Trivalent Yb/Ho/Ce tri-doped core/shell NaYF_4 nanoparticles for tunable upconversion luminescence f

• 作 者: 董明斌 李心悦 迟逢逢 韦先涛 尹民 陈永虎
• 机 构: Key Laboratory of Strongly-Coupled Quantum Matter Physics, Chinese Academy of Sciences, School of Ph
• 出 处: Journal of Rare Earths
• 发表日期: 2017年07期
• 关键词: tunable luminescence relaxation doping tuning coated dispersed hexagonal normali

Three types of β-NaYF_4nanoparticles, uncoated core(NaYF_4:Yb/Ho/Ce), single-layer coated core@shell(NaYF_4:Yb/Ho/Ce@NaYF_4:Yb) and double-layer coated core@shell@shell(NaYF_4:Yb/Ho@NaYF_4:Yb@NaYF_4:Yb) with Ce~(3+) doped in core, first and second shell, respectively, were synthesized through solvothermal method to investigate the cross-relaxation between Ho~(3+) and Ce~(3+) for the tunable upconversion luminescence. By doping Ce~(3+) 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 Ce~(3+) in the same layer of Ho~(3+). And if Ce~(3+) and Ho~(3+) were separated in different layers, the color tuning would be depressed significantly due to the reduced cross-relaxation between Ho~(3+) and Ce~(3+). Moreover, the UC emission intensity of core@shell and core@shell@shell was enhanced significantly compared with that of unmodified core nanoparticles.

Three types of β-NaYF_4nanoparticles, uncoated core (NaYF_4: Yb / Ho / Ce), single-layer coated core @ shell (NaYF_4: Yb / Ho / Ce @ NaYF_4: Yb) and double- Doped in core, first and second shell, respectively, were synthesized through solvothermal method to investigate the cross-relaxation between Ho ~ (3+) and Yb @ NaYF_4: Yb @ NaYF_4: Yb) By doping Ce ~ (3+) 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 dimming concentration of Ce ~ (3+) in the same layer of Ho ~ (3+). And if Ce ~ (3+) and Ho ~ (3+) were separated in the different layers, the color tuning would be depressed significantly due to the reduced cross-relaxation between Ho ~ (3+) and Ce ~ (3+). Moreover, the UC emission intensity of core @ shell a nd core @ shell @ shell was enhanced significantly compared with that of unmodified core nanoparticles.