Wang William, Zhu Peifen
Opt Express. 2018 Dec 24;26(26):34820-34829. doi: 10.1364/OE.26.034820.
Eu nanospheres with sizes of 40-334 nm in diameter were obtained using a low-cost co-precipitation method followed by a thermal annealing process. The sizes of the nanospheres were controlled by tuning the synthesis time and annealing temperature. X-ray diffraction patterns and scanning electron microscopy images were used to determine the structure, shape, and size of the obtained nanoparticles. The optical properties of the nanospheres were investigated with measurements of the photoluminescence excitation and emission spectra. A phase transformation of the nanospheres from an amorphous structure to a cubic crystalline YO structure was observed when the annealing temperature was higher than 500 °C. Intense red photoluminescence emission and UV excitation of the nanospheres with a crystal structure were identified. In addition, the optimal concentration of dopant (Eu) for the red emission was determined to be ~8 mol%. The unique structural and optical properties of the YO:Eu nanospheres could lead to efficient red LED-phosphors for use in generating white light with GaAlN-based UV LEDs.
采用低成本的共沉淀法并结合热退火工艺制备了直径为40 - 334 nm的YO:Eu纳米球。通过调节合成时间和退火温度来控制纳米球的尺寸。利用X射线衍射图谱和扫描电子显微镜图像确定所得纳米颗粒的结构、形状和尺寸。通过测量光致发光激发光谱和发射光谱来研究纳米球的光学性质。当退火温度高于500 °C时，观察到纳米球从非晶结构转变为立方晶系YO结构。鉴定出具有晶体结构的纳米球有强烈的红色光致发光发射和紫外激发。此外，确定红色发射的掺杂剂（Eu）的最佳浓度约为8 mol%。YO:Eu纳米球独特的结构和光学性质可导致用于与基于GaAlN的紫外发光二极管一起产生白光的高效红色发光二极管荧光粉。
