发射比Ba2SiO4相荧光粉绿光发射对应波长更短;随着x值增加T相和Ba2SiO4相荧光粉发射光谱发生蓝移(即T相粉末中(Ca0.3Ba0.7)1.95SiO4∶0.05Eu绿光发射波长最长,Ba2SiO4相粉末中(Ca0.1Ba0.9)1.95SiO4∶0.05Eu绿光发射波长最长);随着x值增加,T相荧光粉亮度提高,而Ba2SiO4相荧光粉亮度降低,即(Ca0.1Ba0.9)1.95SiO4∶0.05Eu粉末的绿色荧光最亮(荧光寿命571.8 ns、量子效率55%)。由绿色荧光粉(x≥0.7)精细发射�(Ca 1-x Ba x)1.95 SiO 4∶0.05Eu(x=0,0.1,0.3,0.5,0.6,0.7,0.8,0.9,1.0)new phosphor series were prepared by high temperature solid-state reaction at 1170℃under a reduction atmosphere for 3.5 hours in this paper.The matrix crystal structure,Eu ion valence,photoluminescence spectra and fluorescence lifetime and quantum efficiency had been investigated.The matrix phase constituents change asγ-Ca 2SiO 4(x=0)→T phase andγ-Ca 2SiO 4 mixture(0<x<0.7)→T phase(0.7≤x<0.9)→Ba 2SiO 4(0.9≤x≤1)as Ba ion content increasing.By XRD analysis,it is known that(Ca 1-x Ba x)2SiO 4 powders form solid solution phases at the Ba-rich end,which are T-phase and Ba 2SiO 4-phase.Precision measurement of lattice parameters had been also done to T-phase(0.7≤x<0.9)and Ba 2SiO 4 phase(x≥0.9).For the former phase powder,the lattice parameters would increase because coordinated numbers for M1,M2,M5 sites are increasing as Ba ion content increasing,While,change from the latter one’s lattice parameters would be neglecting.Moreover,Eu ions enter into the crystal lattice by substituting for alkaline earth ions,with a minor impact.The surveys of X-ray photoelectron spectroscopy(XPS)spectra are similar,which all show characteristic electron binding energy peaks of Ba(3 p 3/2),Ba(3 d 3/2),Ba(3 d 5/2),O(1 s),Eu(4 d)and Si(2 p 3/2).The high-resolution spectrum of O(1 s)has two peaks,corresponding to lattice oxygen and interstitial oxygen defects(caused by Eu ^3+substitution to alkaline earth ion+2),respectively.Moreover,the high-resolution XPS spectrums of the Eu(4 d 5/2)shows that the Eu ^2+/Eu ^3+ratio would increase as the increasing of Ba ions in the T-phase powders,while the Eu ^2+/Eu ^3+ratio of Ba 2SiO 4-phase powders is not obviously changed.Ultraviolet photoluminescence photographs show that Ca 1.95 SiO 4∶0.05Eu(γ-Ca 2SiO 4 phase phosphors)could be used as red phosphors,while(Ca 1-x Ba x)1.95 SiO 4∶0.05Eu(x≥0.7,T-phase(green emission centered at 455 nm)or Ba 2SiO 4-phase phosphors(green emission peak centered at 510 nm)co

关 键 词：碱土硅酸盐 铕 晶体结构 X射线光电子谱 荧光光谱 

分 类 号：TB332[一般工业技术—材料科学与工程]