Er^(3+)和Yb^(3+)共掺杂La_2Ti_2O_7纳米晶的上转换发光  

Up-conversion Luminescence in Er^(3+) and Yb^(3+) Co-doped La_2Ti_2O_7 Nanocrystals

作　　者：李新栓[1] 陈菊[1] 丁玲红[1] 张伟风[1] 

机构地区：[1]河南大学物理与电子学院光伏材料省重点实验室,河南开封475004

出　　处：《中国稀土学报》2012年第6期732-737,共6页Journal of the Chinese Society of Rare Earths

基　　金：河南省高校科技创新团队计划(2012 IRTSTHN004);河南省教育厅自然科学基金(2009B48003)资助

摘　　要：采用溶胶-凝胶法制备了Er3+单掺杂A2Ti2O7(A=La,Y,Gd)和Er3+,Yb3+共掺杂的La2Ti2O7纳米晶样品。用X射线衍射仪、扫描电子显微镜和紫外-可见-近红外光谱仪分别对样品的结构、形貌和光吸收性质进行了表征;测试了样品在980 nm激光激发下的室温上转换光谱。结果发现,样品都发出了很强的绿光(大约在525和549 nm)和红光(大约660 nm)。通过研究这些基质的晶体结构对上转换发光的影响,发现La2Ti2O7基质中Er3+离子的上转换发射最强。对La2Ti2O7纳米晶的上转换发光研究表明,Yb3+离子能够有效地敏化Er3+离子的上转换发射。对上转换发光强度与泵浦功率的依赖分析,发现红光和绿光的发射均属于双光子吸收过程,最后讨论了Er3+和Yb3+的上转换发光机制。Er3＋ doped A2Ti2O7 （A = La, Y and Gd） and Er3＋ , Yb3 ＋ co-doped La2Ti2O7 nanocrystals were prepared by the sol-gel method. The structure, surface morphology and optical absorption of the samples were examined and characterized by X-ray diffractometer,scanning electron microscope, and UV-vis spectrome- ter. The upconversion spectra of the samples were in- vestigated at room temperature excited by 980 nm la- ser. The strong green （about 525 and 549 nm） and red （about 660 nm） luminescences emitted from thesamples could be observed. From the study of the in- fluence on upconversion luminescences by the crystal structure of these host materials, the strongest upcon- version emission of Er3＋ was observed in the La2Ti2O7. The investigation of the upconversion lumi- nescence of Er3＋, Yb3＋ codoped La2Ti2O7 nanocrys-tals indicated that Yb3 ＋ ions could greatly sensitize the upconversion emission of Er3＋ion. The pump power dependence analysis revealed that the green and red e- missions originated from a two-photon absorption process. Moreover the up-conversion mechanism was discussed.

关 键 词：上转换发光 ER3+ YB3+ La2Ti2O7 

分 类 号：O482.31[理学—固体物理]