中文摘要：

采用改进的溶胶凝胶前驱单体法合成了一系列Er3＋单掺和Er3＋-Yb3＋共掺的BaTiO3：Ln3＋上转换发光纳米颗粒,产物经900℃煅烧后得到结晶性极佳的纯立方相BaTiO3纳米晶,尺寸均匀约为100nm。稀土离子浓度较低时不会影响产物的晶体结构和形貌,掺杂浓度达到5%时出现微弱的Ba2TiO4衍射峰,当掺杂浓度达到20%时Ba2TiO4已经占主要部分,此时产物中有大量微米量级的颗粒存在。上转换发光显示：Er3＋单掺浓度为0.5%时能获得最强的绿光发射,此时红绿光强度比约为1∶15。当Er3＋-Yb3＋共掺时,Yb3＋极大地抑制了绿光的发射,同时红光发射明显增强,当Yb3＋/Er3＋大于5∶1后,红绿光强度比稳定在3∶1。上转换机制分析表明,Yb3＋浓度较高时会引起Er3＋-Yb3＋粒子之间的能量逆传递过程,导致红光发射增强,而绿光发射减弱。

英文摘要：

Through optimized sol-gel precursor monomer method, a serial of Er3＋ doped and Er3＋ -Yb3＋ eodoped BaTiO3 ：Ln3＋ nanoparticles were synthesized. The product was pure cubic phase with even size of 100 nm by 900 ℃ calcination. The doped Ln3 ＋ did not affect the crystal structure and morphology of the nanocrystal at low do- ping concentration. The weak XRD pattern of Ba2TiO4 appeared at 5% Ln3＋ doping concentration, while the Lns＋ doping concentration reached 20% , Ba2TiO4 became dominate, and also massive microparticles were observed in the product. The upconversion measurement revealed that the most strong green emission occurred at 0.5 % doping concentration of Er3＋ ions and the ratio of red/green intensity was 1： 15. As for Er3＋-Yb3＋ codoping system, Yb3＋ ions could prevent the green emission and enhance the red emission duo to the energy back transfer process from Er3 ＋ to Yb3 ＋ ions. When the ratio of Yb3 ＋/Er3 ＋ was more than 5： 1, the intensity ratio of red/green emission was stabilized at 3： 1.