摘要
Red-emission （Y0.95Eu0.05）2O3 submicron spheres and microplates were selectively obtained via hydrothermal precursor synthesis （150 °C, 12 h） followed by calcination at 1000 °C. Characterizations of the products were carried out by combined means of XRD, FT-IR, FE-SEM and PL analysis. The precursors could be modulated from basic-carbonate submicron spheres to normal carbonate microplates by increasing the molar ratio of urea to Y＋Eu from 10 to 40-100. The resultant oxides largely retain their respective precursor morphologies at 1000 °C, but morphology confined crystal growth was observed for the microplates, yielding more enhanced exposure of the （400） facets. Both the （Y0.95Eu0.05）2O3 spheres and microplates exhibit nearly identical positions of the PL bands and similar asymmetry factors of luminescence [I（5D0→7F2）/I（5D0→7F1）, ～11] under 250 nm excitation, but the microplates show a significantly strong red emission at ～613 nm （ ～1.33 times that of the spheres） owing to their larger particle size and denser packing of primary phosphor crystallites.
采用先水热合成(150°C,12h)、后煅烧(1000°C)来实现(Y0.95Eu0.05)2O3亚微米球形和微米板片红色荧光颗粒的形貌可控合成。通过XRD、FT-IR、FE-SEM和PL等检测手段对样品进行分析。结果表明:将尿素与Y+Eu的摩尔比由10增大至40～100,得到的前驱体由碱式碳酸盐亚微米球转变为碳酸盐微米片;经1000°C煅烧所得氧化物能够继承前驱体的形貌特征;板片二维形貌的限制内部晶粒自由生长,使更多的(400)晶面暴露在板片颗粒表面;在250nm紫外光的激发下,荧光颗粒的荧光发射峰位及荧光不对称因子[I(5D0→7F2)/I(5D0→7F1),～11]均与颗粒形貌的相关性不强,但荧光强度呈现明显的形貌依存性;微米板片颗粒的尺寸大,从而其比表面积小,因此具有更高的荧光强度(微米板片在～613nm处的荧光强度为球形颗粒的～1.33倍)。
基金
Projects (50172030, 50972025, 50990303, 51172038) supported by the National Natural Science Foundation of China
Project supported by the Liaoning BaiQianWan Talents Program, China
Projects (N110802001, N100702001) supported by the Fundamental Research Funds for the Central Universities, China
Project supported by the China Scholarship Council
