Yb^(3+)/Er^(3+)掺杂比例对BaTiO_3:Yb^(3+),Er^(3+)纳米晶上转换发光分支比的影响  

Effects of Yb^(3+)/Er^(3+) Doping Ratio on Upconversion Branching Ratio of BaTiO_3: Yb^(3+),Er^(3+) Nanocrystal

作　　者：王绩伟[1] 梅勇[1] 谭天亚[1] 夏立新[2] 刘忠坤[1] 宋晓栋[1] 范晓星[1] 任玺[1] 王瑞鑫[1] 卢雪梅[1] 

机构地区：[1]辽宁大学物理学院,辽宁沈阳110036 [2]辽宁大学化学学院,辽宁沈阳110036

出　　处：《中国稀土学报》2015年第1期24-31,共8页Journal of the Chinese Society of Rare Earths

基　　金：国家自然科学基金项目(11274150;21271095);辽宁省高校优秀人才支持计划项目(LR2013001);辽宁大学青年基金项目(2012LDQN04)资助

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。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.

关 键 词：BaTiO3铁电纳米晶 上转换发光 能量逆传递 荧光分支比 稀土 

分 类 号：O482.31[理学—固体物理]