Abstract Orange-red color emission obtained from YPO4: 5 at.% Eu3+ nanocrystalline thin films are prepared by spin coating sol gel route. The thorough study of two different sol gel routes and their effect on structural and luminescent properties of YPO4:Eu3+are investigated. Prepared samples were characterized by X-ray diffraction (XRD), Scanning electron microscopy and photoluminescence spectroscopy. This work demonstrated that the use of relatively stronger solvents during the sol gel route favorize the dissolution of oxide salts’ precursors within solutions and enhance their stabilization. XRD analysis indicated the formation of nanopowders and nanocrystalline thin films. Structural properties showed a strong correlation between the parameters related to samples’ solution and form. All samples showed uniform morphology with different sizes and shapes of particles depending on the solution and the form of the nanophosphor. Under UV excitation, YPO4: Eu3+powders and thin films exhibited, orange-red color emissions assigned to 5D0 → 7FJ (J=1,2,3 and 4) intraconfigurational transitions. Asymmetry ratio (R/O) analysis showed that Eu3+ in YPO4 host matrix tends to occupy high symmetry sites when prepared as thin films compared to powders. The thin film with better crystallinity and bigger particle sizes exhibited better emission efficiency but low symmetry of crystal field near Eu3+ ions (high R/O) and low light extraction ratio.

中文翻译：

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使用溶胶凝胶旋涂法制备和表征发光 YPO4:Eu3+ 薄膜

摘要 通过旋涂溶胶凝胶法制备了由YPO4: 5 at.% Eu3+ 纳米晶薄膜获得的橙红色发射光。深入研究了两种不同的溶胶凝胶路线及其对 YPO4:Eu3+ 结构和发光性能的影响。制备的样品通过 X 射线衍射 (XRD)、扫描电子显微镜和光致发光光谱进行表征。这项工作表明，在溶胶凝胶途径中使用相对较强的溶剂有利于氧化物盐前体在溶液中的溶解并增强它们的稳定性。XRD分析表明形成了纳米粉末和纳米晶体薄膜。结构特性表明与样品溶液和形式相关的参数之间存在很强的相关性。根据溶液和纳米磷光体的形式，所有样品均表现出均匀的形态，具有不同尺寸和形状的颗粒。在紫外激发下，YPO4：Eu3+ 粉末和薄膜表现出橙红色发射分配给 5D0 → 7FJ (J=1,2,3 和 4) 构型内跃迁。不对称比 (R/O) 分析表明，与粉末相比，当制备为薄膜时，YPO4 主体基质中的 Eu3+ 往往占据高对称位点。具有更好结晶度和更大粒径的薄膜表现出更好的发射效率，但 Eu3+ 离子附近的晶体场对称性低（高 R/O）和低光提取率。3 和 4) 构型内转换。不对称比 (R/O) 分析表明，与粉末相比，当制备为薄膜时，YPO4 主体基质中的 Eu3+ 往往占据高对称位点。具有更好结晶度和更大粒径的薄膜表现出更好的发射效率，但 Eu3+ 离子附近的晶体场对称性低（高 R/O）和低光提取率。3 和 4) 构型内转换。不对称比 (R/O) 分析表明，与粉末相比，当制备为薄膜时，YPO4 主体基质中的 Eu3+ 往往占据高对称位点。具有更好结晶度和更大粒径的薄膜表现出更好的发射效率，但 Eu3+ 离子附近的晶体场对称性低（高 R/O）和低光提取率。