CN110643363B - A molybdate up-conversion luminescent material and its preparation method and application - Google Patents

Abstract

The application discloses a molybdate up-conversion luminescent material and a preparation method and application thereof, and relates to the technical field of luminescent materials_{2‑2x‑ 2y}Er_2xYb_2yMo₃O₁₂Wherein Ln is one or more of Y, Lu, La, Gd and Dy, 0<x+y<1. The application solves the problem that the existing up-conversion luminescent material can not realize the regulation and control of the luminescent performance in real time and in situ, and realizes the random regulation and control of the luminescent intensity of the up-conversion luminescent material through temperature.

Description

A molybdate up-conversion luminescent material and its preparation method and application

technical field

The present application relates to the technical field of luminescent materials, in particular to a molybdate up-conversion luminescent material and a preparation method and application thereof.

Background technique

Rare earth doped upconversion luminescent materials are photoluminescent materials capable of converting multiple photons of longer wavelengths (low energy) into photons of shorter wavelengths (high energy). This nonlinear optical characteristic makes it unique and valuable in many fields. Its applications mainly include high-performance blue-green lasers, optical imaging of biological cells, high-efficiency solar cells, temperature sensors, and 3D imaging.

Generally, rare earth doped upconversion luminescent materials are generally composed of three parts: a host material that provides a suitable crystal field for the luminescent center; an activator that can absorb energy and transition to produce luminescence; can absorb and effectively transfer energy to the activator and finally Doping ions that improve the overall luminous efficiency are called sensitizers. In general, upconversion luminescence intensity is determined by luminescence absorption and conversion efficiency. The upconversion light absorption efficiency is mainly determined by the light scattering cross section of the dopant ions and the transparency of the matrix. The upconversion efficiency depends on the excited state kinetics of rare earth ions and their interaction with the matrix matrix.

At present, the regulation of luminescence is mainly by adjusting the type of doping ions, adjusting the concentration of doping ions, and adjusting the crystal phase, crystal size, core-shell structure of the host. However, this conventional luminescence regulation method cannot achieve real-time, in situ regulation of luminescence properties.

SUMMARY OF THE INVENTION

By providing a molybdate up-conversion luminescent material and a preparation method and application thereof in the embodiments of the present application, it is solved that the existing up-conversion luminescent material cannot realize real-time and in-situ luminescence performance regulation, and the up-conversion luminescence can be arbitrarily regulated by temperature. The luminous intensity of the material.

To achieve the above purpose, the application mainly provides the following technical solutions:

On the one hand, the embodiments of the present application provide a molybdate up-conversion luminescent material, the general chemical formula of which is Ln _{2-2x- 2y} Er _2x Yb _2y Mo ₃ O ₁₂ , wherein Ln is the element Y, Lu, La, Gd and one or more of Dy, 0<x+y<1.

Preferably, 0<x≤0.1, 0<y≤0.4.

Preferably, x=0.02, y=0.18.

Preferably, the particle size of the molybdate up-conversion light-emitting material is 0.2-100 μm.

On the other hand, an embodiment of the present application provides a method for preparing a molybdate up-conversion luminescent material, comprising the following steps:

The Ln-containing compound, Er-containing compound, Yb-containing compound and Mo-containing compound are mixed according to the element molar ratio of Ln:Er:Yb:Mo=(2-2x-2y):2x:2y:3. Pre-burning, then grinding, calcining the ground powder, cooling and then grinding to obtain the molybdate up-conversion luminescent material; wherein Ln is one of the elements Y, Lu, La, Gd and Dy or more, 0<x+y<1.

Preferably, the general chemical formula of the molybdate up-conversion light-emitting material is Ln _2-2x-2y Er _2x Yb _2y Mo ₃ O ₁₂ .

Preferably, 0<x≤0.1, 0<y≤0.4.

Preferably, x=0.02, y=0.18.

Preferably, the Ln-containing compound, Er-containing compound, Yb-containing compound and Mo-containing compound are all selected from corresponding oxides, carbonates, oxalates, acetates or compounds existing in the form of hydroxides.

Preferably, the Ln-containing compound, the Er-containing compound and the Yb-containing compound are all selected from corresponding oxides; the Mo-containing compound is MoO ₃ .

Preferably, the purity of the Ln-containing compound, the Er-containing compound, the Yb-containing compound and the Mo-containing compound are all 99.99%.

Preferably, the particle size of the molybdate up-conversion light-emitting material is 0.2-100 μm.

Preferably, the Ln-containing compound, Er-containing compound, Yb-containing compound and Mo-containing compound are uniformly mixed by mechanical ball milling or sol-gel method.

Preferably, the temperature of the calcination is 400°C-600°C, and the calcination time is 2-30 hours.

Preferably, the containers used for the pre-firing and calcination are all ceramic boats or corundum boats.

Preferably, the calcining atmosphere is air or pure oxygen, the calcining temperature is 800°C-1000°C, and the calcining time is 2-10 hours.

The embodiments of the present application also provide applications of the above molybdate up-conversion luminescent materials in the fields of high-temperature up-conversion imaging, temperature sensors and laser anti-counterfeiting.

One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

The molybdate up-conversion light-emitting material provided by the present application uses Ln ₂ Mo ₃ O ₁₂ as the host of the light-emitting material and co-doping with erbium-ytterbium, which breaks the performance of the conventional up-conversion light-emitting material that the temperature increases and the light weakens, and realizes the material temperature To improve the performance of light enhancement, the position of the luminescence peak of the material does not change with the change of luminescence intensity, but the luminescence intensity increases rapidly with the increase of temperature. The luminescent material of the present application creates good conditions for regulating luminescent properties by adjusting temperature, and has the potential to be applied to high-temperature up-conversion imaging, high-temperature, high-sensitivity temperature sensors, and laser anti-counterfeiting.

Description of drawings

Fig. 1 is the normal temperature luminescence spectrum of the luminescent material Lu _2-0.4 Er _0.04 Yb _0.36 Mo ₃ O ₁₂ obtained in Example 1 of the application;

FIG. 2 is a luminescence spectrum diagram of the luminescent material Lu _2-0.4 Er _0.04 Yb _0.36 Mo ₃ O ₁₂ obtained in Example 1 of the application at different temperatures;

FIG. 3 is a graph showing the variation of luminescence intensity with temperature of the luminescent material Lu _2-0.4 Er _0.04 Yb _0.36 Mo ₃ O ₁₂ obtained in Example 1 of the application at specific luminescence peaks (524 and 560 nm);

FIG. 4 is the luminescence spectrum at room temperature of the luminescent material Y _2-0.4 Er _0.04 Yb _0.36 Mo ₃ O ₁₂ obtained in Example 2 of the application;

5 is a luminescence spectrum diagram of up-conversion of the luminescent material Y _2-0.4 Er _0.04 Yb _0.36 Mo ₃ O ₁₂ obtained in Example 2 of the present application at different temperatures;

FIG. 6 is a spectrum diagram of the intensity of the luminescent material Y _2-0.4 Er _0.04 Yb _0.36 Mo ₃ O ₁₂ obtained in Example 2 of the present application as a function of temperature at different luminescence peak positions.

Detailed ways

The present invention will be described in further detail below with reference to specific embodiments, but it is not intended to limit the present invention.

The embodiments of the present application provide a molybdate up-conversion light-emitting material, the general chemical formula of which is Ln _{2-2x- 2y} Er _2x Yb _2y Mo ₃ O ₁₂ , wherein Ln is one of the elements Y, Lu, La, Gd and Dy One or more of , 0<x+y<1. Preferably, 0<x≤0.1, 0<y≤0.4. More preferably, x=0.02, y=0.18.

The particle size of the above-mentioned molybdate up-conversion light-emitting material is 0.2-100 μm.

The molybdate up-conversion light-emitting material provided in the embodiments of the present application uses Ln ₂ Mo ₃ O ₁₂ as the host of the light-emitting material and co-doping with erbium and ytterbium, which breaks the performance of the conventional up-conversion light-emitting material that the temperature increases and the light weakens, and realizes the The light-enhancing performance of the material increases with the temperature. The position of the luminescence peak of the material does not change with the change of the luminous intensity, but the luminous intensity increases rapidly with the increase of the temperature. The luminescent material of the present application creates good conditions for regulating luminescent properties by adjusting temperature, and has the potential to be applied to high-temperature up-conversion imaging, high-temperature, high-sensitivity temperature sensors, and laser anti-counterfeiting.

The embodiments of the present application also provide a method for preparing the above molybdate up-conversion luminescent material, comprising the following steps:

The Ln-containing compound, Er-containing compound, Yb-containing compound and Mo-containing compound are mixed according to the element molar ratio of Ln:Er:Yb:Mo=(2-2x-2y):2x:2y:3. Pre-burning, then grinding, calcining the ground powder, cooling and then grinding to obtain the molybdate up-conversion luminescent material; wherein Ln is one of the elements Y, Lu, La, Gd and Dy or more, 0<x+y<1.

Preferably, 0<x≤0.1, 0<y≤0.4. More preferably, x=0.02, y=0.18.

The general chemical formula of the molybdate up-conversion light-emitting material is Ln _2-2x-2y Er _2x Yb _2y Mo ₃ O ₁₂ .

The Ln-containing compound, the Er-containing compound, the Yb-containing compound and the Mo-containing compound are all selected from the corresponding oxides, carbonates, oxalates, acetates or compounds existing in the form of hydroxides. Preferably, the Ln-containing compound, the Er-containing compound and the Yb-containing compound are all selected from corresponding oxides; the Mo-containing compound is MoO ₃ ; and the purity of these raw materials is all 99.99%.

In the above preparation method, the Ln-containing compound, the Er-containing compound, the Yb-containing compound and the Mo-containing compound are uniformly mixed by mechanical ball milling or sol-gel method.

In the above preparation method, the calcination temperature is 400°C-600°C, and the calcination time is 2-30 hours.

In the above preparation method, the containers used for pre-firing and calcining are both ceramic boats or corundum boats.

In the above preparation method, the calcining atmosphere is air or pure oxygen, the calcining temperature is 800°C-1000°C, and the calcining time is 2-10 hours.

The molybdate upconversion luminescent materials provided in the embodiments of the present application can be applied to the fields of high temperature upconversion imaging, temperature sensors and laser anti-counterfeiting.

The preparation method of the molybdate up-conversion light-emitting material will be described below through specific examples.

Example 1

(1) According to the stoichiometric ratio of Lu, Er, Yb and Mo in the chemical formula Lu _2-0.4 Er _0.04 Yb _0.36 Mo ₃ O ₁₂ , weigh each of Lu ₂ O ₃ , Yb ₂ O ₃ , MoO ₃ and Er ₂ O ₃ Corresponding quality, the purity of these raw materials is 99.99%, grind 2-3 times with absolute ethanol to make it mix evenly;

(2) The ground samples were placed in an oven at 80°C for two hours to dry, then placed in a corundum boat, and then the corundum boat containing the samples was placed in a high-temperature furnace for pre-sintering, and kept at 500°C in an air atmosphere. 6 hours, then cool down to room temperature naturally;

(3) Take out the sample from the high-temperature furnace, grind it with alcohol for 2-3 times, and dry it;

(4) Put the dried sample into the corundum boat, put it into a high-temperature furnace for calcination, slowly heat up to 900° C. in an air atmosphere, keep the temperature for 6 hours, then naturally cool and grind to obtain the molybdate Upconverting luminescent material.

After testing, the particle size of the molybdate up-conversion luminescent material prepared above is 0.2-100 μm.

The luminescent properties of the molybdate up-conversion luminescent material prepared in Example 1 were tested, and the luminescent spectra shown in FIG. 1 , FIG. 2 and FIG. 3 were obtained.

Figure 1 shows the luminescence spectrum of the luminescent material Lu _2-0.4 Er _{0.04 Yb 0.36} Mo ₃ O ₁₂ under the excitation of 980 nm laser light at room _{temperature .} Mo ₃ O ₁₂ emits green light under the irradiation of near-infrared laser;

Figure 2 shows the luminescence spectra of the luminescent material Lu _2-0.4 Er _0.04 Yb _0.36 Mo ₃ O ₁₂ under different temperature conditions under the excitation of 980 nm laser; it can be seen from Figure 2 that the luminescent material Lu _2-0.4 Er _0.04 Yb _0.36 Mo The luminescence peak position of ₃ O ₁₂ does not change with the increase of temperature, but the luminescence intensity increases with the increase of temperature.

Figure 3 is a graph showing the luminescence intensity of the luminescent material Lu _2-0.4 Er _0.04 Yb _0.36 Mo ₃ O ₁₂ at specific luminescence peaks (524 and 560 nm) as a function of temperature; it can be seen from Figure 3 that the luminescent material Lu _2-0.4 Er The luminescence enhancement of _0.04 Yb _0.36 Mo ₃ O ₁₂ at different luminescence peaks has great differences, and the luminescence intensity at 524 nm has the most obvious change with temperature.

It can be seen from the above that the luminescent material Lu _2-0.4 Er _0.04 Yb _0.36 Mo ₃ O ₁₂ has a completely different performance of light enhancement with temperature increase from conventional materials. The position of the luminescence peak of the material does not change with the change of luminous intensity, but the luminous intensity increased rapidly with increasing temperature. Therefore, the molybdate up-conversion luminescent material prepared in this embodiment can arbitrarily control the luminous intensity of the up-conversion luminescent material through temperature, so as to realize real-time and in-situ luminescent performance regulation.

Example 2

(1) According to the stoichiometric ratio of Y, Er, Yb and Mo in the chemical formula Y _2-0.4 Er _0.04 Yb _0.36 Mo ₃ O ₁₂ , weigh each of Y ₂ O ₃ , Yb ₂ O ₃ , MoO ₃ and Er ₂ O ₃ Corresponding quality, the purity of these raw materials are all 99.99%, and they are ground 2-3 times with absolute ethanol to make them evenly mixed.

(2) The ground samples were placed in an oven at 80°C for two hours to dry, then placed in a corundum boat, and then the corundum boat with the samples was placed in a high-temperature furnace for pre-firing, and kept at 500°C in an air atmosphere 6 hours, then cool down to room temperature naturally.

(3) Take out the sample from the high temperature furnace, grind it with alcohol for 2-3 times, and then dry it.

(4) put the dried sample into a corundum boat, put it into a high-temperature furnace for calcination, slowly heat up to 950 ° C in an air atmosphere, keep the temperature for 6 hours, then naturally cool and grind to obtain molybdate Upconverting luminescent material.

After testing, the particle size of the molybdate up-conversion luminescent material prepared above is 0.2-100 μm.

The luminescence properties of the molybdate up-conversion luminescent material prepared in Example 2 were tested, and the luminescence spectra shown in FIG. 4 , FIG. 5 and FIG. 6 were obtained.

Figure 4 shows the luminescence spectrum of the luminescent material Y _2-0.4 Er _0.04 Yb _0.36 Mo ₃ O ₁₂ under the excitation of _980nm laser light at room _{temperature .} Mo ₃ O ₁₂ emits green light under the irradiation of near-infrared laser;

Figure 5 shows the luminescence spectra of the luminescent material Y _2-0.4 Er _0.04 Yb _0.36 Mo ₃ O ₁₂ under different temperature conditions under the excitation of 980 nm laser; it can be seen from Figure 5 that the luminescent material Y _2-0.4 Er _0.04 Yb _0.36 Mo The luminescence peak position of ₃ O ₁₂ does not change with the increase of temperature, but the luminescence intensity increases with the increase of temperature.

Figure 6 is a graph showing the luminescence intensity of the luminescent material Y _2-0.4 Er _0.04 Yb _0.36 Mo ₃ O ₁₂ at specific luminescence peaks (524 and 560 nm) as a function of temperature; it can be seen from Figure 6 that the luminescent material Y _2-0.4 Er The luminescence enhancement of _0.04 Yb _0.36 Mo ₃ O ₁₂ at different luminescence peaks has great differences, and the luminescence intensity at 524 nm has the most obvious change with temperature.

It can be seen from the above that the luminescent material Y _2-0.4 Er _0.04 Yb _0.36 Mo ₃ O ₁₂ has a completely different performance of light-enhancing at elevated temperature from conventional materials. The position of the luminescent peak of the material does not change with the change of luminous intensity, but the luminous intensity increased rapidly with increasing temperature. Therefore, the molybdate up-conversion luminescent material prepared in this embodiment can arbitrarily control the luminous intensity of the up-conversion luminescent material through temperature, so as to realize real-time and in-situ luminescent performance regulation.

It has been proved by experiments that the molybdate up-conversion luminescent material with the general chemical formula Ln _2-2x-2y Er _2x Yb _2y Mo ₃ O ₁₂ , when Ln is one or more of La, Gd and Dy, also has the same properties. The position of the luminescence peak of the material does not change with the change of luminescence intensity, but the luminescence intensity increases rapidly with the increase of temperature.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be Modifications or equivalent substitutions without departing from the spirit and scope of the technical solutions of the present invention should be included in the scope of the claims of the present invention.

Claims (6)

1. A molybdate up-conversion luminescent material is characterized in that the molybdate up-conversion luminescent material is formed by esterificationHas a chemical general formula of Ln_2-2x-2yEr_2xYb_2yMo₃O₁₂Wherein Ln is element Y or Lu, 0<x+y<1；

The preparation method of the molybdate up-conversion luminescent material comprises the following steps:

an Ln-containing compound, an Er-containing compound, an Yb-containing compound and a Mo-containing compound are mixed according to the following formula: er: yb: mo = (2-2x-2 y): 2 x: 2 y: 3, pre-burning and grinding the mixture after the mixture is uniformly mixed, calcining the ground powder, cooling and grinding the powder to obtain the molybdate up-conversion luminescent material; wherein Ln is element Y or Lu, 0< x + Y < 1; x =0.02 and y = 0.18.

2. The molybdate up-conversion phosphor of claim 1, wherein the molybdate up-conversion phosphor has a particle size of 0.2 to 100 μm.

3. The molybdate up-conversion luminescent material of claim 1, wherein the Ln-containing compound, the Er-containing compound, the Yb-containing compound, and the Mo-containing compound are each selected from the corresponding oxides, carbonates, oxalates, acetates, or compounds in the form of hydroxides.

4. The molybdate up-conversion luminescent material of claim 3, wherein said Ln-containing compound, Er-containing compound, and Yb-containing compound are each selected from the group consisting of the corresponding oxides; the Mo-containing compound is MoO₃。

5. The molybdate up-conversion luminescent material of claim 1, wherein the Ln-containing compound, the Er-containing compound, the Yb-containing compound and the Mo-containing compound are all 99.99% pure.

6. Use of a molybdate up-conversion luminescent material, wherein the molybdate up-conversion luminescent material is used in the fields of high-temperature up-conversion imaging, temperature sensors and laser anti-counterfeiting according to any one of claims 1 to 5.

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