Abstract
Core-shell structures are widely used to modulate upconversion emission or mitigate surface quenching and cross-relaxation in lanthanide-doped upconversion nanoparticles (UCNPs) to meet the requirements of various applications. Interfacial cation migration has been found recently to deteriorate the core-shell structures and thus affect their upconversion luminescence when they are subjected to annealing post-treatment. Herein, we demonstrate that the interfacial cation migration largely depends on the crystalline phase of the host lattice. Significant Er3+/Y3+(Yb3+) diffusion and migration occur across the core-shell interface when cubic NaREF4 (RE = Y, Yb, Er) core-shell or core-shell-shell UCNPs are annealed at 200 Ā°C in the solid state, while the cation migration in hexagonal counterparts is negligible and the core-shell (core-shell-shell) structure can be well maintained in the same condition. The loosely packed atoms and large cubic void surrounded by eight F- ions in cubic NaREF4 lattice may facilitate cations diffusion and migration, enabling interfacial cations migration at relatively lower temperature. This finding may help us better understand temperature-dependent upconversion luminescent properties of core-shell UCNPs and better utilize various core-shell structured UCNPs according to different requirements of applications.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
