(Zn, Mg)2GeO4:Mn2+ submicrorods as promising green phosphors for field emission displays: hydrothermal synthesis and luminescence properties
(Zn, Mg)2GeO4:Mn2+ submicrorods as promising green phosphors for field emission displays: hydrothermal synthesis and luminescence properties
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DOI：
10.1039/c1dt10673b
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发表时间：
2011-01-01
影响因子：
4
通讯作者：
Lin, Jun
中科院分区：
文献类型：
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作者：
Shang, Mengmeng;Li, Guogang;Lin, Jun
（Zn1-x-yMgy）(2)GeO4: xMn(2+) （y = 0-0.30; x = 0-0.035）通过简单的水热法制备了形貌均匀的亚微棒荧光粉。利用x射线衍射（XRD）、场发射扫描电镜（FE-SEM）、光致发光（PL）和阴极发光（CL）光谱对样品进行表征。SEM和TEM图像表明，Zn2GeO4:Mn2+样品由长度约为1 ~ 2 μ m，直径约为200 ~ 250 nm的亚微棒组成。提出了Zn2GeO4亚微棒的可能形成机理。PL和CL光谱表征表明，纯Zn2GeO4样品由于缺陷呈现蓝色发光，而Zn2GeO4:Mn2+荧光粉在紫外和低压电子束激发下呈现绿色发光，对应于Mn2+ (T-4(1) -> (6) a(1))的特征跃迁。与固相反应制备的Zn2GeO4:Mn2+样品相比，水热法高温退火法制备的Zn2GeO4:Mn2+荧光粉具有更好的发光性能。此外，在晶格中共掺杂Mg2+离子取代Zn2+离子可以提高Zn2GeO4:Mn2+荧光粉的PL和CL强度。此外，Zn2GeO4:Mn2+荧光粉比商用的ZnO:Zn荧光粉表现出更饱和的绿色发射，有望在场发射显示器中得到应用。
(Zn1-x-yMgy)(2)GeO4: xMn(2+) (y = 0-0.30; x = 0-0.035) phosphors with uniform submicrorod morphology were synthesized through a facile hydrothermal process. X-Ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), photoluminescence (PL), and cathodoluminescence (CL) spectroscopy were utilized to characterize the samples. SEM and TEM images indicate that Zn2GeO4:Mn2+ samples consist of submicrorods with lengths around 1-2 mu m and diameters around 200-250 nm, respectively. The possible formation mechanism for Zn2GeO4 submicrorods has been presented. PL and CL spectroscopic characterizations show that pure Zn2GeO4 sample shows a blue emission due to defects, while Zn2GeO4:Mn2+ phosphors exhibit a green emission corresponding to the characteristic transition of Mn2+ (T-4(1) -> (6)A(1)) under the excitation of UV and low-voltage electron beam. Compared with Zn2GeO4:Mn2+ sample prepared by solid-state reaction, Zn2GeO4:Mn2+ phosphors obtained by hydrothermal process followed by high temperature annealing show better luminescence properties. In addition, codoping Mg2+ ions into the lattice to substitute for Zn2+ ions can enhance both the PL and CL intensity of Zn2GeO4:Mn2+ phosphors. Furthermore, Zn2GeO4:Mn2+ phosphors exhibit more saturated green emission than the commercial FEDs phosphor ZnO:Zn, and it is expected that these phosphors are promising for application in field-emission displays.