Fluoride red fluorescent particle, fluoride red fluorescent powder, preparation method, light-emitting element and light-emitting device

Abstract

The invention provides fluoride red fluorescent particles, fluoride red fluorescent powder and a preparation method thereof, a light-emitting element and a light-emitting device, and belongs to the technical field of fluorescent powder and light-emitting devices. The chemical formula of the fluoride red fluorescent particles is Na2Si (1-X) F6: Mn < 4 + > X, x is more than 0 and less than 0.1, and the fluoride red fluorescent particles are of a sphere-like structure; the spherical-like structure comprises an upper spherical-crown-like structure and a lower spherical-crown-like structure which are symmetrically arranged, and prisms which are positioned between the upper spherical-crown-like structure and the lower spherical-crown-like structure and are respectively jointed with the bottom surface of the upper spherical-crown-like structure and the bottom surface of the lower spherical-crown-like structure. Compared with phosphors in amorphous and rod-like forms, the fluorescent particles of the sphere-like structure have more concentrated particle size distribution and lower distribution coefficient, which indicates that the sphere-like fluorescent particles of the sphere-like structure have better centrality and uniformity.

Description

Technical Field

[0001] The present disclosure belongs to the technical field of phosphors and light-emitting devices, and particularly relates to a fluoride red phosphor particle, a fluoride red phosphor and a preparation method, a light-emitting element, and a light-emitting device. Background Art

[0002] With the rapid development of new optoelectronic materials and technologies, white LED light sources based on light-emitting diode (LED) and phosphor coupling technology have become an important technical support in the field of modern lighting and display, from mobile phone screens to large commercial lighting, from smart homes to car display systems, thanks to their advantages of high luminous efficiency, long life, and low energy consumption. The current mainstream white light LED production solution is based on InGaN-based blue light chips, combined with Y3Al5O 12 :Ce 3+ (YAG:Ce) yellow phosphor constructs a light conversion system. The YAG:Ce phosphor is excited by the blue light chip to produce 550-580nm yellow light emission, and the unabsorbed blue light mixes with the yellow light to form white light. This "blue light-yellow light" binary system occupies the main application scenarios of white light in the world due to its mature technology. However, the defect of this technology is the imbalance of spectral distribution-the red light band (600-700nm) is missing, resulting in a cold color tone of the light source (color temperature > 4000K) and a relatively low color rendering index (Ra) (around 75). This spectral characteristic makes it difficult for traditional white light LEDs to meet high color rendering requirements, and it is impossible to achieve wide color gamut standards such as DCI-P3 in the field of LCD backlight sources.

[0003] To break through this technical bottleneck, in recent years, the focus has been on the development and application of red light fluorescent particles, for example, the construction of a "blue light-yellow light-red light" ternary mixed light system. The color temperature can be reduced to below 3000K, and the color rendering index exceeds 90. 4+ or Eu 3+ It is the main method to obtain red phosphor at present. 4+ The doped fluoride phosphor is particularly eye-catching. It exhibits a narrow-band emission characteristic with a half-maximum width of less than 10nm at 630nm, which enables the color gamut coverage of the backlight display system to reach 120% of the NTSC standard, showing irreplaceable application value in new display technologies such as Mini-LED and Micro-LED.

[0004] Among the related research results, one of the existing technologies, Chinese patent application CN105038775A, discloses a narrow-band red fluoride phosphor containing Na and Si elements, but does not clarify its specific morphological characteristics and performance parameters. One of the existing technologies, Chinese patent application CN114276805A, discloses a method for preparing a long rod-shaped structure Na2SiF6:Mn 4+The synthesis method of fluoride phosphor has obvious sharp narrow band emission near 627nm. During the LED device manufacturing process, these rod-shaped and amorphous Na2SiF6:Mn 4+ Fluorescent particles have problems such as poor coating fluidity and poor color consistency. Summary of the Invention

[0005] The present disclosure aims to at least solve the technical problems existing in the prior art, such as structural instability, poor coating fluidity, and poor color point consistency, and provides a fluoride red fluorescent particle, a fluoride red fluorescent powder, and a preparation method thereof, a light-emitting element, and a light-emitting device.

[0006] In one aspect of the present disclosure, the chemical formula of the fluoride red fluorescent particles is Na2Si (1-X) F6:Mn 4+ X , 0<x<0.1, the fluoride red fluorescent particles have a spherical structure;

[0007] The spherical structure includes an upper spherical cap structure and a lower spherical cap structure that are symmetrically arranged, and a prism located between the upper spherical cap structure and the lower spherical cap structure and respectively connected to the bottom surface of the upper spherical cap structure and the bottom surface of the lower spherical cap structure.

[0008] Optionally, the upper spherical cap structure, the lower spherical cap structure and the prism each have at least six sides; wherein,

[0009] The side surface of the upper spherical cap structure bends and extends upward from the top of the side surface of the prism, and the side surface of the lower spherical cap structure bends and extends downward from the bottom of the side surface of the prism.

[0010] Optionally, the spherical-like structure includes at least a spherical-like structure having eighteen sides.

[0011] Optionally, the ratio of the height of the prism to the longest diagonal perpendicular to the cross section of the prism is 0.2-2.

[0012] Optionally, the ratio of the height of the prism to the sum of the height of the upper spherical cap structure and the height of the lower spherical cap structure is 0.2 to 1.5.

[0013] Optionally, the median particle size of the fluoride red fluorescent particles is 1 μm<D50<50μ.

[0014] Another aspect of the present disclosure provides a fluoride red phosphor. The fluoride red silver phosphor includes the fluoride phosphor particles described above.

[0015] Optionally, in the fluoride red phosphor powder, the content of the fluoride red phosphor particles is higher than 10%.

[0016] Another aspect of the present disclosure provides a method for preparing the fluoride phosphor described above, the method comprising:

[0017] dissolving sodium fluorosilicate and sodium fluoromanganate solid powders in hydrofluoric acid, heating and stirring to obtain a first solution;

[0018] Dissolving NaHF2 solid powder in hydrofluoric acid, heating and stirring to obtain a second solution;

[0019] adding a fluorine-containing organic sodium salt and nitric acid to hydrofluoric acid, placing in an ice bath, and stirring to dissolve to obtain a third solution;

[0020] The first solution and the second solution are added to the reaction container at a first addition rate, and the third solution is added at a second addition rate, and stirred and mixed uniformly under ice-water bath conditions, and the supernatant is poured out, and Na2SiF6:Mn is obtained after washing and drying. 4+ Fluoride red phosphor.

[0021] Optionally, the mass ratio of the sodium fluorosilicate, sodium fluoromanganate solid powder and the hydrofluoric acid is 10:1.5:500;

[0022] The mass ratio of the NaHF2 solid powder to hydrofluoric acid is 9:250;

[0023] The fluorine-containing organic sodium salt is one of sodium trifluoromethanesulfonate, sodium trifluoroacetate and sodium perfluorooctanoate;

[0024] The mass ratio of the fluorine-containing organic sodium salt, the nitric acid and the hydrofluoric acid is 0.5:10:100;

[0025] The first addition speed is 50 g / min, and the second addition speed is 5-32 g / min.

[0026] In another aspect of the present disclosure, a light-emitting element is provided, comprising the fluoride red phosphor described above and a light source.

[0027] In another aspect of the present disclosure, a light-emitting device is provided. The light-emitting device includes the light-emitting element described above.

[0028] The present invention discloses a fluoride red fluorescent particle, a fluoride red fluorescent powder, a preparation method thereof, a light-emitting element, and a light-emitting device. The chemical formula of the fluoride red fluorescent particle is Na2Si (1-X) F6:Mn 4+ X, 0<x<0.1, the fluoride red fluorescent particles have a quasi-spherical structure; the quasi-spherical structure includes a symmetrically arranged upper quasi-spherical cap structure and a lower quasi-spherical cap structure, and a prism located between the upper and lower quasi-spherical cap structures and respectively bonded to the bottom surfaces of the upper and lower quasi-spherical cap structures. Compared to amorphous and rod-shaped morphologies, the quasi-spherical structured phosphor has a more concentrated particle size distribution and a lower distribution coefficient, indicating that the quasi-spherical particles have better concentration and uniformity, thereby providing good coating fluidity and color point consistency during the coating process. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of a spherical structure of fluoride red fluorescent particles according to a specific embodiment of the present disclosure;

[0030] Figure 2 This is a flowchart of a method for preparing fluoride red phosphor according to a specific embodiment of the present disclosure;

[0031] Figure 3 This is a morphology diagram of the fluorescent particles in the fluoride red phosphor prepared in Example 1 of the present disclosure;

[0032] Figure 4 This is a morphology diagram of the fluorescent particles in the fluoride red phosphor prepared in Example 4 of the present disclosure;

[0033] Figure 5 The spherical Na2SiF6:Mn 4+ Excitation spectrum of fluoride fluorescent particles;

[0034] Figure 6 The spherical Na2SiF6:Mn 4+ Emission spectrum of fluoride fluorescent particles;

[0035] Figure 7 The spherical Na2SiF6:Mn 4+ Crystalline X-ray diffraction spectrum of fluoride fluorescent particles;

[0036] Figure 8 The amorphous Na2SiF6:Mn prepared in Comparative Example 1 of the present disclosure 4+ Morphology of fluoride phosphor;

[0037] Figure 9 The rod-shaped Na2SiF6:Mn prepared in Comparative Example 2 of the present disclosure 4+ Morphology of fluoride phosphor;

[0038] Figure 10 The spherical Na2SiF6:Mn of Example 1 and Comparative Examples 1-2 of the present disclosure4+ The LED light color consistency results of fluoride fluorescent particles; among them, Figure 10 (a) is the result of Comparative Example 1, Figure 10 (b) is the result of Comparative Example 2, Figure 10 (c) in the figure is the result of Example 1. DETAILED DESCRIPTION

[0039] To enable those skilled in the art to better understand the technical solutions of the present disclosure, the present disclosure is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to illustrate the present disclosure and are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present disclosure.

[0040] like Figure 1 As shown, in one aspect of this embodiment, a fluoride red fluorescent particle Na2SiF6:Mn 4+ The fluoride red fluorescent particles Na2SiF6:Mn 4+ The chemical formula is Na2Si (1-X) F6:Mn 4+ X , 0<x<0.1, the fluoride red fluorescent particle is a spherical-like structure; the spherical-like structure 100 includes an upper spherical-like cap structure 110 and a lower spherical-like cap structure 120 symmetrically arranged, and a prism 130 located between the upper spherical-like cap structure 110 and the lower spherical-like cap structure 120 and respectively joined to the bottom surface of the upper spherical-like cap structure 110 and the bottom surface of the lower spherical-like cap structure 120.

[0041] Different from the conventional amorphous or rod-like morphology, the Na2SiF6:Mn 4+ Fluoride phosphor particles exhibit a quasi-spherical structure. Due to their inherent symmetry and uniform dispersion in the medium, these spherical particles disperse evenly during the LED phosphor coating process, making them less prone to directional alignment or aggregation. This helps improve distribution stability and effectively enhances light color consistency during the coating process. Furthermore, the relatively symmetrical geometry of these spherical structures allows for more uniform light scattering and absorption by the phosphor particles within LED devices, resulting in more uniform light conversion and emission in all directions, thereby enhancing the color consistency of the entire LED device.

[0042] It should be understood that in the spherical fluorescent particles of this embodiment, the prism has multiple side faces and two upper and lower base faces of the same area. The side faces of the prism are quadrilaterals and the bottom faces are polygonal. The bottom faces of the upper and lower spherical cap structures are the same shape as the bottom faces of the prisms, and the side faces are multiple bent triangles, the number of which is the same as the number of side faces of the prisms. That is, the triangular side faces of the upper spherical cap structure bend upward from the top of the quadrilateral side faces of the prism, and the triangular side faces of the lower spherical cap structure bend downward from the bottom of the quadrilateral side faces of the prism to form a spherical cap-like structure. At the same time, the bottom face of the upper spherical cap structure is joined to the upper base face of the prism, and the bottom face of the lower spherical cap structure is joined to the lower base face of the prism to form a dense overall structure.

[0043] In some preferred embodiments, the prism has at least six sides. Similarly, the upper and lower spherical cap structures should also have at least six bent triangular sides. For example, when the prism is a hexagonal prism, the upper and lower spherical cap structures should have six bent triangular sides. Thus, the fluoride red fluorescent particle is equivalent to forming a spherical structure with 18 sides. Of course, the upper and lower spherical cap structures and the prism can also have a larger number of sides to form other spherical structures, which are not listed here. Of course, it should be noted that in order to illustrate the overall structure of the fluorescent particle, the sides of the upper and lower spherical cap structures are described as bent triangular sides. However, in actual electron microscopic images, these bent triangular sides are connected together to form a continuous and complete spherical cap structure, and the edges at the connection are not obvious.

[0044] As a further preferred embodiment, the spherical-like structure preferably has a spherical-like structure with eighteen sides, and the proportion of the spherical-like structure is higher than 10%, and further preferably, the content of the spherical-like structure with eighteen sides is higher than 50%. In other words, the fluorescent particles at least include a spherical-like structure with eighteen sides. This spherical-like structure with more sides has a more regular and symmetrical overall shape, and the interaction between the fluorescent particles is more uniform. Compared with other irregular shapes, it is not easy to agglomerate or settle due to local shape differences, and can maintain a more stable dispersion state in the medium, thereby ensuring the uniformity of the fluid during the coating process and further improving the coating fluidity. At the same time, this spherical-like structure with multiple side structures can increase the number of interfaces and angle diversity between light and fluorescent particles. When the light emitted by the LED chip is irradiated on the fluorescent particles, multiple sides can scatter and convert the light from more directions and angles, so that the final emitted red fluorescence is more uniform.

[0045] In other preferred embodiments, please refer to Figure 1The ratio of the height (h2) of the prism 130 and the longest diagonal (L) perpendicular to the cross section of the prism 130 is 0.2 to 2, and preferably 0.3 to 0.5. The above ratio range helps to control the packing density of the fluorescent particles in the coating material. When the excitation light is incident on the fluorescent particles, the propagation distance of light of different paths in the prism and spherical cap structure is relatively small.

[0046] In other preferred embodiments, the ratio of the height of the prism (h2) to the sum of the height of the upper spherical cap structure (h1) and the height of the lower spherical cap structure (h3) is 0.2 to 1.5, and more preferably 0.3 to 0.5. Within this height ratio range, the center of gravity of the phosphor particles is relatively stable and moderate. During the flow of the coating medium, the particles can more smoothly follow the fluid, improving the coating fluidity and ensuring a more balanced propagation path of the excitation light within the phosphor particles.

[0047] In other preferred embodiments, the median particle size of the fluoride red phosphor particles is 1 μm < D50 < 50 μm, and more preferably 5 μm < D50 < 35 μm. In the phosphor layer, phosphor particles within this particle size range can fully convert the light emitted by the light-emitting chip into red light, reducing light loss.

[0048] In another aspect of this embodiment, a fluoride red phosphor is provided, comprising the fluoride phosphor particles described above. The fluoride red phosphor particles comprise greater than 10% of the total phosphor content. In other words, the polyhedral phosphor particles comprise at least 10% of the total phosphor content.

[0049] like Figure 2 As shown, another aspect of this embodiment provides a method S200 for preparing the fluoride red phosphor described above, which specifically includes the following steps S210 to S240:

[0050] S210, dissolving solid powders of sodium fluorosilicate and sodium fluoromanganate in hydrofluoric acid, heating and stirring to obtain a first solution.

[0051] In step S210, the mass ratio of sodium fluorosilicate, sodium fluoromanganate solid powder and hydrofluoric acid is 10:1.5:500, the hydrofluoric acid is preferably 50% hydrofluoric acid, and the heating and stirring temperature is preferably 55-65°C, for example, 55°C, 60°C, 65°C, etc.

[0052] S220, dissolving NaHF2 solid powder in hydrofluoric acid, heating and stirring to obtain a second solution.

[0053] In step S220, the mass ratio of NaHF2 solid powder to hydrofluoric acid is 9:250, and the hydrofluoric acid is preferably 50% hydrofluoric acid. The heating and stirring temperature is preferably 55-65°C, for example, 55°C, 60°C, 65°C, etc.

[0054] S230, adding a fluorine-containing organic sodium salt and nitric acid to hydrofluoric acid, stirring and dissolving in an ice bath to obtain a third solution.

[0055] In step S230 , the mass ratio of the fluorine-containing organic sodium salt, the nitric acid, and the hydrofluoric acid is 0.5:10:100, and the hydrofluoric acid is also preferably 50% hydrofluoric acid.

[0056] In step S230, the fluorine-containing organic sodium salt is one of sodium trifluoromethanesulfonate, sodium trifluoroacetate, and sodium perfluorooctanoate.

[0057] S240, adding the first solution and the second solution at a first adding speed, and adding the third solution at a second adding speed to the reaction container, stirring and mixing them uniformly in an ice-water bath, discarding the supernatant, washing and drying to obtain Na2SiF6:Mn 4+ Fluoride phosphor powder.

[0058] In step S240, the first addition rate is 50 g / min, the second addition rate is 5-32 g / min, the stirring and mixing time is 2-5 hours, and the washing treatment includes adding HF (5%) and stirring and washing for 2 hours, and washing with ethanol twice.

[0059] During the powder synthesis process, fluorinated organic sodium salts and nitric acid were introduced to stimulate the lateral expansion and growth of the crystal habit while modifying the surface edges and corners, changing the Na2SiF6:Mn 4+ The crystal growth mode, in which the introduction of fluorine-containing organic sodium salt changes the Na2SiF6 crystal nucleus growth template from rod-shaped nucleus to polyhedral nucleus, and the introduction of nitric acid increases the solubility of the system, making Na2SiF6:Mn 4 It not only retains the outline of the polyhedron, but also shows a phenomenon of edge dissolution at the corners of the polyhedron, thus forming a spherical crown structure with the upper and lower sides of the prism. Compared with the amorphous and rod-like structures, it evolves into uniform and regular spherical particles. This kind of fluorescent particles are evenly dispersed in the LED phosphor coating process, effectively improving the consistency of light color and having a better use effect.

[0060] In another aspect of this embodiment, a light-emitting element is provided. The light-emitting element includes the fluoride red phosphor described above and a light source.

[0061] In another aspect of this embodiment, a light-emitting device is provided. The light-emitting device includes the light-emitting element described above.

[0062] The preparation method of fluoride red phosphor will be further described below with reference to specific examples:

[0063] Example 1

[0064] This example provides a method for preparing a fluoride red phosphor with a spherical morphology, comprising the following steps:

[0065] 1. Take 10g Na2SiF6 sodium fluorosilicate and 1.5g Na2MnF6 sodium fluoromanganate solid powder, dissolve them in 500g commercially available 50% hydrofluoric acid (electronic grade), heat to 60℃ and stir evenly to form the first solution.

[0066] 2. Take 18g of NaHF2 solid powder and dissolve it in 500g of commercially available 50% hydrofluoric acid (electronic grade), heat to 60°C and stir evenly to obtain a second solution.

[0067] 3. Add 0.5 g of sodium trifluoromethanesulfonate and 10 g of nitric acid (30%) to 100 g of 50% hydrofluoric acid (electronic grade), place in an ice bath, and stir to dissolve to obtain a third solution.

[0068] 4. Place a 2000ml Teflon beaker in an ice water bath, add the first solution and the second solution at a rate of 50g / min, and the third solution at a rate of 22g / min into the Teflon beaker respectively, and stir for 3 hours to mix evenly.

[0069] 5. Pour off the supernatant, add HF (5%) and stir and wash for 2h, wash twice with ethanol, and dry to obtain Na2SiF6:Mn 4+ Fluoride phosphor powder.

[0070] The Na2SiF6:Mn prepared in this example 4+ A fluoride phosphor powder comprising phosphor particles having a quasi-spherical structure, wherein the content of the phosphor particles having this structure is greater than 10%. In the quasi-spherical structure phosphor particles having eighteen sides, the ratio of the sum of the height of the prism (h2), the height of the upper quasi-spherical cap structure (h1), and the height of the lower quasi-spherical cap structure (h3) is h2 / (h1+h3)=1.0, and the ratio of the height of the prism 130 (h2) to the longest diagonal (L) of the prism 130 is 0.5.

[0071] As shown in Table 1, the phosphor prepared in this embodiment has D10=20.9 μm, D50=30.2 μm, D90=49.8 μm, D99=60.1 μm, and a Span distribution coefficient of 0.957.

[0072] Example 2

[0073] This example provides a method for preparing a fluoride red phosphor with a spherical morphology, comprising the following steps:

[0074] 1. Take 10g Na2SiF6 sodium fluorosilicate and 1.5g Na2MnF6 sodium fluoromanganate solid powder, dissolve them in 500g commercially available 50% hydrofluoric acid (electronic grade), heat to 60℃ and stir evenly to form the first solution.

[0075] 2. Take 18g of NaHF2 solid powder and dissolve it in 500g of commercially available 50% hydrofluoric acid (electronic grade), heat to 60°C and stir evenly to obtain a second solution.

[0076] 3. Add 0.5 g of sodium trifluoromethanesulfonate and 10 g of nitric acid (30%) to 100 g of 50% hydrofluoric acid (electronic grade), place in an ice bath, and stir to dissolve to obtain a third solution.

[0077] 4. Place a 2000ml Teflon beaker in an ice water bath, add the first solution and the second solution at a rate of 50g / min, and the third solution at 32g / min into the Teflon beaker respectively, and stir for 3h to mix evenly.

[0078] 5. Pour off the supernatant, add HF (5%) and stir and wash for 2h, wash twice with ethanol, and dry to obtain Na2SiF6:Mn 4+ Fluoride phosphor powder.

[0079] The Na2SiF6:Mn prepared in this example 4+ A fluoride red phosphor powder comprising phosphor particles with a quasi-spherical structure, wherein the content of the phosphor particles with this structure is greater than 10%. In the quasi-spherical structure phosphor particles having eighteen sides, the ratio of the sum of the height of the prism (h2) to the height of the upper quasi-spherical cap structure (h1) and the height of the lower quasi-spherical cap structure (h3) is h2 / (h1+h3) = 0.2, and the ratio of the height of the prism 130 (h2) to the longest diagonal (L) of the prism 130 is 0.3.

[0080] The following is an analysis of the prepared phosphor with an 18-sided spherical structure. The excitation spectrum, emission spectrum, and crystal phase X-ray diffraction results are as follows:

[0081] like Figure 5 As shown, the excitation spectrum covers a wavelength range from about 300 nm to 550 nm, which indicates that the fluorescent particles can be excited in a wide UV-visible light region.

[0082] like Figure 6 As shown, spherical Na2SiF6:Mn 4+The emission spectrum of the fluorescent particles under 455nm excitation has a peak wavelength of 627.1nm near the red spectrum narrowband emission, and belongs to Na2SiF6:Mn 4+ Characteristic emission spectrum of phosphor.

[0083] like Figure 7 As shown, spherical Na2SiF6:Mn 4+ The diffraction peaks of the fluorescent particles show that they are consistent with the hexagonal Na2SiF6 (PDF#33-1280) standard card, and have high crystallinity and no other impurities.

[0084] As shown in Table 1, the phosphor prepared in this embodiment has D10=20.3 μm, D50=30.5 μm, D90=50.8 μm, D99=62.3 μm, and a Span distribution coefficient of 0.998.

[0085] Example 3

[0086] This example provides a method for preparing a fluoride red phosphor with a spherical morphology, comprising the following steps:

[0087] 1. Take 10g Na2SiF6 sodium fluorosilicate and 1.5g Na2MnF6 sodium fluoromanganate solid powder, dissolve them in 500g commercially available 50% hydrofluoric acid (electronic grade), heat to 60℃ and stir evenly to form the first solution.

[0088] 2. Take 18g of NaHF2 solid powder and dissolve it in 500g of commercially available 50% hydrofluoric acid (electronic grade), heat to 60°C and stir evenly to obtain a second solution.

[0089] 3. Add 0.5 g of sodium trifluoromethanesulfonate and 10 g of nitric acid (30%) to 100 g of 50% hydrofluoric acid (electronic grade), place in an ice bath, and stir to dissolve to obtain a third solution.

[0090] 4. Place a 2000ml Teflon beaker in an ice water bath, add the first solution and the second solution at a rate of 50g / min, and the third solution at a rate of 5g / min into the Teflon beaker respectively and stir for 3h to mix evenly.

[0091] 5. Pour off the supernatant, add HF (5%) and stir and wash for 2h, wash twice with ethanol, and dry to obtain Na2SiF6:Mn 4+ Fluoride phosphor powder.

[0092] The Na2SiF6:Mn prepared in this example 4+A fluoride phosphor powder comprising phosphor particles having a quasi-spherical structure, wherein the content of the phosphor particles having this structure is greater than 10%. In the quasi-spherical structure phosphor particles having eighteen sides, the ratio of the sum of the height of the prism (h2), the height of the upper quasi-spherical cap structure (h1), and the height of the lower quasi-spherical cap structure (h3) is h2 / (h1+h3)=1.5, and the ratio of the height of the prism 130 (h2) to the longest diagonal (L) of the prism 130 is 1.

[0093] As shown in Table 1, the phosphor prepared in this embodiment has D10=20.7 μm, D50=30.1 μm, D90=49.6 μm, D99=62.3 μm, and a Span distribution coefficient of 0.960.

[0094] Example 4

[0095] This example provides a method for preparing a fluoride red phosphor with a spherical morphology, comprising the following steps:

[0096] 1. Take 10g Na2SiF6 sodium fluorosilicate and 1.5g Na2MnF6 sodium fluoromanganate solid powder, dissolve them in 500g commercially available 50% hydrofluoric acid (electronic grade), heat to 60℃ and stir evenly to form the first solution.

[0097] 2. Take 18g of NaHF2 solid powder and dissolve it in 500g of commercially available 50% hydrofluoric acid (electronic grade), heat to 60°C and stir evenly to obtain a second solution.

[0098] 3. Add 0.5 g of sodium trifluoromethanesulfonate to 100 g of 50% hydrofluoric acid (electronic grade), place in an ice bath, and stir to dissolve to obtain a third solution.

[0099] 4. Place a 2000ml Teflon beaker in an ice water bath, add the first solution and the second solution at a rate of 50g / min, and the third solution at a rate of 22g / min into the Teflon beaker respectively, and stir for 3 hours to mix evenly.

[0100] 5. Pour off the supernatant, add HF (5%) and stir and wash for 2h, wash twice with ethanol, and dry to obtain Na2SiF6:Mn 4+ Fluoride phosphor powder.

[0101] The Na2SiF6:Mn prepared in this example 4+Fluoride phosphor powder, comprising phosphor particles with a quasi-spherical structure, wherein the content of the phosphor particles with this structure is greater than 10%. In the quasi-spherical structured phosphor particles having eighteen sides, the ratio of the sum of the prism height (h2) to the height of the upper quasi-spherical cap structure (h1) and the height of the lower quasi-spherical cap structure (h3) is h2 / (h1+h3) = 1.0, and the ratio of the height (h2) of the prism 130 to the longest diagonal (L) of the prism 130 is 0.5. Because nitric acid was not introduced during the synthesis stage to alter solubility, the crystal habit planes and corners are clearly visible, and the sphericity is relatively low.

[0102] As shown in Table 1, the phosphor prepared in this embodiment has D10=20.5 μm, D50=30.3 μm, D90=41.6 μm, D99=62.5 μm, and a Span distribution coefficient of 1.026.

[0103] In summary, according to the results of Examples 1-3, the h2 / (h1+h3) ratio parameters of the spherical phosphor can be regulated by adjusting the feeding rate of the third solution. The faster the feeding rate, the smaller the h2 / (h1+h3) ratio. The introduction of sodium trifluorosulfonate in the system changes the Na2SiF6 crystal nucleus growth template from rod-shaped nuclei to icosahedral nuclei. The introduction of nitric acid increases the solubility of the system, making Na2SiF6:Mn 4+ While retaining the outline of the icosahedron, the corners of the icosahedron are dissolved, so that the prisms on the upper and lower sides are transformed into spherical cap structures, thus forming the spherical phosphor particles with eighteen sides of the above embodiment.

[0104] Comparative Example 1

[0105] This example provides a method for preparing amorphous fluoride red phosphor, including the following steps:

[0106] 1. Measure 1.5 g of Na2MnF6 and dissolve it in 50 g of commercially available 10%-15% hydrofluorosilicic acid to obtain a first solution.

[0107] 2. Dissolve 16.4 g of NaHF2 in 500 g of 50% hydrofluoric acid (electronic grade) to obtain a second solution.

[0108] 3. The first solution was injected into the second solution at a speed of 50 g / min and mechanically stirred at 40 ° C. After the reaction solution was stirred for 2 hours, the supernatant was discarded, HF (5%) was added and stirred for 2 hours, washed with ethanol twice, and dried to obtain Na2SiF6:Mn 4+ Fluoride phosphor powder.

[0109] like Figure 8 As shown, the Na2SiF6:Mn prepared in this embodiment 4+Fluoride phosphor powder has an amorphous morphology.

[0110] As shown in Table 1, the phosphor prepared in this comparative example has D10=14.8 μm, D50=30.3 μm, D90=51.7 μm, D99=72.5 μm, and a Span distribution coefficient of 1.218.

[0111] According to the results of Comparative Example 1 and Examples 1-3, when the phosphor morphology is amorphous, the Span distribution coefficient is greater than that of the examples, indicating that the particle size distribution of Examples 1-3 is more concentrated, and Comparative Example 1 has a wider particle size distribution (with more extremely small and extremely large particles), while the particle sizes of Examples 1-3 are more uniform and their optical properties are more consistent.

[0112] Comparative Example 2

[0113] This example provides a method for preparing a rod-shaped fluoride red phosphor, comprising the following steps:

[0114] 1. Take 10g Na2SiF6 sodium fluorosilicate and 1.5g Na2MnF6 sodium fluoromanganate solid powder, dissolve them in 500g commercially available 50% hydrofluoric acid (electronic grade), heat to 60℃ and stir evenly to form the first solution.

[0115] 2. Take 18g of NaHF2 solid powder and dissolve it in 500g of commercially available 50% hydrofluoric acid (electronic grade), heat to 60°C and stir evenly to obtain a second solution.

[0116] 3. Place a 1500ml Teflon beaker in an ice water bath, add the first solution and the second solution into the Teflon beaker at a rate of 50g / min and stir for 3h to mix evenly.

[0117] 4. Pour off the supernatant, add HF (5%) and stir and wash for 2h, wash twice with ethanol, and dry to obtain Na2SiF6:Mn 4+ Fluoride phosphor powder.

[0118] like Figure 9 As shown, the Na2SiF6:Mn 4+ The fluoride phosphor powder has a rod-like morphology.

[0119] As shown in Table 1, the phosphor prepared in this comparative example has D10=12.1 μm, D50=30.2 μm, D90=61.7 μm, D99=80.7 μm, and a span distribution coefficient of 1.642.

[0120] According to the results of Comparative Example 2 and Examples 1-3, when the phosphor morphology is rod-like, the Span distribution coefficient is significantly greater than that of the examples, indicating that the particle size distribution of Examples 1-3 is more concentrated, Comparative Example 2 has a wider particle size distribution, and the particle size of Examples 1-3 is more uniform, and their optical properties are more consistent.

[0121] Figure 10 This is the color point concentration target diagram of Example 1 and Comparative Example 1 and Comparative Example 2 tested in the LED coating process. Figure 10 The same median particle size parameters can be seen in Example 1 (spherical fluorescent particles, corresponding to Figure 10 (c)) compared to Comparative Example 1 (amorphous fluorescent particles, corresponding to Figure 10 (a)) and Comparative Example 2 (rod-shaped fluorescent particles, corresponding to Figure 10 In the color area covered by (b), the color points are more consistent and concentrated.

[0122] In summary, according to the data in the particle size distribution table and the figure, Na2SiF6:Mn 4+ Compared with amorphous and rod-shaped particles, spherical particles have a more concentrated particle size distribution and a lower distribution coefficient, which indicates that spherical particles have better concentration and uniformity.

[0123] Table 1 Results of the particle sizes of phosphors

[0124] Particle size distribution D10 D50 D90 D99 Span distribution coefficient Comparative Example 1 14.8 30.3 51.7 72.5 1.218 Comparative Example 2 12.1 30.2 61.7 80.7 1.642 Example 1 20.9 30.2 49.8 60.1 0.957 Example 2 20.3 30.5 50.8 62.3 0.998 Example 3 20.7 30.1 49.6 62.3 0.960 Example 4 20.5 30.3 51.6 62.5 1.026

[0125] The present invention discloses a fluoride red fluorescent particle, a fluoride red fluorescent powder and a preparation method thereof, a light-emitting element and a light-emitting device, which have the following beneficial effects compared with the prior art: the present invention synthesizes spherical Na2SiF6:Mn by a wet synthesis process. 4+ Fluoride fluorescent particles are significantly different from the currently disclosed rod-shaped or amorphous phosphors. Based on this difference in morphology and structure, the spherical structure phosphor disclosed in the present invention has better coating effect and light color consistency.

[0126] It is understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present disclosure, and the present disclosure is not limited thereto. Those skilled in the art may make various modifications and improvements without departing from the spirit and substance of the present disclosure, and such modifications and improvements are also considered to be within the scope of protection of the present disclosure.

Claims

1. A fluoride red fluorescent particle, characterized in that: The chemical formula of the fluoride red fluorescent particles is Na2Si (1-X) F6:Mn 4+ X , 0<x<0.1, the fluoride red fluorescent particles have a spherical structure; The spherical structure includes an upper spherical cap structure and a lower spherical cap structure that are symmetrically arranged, and a prism located between the upper spherical cap structure and the lower spherical cap structure and respectively connected to the bottom surface of the upper spherical cap structure and the bottom surface of the lower spherical cap structure.

2. The fluoride red fluorescent particle according to claim 1, characterized in that: The upper spherical cap structure, the lower spherical cap structure and the prism all have at least six sides; wherein, The side surface of the upper spherical cap structure bends and extends upward from the top of the side surface of the prism, and the side surface of the lower spherical cap structure bends and extends downward from the bottom of the side surface of the prism.

3. The fluoride red fluorescent particle according to claim 2, characterized in that: The spherical-like structure at least includes a spherical-like structure with eighteen sides.

4. The fluoride red fluorescent particle according to claim 1, characterized in that: The ratio of the height of the prism to the longest diagonal perpendicular to the cross section of the prism is 0.2-2.

5. The fluoride red fluorescent particle according to claim 1, characterized in that: The ratio of the sum of the height of the prism, the height of the upper spherical cap structure, and the height of the lower spherical cap structure is 0.2 to 1.

5.

6. The fluoride red fluorescent particle according to claim 1, characterized in that: The median particle size of the fluoride red fluorescent particles is 1 μm<D50<50 μm.

7. A fluoride red phosphor, characterized in that: The fluoride red phosphor comprises the fluoride fluorescent particles according to any one of claims 1 to 6.

8. The fluoride red phosphor according to claim 7, characterized in that: In the fluoride red phosphor powder, the content of the fluoride red phosphor particles is higher than 10%.

9. A method for preparing the fluoride red phosphor according to any one of claims 7 or 8, characterized in that: The method comprises: dissolving sodium fluorosilicate and sodium fluoromanganate solid powders in hydrofluoric acid, heating and stirring to obtain a first solution; Dissolving NaHF2 solid powder in hydrofluoric acid, heating and stirring to obtain a second solution; adding a fluorine-containing organic sodium salt and nitric acid to hydrofluoric acid, stirring and dissolving in an ice bath to obtain a third solution; The first solution and the second solution are added to the reaction container at a first addition rate, and the third solution is added at a second addition rate, and stirred and mixed uniformly under ice-water bath conditions, and the supernatant is poured out, and Na2SiF6:Mn is obtained after washing and drying. 4+ Fluoride red phosphor.

10. The method according to claim 9, characterized in that The mass ratio of the sodium fluorosilicate, sodium fluoromanganate solid powder and the hydrofluoric acid is 10:1.5:500; The mass ratio of the NaHF2 solid powder to hydrofluoric acid is 9:250; The fluorine-containing organic sodium salt is one of sodium trifluoromethanesulfonate, sodium trifluoroacetate and sodium perfluorooctanoate; The mass ratio of the fluorine-containing organic sodium salt, the nitric acid and the hydrofluoric acid is 0.5:10:100; The first addition speed is 50 g / min, and the second addition speed is 5-32 g / min.

11. A light-emitting element, characterized in that: The light-emitting element comprises the fluoride red phosphor according to claim 7 or 8 and a light source.

12. A light emitting device, characterized in that: The light-emitting device includes the light-emitting element according to claim 11.

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