Anti-deterioration red fluorescent powder, and preparation method therefor and use thereof

Abstract

The present invention relates to an anti-deterioration red fluorescent powder, and a preparation method therefor and the use thereof, and belongs to the technical field of fluorescent powder materials. The anti-deterioration red fluorescent powder has a core-shell structure, and the core-shell structure comprises an inner core and an outer shell, wherein the inner core and the outer shell are independently selected from substances shown in chemical formula I: chemical formula I: A2M(1-x)F6:xMn4+. By controlling the atomic percent of Mn4+ to be the lowest in the innermost layer of the inner core and the highest in the outermost layer of the inner core, and arranging the outer shell having an extremely low content of Mn4+ or even without same to coat the inner core of the fluorescent powder in cooperation, the moisture resistance and anti-deterioration property of the fluorescent powder are improved, and also favorably keeps a relatively high light-emitting efficiency in cooperation with the inner core.

Description

A kind of anti-degradation red phosphor and its preparation method and application

[0001] This application claims priority to Chinese patent application No. 2023107245653, filed on June 25, 2023, entitled “A Degradation-Resistant Red Phosphor, Preparation Method and Application Thereof,” the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present application relates to a degradation-resistant red phosphor and a preparation method and application thereof, belonging to the technical field of phosphor materials. Background Art

[0003] In LED lighting, phosphor is typically dispersed with silica gel and then applied to the LED package's support cup by spin-coating. During application, excitation light emitted from the blue chip is absorbed by the phosphor in the LED package. The phosphor then emits light through reflection and refraction. However, when the excitation light strikes the phosphor surface, it scatters, reducing some of the phosphor's light efficiency.

[0004] High-efficiency red phosphors should meet the following conditions: 1) strong absorption around 450nm, 2) narrow emission around 630nm, and 3) smaller emission above 650nm. 4+ The fluorescent material has an emission spectrum that meets this characteristic, and the color rendering index CRI is greater than 90, and its luminous efficiency is significantly better than that of traditional red nitride phosphors. 2- The surface of the group is hydrolyzed, and the moisture resistance of the fluoride phosphor is poor, which causes the corresponding LED packaging device to easily deteriorate in performance during long-term service.

[0005] The prior art proposes a tetravalent Mn-doped fluoride phosphor with a core-shell structure, which is treated with a reducing agent to treat the surface of the phosphor particles. 4+ Activation center failure treatment, after treatment, the phosphor particles are closer to the shell Mn from the inside to the outside 4+ Although this method improves the moisture resistance of the phosphor to a certain extent, it will have a negative impact on the luminous efficiency of the phosphor.

[0006] Summary of the Invention

[0007] In response to the shortcomings of the existing technology, the present application provides a degradation-resistant red phosphor and its preparation method and application. It adopts a core-shell structure, controls the activator concentration to be lowest in the innermost layer of the core and highest in the outermost layer of the core, and sets a shell with very little or no activator content to cover the phosphor core, thereby improving the moisture resistance and degradation resistance of the phosphor, and at the same time, cooperating with the core to maintain a high luminous efficiency.

[0008] The first object of this application is to provide a red phosphor that is resistant to degradation, and the technical solution adopted is as follows:

[0009] A red phosphor with an anti-degradation property, wherein the red phosphor has a core-shell structure, wherein the core-shell structure comprises a core and an outer shell, wherein the core and the outer shell are independently selected from the substances shown in Chemical Formula I: A2M (1-x) F6:xMn 4+ In the chemical formula I, A comprises at least one of Li, Na, K, Rb, and Cs, and M comprises at least one of Si, Ge, and Ti; wherein the innermost layer of the core is Mn 4+ The atomic percentage of the outermost layer of the core is a. 4+ The atomic percentage of Mn in the inner part of the core particle is b, b>a; 4+ The atomic percentage of Mn in the shell is x1, and the value range of x is a≤x1≤b; 4+ The atomic percentage of x2 is x2, and the value range of x2 is 0≤x2≤0.1%. The phosphor powder in this application is granular, and the innermost layer of the core refers to the central layer inside the phosphor powder particle, which is also Mn 4+ The outermost layer of the core refers to the Mn in the phosphor. 4+ The outer shell refers to the portion of the phosphor other than the outermost layer of the core, that is, the portion from the outermost layer of the core to the outer surface of the phosphor. 4+ The atomic percentage of Mn is lowest in the innermost layer of the core and highest in the outermost layer, which reduces the concentration of the activator in the center of the phosphor core, which is beneficial to suppress the thermal quenching effect and improve thermal stability. In addition, the concentration of the activator ions on the core surface is increased, thereby increasing the absorption rate of the phosphor to the excitation light, thereby suppressing the scattering effect, which is beneficial to improve the luminous efficiency of the corresponding LED device. By setting Mn 4+ The shell with a very small content covers the phosphor core, avoiding the contact of the luminescent center with the external environment, improving the moisture resistance and anti-degradation ability of the phosphor. At the same time, it does not affect the luminous efficiency of the phosphor when combined with the core, which is beneficial for the phosphor to maintain a high luminous intensity during long-term service.

[0010] Furthermore, in the shell, the value range of x2 is 0≤x2≤0.05%, so as to further improve the moisture resistance and degradation resistance of the phosphor particles.

[0011] Preferably, x1 shows an increasing trend from the inside to the outside in the radial direction of the core. In this application, x1 shows an increasing trend from the inside to the outside in the radial direction refers to the inside of the phosphor particles, Mn 4+The content of Mn increases from the inside to the outside in the radial direction. That is to say, with the distance from the innermost layer in the radial direction as the horizontal axis, the Mn 4+ The correlation curve drawn with the content as the vertical axis shows an increasing trend. However, in the radial direction of the phosphor particles, from the inner to the outer adjacent layers, Mn 4+ The atomic percentage of Mn may increase, decrease or remain unchanged. 4+ The atomic percentage of Mn increases from the inside to the outside in the radial direction of the core, ensuring that the innermost and outermost layers of the phosphor core are 4+ Content relationship, while the Mn inside the core 4+ The content transitions smoothly from the inside to the outside in the radial direction, which ensures the absorption efficiency of the inner core to the excitation light and is beneficial to promoting the improvement of the luminous efficiency of the phosphor particles.

[0012] Preferably, the increasing trend is that x1 increases linearly and uniformly from the inside to the outside in the radial direction of the core. In this application, linear and uniform increase means that Mn increases linearly and uniformly from the inside to the outside in the radial direction of the core. 4+ The atomic percentage of Mn in the core maintains the same linear growth trend. 4+ The atomic percentage of Mn increases linearly and evenly, so that the closer the phosphor particles are to the outermost layer of the core, the 4+ The higher the concentration of Mn 4+ The content shows a uniformly increasing distribution trend on the core, which enables the phosphor to fully absorb the excitation light and improve the conversion efficiency of the phosphor, which is conducive to further improving the luminous efficiency of the phosphor.

[0013] Preferably, in the kernel, the value range of a is 0≤a≤0.1%, and the value range of b is 0.3%≤b≤5%. 4+ The atomic percentage range of Mn 4+ The content distribution from the innermost layer to the outermost layer of the core ensures the activator concentration on the surface and inside of the core, which is beneficial to improving the absorption efficiency of the phosphor.

[0014] Preferably, in the inner core, 0.2%≤(ba)≤5%, more preferably 0.5%≤(ba)≤2%.

[0015] Illustratively, the value range of a is 0≤a≤0.01%, and the value range of b is 0.5%≤b≤1.5%.

[0016] Preferably, in the kernel, the value of a is 0, and the value range of b is 0.7%≤b≤1%. For example, in the kernel, the value of a is 0, and the value range of b is 0.7%≤b≤0.85%.

[0017] Preferably, in the phosphor, b>x2.

[0018] Preferably, in the phosphor, 0≤x2 / b≤1 / 10.

[0019] Preferably, the average particle size of the anti-degradation red phosphor is 5 to 40 μm. For example, the average particle size of the anti-degradation red phosphor is 25 to 40 μm.

[0020] Preferably, the average thickness of the shell is 0.1-2 μm. Using a shell with this average thickness can improve the moisture resistance and degradation resistance of the phosphor while avoiding scattering of the excitation light, which is conducive to promoting the core to fully exert its light effect.

[0021] The second object of this application is to provide a method for preparing a degradation-resistant red phosphor, the technical solution adopted is as follows:

[0022] A method for preparing any of the above-mentioned degradation-resistant red phosphors comprises the following steps: 1) dissolving a salt A in a hydrofluoric acid solution, referred to as base solution A; 2) dissolving a series of K2MnF6 in equal masses of H2MF6 solutions to prepare a series of BX solutions having different K2MnF6 concentrations; 3) sequentially adding the series of BX solutions to the base solution A, controlling the K2MnF6 concentration of the first BX solution added to be the lowest and the K2MnF6 concentration of the last BX solution added to be the highest, thereby obtaining a core mixture system for preparing the core; and then adding H2MF6 solution to the core mixture system to prepare the outer shell, thereby obtaining the degradation-resistant red phosphor. The salt A is selected from at least one of fluoride, bifluoride, sulfate, nitrate, bisulfate, carbonate, and bicarbonate of A, and A is selected from any one of Li, Na, K, Rb, and Cs. In the H2MF6, M is selected from any one of Si, Ge, and Ti. In this application, K2MnF6 and H2MF6 solutions are used to prepare a series of BX solutions with increasing K2MnF6 concentrations, which react instantly when mixed with the base solution A to prepare A2MF6:Mn 4+ Precipitation, by controlling the concentration of K2MnF6 added to the BX solution for the first and last time, Mn 4+ The atomic percentage is lowest in the innermost layer of the core and highest in the outermost layer, which is beneficial to improving the overall thermal stability and luminous efficiency of the phosphor; then H2MF6 is reacted with the base liquid A solution to prepare the outer shell, which improves the moisture resistance and anti-degradation ability of the phosphor without affecting the luminous efficiency of the phosphor.

[0023] Preferably, step 3) adding the series of BX solutions to the base solution A in sequence is to add the series of BX solutions to the base solution A in sequence according to the order of increasing K2MnF6 concentration. In this application, the series of BX solutions are added in sequence according to the order of increasing K2MnF6 concentration to obtain the activator Mn4+ The atomic percentage of the core increases radially from the inside to the outside, further improving the absorption rate of the phosphor to the excitation light.

[0024] Preferably, in step 2), the series of K2MnF6 is obtained by sequentially taking K2MnF6 with a mass increasing in an arithmetic progression. 4+ The atomic percentage of the phosphor increases linearly and uniformly from the inside to the outside in the radial direction, which is beneficial to improving the absorption effect and conversion efficiency of the phosphor to the excitation light. Optionally, the tolerance of the mass increasing in an arithmetic progression is 0.1 to 0.3 g.

[0025] Preferably, the mass concentration of the H2MF6 solution is 10-15%; and the mass of K2MnF6 used in the series BX solutions is 0-3g for every 5-7.5g H2MF6.

[0026] Preferably, the mass concentration of the hydrofluoric acid solution is 35-55%; in the base solution A, the volume of the hydrofluoric acid solution used for every 15-25 g of salt A is 200-300 mL.

[0027] Preferably, the mass of the series of BX solutions added in step 3) is 100-1300 g; the mass of the H2MF6 solution added to the core mixing system is 5-200 g.

[0028] Preferably, the series of BX solutions and H2MF6 solutions are stirred at 10-50°C during the addition process, and after the stirring is completed, the supernatant is removed for washing and drying.

[0029] Preferably, the addition rate of the series of BX solutions and H2MF6 solutions is 10-50 mL / s; and the stirring time is 2-5 h.

[0030] Preferably, in the salt A, A is element K, i.e., salt A is a potassium salt. Alternatively, salt A is potassium bifluoride.

[0031] Furthermore, the mass concentration of the hydrofluoric acid solution is 40% to 55%.

[0032] Preferably, in the H2MF6, M is Si, and the H2MF6 solution is a H2SiF6 solution, that is, a fluorosilicic acid solution.

[0033] The third object of the present invention is to provide an application of any one of the above-mentioned degradation-resistant red phosphors or the degradation-resistant red phosphors prepared by any one of the above-mentioned preparation methods in the field of liquid crystal backlight or LED lighting.

[0034] The fourth object of the present invention is to provide a liquid crystal backlight source, comprising an excitation chip and a phosphor coated on the excitation chip; the phosphor is any one of the above-mentioned anti-degradation red phosphors; or, the phosphor is an anti-degradation red phosphor prepared by any one of the above-mentioned preparation methods.

[0035] The fifth object of the present invention is to provide a lighting device, characterized in that it includes a light-emitting device; the light-emitting device includes an excitation chip and a phosphor coated on the excitation chip; the phosphor is any one of the above-mentioned anti-degradation red phosphors; or, the phosphor is an anti-degradation red phosphor prepared by any one of the above-mentioned preparation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] FIG1 is a schematic diagram showing the radial distribution of the relative content of Mn4+ in the anti-degradation red phosphor particles of Examples 1 to 5;

[0037] FIG2 is an SEM image of phosphor particles before cutting in a specific embodiment, wherein the left side is a top view SEM image of the phosphor particles; the right side is a 45° side SEM image of the phosphor particles after cutting to reveal a fresh cross section;

[0038] FIG3 is a position diagram of an EDS point scanning analysis of the anti-degradation red phosphor particles of Example 1;

[0039] FIG4 is a position diagram of an EDX line scan analysis of the anti-degradation red phosphor particles of Example 5;

[0040] FIG. 5 is an EDX line scan analysis result of the anti-degradation red phosphor particles of Example 5. FIG. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of this application more clear, the following is a further detailed description of this application in conjunction with specific embodiments. It should be understood that the following embodiments are only exemplary embodiments used to illustrate the principles of this application, namely, the red phosphor A2M (1-x) F6:xMn 4+ , A and M are preferably K and Si, respectively, and the synthetic raw materials are preferably potassium bifluoride, fluosilicic acid, etc., but the present invention is not limited thereto. Those skilled in the art may make various modifications and improvements without departing from the spirit and essence of the present invention, and such modifications and improvements are also considered to be within the scope of protection of the present invention.

[0042] For simplicity, this application only explicitly discloses certain numerical ranges. However, any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, and similarly, any upper limit can be combined with any other upper limit to form an unspecified range. In addition, although not explicitly stated, unless otherwise specified, each point or individual value between the endpoints of a range is included in the range. Thus, each point or individual value can serve as its own lower limit or upper limit and be combined with any other point or individual value, or with other lower limits or upper limits, to form an unspecified range.

[0043] K2SiF6:Mn 4+ Red phosphors offer the advantage of high luminous efficacy compared to traditional red phosphors, but their poor moisture resistance can easily lead to performance degradation, impacting their effectiveness in LED lighting applications. While improving the moisture resistance of existing red phosphors inevitably negatively impacts luminous efficiency, a red phosphor with both high moisture resistance and high luminous efficiency is urgently needed.

[0044] In order to solve the above problems, the present application provides a degradation-resistant red phosphor, which has a core-shell structure. The core-shell structure includes a core and an outer shell. The core and the outer shell are independently selected from the substances shown in Chemical Formula I. Chemical Formula I: A2M (1-x) F6:xMn 4+ In the chemical formula I, A comprises at least one of Li, Na, K, Rb, and Cs, and M comprises at least one of Si, Ge, and Ti; wherein the innermost layer of the core is Mn 4+ The atomic percentage of the outermost layer of the core is a. 4+ The atomic percentage of Mn in the inner part of the core particle is b, b>a; 4+ The atomic percentage of Mn in the shell is x1, and the value range of x is a≤x1≤b; 4+ The atomic percentage is x2, and the value range of x2 is 0≤x2≤0.1%.

[0045] Illustratively, in Chemical Formula I, 0<x≤0.05.

[0046] In some embodiments, x1 exhibits an increasing trend from the innermost to the outermost direction of the core. In this application, "from the innermost to the outermost direction of the core" refers to the direction from the innermost core layer to the point on the outermost core layer closest to the innermost core layer. The innermost core layer refers to the first core layer formed during the preparation of the anti-degradation red phosphor, specifically, the first core layer formed by the reaction of the base solution A with the initially added BX solution. In the phosphor particles of this application, the innermost core layer is located in the region with the lowest activator concentration.

[0047] In some specific embodiments, the core is divided into n layers from the inside to the outside in the radial direction, where n is an integer and the value range of n is 5≤n≤20; in the same layer, Mn 4+ The atomic percentage of Mn is the same, and the different layers are radially from the inside to the outside of the core. 4+ The atomic percentage showed an increasing trend.

[0048] In some specific embodiments, the lower limit of n is selected from any value of 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, and 19; the upper limit of n is selected from any value of 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, and 20; and the value range of n is selected from the range consisting of any value selected from the lower limit and the upper limit.

[0049] In some specific embodiments, the increasing trend is that x1 increases linearly or nonlinearly from the inside to the outside in the radial direction of the core.

[0050] In some specific embodiments, the increasing trend is that x1 increases linearly and uniformly from the inside to the outside in the radial direction of the core. 4+ The atomic percentage of Mn maintains the same linear growth trend, for example, in Example 1 in FIG1 4+ The growth trend of relative content, that is, the Mn between any two adjacent layers of the core 4+ The increasing trend of the atomic percentage is the same.

[0051] The present application also provides a method for preparing a degradation-resistant red phosphor, which is used to prepare any of the above-mentioned degradation-resistant red phosphors, comprising the following steps: 1) dissolving salt A in a hydrofluoric acid solution, which is referred to as base solution A; 2) dissolving a series of K2MnF6 in H2MF6 solutions of equal mass to prepare a series of BX solutions with different K2MnF6 concentrations; 3) sequentially adding the series of BX solutions to the base solution A, controlling the K2MnF6 concentration of the first added BX solution to be the lowest and the K2MnF6 concentration of the last added solution to be the highest. The BX solution added has the highest K2MnF6 concentration, thereby obtaining a core mixed system for preparing a core; then, an H2MF6 solution is added to the core mixed system to prepare a shell, thereby obtaining the anti-degradation red phosphor; the A salt is selected from at least one of A's fluoride, hydrogen fluoride, sulfate, nitrate, hydrogen sulfate, carbonate, and hydrogen carbonate, and A is selected from any one of Li, Na, K, Rb, and Cs; and in the H2MF6, M is selected from any one of Si, Ge, and Ti.

[0052] In some exemplary embodiments, the fluoride of A can be selected from any one of lithium fluoride, sodium fluoride, potassium fluoride, rubidium fluoride, and cesium fluoride; the hydrogen fluoride salt of A can be selected from any one of LiHF2, NaHF2, KHF2, RbHF2, and CsHF2; the sulfate of A can be selected from any one of Li2SO4, Na2SO4, K2SO4, Rb2SO4, and Cs2SO4; the nitrate of A can be selected from any one of LiNO3, NaNO3, KNO3, Any one of RbNO3 and CsNO3; the bisulfate of A can be selected from any one of LiHSO4, NaHSO4, KHSO4, RbHSO4, and CsHSO4; the carbonate of A can be selected from any one of Li2CO3, Na2CO3, K2CO3, Rb2CO3, and Cs2CO3; the bicarbonate of A can be selected from any one of LiHCO3, NaHCO3, KHCO3, RbHCO3, and CsHCO3.

[0053] In some exemplary embodiments, H2MF6 may be selected from any one of H2SiF6, H2GeF6, and H2TiF6.

[0054] In some embodiments, step 3) sequentially adding the series of BX solutions to the base solution A is adding the series of BX solutions to the base solution A in order of increasing K2MnF6 concentrations.

[0055] In some specific embodiments, step 2) takes a series of K2MnF6 with masses of a1, a2, a3, ..., a n K2MnF6 raw materials; a1, a2, a3, ..., a n They show an increasing trend in sequence, n is an integer and the value range of n is 5≤n≤20.

[0056] In some specific embodiments, the value range of n is 10≤n≤20.

[0057] In some specific embodiments, the masses are respectively a1, a2, a3, ..., a n The K2MnF6 raw materials were dissolved in H2MF6 solution, and the prepared series of BX solutions with increasing K2MnF6 concentration were recorded as BX1, BX2, BX3, ..., BX n ;BX1, BX2, BX3,…,BX n The concentration of K2MnF6 in the solution showed an increasing trend.

[0058] In some specific embodiments, the value range of a1 is 0≤a1≤0.01g; when a1 is 0, it means that the mass of K2MnF6 increases from 0, and the K2MnF6 concentration of the BX1 solution in the prepared series of BX solutions is 0.

[0059] In some specific embodiments, the series of BX solutions are added to the base solution A in increasing order of concentration to prepare BX1 to BX n The solutions are sequentially added to the base liquid A solution, and reacted sequentially to prepare an inner core. The inner core is divided into n layers from the inside to the outside in the radial direction. Each time the BX solution is added, it reacts with the base liquid A solution to form a layer of the inner core.

[0060] In some specific embodiments, the masses of the BX solution and the H2MF6 in the H2MF6 solution added each time in step 3) are the same; and the number of times the H2MF6 solution is added to the core mixing system is 1 to 5 times.

[0061] In some specific embodiments, a n The value range is 2.5g≤a n ≤3g.

[0062] In some specific embodiments, the mass concentration of the H2MF6 solution is 10-15%; the mass of the H2MF6 solution is 40-60 g, for example, the mass of the H2MF6 solution is 50 g.

[0063] In some specific embodiments, the mass of the A salt is 15-25 g.

[0064] In some specific embodiments, the mass concentration of the hydrofluoric acid solution is 35-55%; the volume of the hydrofluoric acid solution is 200-300 mL, for example, the volume of the hydrofluoric acid solution is 250 mL.

[0065] In some specific embodiments, the washing is performed by sequentially adding an HF aqueous solution and anhydrous ethanol for stirring and washing; the mass concentration of the HF aqueous solution is 3-10%.

[0066] In some specific embodiments, the drying is performed at 50-70°C.

[0067] Example

[0068] The technical solutions of the present application are described below with reference to specific embodiments. The raw materials used in the following embodiments are all from common commercially available products, and the devices or equipment used are all purchased from conventional market sales channels.

[0069] Example 1

[0070] The anti-degradation red phosphor of this embodiment has a core-shell structure, which includes a core and an outer shell. The core and the outer shell are independently selected from substances shown in Chemical Formula I. Chemical Formula I: K2Si (1-x) F6:xMn 4+ ; Wherein, the Mn 4+ The atomic percentage of Mn in the shell is x1, and x1 shows a linear uniform increasing trend from the inside to the outside in the radial direction of the core, and the value range of x1 is 0≤x1≤0.77%; 4+ The atomic percentage of x2 is x2, and the value range of x2 is 0≤x2≤0.01%. The average particle size of the anti-degradation red phosphor of this embodiment is 30 μm, wherein the average thickness of the shell is 1.8 μm.

[0071] The method for preparing the degradation-resistant red phosphor of this embodiment includes the following steps:

[0072] 1) Dissolve 21 g of KHF2 in 250 mL of 40% hydrofluoric acid solution to prepare base solution A;

[0073] 2) Take a series of K2MnF6 and dissolve them in 50g of 10% fluosilicic acid solution in ascending order of mass to prepare a series of BX solutions with increasing K2MnF6 concentrations;

[0074] 3) Add the series of BX solutions to the base solution A in increasing order of concentration, and the number of additions is recorded as A1, A2, A3, ..., A 16 , obtain a core mixed system for preparing the core; then add 50g of 10% fluosilicic acid solution by mass to the core mixed system three times, the number of additions is recorded as A 17 、A 18 、A 19 , used to prepare the shell (addition times A1~A 19 The mass of the K2MnF6 raw material contained in the solution is shown in Table 1 below); the series of BX solutions and fluorosilicic acid solutions were stirred at 40°C during the addition process. After stirring for 2 hours, the supernatant was poured out, and a 5% by mass HF aqueous solution was added and stirred and washed twice. The mixture was then washed twice with anhydrous ethanol and then dried under a forced air drying condition at 60°C to obtain the anti-degradation red phosphor of the present application.

[0075] Example 2

[0076] The anti-degradation red phosphor of this embodiment has a core-shell structure, which includes a core and an outer shell. The core and the outer shell are independently selected from substances shown in Chemical Formula I. Chemical Formula I: K2Si (1-x)F6:xMn 4+ ; Wherein, the Mn 4+ The atomic percentage of Mn in the shell is x1, and x1 shows an increasing trend from the inside to the outside in the radial direction of the core, and the value range of x1 is 0≤x1≤0.80%; 4+ The atomic percentage of x2 is x2, and the value range of x2 is 0≤x2≤0.01%. The average particle size of the anti-degradation red phosphor of this embodiment is 30 μm, wherein the average thickness of the shell is 1.8 μm.

[0077] The method for preparing the degradation-resistant red phosphor of this embodiment differs from that of Example 1 only in that: Step 2) additional K2MnF6 raw materials of increasing mass are prepared into a series of BX solutions, and Step 3) the mass of the K2MnF6 raw materials contained in the series of BX solutions is shown in Table 1 below.

[0078] Example 3

[0079] The anti-degradation red phosphor of this embodiment has a core-shell structure, which includes a core and an outer shell. The core and the outer shell are independently selected from substances shown in Chemical Formula I. Chemical Formula I: K2Si (1-x) F6:xMn 4+ ; Wherein, the Mn 4+ The atomic percentage of Mn in the shell is x1, and x1 shows an increasing trend from the inside to the outside in the radial direction of the core, and the value range of x1 is 0≤x1≤0.82%; 4+ The atomic percentage of x2 is x2, and the value range of x2 is 0≤x2≤0.02%. The average particle size of the anti-degradation red phosphor of this embodiment is 30 μm, wherein the average thickness of the shell is 1.8 μm.

[0080] The method for preparing the degradation-resistant red phosphor of this embodiment differs from that of Example 1 only in that: Step 2) additional K2MnF6 raw materials of increasing mass are prepared into a series of BX solutions, and Step 3) the mass of the K2MnF6 raw materials contained in the series of BX solutions is shown in Table 1 below.

[0081] Example 4

[0082] The anti-degradation red phosphor of this embodiment has a core-shell structure, which includes a core and an outer shell. The core and the outer shell are independently selected from substances shown in Chemical Formula I. Chemical Formula I: K2Si (1-x) F6:xMn 4+ ; Wherein, the Mn 4+The atomic percentage of Mn in the shell is x1, and x1 shows an increasing trend from the inside to the outside in the radial direction of the core, and the value range of x1 is 0≤x1≤0.79%; 4+ The atomic percentage of x2 is x2, and the value range of x2 is 0≤x2≤0.01%. The average particle size of the anti-degradation red phosphor of this embodiment is 30 μm, wherein the average thickness of the shell is 1.8 μm.

[0083] The method for preparing the degradation-resistant red phosphor of this embodiment differs from that of Example 1 only in that: Step 2) additional K2MnF6 raw materials of increasing mass are prepared into a series of BX solutions, and Step 3) the mass of the K2MnF6 raw materials contained in the series of BX solutions is shown in Table 1 below.

[0084] Example 5

[0085] The anti-degradation red phosphor of this embodiment has a core-shell structure, which includes a core and an outer shell. The core and the outer shell are independently selected from substances shown in Chemical Formula I. Chemical Formula I: K2Si (1-x) F6:xMn 4+ ; Wherein, the Mn 4+ The atomic percentage of Mn in the shell is x1, and x1 shows an increasing trend from the inside to the outside in the radial direction of the core, and the value range of x1 is 0≤x1≤0.81%; 4+ The atomic percentage of x2 is x2, and the value range of x2 is 0≤x2≤0.02%. The average particle size of the anti-degradation red phosphor of this embodiment is 30 μm, wherein the average thickness of the shell is 1.8 μm.

[0086] The method for preparing the degradation-resistant red phosphor of this embodiment differs from that of Example 1 only in that: Step 2) additional K2MnF6 raw materials of increasing mass are prepared into a series of BX solutions, and Step 3) the mass of the K2MnF6 raw materials contained in the series of BX solutions is shown in Table 1 below.

[0087] Example 6

[0088] The anti-degradation red phosphor of this embodiment has a core-shell structure, which includes a core and an outer shell. The core and the outer shell are independently selected from substances shown in Chemical Formula I. Chemical Formula I: K2Si (1-x) F6:xMn 4+ Among them, the Mn in the innermost layer of the phosphor core 4+ The atomic percentage is 0, and the outermost layer of the core is Mn 4+ The atomic percentage is 0.77%, and the Mn 4+The atomic percentage of the outer shell is x1, and x1 is randomly distributed from the inside to the outside of the inner core radial direction except for the innermost layer and the outermost layer of the inner core, and the value range of x1 is 0≤x1≤0.77%; the outer shell Mn 4+ The atomic percentage of x2 is x2, and the value range of x2 is 0≤x2≤0.01%. The average particle size of the anti-degradation red phosphor of this embodiment is 30 μm, wherein the average thickness of the shell is 1.8 μm.

[0089] The method for preparing the degradation-resistant red phosphor of this embodiment differs from that of Example 1 only in that: Step 2) K2MnF6 raw material is used to prepare a series of BX solutions, and Step 3) the mass of the K2MnF6 raw material contained in the series of BX solutions is shown in Table 1 below.

[0090] Example 7

[0091] The anti-degradation red phosphor of this embodiment has a core-shell structure, which includes a core and an outer shell. The core and the outer shell are independently selected from substances shown in Chemical Formula I. Chemical Formula I: K2Si (1-x) F6:xMn 4+ Among them, the Mn in the innermost layer of the phosphor core 4+ The atomic percentage is 0, and the outermost layer of the core is Mn 4+ The atomic percentage is 5%, and the Mn 4+ The atomic percentage of Mn in the shell is x1, and x1 shows a linear uniform increasing trend from the inside to the outside in the radial direction, and the value range of x1 is 0≤x1≤5%; 4+ The atomic percentage is x2, and the value range of x2 is 0≤x2≤0.1%.

[0092] Example 8

[0093] The anti-degradation red phosphor of this embodiment has a core-shell structure, which includes a core and an outer shell. The core and the outer shell are independently selected from substances shown in Chemical Formula I. Chemical Formula I: K2Si (1-x) F6:xMn 4+ Among them, the Mn in the innermost layer of the phosphor core 4+ The atomic percentage is 0.1%, and the outermost layer of the core is Mn 4+ The atomic percentage is 0.3%, and the Mn 4+ The atomic percentage of Mn in the shell is x1, and x1 shows a linear and uniform increasing trend from the inside to the outside in the radial direction, and the value range of x1 is 0.1%≤x1≤0.3%; 4+ The atomic percentage is x2, and the value range of x2 is 0≤x2≤0.01%.

[0094] Example 9

[0095] The anti-degradation red phosphor of this embodiment has a core-shell structure, which includes a core and an outer shell. The core and the outer shell are independently selected from substances shown in Chemical Formula I. Chemical Formula I: K2Si (1-x) F6:xMn 4+ Among them, the Mn in the innermost layer of the phosphor core 4+ The atomic percentage is 0, and the outermost layer of the core is Mn 4+ The atomic percentage is 2%, and the Mn 4+ The atomic percentage of Mn in the shell is x1, and x1 shows a linear uniform increasing trend from the inside to the outside in the radial direction, and the value range of x1 is 0≤x1≤2%; 4+ The atomic percentage is x2, and the value range of x2 is 0≤x2≤0.05%.

[0096] Example 10

[0097] The anti-degradation red phosphor of this embodiment has a core-shell structure, which includes a core and an outer shell. The core and the outer shell are independently selected from substances shown in Chemical Formula I. Chemical Formula I: K2Si (1-x) F6:xMn 4+ Among them, the Mn in the innermost layer of the phosphor core 4+ The atomic percentage is 0, and the outermost layer of the core is Mn 4+ The atomic percentage is 0.5%, and the Mn 4+ The atomic percentage of Mn in the shell is x1, and x1 shows a linear and uniform increasing trend from the inside to the outside in the radial direction, and the value range of x1 is 0≤x1≤0.5%; 4+ The atomic percentage is x2, and the value range of x2 is 0≤x2≤0.01%.

[0098] Example 11

[0099] The anti-degradation red phosphor of this embodiment has a core-shell structure, which includes a core and an outer shell. The core and the outer shell are independently selected from substances represented by Chemical Formula I. Chemical Formula I: Li2Si (1-x) F6:xMn 4+ ; Wherein, the Mn 4+ The atomic percentage of Mn in the shell is x1, and x1 shows a linear uniform increasing trend from the inside to the outside in the radial direction of the core, and the value range of x1 is 0≤x1≤0.81%; 4+The atomic percentage of x2 is x2, and the value range of x2 is 0≤x2≤0.01%. The average particle size of the anti-degradation red phosphor of this embodiment is 30 μm, wherein the average thickness of the shell is 1.8 μm.

[0100] The method for preparing the anti-degradation red phosphor of this embodiment is different from that of Example 1 only in that: in step 1), Li 2 CO 3 is used instead of KHF 2 to be dissolved in the hydrofluoric acid solution.

[0101] Example 12

[0102] The anti-degradation red phosphor of this embodiment has a core-shell structure, which includes a core and an outer shell. The core and the outer shell are independently selected from substances represented by Chemical Formula I. Chemical Formula I: Cs2Si (1-x) F6:xMn 4+ ; Wherein, the Mn 4+ The atomic percentage of Mn in the shell is x1, and x1 shows a linear uniform increasing trend from the inside to the outside in the radial direction of the core, and the value range of x1 is 0≤x1≤0.80%; 4+ The atomic percentage of x2 is x2, and the value range of x2 is 0≤x2≤0.01%. The average particle size of the anti-degradation red phosphor of this embodiment is 30 μm, wherein the average thickness of the shell is 1.8 μm.

[0103] The method for preparing the anti-degradation red phosphor of this embodiment is different from that of embodiment 1 only in that: in step 1), CsF is used instead of KHF2 to be dissolved in the hydrofluoric acid solution.

[0104] Example 13

[0105] The anti-degradation red phosphor of this embodiment has a core-shell structure, which includes a core and an outer shell. The core and the outer shell are independently selected from substances shown in Chemical Formula I. Chemical Formula I: K2Ge (1-x) F6:xMn 4+ ; Wherein, the Mn 4+ The atomic percentage of Mn in the shell is x1, and x1 shows a linear uniform increasing trend from the inside to the outside in the radial direction of the core, and the value range of x1 is 0≤x1≤0.82%; 4+ The atomic percentage of x2 is x2, and the value range of x2 is 0≤x2≤0.01%. The average particle size of the anti-degradation red phosphor of this embodiment is 30 μm, wherein the average thickness of the shell is 1.8 μm.

[0106] The method for preparing the degradation-resistant red phosphor of this embodiment differs from that of embodiment 1 only in that H2GeF6 solution is used in place of fluorosilicic acid solution in step 2) and step 3).

[0107] Example 14

[0108] The anti-degradation red phosphor of this embodiment has a core-shell structure, which includes a core and an outer shell. The core and the outer shell are independently selected from substances represented by Chemical Formula I. Chemical Formula I: K2Ti (1-x) F6:xMn 4+ ; Wherein, the Mn 4+ The atomic percentage of Mn in the shell is x1, and x1 shows a linear uniform increasing trend from the inside to the outside in the radial direction of the core, and the value range of x1 is 0≤x1≤0.81%; 4+ The atomic percentage of x2 is x2, and the value range of x2 is 0≤x2≤0.01%. The average particle size of the anti-degradation red phosphor of this embodiment is 30 μm, wherein the average thickness of the shell is 1.8 μm.

[0109] The method for preparing the degradation-resistant red phosphor of this embodiment differs from that of embodiment 1 only in that H2TiF6 solution is used in place of fluorosilicic acid solution in step 2) and step 3).

[0110] Comparative Example 1

[0111] The phosphor of this comparative example is different from that of Example 1 in that it only includes the core of the anti-degradation red phosphor of Example 1 and does not include the shell.

[0112] The preparation method of the phosphor of this comparative example is different from that of Example 6 only in that: Step 3) the series of BX solutions are added to the base solution A in increasing order of concentration, and the number of additions is recorded as A1, A2, A3, ..., A 16 , adding times A1~A 16 The mass of K2MnF6 raw materials contained in the raw materials is shown in Table 1 below, which is the same as that of A1 to A2 in step 3 of Example 1. 16 The corresponding K2MnF6 raw materials have the same mass, and no fluorosilicic acid solution is added after the BX solution is added.

[0113] Comparative Example 2

[0114] The phosphor of this comparative example is different from that of Example 1 only in that the Mn 4+ The atomic percentage is x1, and x1 is uniformly distributed from the inside to the outside in the radial direction.

[0115] The preparation method of the phosphor of this comparative example differs from that of Example 1 only in that: Step 2) 16 equal portions of K2MnF6 raw material are taken, 1.35 g of each portion is dissolved in 50 g of a 10% by mass silicofluoric acid solution to prepare a series of BX solutions with equal K2MnF6 concentrations; Step 3) the series of BX solutions are added to the base solution A, and the number of additions is recorded as A1, A2, A3, ..., A4, respectively. 16 , used to prepare Mn 4+ The preparation of the outer shell is the same as that in Example 1.

[0116] Comparative Example 3

[0117] The phosphor powder of this comparative example is different from that of comparative example 2 in that the phosphor powder of this comparative example only includes the core of the phosphor powder of comparative example 2 and does not include the shell.

[0118] The preparation method of the phosphor in this comparative example is different from that in comparative example 2 only in that: in step 3), after the series of BX solutions are added to the base solution A respectively, no fluorosilicic acid solution is added.

[0119] Table 1 Mass of K2MnF6 in the series of BX solutions and fluorosilicic acid solutions added in step 3) of Examples 1 to 6 and Comparative Example 1

[0120] As shown in Table 1, Examples 1 to 5 use K2MnF6 raw materials with a gradually increasing mass to prepare a series of BX solutions for the preparation of the core. The mass of the K2MnF6 raw material used in the preparation of the core in Example 1 increases in an arithmetic progression with a tolerance of 0.18 g, while the increasing trend in Examples 2 to 5 is nonlinear. In Example 6, when preparing the core, only the mass of the K2MnF6 raw material contained in the first and last added BX solutions is controlled to have a minimum mass of 0 g and a maximum mass of 2.70 g, respectively. The mass of the K2MnF6 raw material in the remaining additions is randomly arranged. The mass of the K2MnF6 raw material used in the preparation of the core in Comparative Example 1 is the same as that in Example 1, but the shell is not prepared.

[0121] Test Example 1

[0122] The degradation-resistant red phosphors of Examples 1-5 were milled using a FIB-SEM with dual ion beam scanning electron microscopy. EDS spectrometry was performed on the fresh surface from the center of the body to the surface. Using Example 1 as an example, Figure 2 shows an SEM image of the degradation-resistant red phosphor particles before milling. The left image is a top-down SEM image of the phosphor particles; the right image is a 45° side SEM image of the fresh cross-section of the phosphor particles after milling. Figure 3 shows the scanning positions for EDS point scanning analysis of the degradation-resistant red phosphor particles of Example 1. The radial distribution of Mn atomic percentages from the innermost layer of the core to the outermost layer of the shell of the degradation-resistant red phosphor particles of Examples 1-5, as obtained by EDS spectrometry, is shown in Table 2 below.

[0123] Table 2 Distribution of Mn atomic percentage in radial direction of Examples 1 to 5

[0124] As can be seen from Table 2, the degradation-resistant red phosphors of Examples 1 to 5 are divided into 16 layers from the inside to the outside in the radial direction of the core, and the outer shell is divided into 3 layers from the inside to the outside in the radial direction. The Mn atomic percentage shows an increasing trend from the inside to the outside in the radial direction of the core. Although there are individual values ​​that are equal to or slightly smaller than the previous value, this does not affect the overall increasing trend of the Mn atomic percentage in the radial direction of the core. The innermost layer of the core does not contain Mn atoms, and the Mn atomic percentage is 0%. The Mn atomic percentage of the outermost layer of the core is between 0.77% and 0.82%; the Mn atomic percentage in the outer shell is between 0% and 0.02%. Among them, the Mn atomic percentage of Example 1 increases linearly and uniformly in the radial direction of the core as a whole.

[0125] In order to more intuitively reflect the increasing trend of the Mn element content in Examples 1 to 5, the Mn content in the anti-degradation red phosphor particles of Examples 1 to 5 is as follows: 4+ The distribution diagram of the relative content of Mn in the radial direction is shown in FIG1 . In FIG1 , the content of the outermost layer of the core of each embodiment is taken as the standard (denoted as 1.0), and the solid points on the image represent the Mn content at different positions in the inner diameter direction of the phosphor particles. 4+ As shown in Figure 1, the center of the anti-degradation red phosphor particles of Examples 1 to 5 does not contain Mn. 4+ , in the process of moving away from the body center and approaching the outermost layer of the core, Mn 4+ The relative content of Mn in Example 1 showed an increasing trend. 4+ The relative content of Mn in the phosphor particles of Examples 1 to 5 shows a linear and uniform increasing trend. 4+ The relative content of Mn reaches its maximum in the outermost layer of the core, and then the Mn 4+ The relative content is close to or reaches 0.

[0126] The surface of the anti-degradation red phosphor particles of Example 5 after cutting was subjected to EDX testing from the center of the body to the surface using a FIB-SEM focused ion beam scanning electron microscope. The EDX line scan position is shown in FIG4 , and the obtained EDX line scan analysis results are shown in FIG5 . It can be seen from the line scan result diagram that the Mn content of the anti-degradation red phosphor particles shows a gradient increasing trend from the innermost layer of the core to the outermost layer of the core, while the Mn content in the outer shell activator shows a sharp decreasing trend.

[0127] Test Example 2

[0128] Aging tests were performed on the phosphors of Examples 1 to 6 and Comparative Examples 1 to 3, and the luminous flux of each Example and Comparative Example at 0, 250, 500, 750, and 1000 hours was tested. Table 3 shows the test method and equipment for the 1000-hour aging test in this application, and Table 4 shows the aging test data of the KSF phosphors prepared in the Examples and Comparative Examples. (Note: KSF-0 is the sample of Comparative Example 1, KSF-1 is the sample of Example 1, KSF-2 is the sample of Example 2, KSF-3 is the sample of Example 3, KSF-4 is the sample of Example 4, KSF-5 is the sample of Example 5, KSF-6 is the sample of Example 6, KSF-7 is the sample of Comparative Example 2, and KSF-8 is the sample of Comparative Example 3)

[0129] Table 3 Test methods and equipment for aging tests of Examples 1 to 6 and Comparative Examples 1 to 3

[0130] Table 4 Luminous flux and brightness ratio results of Examples 1 to 6 and Comparative Examples 1 to 3 in aging test

[0131] As shown in Table 4, the LED devices fabricated using the phosphors of Examples 1 to 6 and Comparative Example 1 have an initial luminous flux of 126.34 lm to 128.35 lm in an environment of 85°C and 85 RH%. However, the LED device using the phosphor of Comparative Example 2 has an initial luminous flux of only 117.48 lm. In contrast, the initial luminous flux of Comparative Example 3 is 120.83 lm, indicating that the initial luminous flux of the core of Comparative Example 2 is reduced by 2.8% after the shell is added. This shows that the present invention, by controlling the Mn content of the innermost and outermost layers of the core and using a shell with a low Mn atomic percentage, does not affect the luminous efficiency of the phosphor, thereby ensuring a high luminous intensity of the phosphor. As the test time increases, the luminous flux of the LED device using the phosphor of Comparative Example 1 gradually decreases, and the brightness ratio decreases by about 1% every 250 hours. After 1000 hours, the luminous flux is only 123.47lm, and the brightness is only 96.2% of the initial brightness, which is a year-on-year decrease of 3.8%. However, the luminous flux of the LED device corresponding to the anti-degradation red phosphor of Examples 1 to 6 decreases less. After 1000 hours of high temperature and high humidity environment testing, the luminous flux is still maintained at 125.10lm~127.05lm, and the brightness can still reach 98.9%~99.2% of the initial brightness, basically maintaining a brightness ratio level of 99%. It can be seen that the present application achieves a better performance by setting Mn 4+ The shell with very little or no content covers the phosphor core, which greatly improves the moisture resistance and anti-degradation ability of the phosphor without affecting the luminous efficiency of the phosphor, so that the phosphor can maintain a high luminous intensity even in harsh environments with long-term high temperature and high humidity.

[0132] In addition, a horizontal comparison of Examples 1 to 5 shows that Example 1 adopts a scheme in which the Mn atomic percentage increases linearly and uniformly in the radial direction of the core. The measured initial luminous flux is the highest, which is 128.21 lm, and its luminous flux decreases the least in the aging test experiment. After 1000 hours, the brightness ratio is still maintained at 99.2%, which is only reduced by 1.8%. It can be seen that the present application ensures the conversion efficiency of the phosphor by controlling the linear and uniform increase of the Mn atomic percentage in the radial direction of the core. After being matched with the shell, its luminous flux is less affected by the harsh environment in long-term service, which is conducive to further ensuring a higher luminous efficiency.

[0133] Test Example 3

[0134] The phosphor samples of Examples 1 and 7 to 10 were packaged into lamp beads according to the method in Table 3 of Test Example 2. The luminous flux of the samples of each example was tested. The results are shown in Table 5 below.

[0135] Table 5 Luminous flux results of samples of Example 1 and Examples 7 to 10

[0136] As shown in Table 5, the luminous flux of the phosphor samples of Example 1 and Examples 7 to 10 can reach between 119.35 and 128.21 lm, showing strong luminous performance. Among them, the luminous flux of the phosphors of Examples 1, 9, and 10, in which the atomic percentage difference of the activator between the outermost layer and the innermost layer of the core is 0.5% to 2%, is 124.20 to 128.21 lm, which is further improved compared with Examples 7 and 8. It can be seen that the present invention can achieve a better luminous performance by controlling the Mn content in the core. 4+ The atomic percentage distribution of the phosphor is beneficial to improving the absorption efficiency of the phosphor and obtaining better luminescence performance.

[0137] The above description is merely a specific embodiment of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this disclosure should be included in the scope of protection of the present disclosure. Therefore, equivalent modifications made according to the claims of this disclosure are still within the scope of protection of the present disclosure.

Claims

1. A red phosphor that resists degradation, It is characterized in that The anti-degradation red phosphor has a core-shell structure, wherein the core-shell structure includes a core and an outer shell, wherein the core and the outer shell are independently selected from substances shown in Chemical Formula I, 2 M (1-x) F 6 :xMn 4+ Chemical formula I; In the chemical formula I, A comprises at least one of Li, Na, K, Rb, and Cs, and M comprises at least one of Si, Ge, and Ti; Among them, the innermost layer of the core Mn 4+ The atomic percentage of the outermost layer of the core is a. 4+ The atomic percentage of Mn in various locations within the core particles is b, b>a; 4+ The atomic percentage is x 1 , the value range of x is a≤x 1 ≤ b; The Mn in the shell 4+ The atomic percentage is x 2 , x 2 The value range is 0≤x 2 ≤0.1%.

2. The anti-degradation red phosphor according to claim 1, It is characterized in that x 1 In the radial direction of the inner core, the inner diameter increases from the inside to the outside.

3. The anti-degradation red phosphor according to claim 2, It is characterized in that The increasing trend is x 1 The inner core increases linearly and uniformly from the inside to the outside in the radial direction.

4. The anti-degradation red phosphor according to claim 1, It is characterized in that In the kernel, the value range of a is 0≤a≤0.1%, and the value range of b is 0.3%≤b≤5%.

5. The anti-degradation red phosphor according to claim 4, It is characterized in that In the kernel, the value range of a is 0≤a≤0.01%, and the value range of b is 0.5%≤b≤1.5%.

6. The anti-degradation red phosphor according to claim 1, It is characterized in that In the phosphor, b>x 2 .

7. The anti-degradation red phosphor according to claim 1, It is characterized in that In the phosphor, 0≤x 2 / b≤1 / 10.

8. The anti-degradation red phosphor according to claim 1, It is characterized in that The average particle size of the anti-degradation red phosphor is 5-40 μm; the average thickness of the shell is 0.1-2 μm.

9. The method for preparing the anti-degradation red phosphor according to any one of claims 1 to 8, It is characterized in that The following steps are involved: 1) Dissolve salt A in hydrofluoric acid solution, which is referred to as base solution A; 2) Take series K 2 Mn 6 Dissolved in equal amounts of H 2 MF 6 Solution, prepared to obtain K 2 Mn 6 A series of BX solutions with different concentrations; 3) Add the series of BX solutions to the base solution A in sequence, and control the K of the first added BX solution. 2 Mn 6 The concentration is the lowest, and the K of the BX solution added last 2 Mn 6 The concentration is the highest, and a core mixed system is obtained to prepare the core; then H is added to the core mixed system. 2 MF 6 Solution, used to prepare the shell, that is, the anti-degradation red phosphor; The A salt is selected from at least one of fluoride, bifluoride, sulfate, nitrate, bisulfate, carbonate and bicarbonate of A, and A is selected from any one of Li, Na, K, Rb and Cs; the H 2 MF 6 In the embodiment, M is selected from any one of Si, Ge and Ti.

10. The method for preparing the anti-degradation red phosphor according to claim 9, It is characterized in that Step 3) adding the series of BX solutions to the base solution A solution in sequence to adjust the series of BX solutions according to K 2 Mn 6 The concentrations are sequentially added to the base solution A in increasing order.

11. The method for preparing the anti-degradation red phosphor according to claim 10, It is characterized in that Step 2) Take series K 2 Mn 6 To take K whose mass increases in an arithmetic progression 2 Mn 6 .

12. The method for preparing the anti-degradation red phosphor according to claim 9, It is characterized in that The H 2 MF 6 The mass concentration of the solution is 10-15%; each 5-7.5 g H 2 MF 6 The corresponding K 2 Mn 6 Mass: 0 to 3 g; The mass concentration of the hydrofluoric acid solution is 35-55%. In the base solution A, the volume of the hydrofluoric acid solution used for every 15-25 g of salt A is 200-300 mL.

13. The method for preparing the anti-degradation red phosphor according to claim 9, It is characterized in that Step 3) The mass of the series of BX solutions added is 100-1300 g; H is added to the core mixing system. 2 MF 6 H added to the solution 2 MF 6 The mass of the solution is 5 to 200 g.

14. Use of the anti-degradation red phosphor according to any one of claims 1 to 8 or the anti-degradation red phosphor prepared by the preparation method according to any one of claims 9 to 13 in the field of liquid crystal backlight or LED lighting.

15. A liquid crystal backlight source, It is characterized in that It includes an excitation chip and phosphor coated on the excitation chip; The phosphor is the anti-degradation red phosphor according to any one of claims 1 to 8; or The phosphor is a degradation-resistant red phosphor prepared by the preparation method according to any one of claims 9 to 13.

16. A lighting device, It is characterized in that including a light emitting device; The light emitting device comprises an excitation chip and phosphor coated on the excitation chip; The phosphor is the anti-degradation red phosphor according to any one of claims 1 to 8; or The phosphor is a degradation-resistant red phosphor prepared by the preparation method according to any one of claims 9 to 13.

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