Rare earth nano-material with both up/down conversion fluorescence and photothermal properties

Abstract

The invention provides a rare earth nano-material with both up / down conversion fluorescence emission and photothermal properties, and a synthesis method thereof. The rare earth nano-material has a multi-level core-shell structure with a controllable size (30-50nm). The innermost layer is NaGdF4:0.3%Nd<3+> with the best down conversion fluorescence property. The layer outside the innermost layer is inert NaGdF4. From the inert NaGdF4 layer to the outside, there are three shell layers which are NaNdF4:10%Yb<3+> / 1%Er<3+>, NaGdF4:10%Yb<3+>, and NaNdF4:10%Yb<3+>. Under 808nm near-infrared laser irradiation, the material has both 500-700nm up conversion fluorescence emission and 850-920nm down conversion fluorescence emission. The two fluorescence emissions do not interfere with each other. Also, considerable photothermal effect is produced. According to the invention, for a first time, up / down conversion fluorescence mechanisms and photothermal effect are realized in a same material.

Description

technical field [0001] The invention relates to a rare earth nano material, and also relates to a synthesis method of the rare earth nano material. Specifically, it relates to the design and synthesis method of a rare earth nanomaterial with up / down conversion fluorescence emission and photothermal performance. Background technique [0002] The rare earth upconversion fluorescence process refers to the luminescent process that absorbs two or more low-energy phonons and emits a high-energy phonon, usually using Yb 3+ For sensitization, 980nm near-infrared light is used as the excitation light source. However, water, the main component of animals and human bodies, exhibits a high photon absorption rate at 980nm, which greatly reduces the intensity of laser light passing through biological tissues, and even makes the absorbed light Can be converted into heat energy that burns the superficial skin. Nd 3+ Sensitized upconversion fluorescent materials can be excited by 808nm l...

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Problems solved by technology

[0003] We found through research that Nd 3+ Higher concentration of Nd is required for sensitized upconversion fluorescence process 3+ doping to achieve high-intensity fluorescence emission, and its down-conversion emission needs to be controlled at a concentration of about 0.3% to achieve the strongest fluorescence intensity, but in Nd 3+ When doped with high concentration, its photothermal performance is better

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