ABSTRACT

Eu³⁺-doped CaWO₄ nanophosphors were synthesised in series for different atomic wt% concentrations (0, 0.5, 1, 2, 5 and 10) of Bi³⁺ by polyol method. Their structure and morphology were characterised using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The photoluminescence properties and energy transfer from Bi³⁺ to Eu³⁺ in CaWO₄:Eu³⁺/Bi³⁺ nanophosphors were also investigated. The results revealed that red luminescence of CaWO₄:2Eu³⁺/1Bi³⁺ nanophosphor is 5.4 times stronger than CaWO₄:2Eu³⁺. It was observed that the forces exist between Bi³⁺ and Eu³⁺ are due to the interaction of electric dipole-dipole interactions. The chroma of CaWO₄:2Eu³⁺/1Bi³⁺ nanophosphors was calculated to be 97.40%. The energy transfer process was studied by measuring the decay curves due to Bi³⁺ and Eu³⁺ dopants. Enhanced red emission, high thermal stability, stronger ⁵D₀ → ⁷F₂ absorption intensity, high colour purity and decay studies indicate that CaWO₄:Eu³⁺/Bi³⁺ nanophosphors are potential candidates to be used in white light-emitting diode (wLEDs).

摘要

Eu ³⁺掺杂的CaWO ₄纳米荧光粉通过多元醇法针对Bi ³⁺的不同原子重量百分比浓度（0、0.5、1、2、5和10）串联合成。使用 X 射线衍射 (XRD) 和扫描电子显微镜 (SEM) 对其结构和形态进行了表征。还研究了CaWO ₄ :Eu ³⁺ /Bi ^{3+纳米荧光粉中Bi 3+}到Eu ³⁺的光致发光特性和能量转移。结果表明，CaWO ₄ :2Eu ³⁺ /1Bi ^{3+纳米荧光粉的红色发光强度是CaWO} ₄ :2Eu ³⁺的5.4倍。. 据观察，Bi ³⁺和Eu ³⁺之间存在的力是由于电偶极-偶极相互作用的相互作用。CaWO ₄ :2Eu ³⁺ /1Bi ³⁺纳米荧光粉的色度计算为97.40%。通过测量由Bi ³⁺和Eu ³⁺掺杂剂引起的衰减曲线来研究能量转移过程。增强的红色发射、高热稳定性、更强的⁵ D ₀ → ⁷ F ₂吸收强度、高色纯度和衰减研究表明 CaWO ₄ :Eu ³⁺ /Bi ³⁺纳米荧光粉是用于白光发光二极管 ( w LED) 的潜在候选材料。