Owing to the active shell, the lanthanide emitters inside the core are effectively prevented from the surface quenchers, and the excitation energy is absorbed more efficiently via the additional luminescence sensitizer Yb3+embedded in the shell. The details of underlying physics were investigated and discussed. The results present a good ultrasmall luminescent material system for achieving efficient multiphoton upconversion, which shows great potential in versatile industrial and biological applications.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics