Potassium lutetium fluoride nanocrystal with delayed phase transition and greatly increased up-conversion luminescence intensity and preparation method thereof

Abstract

The invention discloses a lutetium potassium fluoride nanocrystal with phase change delay and greatly improved up-conversion luminescence intensity. The chemical formula of the lutetium potassium fluoride nanocrystal is K(Lu<x>Y<1-x>)<2>F<7>:18%Yb<3+>,2%Er<3+> or K(Lu<x>Gd<1-x>)<2>F<7>:18%Yb<3+>,2%Er<3+>, wherein x=10-40 mmol%; a preparation method of the lutetium potassium fluoride nanocrystal comprises the steps of: S1, mixing lutetium nitrate, ytterbium nitrate, erbium nitrate and yttrium nitrate or a yttrium nitrate solution with deionized water, performing stirring, adding a chelating agent, performing stirring to form white turbid liquid, then adding a potassium fluoride solution, and performing stirring to form transparent colloid; S2, performing a hydrothermal reaction on the colloid at 180-260 DEG C for 10-15 hours; and S3, performing centrifugation on the turbid liquid obtained after the reaction is conducted, and performing washing and drying to obtain the lutetium potassiumfluoride nanocrystal doped with yttrium ions or high content of yttrium. The lutetium potassium fluoride nanocrystal has broad application prospects in fields of multicolor display, biomedicine, photocatalysis, solar energy and the like, and the preparation method has simple equipment and easy operation, and is suitable for large-scale production and promotion.

Description

technical field [0001] The invention belongs to the field of luminescent materials, and more particularly relates to a potassium lutetium fluoride nanocrystal with delayed phase transition and greatly improved up-conversion luminescence intensity and a preparation method thereof. Background technique [0002] Rare earth-based upconversion luminescent nanocrystals have attracted much attention due to their unique properties that convert low-energy photons into high-energy photons, extending their potential applications in multicolor imaging, biomarkers, photocatalysis, and solar energy. . And the optimization of luminescence performance, one of the important means is the choice of doping host. Currently, β-NaYF 4 It is recognized as the host material with the most efficient upconversion luminescence properties. In recent years, other rare earth fluorides, such as Gd-based and Lu-based fluorides, have also been extensively studied. Recently, the orthorhombic KYb 2 F 7 Na...

AI Technical Summary

Problems solved by technology

However, high-concentration ion doping can cause phase transitions that are not conducive to luminescent properties, such as β-NaYF 4 Highly doped La in the system 3+ Will cause a phase transition from hexagonal to cubic; KYb 2 f 7 Incorporation of Gd into nanocrystals 3+ It also causes a phase transition from orthorhombic to cubic. Since the luminous efficiency of the cubic system is much lower than that of the orthorhombic system in general, the upconversion luminescence of these systems is also greatly reduced when the phase transition occurs. Small

[0004] It can be seen that it is of far-reaching significance to realize the phase transition delay and improve the up-conversion luminescence under high doping concentration. This method not only realizes the simultaneous regulation of phase transition and up-conversion luminescence, but also can be extended to other up-conversion rare earth-based luminescent host systems. , so far there is no report on achieving delayed phase transition and improving upconversion luminescence in potassium lutetium fluoride nanocrystals

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