Luminescence behavior of YVO4:Dy3+ phosphors with enhanced photoluminescence on co-doping Bi3+ ions
Luminescence behavior of YVO4:Dy3+ phosphors with enhanced photoluminescence on co-doping Bi3+ ions
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DOI：
10.1016/j.jallcom.2013.08.139
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发表时间：
2014-01
影响因子：
6.2
通讯作者：
C. Devi;G. Phaomei;N. Yaiphaba;N. R. Singh
中科院分区：
文献类型：
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作者：
C. Devi;G. Phaomei;N. Yaiphaba;N. R. Singh
采用共沉淀法，以乙二醇为封端剂，在150 °C的较低温度下成功制备了YVO 4：Dy 3+，Bi 3+荧光粉。所有样品的XRD图谱都很好地结晶为纯的四方相YVO 4。晶胞体积随Bi ~（3+）离子浓度的增加而线性增加，表明Bi ~（3+）离子在YVO_4基质中的Y3+晶格位置上定量掺入。在引入Bi 3+离子时，VO 43 −激发带向更长的波长移动。观察到从V5+-Bi ~（3+）CT态到Dy ~（3+）态的能量转移，从而产生Dy ~（3+）的特征可见光发射。Bi ~（3+）的共掺杂显著增强了Dy ~（3+）的电偶极跃迁和磁偶极跃迁的发光强度。Dy ~（3+）的最佳掺杂浓度为1at.%在500 °C退火样品中，Bi ~（3+）的发光强度增加。此外，通过改变激发波长，YVO 4：5 Dy 3+的发光颜色可以从蓝绿色变为近白色，而在共掺杂Bi 3+时，YVO 4：5 Dy 3+的发光颜色可以从蓝绿色变为黄白色，这使得YVO 4：5 Dy 3+在荧光灯和场发射显示器（FED）中具有很大的应用潜力。
YVO4:Dy3+, Bi3+phosphors were prepared successfully by co-precipitation method using ethylene glycol as a capping agent as well as reaction medium at a relatively low temperature of 150 °C. XRD patterns of all samples are well crystallized to a pure tetragonal phase of YVO4. The unit cell volume increases linearly with the Bi3+ion concentrations suggesting the quantitative incorporation of Bi3+ions in lattice sites of Y3+in YVO4matrix. On introduction of Bi3+ions, the VO43−excitation band shifts to longer wavelengths. Energy transfer from V5+–Bi3+CT state to Dy3+was observed, giving rise to the characteristic visible emissions from Dy3+. The luminous intensity of the electric dipole transition as well as magnetic dipole transitions of Dy3+are enhanced significantly on co-doping of Bi3+ions. The optimum concentration of Dy3+for highest luminescence is found to be 1 at.% Bi3+and the luminescence intensity increases on annealing samples at 500 °C. Furthermore, the emission colors of YVO4:5Dy3+can be tuned from greenish blue to near white by changing the excitation wavelength and then to yellowish white on co-doping Bi3+ions, making the phosphors a great potential for applications in fluorescent lamps and field emission displays (FEDs).