Preparation and upconversion properties of rare earth doped core-shell Y (OH)3 and β-NaYF4 hybrid nanorods

Er3+/Yb3+-doped Y(OH)(3)@beta-NaYF4 core-shell nanorods are synthesized through in situ ion exchange reaction using Y(OH)(3) nanorods as templates. Further, inert shells of beta-NaYF4 without activated dopants are coated by a facile hydrothermal method. Upconversion intensity increases dramatically by ion exchange reaction, and it can be further enhanced through coating inert shells. The maximal enhanced factor of inert coating reaches 6.58. On the basis of the structural tests and spectral data, formation mechanisms of the core-shell nanorods are discussed, as well as their upconversion properties.