Core-shell-shell heterostructures of α-NaLuF4:Yb/Er@NaLuF4:Yb@MF2 (M = Ca, Sr, Ba) with remarkably enhanced upconversion luminescence

Yue Su; Xiuling Liu; Pengpeng Lei; Xia Xu; Lile Dong; Xianmin Guo; Xingxu Yan; Peng Wang; Shuyan Song; Jing Feng; Hongjie Zhang

doi:10.1039/c6dt01005a

Core-shell-shell heterostructures of α-NaLuF4:Yb/Er@NaLuF4:Yb@MF2 (M = Ca, Sr, Ba) with remarkably enhanced upconversion luminescence

Dalton Trans. 2016 Jul 5;45(27):11129-36. doi: 10.1039/c6dt01005a.

Authors

Yue Su¹, Xiuling Liu¹, Pengpeng Lei¹, Xia Xu¹, Lile Dong¹, Xianmin Guo², Xingxu Yan³, Peng Wang³, Shuyan Song⁴, Jing Feng⁴, Hongjie Zhang⁴

Affiliations

¹ State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Science, 5625 Renmin Street, Changchun 130022, China. fengj@ciac.ac.cn hongjie@ciac.ac.cn and University of Chinese Academy of Sciences, Beijing 100049, China.
² Changchun Normal University, Changchun 130032, China.
³ National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
⁴ State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Science, 5625 Renmin Street, Changchun 130022, China. fengj@ciac.ac.cn hongjie@ciac.ac.cn.

PMID: 27327414
DOI: 10.1039/c6dt01005a

Abstract

Core-shell-shell heterostructures of α-NaLuF4:Yb/Er@NaLuF4:Yb@MF2 (M = Ca, Sr, Ba) have been successfully fabricated via the thermal decomposition method. Upconversion nanoparticles (UCNPs) were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), upconversion luminescence (UCL) spectroscopy, etc. Under 980 nm excitation, the emission intensities of the UCNPs are remarkably enhanced after coating the MF2 (M = Ca, Sr, and Ba) shell. Among these samples, CaF2 coated UCNPs show the strongest overall emission, while BaF2 coated UCNPs exhibit the longest lifetime. These results demonstrate that alkaline earth metal fluorides are ideal materials to improve the UCL properties. Meanwhile, although the lattice mismatch between the ternary NaREF4 core and the binary MF2 (M = Sr and Ba) shell is relatively large, the successfully synthesized NaLuF4:Yb/Er@NaLuF4:Yb@MF2 indicates a new outlook on the fabrication of heterostructural core-shell UCNPs.