水热法合成纳米晶NaYF4 : Er3+,Tm3+,Yb3+ 的上转换发光特性

以EDTA为络合剂,用水热法合成了Er³⁺,Tm³⁺和Yb³⁺共掺杂的NaYF₄纳米晶。XRD和TEM的结果表明:粒径约为30 nm,属于六方晶系。在980 nm半导体激光器激发下,研究了不同Er³⁺离子掺杂浓度对Tm³⁺和Er³⁺离子上转换发光性能的影响,光强与泵浦功率的双对数曲线表明,474,525,539,650 nm的发射均属于双光子过程,408 nm的发射属于三光子过程。讨论了样品的协作敏化和声子辅助共振能量传递的上转换发光机制。

The Upconversion Luminescence Properties of Nanocrystal NaYF₄ : Er³⁺,Tm³⁺, Yb³⁺ Synthesized by Hydrothermal Method

Nanocrystals of up-conversion phosphor Er³⁺,Tm³⁺ and Yb³⁺ co-doped NaYF₄ were prepared by hydrothermal method in the prescence of complexing agent EDTA. Under 980 nm diode laser exciting, the impact of different concentration of Er³⁺ ion on the up-conversion luminescence intensity was discussed.
The samples were characterized by transmission electron microscopy and X-ray diffraction, the results showed that hexagonal nanocrystal NaYF₄:Er³⁺,Tm³⁺ and Yb³⁺ was prepared by hydrothermal method. According to the law of luminescence intensity versus excitation power, the 474 nm blue emission, 525 nm and 539 nm green emission, 650 nm red emission are all due to double photon process, while the 408 nm violet emission is a three-photon process. The up-conversion mechanism and processes were also analyzed.