Nd(3+)-Sensitized Ho(3+) Single-Band Red Upconversion Luminescence in Core-Shell Nanoarchitecture.
A strategy to achieve 808 nm excited single-band red upconversion luminescence of Ho(3+) via the core-shell nanoarchitecture design was provided. Specifically, the synthesized Yb/Ho/Ce: NaGdF4@Yb/Nd: NaYF4 active-core@active-shell nanoparticles were evidenced to enable high-content doping of Nd(3+) (∼10 mol %) in the shell layer and, thus, markedly enhance red upconversion emission from Ho(3+) activators in the core with the assistance of spatially confined doping of Nd(3+) ions and efficient energy transfer of Nd(3+) → Yb(3+)(shell) → Yb(3+)(core) → Ho(3+). Importantly, introducing Ce(3+) into the core was beneficial to the competition of radiation transitions from the two intermediate excited states of Ho(3+): (5)S2,(5)F4 (green-emitting) and Ho(3+): (5)F5 (red-emitting), which induced great enhancement in the red to green intensity ratio and ultimately intense single-band red upconversion emission. We believe that this preliminary study will provide an important advance in developing luminescent markers suitable for biolabeling applications.
Daqin
D
Chen
Lu
L
Liu
‡State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, P. R. China.
Ping
P
Huang
Mingye
M
Ding
Jiasong
J
Zhong
Zhenguo
Z
Ji
D004735:Energy Transfer; D006695:Holmium / Q000737:chemistry*; D049449:Luminescence; D053758:Nanoparticles / Q000737:chemistry*; D009354:Neodymium / Q000737:chemistry*
D009354:Neodymium; D006695:Holmium
NaYF4; biolable; energy transfer; lanthanide; nanocrystals; upconversion