Y2O3∶Eu$1纳米晶的尺寸调控与发光性能研究

以尿素为沉淀剂，柠檬酸为表面活性剂，通过水热法得到了非晶态的水合硝酸氧钇前驱体，进一步烧结处理后生成了立方相Y2O3纳米晶.利用X-射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、红外光谱(FTIR)和荧光光谱(PL)分别对所得样品的相结构、形貌粒度、表面结构以及发光性能进行研究.结果表明：当烧结温度从600 ℃升高到900 ℃，Y2O3:Eu3+纳米颗粒的结晶性增强，并实现了粒径调控，由13.0 nm增加至27.9 nm.随着Y2O3:Eu3+纳米颗粒尺寸的增加，比表面积减小会导致发光离子附近的表面晶格缺陷降低，同时纳米晶表面吸附水、硝酸根以及柠檬酸根等杂质离子逐渐被去除，减少了荧光猝灭中心，从而有利于增强荧光发射强度以及延长荧光寿命.
Y2O3:Eu3+red nanophosphors were synthesized by a hydrothermal method with citric acid as a complex agent and urea as precipitant and an annealing process at different temperatures ranging from 600 to 900 ℃. The obtained powders were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and photoluminescence spectroscopy (PL). Effects of annealing treatment on structural, morphological and photoluminescence properties of Y2O3:Eu3+are investigated. XRD results revealed that Y2O3:Eu3+powders crystallized in cubic phase after annealing treatment. The average crystallite size increased from 13.0 to 27.9 nm as temperature increasing. Moreover, it is demonstrated that annealing treatment can give rise to changes in surface structures. The luminescence emission intensity and average lifetimes of Y2O3:Eu3+powders are enhanced with increasing crystallite size, which is attributed to the decrease of the surface defect states due to the declined ratio of surface to volume and the removal of surface absorbance such as hydroxyl groups, nitrate and citric species.