Multicolor tunable luminescence and energy transfer of core-shell structured SiO 2 @Gd 2 O 3 microspheres co-activated with Dy 3+ /Eu 3+ under single UV excitation.

Optimizing structure and varying doped ions are two main strategies to obtain excellent luminescence performance. Spherical morphology is considered to be the most ideal phosphor structure due to the least surface defects. Herein, a series of spherical and monodispersed Dy3+/Eu(3+)co-activated SiO2@Gd(2)O(3)core-shell phosphors with multicolor tunable luminescence were successfully preparedviaa facile urea assisted precipitation method. Related chemical reactions and the possible growth mechanism of Gd2O3:Ln(3+)directional deposition on the surface of SiO(2)microspheres were put forward. Upon 273 nm UV radiation excitation, SiO2@Gd2O3:Dy(3+)and SiO2@Gd2O3:Eu(3+)samples exhibited characteristic yellow (F-4(9/2)-H-6(13/2)) and blue (F-4(9/2)-H-6(15/2)) emissions of Dy(3+)and red (D-5(0)-F-7(2)) emission of Eu3+, respectively. Meanwhile, multicolor emissions (warm white, yellow and orange) could be easily obtained by modulating the relative content of Dy(3+)and Eu(3+)in SiO2@Gd2O3:Ln(3+)samples under a single excitation wavelength. Moreover, it was confirmed that Dy(3+)could transfer energy to Eu(3+)in the form of quadrupole-quadrupole interaction and further improved the luminescence intensity of Eu(3+)by comparing experimental data with theoretical calculations. These results imply that tunable luminescence Dy3+,Eu(3+)co-doped SiO2@Gd(2)O(3)microspheres have great potential applications in multicolor displays and biolabeling fields.