Yb^(3+)/Tm^(3+)共掺杂BST铁电厚膜的制备及其上转换发光

Preparation and upconversion luminescence properties of Yb^(3+)/Tm^(3+) codoped(Ba,Sr)TiO_3 ferroelectric thick films

利用丝网印刷工艺制备出稀土Yb3+/Tm3+共掺杂的Ba0.8Sr0.2TiO3铁电陶瓷厚膜,利用XRD、SEM、EDS、Raman和荧光光谱仪研究了稀土掺杂对厚膜微结构和发光性能的影响。实验发现,在低掺杂量时Yb3+、Tm3+离子在BST晶格中首先替代B位离子,高掺杂量时则同时占据A位和B位离子。掺杂后的厚膜仍表现为典型的铁电四方相结构。在800nm近红外激光激发下,共掺杂的BST厚膜中的Tm3+离子通过Yb3+离子的敏化作用在468与533nm处实现了间接上转换蓝色与绿色荧光输出,分别对应于Tm3+离子的1 G4→3 H6跃迁和1 D2→3F4跃迁。468nm蓝色荧光强度随着Yb3+、Tm3+离子比的增加先增强后减弱,在Yb3+、Tm3+离子共掺比为2∶1达到最大,并对上转换发光的机理进行了分析。

The Yb3+/Tm3+ co-doped BST thick films were prepared by screen printing process on alumina sub-strates.The effect of rare earth ions doping on the microstructure and photoluminescence properties were inves-tigated.It was found that Tm3+ and Yb3+ ions substituted for B site ions when the concentration was small.The RE ions can substitute both A site and B site with increasing RE ions concentration.The PL spectra of the Yb, Tm co-doped BST thick films were measured with 800 nm excitation source at room temperature.The 468 nm blue up-conversion luminescence was assigned to 1 G4→3 H6 transition of the Tm3+,and the 533 nm green up-conversion luminescence was assigned to 1 D2→3 F4 transition of the Tm3+ with the sensitization of Yb3+.The in-tensity of the 468 nm luminescence peeks first became stronger then decreased as increasing the ratio of the Yb3+ and Tm3+,the luminescence intensity reached the maximum at the ratio of 2∶1 for Yb3+ and Tm3+.The mechanism of indirect up-conversion luminescence was also studied.