Trivalent Yb/Ho/Ce tri-doped core/shell NaYF₄ nanoparticles for tunable upconversion luminescence from green to red

董明斌，李心悦，迟逢逢，韦先涛，尹民，陈永虎

Key Laboratory of Strongly-Coupled Quantum Matter Physics, Chinese Academy of Sciences, School of Physical Sciences, University of Science and Technology of China

摘 要：Three types of β-NaYF₄nanoparticles, uncoated core（NaYF₄:Yb/Ho/Ce）, single-layer coated core@shell（NaYF₄:Yb/Ho/Ce@NaYF₄:Yb） and double-layer coated core@shell@shell（NaYF₄:Yb/Ho@NaYF₄:Yb@NaYF₄:Yb） with Ce³⁺ doped in core, first and second shell, respectively, were synthesized through solvothermal method to investigate the cross-relaxation between Ho³⁺ and Ce³⁺ for the tunable upconversion luminescence. By doping Ce³⁺ into different layers with different doping concentrations, a systematical investigation on the tunable upconversion luminescence from green to red was conducted. The results showed that a remarkable color tuning could be achieved from green to red when increasing the doping concentration of Ce³⁺ in the same layer of Ho³⁺. And if Ce³⁺ and Ho³⁺ were separated in different layers, the color tuning would be depressed significantly due to the reduced cross-relaxation between Ho³⁺ and Ce³⁺. Moreover, the UC emission intensity of core@shell and core@shell@shell was enhanced significantly compared with that of unmodified core nanoparticles.

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