Photon upconversion in Yb/Tb co-sensitized core-shell nanocrystals by interfacial energy transfer

Abstract

We report the realization of photon upconversion through interfacial energy transfer in Yb3+/Tb3+ coupled core-shell nanostructure. The spatial separation of sensitizer and activator at different layers through the core-shell structure enables the enhancement of photon emission by minimizing the non-radiative decays of the activator. Furthermore, the energy migration among Tb3+ ions within the core matrix lattice effectively facilitates the energy transfer to a much farther distance, resulting in efficient photon upconversion by the Tb3+-mediated interfacial energy transfer. Our result offers a novel and widespread approach for achieving photon upconversion of lanthanide-doped nanocrystals that would help develop a new class of efficient upconverting materials.