Phosphor material for light sources and method of manufacturing the same

Abstract

This application relates to phosphor materials for light sources and methods for manufacturing the same. One method includes: mixing a first fluoride phosphor powder doped with tetravalent manganese with a processing solution for a specified time period; stopping the mixing to allow the fluoride phosphor powder to settle; removing at least some liquid that has separated from the first fluoride phosphor powder; repeating the steps of (a) mixing, (b) stopping the mixing, and (c) removing at least some of the liquid during one or more additional cycles; and obtaining a second fluoride phosphor powder after repeating the steps of mixing, stopping the mixing, and removing at least some of the liquid. The second fluoride phosphor powder contains a reduced amount of manganese compared to the first fluoride phosphor powder.

Description

[0001] This application was filed on April 10, 2017, with application number [Application Number Missing]. This is a divisional application of the invention patent application entitled "Phosphor material for light source and method of manufacturing the same".

[0002] Cross-references to related applications This application claims priority to U.S. Provisional Application No. 62 / 322,366, filed April 14, 2016, the entire disclosure of which is incorporated herein by reference. Background Technology

[0003] Some light sources include a phosphor body disposed on or near the light source. These phosphor bodies or phosphors receive at least some of the light generated by the light source. The received light causes the phosphor to emit light. For example, some light-emitting diodes (LEDs) include a red-emitting phosphor that receives light generated by the LED and emits light.

[0004] Red-emitting phosphors can be based on tetravalent manganese (Mn) 4+ Activated composite fluoride materials. When these phosphors with tetravalent manganese doping are exposed to moisture in the air, the tetravalent manganese can be oxidized to produce manganese dioxide (MnO2). This leads to a decrease in the brightness and reliability of the phosphor.

[0005] One attempt to remove tetravalent manganese from phosphors involves adding the phosphor to a saturated K₂SiF₆ / HF solution, where the liquid-to-powder ratio is in the range of 10:1 to 20:1 (this ratio is a volume-to-weight ratio, such as ml / g). After mixing for approximately 30 minutes, most of the surface manganese dissolves from the powder into the solution. However, the yield of this method is relatively low, and the removal of surface manganese may not be sufficient to significantly improve the brightness or reliability of the phosphor. Summary of the Invention

[0006] In one embodiment, a method includes mixing a first fluoride phosphor powder doped with tetravalent manganese with a treatment solution in a container for a specified time period; stopping the mixing of the first fluoride phosphor powder and the treatment solution in the container to allow the fluoride phosphor powder to settle in the treatment solution and separate at least some liquid in the container from the first fluoride phosphor powder; removing at least some of the liquid that has separated from the first fluoride phosphor powder from the container; repeating the steps of (a) mixing the first fluoride phosphor powder with the treatment solution, (b) stopping the mixing of the first fluoride phosphor powder with the treatment solution, and (c) removing at least some liquid during one or more additional cycles; and repeating the steps of mixing the first fluoride phosphor powder with the treatment solution, stopping the mixing of the first fluoride phosphor powder with the treatment solution, and removing at least some liquid during one or more additional cycles to obtain a second fluoride phosphor powder from the container as a residual amount of the first fluoride phosphor powder. The second fluoride phosphor powder contains a reduced amount of manganese compared to the first fluoride phosphor powder.

[0007] In one embodiment, a method includes mixing a first fluoride phosphor powder doped with a dopant with a processing solution to form a mixture; stirring the mixture of the first fluoride phosphor powder and the processing solution for at least a first specified time period; stopping the stirring of the mixture for at least a second specified time period to allow liquid in the mixture to separate from the mixture; removing at least some of the liquid from the mixture; repeating the steps of (a) mixing the first fluoride phosphor powder with the processing solution, (b) stirring the mixture, (c) stopping the stirring of the mixture, and (d) removing at least some of the liquid from the mixture; and obtaining a second fluoride phosphor powder from the mixture obtained after repeating the steps of mixing the first PFS powder with the processing solution, stirring the mixture, stopping the stirring, and removing at least some of the liquid from the mixture. The second fluoride phosphor powder contains a reduced amount of dopant compared to the first fluoride phosphor powder.

[0008] In one embodiment, a method includes mixing a first fluoride phosphor powder doped with tetravalent manganese with a hydrofluoric acid solution to form a mixture; stirring the mixture of the first fluoride phosphor powder and the hydrofluoric acid solution for at least a first specified time period; stopping the stirring of the mixture for at least a second specified time period to allow liquid in the mixture to separate from the mixture; removing at least some of the liquid from the mixture; repeating the steps of (a) mixing the first fluoride phosphor powder with the hydrofluoric acid solution, (b) stirring the mixture, (c) stopping the stirring of the mixture, and (d) removing at least some of the liquid from the mixture; and obtaining a second fluoride phosphor powder from the mixture obtained after repeating the steps of mixing the first PFS powder with the hydrofluoric acid solution, stirring the mixture, stopping the stirring, and removing at least some of the liquid from the mixture. The second fluoride phosphor powder contains a reduced amount of manganese compared to the first fluoride phosphor powder. Attached Figure Description

[0009] The subject matter described herein will be better understood by referring to the following description of non-limiting embodiments, in which: Figure 1 A flowchart illustrating one embodiment of a method for manufacturing materials used in phosphors; Figure 2 The formation of the treatment solution is shown according to one example; Figure 3 The addition of PFS powder is shown. Figure 2 The treatment solution shown is used to form a mixture of powder and treatment solution; Figure 4 An example of mixing PFS powder and a treatment solution is shown; Figure 5 This illustrates, according to one embodiment, the process after mixing and after allowing the PFS powder to settle. Figure 3 The mixture shown; Figure 6 This illustrates, based on an example, the process after removing the separated liquid. Figure 3 The mixture shown; and Figure 7 This illustrates how, according to one embodiment, more treatment solution is added to the previously obtained mixture to obtain a new diluted mixture. Detailed Implementation

[0010] The inventive subject described herein provides a method for manufacturing phosphors and the resulting phosphors produced by said method. The method described herein can be used to produce red-emitting phosphors with better manufacturability and improved water resistance (compared to red-emitting phosphors produced using other methods). The red-emitting phosphors are based on phosphors produced by tetravalent manganese (Mn). 4+) activated composite fluoride materials (e.g., those produced using them). As described herein, the method includes using materials containing tetravalent manganese activated and produced by formula K2[M 1-a Mn 4+ a F6] represents a solution of a fluoride phosphor, wherein M is at least one selected from group IV elements of titanium (Ti), zirconium (Zr), and hafnium (Hf) and group IVB elements of silicon (Si), germanium (Ge), and tin (Sn), and wherein a It has a value greater than 0 and less than 0.2. Although the description herein focuses on potassium hexafluorosilicate (K2SiF6), not all embodiments of the subject matter of this invention are limited to potassium hexafluorosilicate, and one or more embodiments can be made with another activated with tetravalent manganese and via the formula K2[M 1-a Mn 4+ a F6] represents the practice of using fluoride phosphors. Optionally, another phosphor material, such as that expressed by formula A, can be used. x [MF y ]:Mn 4+ The phosphor is indicated by A, where A represents lithium, sodium, potassium, rubidium, cesium, or a combination of two or more of these materials, and M represents silicon, germanium, tin, titanium, zirconium, aluminum, gallium, indium, scandium, hafnium, yttrium, lanthanum, niobium, tantalum, bismuth, gadolinium, or a combination of two or more of these elements. x The value is [MF y The absolute value of the charge of an ion, and y The value is 5, 6, or 7.

[0011] One or more embodiments of the method described herein use a solution containing fluoride phosphor and hydrofluoric acid (HF) with a low liquid-to-powder ratio (e.g., a liquid volume to weight ratio in the range of 2:1 to 5:1 mL / g) and a much shorter mixing time. After mixing, the clear liquid at the top is decanted from the solution, and fresh K2SiF6 / HF solution with the same liquid-to-powder ratio is added. This cycle is repeated several times until almost no visible brown color is found in the decanted liquid. By using this novel treatment, the phosphor yield is significantly increased, and the resulting phosphor exhibits better water resistance because more tetravalent manganese is removed from the surface of the phosphor powder.

[0012] When red phosphor powder, such as manganese-doped potassium hexafluorosilicate (K₂SiF₆), is mixed with a saturated K₂SiF₆ / HF solution, two reactions occur. The first reaction involves the manganese-doped potassium hexafluorosilicate (K₂SiF₆:Mn) leaving the solid phase and entering the liquid phase. The second reaction involves this same material precipitating from the liquid phase and then redepositing onto the solid surface. To remove more manganese from the solid surface, the second reaction needs to be limited. Compared to current processes used to manufacture some red phosphors, the new manufacturing process significantly limits the second reaction and promotes the first reaction, resulting in better removal of manganese from the surface of the potassium hexafluorosilicate powder. This new process also uses a lower liquid-to-powder ratio, which allows for the manufacture of phosphors with the same amount of starting material while increasing the yield of potassium hexafluorosilicate.

[0013] Figure 1 A flowchart illustrating one embodiment of a method 100 for manufacturing materials used in phosphors (such as red phosphors) is shown. At 102, a fluoride phosphor powder, such as potassium fluorosilicate (PFS) powder, is obtained. This powder may include doped with tetravalent manganese (Mn). 4+ Potassium hexafluorosilicate, which can be represented as K2SiF6:Mn 4+ PFS powder can be calcined in the presence of a fluorine source.

[0014] At position 104, a treatment solution is obtained. The treatment solution can be formed from a fluoride powder mixed with an acid (such as hydrofluoric acid (HF)). In one embodiment, the treatment solution is formed from potassium hexafluorosilicate mixed with hydrofluoric acid. The potassium hexafluorosilicate in the treatment solution may not be doped with tetravalent manganese. (Continue to reference...) Figure 1 The flowchart of method 100 shown is as follows. Figure 2 The formation of a treatment solution 200 according to one example is shown. As described above, the treatment solution 200 can be formed by mixing potassium hexafluorosilicate powder 202 with hydrofluoric acid 204.

[0015] exist Figure 1 At position 106, the PFS powder obtained at position 102 will be mixed with the treatment solution obtained at position 104. Figure 3 The diagram illustrates the addition of PFS powder 300 to a treatment solution 200 to form a mixture 302 of powder 300 and treatment solution 200. In one embodiment, the PFS powder 300 may comprise potassium hexafluorosilicate doped with tetravalent manganese. The amounts of PFS powder 300 and treatment solution 200 used to form mixture 302 may be based on a ratio of the specified volume of treatment solution 200 (e.g., in milliliters) to the weight of PFS powder 300 (e.g., in grams), such as a ratio of at least 2:1 to no more than 5:1. Alternatively, another ratio may be used, such as no more than 6:1 or no more than 7:1.

[0016] In one embodiment, the mixture 302 of PFS powder 300 and treatment solution 200 can be stirred for a specified period of time. Figure 4 An example of a mixture 302 of PFS powder 300 and treatment solution 200 is shown. The mixture 302 can be stirred by moving the container 400 containing the mixture 302 and / or by shaking the mixing body 402 (such as a paddle, stirring rod, stir bar, magnet, etc.) within the mixture 302. The mixture 302 can be stirred or mixed for approximately 5 minutes, such as at least 4 minutes and no more than 6 minutes, at least 4.5 minutes and no more than 5.5 minutes, or another time period.

[0017] At point 108, the mixing or stirring of mixture 302 is stopped, and the PFS powder 300 in mixture 302 is allowed to settle. Mixing may be stopped for at least a specified period of time, such as approximately 1 minute, at least 3 minutes, at least 2 minutes but no more than 4 minutes, at least 2.5 minutes but no more than 3.5 minutes, or another period of time. Stopping the mixing of mixture 302 allows the PFS powder 300 to settle towards the bottom of container 400. Figure 5 The image shows mixture 302 after mixing at point 106 according to one embodiment and after the PFS powder 300 has settled. (See image for details.) Figure 5 As shown, some liquid components in mixture 302 can be separated from powder 300 as a separated liquid 500 in container 400. The liquid 500 may be half or approximately half of the total amount of mixture 302.

[0018] Liquid 500 can be separated from mixture 302 because liquid 500 may be free of powder 300 or may contain less powder 300 than mixture 302. For example, liquid 500 may be free of any powder 300, liquid 500 may contain some tetravalent manganese (but less than mixture 302), and / or liquid 500 may contain some powder 300 (but less than mixture 302). In one embodiment, liquid 500 may be formed from a mixture of hydrofluoric acid and a manganese dopant of powder 300.

[0019] At point 110, the separated liquid 500 is decanted from container 400. Liquid 500 can be decanted from container 400 by removing it without damaging the powder 300 that has at least partially settled in container 400. For example, liquid 500 can be removed by pouring it out of container 400, by pumping it out of container 400, or by other means. Figure 6 The diagram illustrates, according to one example, a mixture 302 after the separated liquid 500 has been removed from container 400. (See diagram for reference.) Figure 6As shown, the total amount of mixture 302 in container 400 has been reduced due to the removal of the separated liquid 500. The separated liquid 500 may contain some tetravalent manganese from the powder 300 in mixture 302, and the removal of liquid 500 can reduce the total amount of manganese in mixture 302 and on powder 300.

[0020] At 112, it is determined whether the following process should be repeated once or more: mixing PFS powder in a treatment solution, followed by decanting the separated liquid from the mixture of powder and treatment solution. For example, it may be decided whether to perform the following process once or more: adding another treatment solution 200 to a mixture 302 of PFS powder 300 and treatment solution 200, stirring the new mixture and allowing it to stand, and then removing the separated liquid 500 from the new mixture. If this process is to be repeated, the flow of method 100 can proceed to 114. If this process is not to be repeated, the flow of method 100 can proceed to 116.

[0021] At 114, an additional amount of treatment solution 200 is mixed with powder 300 and the remaining mixture 302 of treatment solution 200. Figure 7 The illustration shows the addition of more treatment solution 200 to the previously obtained mixture 302 according to one embodiment to obtain a new diluted mixture 700. The new mixture 700 may be diluted because the amount of manganese in the new mixture 700 is less than the amount of manganese in the previous mixture 302. The amount of powder 300 in the new mixture 700 may be undiluted relative to one or more previous mixtures. Figure 6 The mixture 302 shown can be mixed with another treatment solution 200 to bring the liquid-to-solid ratio in the new mixture 700 within the range described above (e.g., at least 2:1 to no more than 5:1). The process of method 100 can then return to 108. For example, the new mixture 700 can be stirred and then allowed to stand (e.g., at 114 and 108). As described above, stopping the stirring separates the manganese-containing liquid 500 from the new mixture 700. This liquid 500 can then be removed from the new mixture 700 at 110 to reduce the manganese content in the mixture 700. When method 100 returns to 112, it can be determined again whether to perform one or more of the following processes: mixing in more treatment solutions, separating the manganese-containing liquid, and removing the liquid. In one embodiment, after performing the initial processes of mixing the powder and treatment solution, separating the liquid, and removing the liquid, the process can be repeated a specified number of times, such as at least four more times, at least five more times, at least six more times, etc. Once the processes of mixing, separating, and removing the liquid have been performed a specified number of times, the process of method 100 can proceed to 116.

[0022] At 116, the remaining PFS powder 300 in the mixture 700 is filtered. For example, the mixture 700 may flow through a fiber filter (such as filter paper) once or multiple times. This filtration can extract the PFS powder 300 from the mixture 700. Due to the repeated separation of manganese from the PFS powder 300, the amount of manganese in the PFS powder 300 is reduced without reducing the amount of PFS powder 300 (or the amount of PFS powder 300 is reduced by a relatively small amount, such as less than 3%, less than 1%, or less than 0.1%). The filtered PFS powder 300 can then be washed (e.g., with acetone) and dried (e.g., by vacuuming the filter paper on which the filtered PFS powder 300 is disposed). The PFS powder 300 can then be used to form one or more phosphors for a light source, such as by mixing the PFS powder 300 with a resin material (e.g., silicone) and placing the mixture on the light source.

[0023] The amount of manganese in the mixture can be gradually reduced by repeatedly mixing the powder with the treatment solution, allowing the PFS powder to settle in the mixture, decanting the separated liquid containing at least some tetravalent manganese, and repeating this process once or more. This prevents manganese from settling on the PFS powder. A lower ratio of treatment solution to PFS powder (relative to other known processes) can reduce the amount of PFS powder lost or not recovered during mixing for phosphor production.

[0024] Removing tetravalent manganese from PFS powder can also provide phosphors with a higher quantum efficiency (QE) compared to phosphors produced using PFS powder containing tetravalent manganese or more. For example, 50 g of PFS powder 300 was mixed with 1,000 mL of treatment solution 200 for 30 minutes, then the mixture of PFS powder 300 and treatment solution 200 was filtered, the filtered powder was washed with acetone, and then the powder was vacuum dried to produce PFS powder in which 0.017% of tetravalent manganese was removed. After exposing the PFS powder to a high temperature and high humidity (HTHH) environment of 85°C and 85% humidity for 48 hours, the QE of the PFS powder was measured to be 96.8%.

[0025] In contrast, 200 g of the same PFS powder 300 was mixed with only 600 mL of the same treatment solution 200. The mixture was allowed to stand for 5 minutes, and the separated liquid on top of the standing mixture was decanted. A second 600 mL of the same treatment solution 200 was added, and the mixture was allowed to stand for 5 minutes, followed by decanting. A third 600 mL of the same treatment solution 200 was added, and the mixture was allowed to stand for 5 minutes, followed by decanting. A fourth 600 mL of the same treatment solution 200 was added, and the mixture was allowed to stand... After standing for 5 minutes, the separated liquid on top of the mixture was decanted and allowed to stand. A fifth addition of 600 mL of the same treatment solution 200 was made, and the mixture was allowed to stand for 5 minutes. The separated liquid on top of the mixture was then decanted and allowed to stand again. A sixth addition of 600 mL of the same treatment solution 200 was made, and the mixture was allowed to stand for 5 minutes. The separated liquid on top of the mixture was then decanted and allowed to stand again. The mixture of PFS powder 300 and treatment solution 200 was then filtered. The resulting powder was washed with acetone and then vacuum dried to produce PFS powder in which 0.025% of tetravalent manganese was removed. After exposing the PFS powder to the same HTHH for 48 hours, the QE of the PFS powder was measured to be 97.2%. The difference between the QEs of 96.8% and 97.2% for different PFS powders was significant because the QE of the powder could decrease with respect to time in a linear or substantially linear manner. Therefore, the QE of PFS powder mixed with the treatment solution only once will be 6% smaller than that of PFS powder mixed with the treatment solution multiple times after 30 days of exposure to HTHH, 12% smaller after 60 days of exposure to HTHH, 18% smaller after 90 days of exposure to HTHH, and so on.

[0026] In one embodiment, a method includes mixing a first fluoride phosphor powder doped with tetravalent manganese with a treatment solution in a container for a specified time period; stopping the mixing of the first fluoride phosphor powder and the treatment solution in the container to allow the fluoride phosphor powder to settle in the treatment solution and separate at least some liquid in the container from the first fluoride phosphor powder; removing at least some of the liquid that has separated from the first fluoride phosphor powder from the container; repeating the steps of (a) mixing the first fluoride phosphor powder with the treatment solution, (b) stopping the mixing of the first fluoride phosphor powder with the treatment solution, and (c) removing at least some liquid during one or more additional cycles; and repeating the steps of mixing the first fluoride phosphor powder with the treatment solution, stopping the mixing of the first fluoride phosphor powder with the treatment solution, and removing at least some liquid during one or more additional cycles to obtain a second fluoride phosphor powder from the container as a residual amount of the first fluoride phosphor powder. The second fluoride phosphor powder contains a reduced amount of manganese compared to the first fluoride phosphor powder.

[0027] In one example, the first and second fluoride phosphor powders comprise powders activated with tetravalent manganese and processed with K2[M] 1-a Mn 4 + a F6] represents a fluoride phosphor, wherein M is at least one element selected from the group consisting of titanium (Ti), zirconium (Zr), hafnium (Hf), silicon (Si), germanium (Ge), and tin (Sn), and a It has a value greater than 0 and less than 0.2.

[0028] In one example, mixing the first fluoride phosphor powder with the treatment solution includes stirring the mixture of the first fluoride phosphor powder and the treatment solution, and stopping the mixing includes stopping the stirring of the mixture of the first fluoride phosphor powder and the treatment solution.

[0029] In one example, mixing the first fluoride phosphor powder with the treatment solution includes placing the first fluoride phosphor powder in the treatment solution at a volume-to-weight ratio of at least 2.

[0030] In one instance, mixing the first fluoride phosphor powder with the treatment solution includes placing the first fluoride phosphor powder in the treatment solution at a volume-to-weight ratio not exceeding 5.

[0031] In one instance, the treatment solution contains hydrofluoric acid.

[0032] In one instance, the treatment solution contained manganese-free tertiary fluoride phosphor powder.

[0033] In one instance, removing at least some of the liquids includes decanting liquids from a mixture of the first fluoride phosphor powder and the treatment solution.

[0034] In one instance, stopping the mixing of the first fluoride phosphor powder with the treatment solution in the container includes allowing the first fluoride phosphor powder to settle in the mixture of the first fluoride phosphor powder and the treatment solution for at least a second specified time period.

[0035] In one example, the method further includes filtering the second fluoride phosphor powder, rinsing the second fluoride phosphor powder, and drying the rinsed second fluoride phosphor powder.

[0036] In one embodiment, a method includes mixing a first fluoride phosphor powder doped with a dopant with a processing solution to form a mixture; stirring the mixture of the first fluoride phosphor powder and the processing solution for at least a first specified time period; stopping the stirring of the mixture for at least a second specified time period to allow liquid in the mixture to separate from the mixture; removing at least some of the liquid from the mixture; repeating the steps of (a) mixing the first fluoride phosphor powder with the processing solution, (b) stirring the mixture, (c) stopping the stirring of the mixture, and (d) removing at least some of the liquid from the mixture; and obtaining a second fluoride phosphor powder from the mixture obtained after repeating the steps of mixing the first PFS powder with the processing solution, stirring the mixture, stopping the stirring, and removing at least some of the liquid from the mixture. The second fluoride phosphor powder contains a reduced amount of dopant compared to the first fluoride phosphor powder.

[0037] In one example, the first and second fluoride phosphor powders comprise powders activated with tetravalent manganese and processed with K2[M] 1-a Mn 4 + a F6] represents a fluoride phosphor, wherein M is at least one element selected from the group consisting of titanium (Ti), zirconium (Zr), hafnium (Hf), silicon (Si), germanium (Ge), and tin (Sn), and a It has a value greater than 0 and less than 0.2.

[0038] In one instance, the dopant included tetravalent manganese.

[0039] In one example, mixing the first fluoride phosphor powder with the treatment solution includes placing the first PFS powder in the treatment solution at a volume-to-weight ratio of at least 2.

[0040] In one instance, mixing the first fluoride phosphor powder with the treatment solution includes placing the first fluoride phosphor powder in the treatment solution at a volume-to-weight ratio not exceeding 5.

[0041] In one instance, the treatment solution contains hydrofluoric acid.

[0042] In one instance, the processing solution contains dopant-free third fluoride phosphor powder.

[0043] In one instance, removing at least some liquid includes decanting at least some liquid from a mixture of the first fluoride phosphor powder and the treatment solution.

[0044] In one embodiment, a method includes mixing a first fluoride phosphor powder doped with tetravalent manganese with a hydrofluoric acid solution to form a mixture; stirring the mixture of the first fluoride phosphor powder and the hydrofluoric acid solution for at least a first specified time period; stopping the stirring of the mixture for at least a second specified time period to allow liquid in the mixture to separate from the mixture; removing at least some of the liquid from the mixture; repeating the steps of (a) mixing the first fluoride phosphor powder with the hydrofluoric acid solution, (b) stirring the mixture, (c) stopping the stirring of the mixture, and (d) removing at least some of the liquid from the mixture; and obtaining a second fluoride phosphor powder from the mixture obtained after repeating the steps of mixing the first PFS powder with the hydrofluoric acid solution, stirring the mixture, stopping the stirring, and removing at least some of the liquid from the mixture. The second fluoride phosphor powder contains a reduced amount of manganese compared to the first fluoride phosphor powder.

[0045] In one example, the first and second fluoride phosphor powders comprise powders activated with tetravalent manganese and processed with K2[M] 1-a Mn 4 + a F6] represents a fluoride phosphor, wherein M is at least one element selected from the group consisting of titanium (Ti), zirconium (Zr), hafnium (Hf), silicon (Si), germanium (Ge), and tin (Sn), and a It has a value greater than 0 and less than 0.2.

[0046] In one example, mixing the first fluoride phosphor powder with the hydrofluoric acid solution includes placing the first fluoride phosphor powder in the hydrofluoric acid solution at a volume-to-weight ratio of at least 2 and not more than 5.

[0047] In one instance, the hydrofluoric acid solution contains manganese-free tertiary fluoride phosphor powder.

[0048] In one instance, removing at least some liquid includes decanting at least some liquid from a mixture of first fluoride phosphor powder and hydrofluoric acid solution.

[0049] Unless otherwise defined, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” etc., as used herein do not indicate any order, quantity, or importance, but are used to distinguish one element from another. Furthermore, the terms “an” and “a” do not indicate a limitation in quantity, but rather indicate the presence of at least one of the referenced items. The use herein of “comprising,” “including,” or “having,” and variations thereof, is intended to cover the items listed thereafter and their equivalents, as well as any additional items. The terms “connection” and “linkage” are not limited to physical or mechanical connections or linkages, and may include electrical and optical connections or linkages, whether direct or indirect.

[0050] Furthermore, those skilled in the art will recognize the interchangeability of various features from different implementations. Those skilled in the art can combine and match the various features described, as well as other known equivalents of each feature, to construct additional systems and techniques in accordance with the principles of this disclosure.

[0051] In describing alternative embodiments of the claimed device, specific terminology has been used for clarity. However, the invention is not intended to be limited to the specific terminology chosen. Therefore, it should be understood that each particular element includes all technical equivalents that operate in a similar manner to achieve similar functionality.

[0052] It should be noted that the various non-limiting embodiments described and claimed herein may be used alone, in combination, or selectively combined for a particular application.

[0053] Furthermore, some of the features of the various non-limiting embodiments described above can be used advantageously without the need to use the other described features accordingly. Therefore, the foregoing description should be considered merely as an illustration of the principles, teachings, and exemplary embodiments of the invention, and not as a limitation thereof.

[0054] Furthermore, the limitations of the following claims are not drafted in a component-plus-function format and are not intended to be interpreted based on 35 U.SC § 112(f), unless and until such claims are limited by the phrase “means for…” followed by a functional statement without further structure.

Claims

1. A method comprising: Fluoride phosphor powder doped with tetravalent manganese is mixed with a treatment solution in a container for a specified time period of time, wherein the fluoride phosphor powder is a composite fluoride phosphor activated with tetravalent manganese. Stop mixing the fluoride phosphor powder with the treatment solution in the container to allow the fluoride phosphor powder to settle in the treatment solution and to separate at least some of the liquid in the container from the fluoride phosphor powder; Remove at least some of the liquid that has been separated from the fluoride phosphor powder from the container; Add a second treatment solution to the remaining treatment solution in the container, wherein the second treatment solution is of the same type as the treatment solution and comprises no more than 5% of the same treatment solution volume to powder weight ratio; The following steps are repeated during one or more additional cycles: mixing the fluoride phosphor powder with the remaining treatment solution and the second treatment solution, stopping the mixing of the fluoride phosphor powder with the remaining treatment solution and the second treatment solution, and removing at least some of the liquid. as well as The steps of mixing the fluoride phosphor powder with the treatment solution, stopping the mixing of the fluoride phosphor powder with the treatment solution, and removing at least some of the liquid are repeated during one or more additional cycles, after which the fluoride phosphor powder is obtained from the container as the remaining amount of fluoride phosphor powder. The fluoride phosphor powder obtained as the remaining amount contains a reduced amount of manganese, relative to the fluoride phosphor powder obtained before mixing the fluoride phosphor powder with the treatment solution, stopping the mixing of the fluoride powder, removing at least some of the liquid, and repeating the mixing, stopping the mixing, and removing at least some of the liquid. Mixing the fluoride phosphor powder with the treatment solution includes placing the fluoride phosphor powder in the treatment solution at a volume-to-weight ratio not exceeding 5. The treatment solution contains hydrofluoric acid and contains manganese-free fluoride powder.

2. The method according to claim 1, wherein the fluoride phosphor powder comprises activated with tetravalent manganese and processed by K2[M] 1-a Mn 4+ a F6] represents fluoride phosphors, Where M is at least one element selected from the group consisting of titanium (Ti), zirconium (Zr), hafnium (Hf), silicon (Si), germanium (Ge), and tin (Sn), and in a It has a value greater than 0 and less than 0.

2.

3. The method of claim 1, wherein the fluoride phosphor comprises A x [MF y ]:Mn 4+ The fluoride phosphor represents Where A represents one or more of lithium, sodium, potassium, rubidium, or cesium. Where M represents one or more of silicon, germanium, tin, titanium, zirconium, aluminum, gallium, indium, scandium, hafnium, yttrium, lanthanum, niobium, tantalum, bismuth, or gadolinium, and in x The value is [MF y The absolute value of the charge of an ion, and y The value is 5, 6, or 7.

4. The method of claim 1, wherein mixing the fluoride phosphor powder with the treatment solution comprises stirring the mixture of the fluoride phosphor powder and the treatment solution, and stopping the mixing comprises stopping the stirring of the mixture of the fluoride phosphor powder and the treatment solution.

5. The method of claim 1, wherein mixing the fluoride phosphor powder with the treatment solution comprises placing the fluoride phosphor powder in the treatment solution at a volume-to-weight ratio of at least 2.

6. The method of claim 1, wherein removing at least some of the liquid comprises decanting the liquid from the mixture of the fluoride phosphor powder and the treatment solution.

7. The method of claim 1, wherein stopping the mixing of the fluoride phosphor powder and the treatment solution in the container comprises allowing the fluoride phosphor powder to settle in the mixture of the fluoride phosphor powder and the treatment solution for at least a second specified time period.

8. The method according to claim 1, further comprising filtering the fluoride phosphor powder, rinsing the fluoride phosphor powder, and drying the rinsed fluoride phosphor powder.

9. A method comprising: Fluoride phosphor powder doped with a dopant is mixed with a processing solution to form a mixture, wherein the dopant includes tetravalent manganese, and wherein the fluoride powder is a composite fluoride phosphor activated with tetravalent manganese. The mixture of the fluoride phosphor powder and the treatment solution is stirred for at least a first specified time period; The stirring of the mixture is stopped for at least a second specified time period to allow the liquid in the mixture to separate from the mixture; Remove at least some of the liquid from the mixture; A second treatment solution is added to the mixture, wherein the second treatment solution is of the same type as the treatment solution and comprises no more than 5% of the same treatment solution volume to powder weight ratio; Repeat the following steps one or more times: mix the fluoride phosphor powder with the remaining treatment solution and the second treatment solution, stir the mixture, stop stirring the mixture, and remove at least some of the liquid from the mixture; as well as The remaining amount of the fluorinated phosphor powder is obtained from the mixture obtained by repeating the following steps: mixing the fluorinated phosphor powder with the treatment solution, stirring the mixture, stopping the stirring, and removing at least some of the liquid from the mixture, after one or more additional cycles. The remaining amount of fluoride phosphor powder, relative to the amount of dopant before mixing the fluoride phosphor powder with the processing solution, stirring the mixture, stopping the stirring, and removing at least some of the liquid from the mixture, contains a reduced amount of the dopant; the mixing of the fluoride phosphor powder with the processing solution comprises placing the fluoride phosphor powder in the processing solution at a volume-to-weight ratio not exceeding 5; and the processing solution contains hydrofluoric acid, and the processing solution contains fluoride powder without the dopant.

10. The method of claim 9, wherein the fluoride phosphor powder comprises activated with tetravalent manganese and processed by K2[M] 1-a Mn 4+ a F6] represents fluoride phosphors, Where M is at least one element selected from the group consisting of titanium (Ti), zirconium (Zr), hafnium (Hf), silicon (Si), germanium (Ge), and tin (Sn), and in a It has a value greater than 0 and less than 0.

2.

11. The method of claim 9, wherein the fluoride phosphor comprises A x [MF y ]:Mn 4+ The fluoride phosphor represents Where A represents one or more of lithium, sodium, potassium, rubidium, or cesium. Where M represents one or more of silicon, germanium, tin, titanium, zirconium, aluminum, gallium, indium, scandium, hafnium, yttrium, lanthanum, niobium, tantalum, bismuth, or gadolinium, and in x The value is [MF y The absolute value of the charge of an ion, and y The value is 5, 6, or 7.

12. The method of claim 9, wherein mixing the fluoride phosphor powder with the treatment solution comprises placing the fluoride phosphor powder in the treatment solution at a volume-to-weight ratio of at least 2.

13. The method of claim 9, wherein removing at least some of the liquid comprises decanting at least some of the liquid from the mixture of the fluoride phosphor powder and the treatment solution.

14. A method comprising: Fluoride phosphor powder doped with tetravalent manganese is mixed with hydrofluoric acid solution to form a mixture, wherein the fluoride phosphor powder is a composite fluoride phosphor activated with tetravalent manganese. The mixture of the fluoride phosphor powder and the hydrofluoric acid solution is stirred for at least a first specified time period; The stirring of the mixture is stopped for at least a second specified time period to allow the liquid in the mixture to separate from the mixture; Remove at least some of the liquid from the mixture; Add a second hydrofluoric acid solution, wherein the second hydrofluoric acid solution comprises no more than 5 times the same hydrofluoric acid solution volume to powder weight ratio; Repeat the following steps once or more: mix the fluoride phosphor powder with the hydrofluoric acid solution and the second hydrofluoric acid solution, stir the mixture, stop stirring the mixture, and remove at least some of the liquid from the mixture; as well as A certain amount of the fluoride phosphor powder is obtained by repeating the following steps: mixing the fluoride phosphor powder with the hydrofluoric acid solution, stirring the mixture, stopping the stirring, and removing at least some of the liquid from the mixture. The fluoride phosphor powder is present in a quantity containing a reduced amount of manganese, prior to repeating the following steps: mixing the fluoride phosphor powder with the hydrofluoric acid solution, stirring the mixture, stopping the stirring, and removing at least some of the liquid from the mixture.

15. The method of claim 14, wherein the fluoride phosphor powder comprises activated with tetravalent manganese and processed by K2[M] 1-a Mn 4+ a F6] represents fluoride phosphors, Where M is at least one element selected from the group consisting of titanium (Ti), zirconium (Zr), hafnium (Hf), silicon (Si), germanium (Ge), and tin (Sn), and in a It has a value greater than 0 and less than 0.

2.

16. The method of claim 14, wherein the fluoride phosphor comprises A x [MF y ]:Mn 4+ The fluoride phosphor represents Where A represents one or more of lithium, sodium, potassium, rubidium, or cesium. Where M represents one or more of silicon, germanium, tin, titanium, zirconium, aluminum, gallium, indium, scandium, hafnium, yttrium, lanthanum, niobium, tantalum, bismuth, or gadolinium, and in x The value is [MF y The absolute value of the charge of an ion, and y The value is 5, 6, or 7.

17. The method of claim 14, wherein removing at least some of the liquid comprises decanting at least some of the liquid from the mixture of the fluoride phosphor powder and the hydrofluoric acid solution.

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