1. The Mn4+ -activated antimonate narrow-band red phosphor is characterized in that the chemical general formula of the phosphor is Li₄M_1-0.5xSb_1-0.5xO₆:xMn⁴⁺；

Wherein M is at least one of Al and Ga, and x is Mn⁴⁺The mol ratio of doping is more than 0 and less than or equal to 0.03.

2. The Mn4+ -activated narrow-band red antimonate phosphor of claim 1, wherein the Mn is selected from the group consisting of⁴⁺The preferred range of the doping molar ratio x is 0.001 < x.ltoreq.0.01.

3. The Mn4+ -activated narrow-band red antimonate phosphor of claim 1, wherein the phosphor emits narrow-band red fluorescence with a dominant wavelength of 673nm under excitation of ultraviolet, near ultraviolet or blue light.

4. The method for preparing Mn4+ -activated antimonate narrow-band red phosphor according to any one of claims 1 to 3, wherein the method for preparing the phosphor adopts a high-temperature solid-phase method, and comprises the following steps:

1) according to the general chemical formula Li₄M_1-0.5xSb_1-0.5xO₆:xMn⁴⁺The stoichiometric ratio of each element in the Li-ion-containing solution is respectively weighed⁺Compound of (2), Al containing aluminum ion³⁺Or gallium ion Ga³⁺Compound of (2), antimony ion-containing Sb⁵⁺Compound of (2), containing manganese ion Mn⁴⁺The compound of (1) is used as a reaction raw material;

2) mixing the reaction raw materials weighed in the step 1) with a proper amount of ethanol solution, and fully grinding to obtain a precursor;

3) heating and calcining the precursor obtained in the step 2) in the air atmosphere, naturally cooling to room temperature after the reaction is finished, taking out and grinding to obtain Mn⁴⁺Activated antimonate narrow-band red phosphor.

5. The method for preparing Mn4+ -activated antimonate narrow-band red phosphor according to claim 4, wherein the compound of lithium ion is one or more of lithium oxide, lithium carbonate and lithium hydroxide.

6. The method for preparing Mn4+ -activated antimonate narrow-band red phosphor according to claim 4, wherein the compound of aluminum ion is one or more of aluminum oxide, aluminum carbonate, aluminum hydroxide and aluminum nitrate.

7. The method for preparing Mn4+ -activated antimonate narrow-band red phosphor according to claim 4, wherein the compound of gallium ion is one or more of gallium oxide, gallium carbonate, gallium oxalate and gallium nitrate.

8. The method for preparing Mn4+ -activated antimonate narrow-band red phosphor according to claim 4, wherein the compound of antimony ions is one or two of antimony pentoxide and antimony trioxide.

9. The method for preparing Mn4+ -activated antimonate narrow-band red phosphor according to claim 4, wherein the compound of manganese ion is one or more of manganese carbonate, manganese nitrate, manganese acetate, manganese oxalate and manganese dioxide.

10. The method for preparing Mn4+ -activated antimonate narrow-band red phosphor according to claim 4, wherein the temperature rise and calcination temperature in step 3) is 850-1050 ℃, and the calcination time is 5-8 hours.

Background

Compared with the traditional incandescent lamp and fluorescent lamp as the illumination light source, the white light LED is known as a green solid-state illumination light source of a new generation due to the advantages of small volume, low energy consumption, long service life, no pollution and the like, and has very important application value and wide market prospect.

So far as the number of the conventional methods,the method for obtaining white light is the most mature and easy to realize method by using blue InGaN chip and commercial yellow fluorescent powder Y₃Al₅O₁₂:Ce³⁺(YAG:Ce³⁺) The principle of the composition is YAG to Ce³⁺The fluorescent powder absorbs part of blue light emitted by the chip and then emits yellow light which is mixed with the unabsorbed blue light to form white light. However, due to the lack of red component in the spectrum of the conversion technology, the color temperature and the color rendering index of the device are higher. The other scheme is that a near ultraviolet LED chip is used for exciting red, green and blue fluorescent powders, and light of the three fluorescent powders is mixed into white light so as to realize a higher color rendering index. Either implementation mode requires red fluorescent powder capable of emitting red light under the excitation of blue light or near ultraviolet light, so as to obtain warm white light with low color temperature and high color rendering index.

At present, the red phosphor is mainly realized by doping rare earth ions, such as typical commercial phosphor Sr₂Si₅N₈:Eu²⁺，CaAlSiN₃:Eu²⁺And the like. However, due to the fact that the re-absorption phenomenon is easy to occur and the synthesis conditions are harsh, researchers turn more attention to non-rare earth Mn⁴⁺Doped red phosphor. Transition metal ion Mn⁴⁺Having a unique 3d³Outer electronic configuration, Mn⁴⁺Doped phosphors typically exhibit characteristics of broadband absorption and narrow-band red emission. Wherein Mn is⁴⁺Doped fluoride red phosphors have received much attention because of their outstanding advantages of high luminous efficiency, high color purity, etc. However, such substances are synthesized mainly using a liquid phase method, and have low yield, and are unstable in physical properties using toxic HF. Therefore, there is a need to develop a new Mn that is simple to prepare and environmentally friendly⁴⁺Activated red phosphor.

Disclosure of Invention

In order to overcome the defects and shortcomings in the prior art and solve the bottleneck problem of the red light component of the current white light LED, the invention provides Mn capable of emitting red fluorescence when excited by excitation light sources such as ultraviolet light, near ultraviolet light or blue light and the like⁴⁺Activated antimonate narrow-band red fluorescent powder and preparation method thereofThe method is realized by the following technical scheme:

mn4+ activated antimonate narrow-band red phosphor powder, wherein the chemical general formula of the phosphor powder is Li₄M_{1- 0.5x}Sb_1-0.5xO₆:xMn⁴⁺；

Wherein M is at least one of Al and Ga, and x is Mn⁴⁺The mol ratio of doping is more than 0 and less than or equal to 0.03.

Further, the Mn⁴⁺The preferred range of the doping molar ratio x is 0.001 < x.ltoreq.0.01.

Further, the fluorescent powder emits narrow-band red fluorescence with the dominant wavelength of 673nm under the excitation of near ultraviolet to blue light with the wavelength of 250-550 nm.

A preparation method of Mn4+ -activated antimonate narrow-band red phosphor adopts a high-temperature solid-phase method, and comprises the following steps:

1) according to the general chemical formula Li₄M_1-0.5xSb_1-0.5xO₆:xMn⁴⁺The stoichiometric ratio of each element in the Li-ion-containing solution is respectively weighed⁺Compound of (2), Al containing aluminum ion³⁺Or gallium ion Ga³⁺Compound of (2), antimony ion-containing Sb⁵⁺Compound of (2), containing manganese ion Mn⁴⁺The compound of (1) is used as a reaction raw material;

2) mixing the reaction raw materials weighed in the step 1) with a proper amount of ethanol solution, and fully grinding to obtain a precursor;

3) heating and calcining the precursor obtained in the step 2) in the air atmosphere, naturally cooling to room temperature after the reaction is finished, taking out and grinding to obtain Mn⁴⁺Activated antimonate narrow-band red phosphor.

Further, the compound of the lithium ion is one or more of lithium oxide, lithium carbonate and lithium hydroxide.

Further, the compound of the aluminum ion is one or more of aluminum oxide, aluminum carbonate, aluminum hydroxide and aluminum nitrate.

Further, the compound of the gallium ion is one or more of gallium oxide, gallium carbonate, gallium oxalate and gallium nitrate.

Further, the compound of the antimony ions is one or two of antimony pentoxide and antimony trioxide.

Further, the compound of manganese ions is one or more of manganese carbonate, manganese nitrate, manganese acetate, manganese oxalate and manganese dioxide.

Further, the grinding time in the step 2) is 0.5-1 hour.

Further, the temperature rise calcination temperature in the step 3) is 850-1050 ℃, and the calcination time is 5-8 hours.

Compared with the prior art, the invention has the beneficial effects that:

1. the excitation wavelength of the fluorescent powder is in the near ultraviolet to blue light region of 250-550nm, and the fluorescent powder can be well matched with a commercial near ultraviolet or blue light LED chip.

2. The fluorescent powder can emit red fluorescence with the dominant wavelength of 673nm under the excitation of ultraviolet, near ultraviolet or blue light, and has narrow emission peak and high color purity.

3. The fluorescent powder provided by the invention has the advantages of simple preparation process, low synthesis temperature, stable chemical performance and no pollution, and has great practical value and application prospect in the field of fluorescent powder for white light LEDs.

Drawings

FIG. 1 is Li prepared in examples 2 and 5 of the present invention₄AlSbO₆:0.5％Mn⁴⁺And Li₄GaSbO₆:0.5％Mn⁴⁺X-ray diffraction pattern of the phosphor.

FIG. 2 is Li prepared in example 2 of the present invention₄AlSbO₆:0.5％Mn⁴⁺Excitation and emission spectrograms of the fluorescent powder.

FIG. 3 is Li prepared in example 5 of the present invention₄GaSbO₆:0.5％Mn⁴⁺Excitation and emission spectrograms of the fluorescent powder.

FIG. 4 is Li prepared in example 8 of the present invention₄(Al_0.5Ga_0.5)SbO₆:0.5％Mn⁴⁺Excitation and emission spectrograms of the fluorescent powder.

FIG. 5 is the present inventionLi prepared in inventive example 2₄AlSbO₆:0.5％Mn⁴⁺Scanning electron micrographs of the phosphors.

Detailed Description

In order to make the technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be described more clearly and completely with reference to the following embodiments. The examples do not show the specific conditions, and the reagents or apparatuses used are not shown in the manufacturers, and all of them are conventional products commercially available.

Example 1

According to Li₄Al_1-0.5xSb_1-0.5xO₆:0.3％Mn⁴⁺Accurately weighing the following raw materials in a stoichiometric ratio: 1.4778 grams of lithium carbonate, 0.5090 grams of alumina, 1.6152 grams of antimony pentoxide, and 0.0034 grams of manganese carbonate. The raw materials and a proper amount of ethanol solution are fully and uniformly ground in an agate mortar, and the obtained mixture is put into a muffle furnace to be heated to 950 ℃ under the air atmosphere for calcination for 7 hours. After calcining and sintering, naturally cooling to room temperature, taking out and grinding uniformly again to obtain Li₄AlSbO₆:0.3％Mn⁴⁺And (4) red fluorescent powder.

Example 2

According to Li₄Al_1-0.5xSb_1-0.5xO₆:0.5％Mn⁴⁺Accurately weighing the following raw materials in a stoichiometric ratio: 1.4778 grams of lithium carbonate, 0.5085 grams of alumina, 1.6136 grams of antimony pentoxide, and 0.0057 grams of manganese carbonate. The raw materials and a proper amount of ethanol solution are fully and uniformly ground in an agate mortar, and the obtained mixture is put into a muffle furnace to be heated to 1000 ℃ under the air atmosphere for calcination for 6 hours. After calcining and sintering, naturally cooling to room temperature, taking out and grinding uniformly again to obtain Li₄AlSbO₆:0.5％Mn⁴⁺And (4) red fluorescent powder.

Referring to the attached figure 1, the X-ray powder diffraction pattern of the sample prepared according to the technical scheme of the embodiment shows that the prepared sample has better crystallinity and is a single-phase material.

Referring to FIG. 2, it is the excitation and emission spectra of the sample prepared according to the technical scheme of this embodiment, when the monitoring wavelength is 673nm, the excitation spectral range of the sample is 250-550nm and the strongest absorption is at 467 nm; the sample emits narrow-band red fluorescence with a dominant wavelength of 673nm under excitation of blue light with a wavelength of 467 nm.

Referring to FIG. 5, it is a scanning electron micrograph of a sample prepared according to the technical scheme of this example, the sample presents an irregular block structure, and the particle size is in micron level; the surface of the sample is relatively smooth, which indicates that the crystallinity is good.

Example 3

According to Li₄Al_1-0.5xSb_1-0.5xO₆:0.7％Mn⁴⁺Accurately weighing the following raw materials in a stoichiometric ratio: 1.4778 g of lithium carbonate, 0.5080 g of alumina, 1.6119 g of antimony pentoxide and 0.0080 g of manganese carbonate. The raw materials and a proper amount of ethanol solution are fully and uniformly ground in an agate mortar, and the obtained mixture is put into a muffle furnace to be heated to 1050 ℃ under the air atmosphere for calcination for 5 hours. After calcining and sintering, naturally cooling to room temperature, taking out and grinding uniformly again to obtain Li₄AlSbO₆:0.7％Mn⁴⁺And (4) red fluorescent powder.

Example 4

According to Li₄Ga_1-0.5xSb_1-0.5xO₆:0.3％Mn⁴⁺Accurately weighing the following raw materials in a stoichiometric ratio: 1.4778 grams of lithium carbonate, 0.9358 grams of gallium oxide, 1.6152 grams of antimony pentoxide, and 0.0034 grams of manganese carbonate. The raw materials and a proper amount of ethanol solution are fully and uniformly ground in an agate mortar, and the obtained mixture is put into a muffle furnace to be heated to 850 ℃ under the air atmosphere for calcination for 8 hours. After calcining and sintering, naturally cooling to room temperature, taking out and grinding uniformly again to obtain Li₄GaSbO₆:0.3％Mn⁴⁺And (4) red fluorescent powder.

Example 5

According to Li₄Ga_1-0.5xSb_1-0.5xO₆:0.5％Mn⁴⁺Accurately weighing the following raw materials in a stoichiometric ratio: 1.4778 g lithium carbonate, 0.9349 g gallium oxide, 1.6136 g pentaAntimony oxide and 0.0057 grams of manganese carbonate. The raw materials and a proper amount of ethanol solution are fully and uniformly ground in an agate mortar, and the obtained mixture is put into a muffle furnace to be heated to 900 ℃ under the air atmosphere for calcination for 7 hours. After calcining and sintering, naturally cooling to room temperature, taking out and grinding uniformly again to obtain Li₄GaSbO₆:0.5％Mn⁴⁺And (4) red fluorescent powder.

Referring to the attached figure 1, the X-ray powder diffraction pattern of the sample prepared according to the technical scheme of the embodiment shows that the prepared sample has better crystallinity and is a single-phase material.

Referring to FIG. 3, it is the excitation and emission spectrum of the sample prepared according to the technical scheme of this embodiment, when the monitoring wavelength is 673nm, the excitation spectrum range of the sample is 250-550nm and the strongest absorption is at 467 nm; the sample emits narrow-band red fluorescence with a dominant wavelength of 673nm under excitation of blue light with a wavelength of 467 nm.

Example 6

According to Li₄Ga_1-0.5xSb_1-0.5xO₆:0.7％Mn⁴⁺Accurately weighing the following raw materials in a stoichiometric ratio: 1.4778 g lithium carbonate, 0.9339 g gallium oxide, 1.6119 g antimony pentoxide and 0.0080 g manganese carbonate. The raw materials and a proper amount of ethanol solution are fully and uniformly ground in an agate mortar, and the obtained mixture is put into a muffle furnace to be heated to 950 ℃ under the air atmosphere for calcination for 6 hours. After calcining and sintering, naturally cooling to room temperature, taking out and grinding uniformly again to obtain Li₄GaSbO₆:0.7％Mn⁴⁺And (4) red fluorescent powder.

Example 7

According to Li₄(Al_0.3Ga_0.7)_1-0.5xSb_1-0.5xO₆:0.5％Mn⁴⁺Accurately weighing the following raw materials in a stoichiometric ratio: 1.4778 grams of lithium carbonate, 0.1526 grams of alumina, 0.6544 grams of gallium oxide, 1.6136 grams of antimony pentoxide, and 0.0057 grams of manganese carbonate. The raw materials and a proper amount of ethanol solution are fully and uniformly ground in an agate mortar, and the obtained mixture is put into a muffle furnace to be heated to 850 ℃ under the air atmosphere for calcination for 6 hours. Calcining and sinteringAfter that, after the mixture is naturally cooled to room temperature, the mixture is taken out and ground again to obtain Li₄(Al_0.3Ga_0.7)SbO₆:0.5％Mn⁴⁺And (4) red fluorescent powder.

Example 8

According to Li₄(Al_0.5Ga_0.5)_1-0.5xSb_1-0.5xO₆:0.5％Mn⁴⁺Accurately weighing the following raw materials in a stoichiometric ratio: 1.4778 grams of lithium carbonate, 0.2543 grams of alumina, 0.4675 grams of gallium oxide, 1.6136 grams of antimony pentoxide, and 0.0057 grams of manganese carbonate. The raw materials and a proper amount of ethanol solution are fully and uniformly ground in an agate mortar, and the obtained mixture is put into a muffle furnace to be heated to 900 ℃ under the air atmosphere for calcination for 6 hours. After calcining and sintering, naturally cooling to room temperature, taking out and grinding uniformly again to obtain Li₄(Al_0.5Ga_0.5)SbO₆:0.5％Mn⁴⁺And (4) red fluorescent powder.

Referring to FIG. 4, it is the excitation and emission spectrum of the sample prepared according to the technical scheme of this embodiment, when the monitoring wavelength is 673nm, the excitation spectrum range of the sample is 250-550nm and the strongest absorption is at 467 nm; the sample emits narrow-band red fluorescence with a dominant wavelength of 673nm under excitation of blue light with a wavelength of 467 nm.

Example 9

According to Li₄(Al_0.7Ga_0.3)_1-0.5xSb_1-0.5xO₆:0.5％Mn⁴⁺Accurately weighing the following raw materials in a stoichiometric ratio: 1.4778 grams of lithium carbonate, 0.3560 grams of alumina, 0.2805 grams of gallium oxide, 1.6136 grams of antimony pentoxide, and 0.0057 grams of manganese carbonate. The raw materials and a proper amount of ethanol solution are fully and uniformly ground in an agate mortar, and the obtained mixture is put into a muffle furnace to be heated to 950 ℃ under the air atmosphere for calcination for 6 hours. After calcining and sintering, naturally cooling to room temperature, taking out and grinding uniformly again to obtain Li₄(Al_0.7Ga_0.3)SbO₆:0.5％Mn⁴⁺And (4) red fluorescent powder.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solutions of the present application and not to limit them; although the present application has been described in detail with reference to preferred embodiments, those of ordinary skill in the art will understand that: modifications to the embodiments of the present application or equivalent replacements of some technical features may still be made, which should all be covered by the scope of the technical solution claimed in the present application.