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

Abstract

The invention provides fluoride fluorescent particles, fluoride 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 fluorescent particle is Na2Si (1-X) F6: Mn4 + X, x is greater than 0 and less than 0.1, the fluoride fluorescent particle is of a polyhedral structure, and the polyhedral structure comprises an upper prismatic table, a lower prismatic table and prisms, the upper prismatic table and the lower prismatic table are symmetrically arranged, and the prisms are positioned between the upper prismatic table and the lower prismatic table and are respectively jointed with the lower bottom surface of the upper prismatic table and the lower bottom surface of the lower prismatic table. The fluorescent particle with the polyhedral structure has the characteristics of high emission intensity and high stability, and compared with a rod-shaped structure and an amorphous structure, the fluorescent particle with the polyhedral structure has the advantages that the contact area with water / water vapor after LED packaging is reduced, the dissociation speed is reduced, and the service life of an LED device is prolonged.

Description

Technical Field

[0001] The present disclosure belongs to the technical field of phosphors and light-emitting devices, and particularly relates to fluoride phosphor particles, fluoride phosphors and preparation methods, light-emitting elements, and light-emitting devices. Background Art

[0002] With the continuous research on lighting display light sources around the world, white light emitting diodes (white LEDs) composed of light emitting diodes (LEDs) and phosphors have been widely used in display backlight sources and lighting devices in recent years.

[0003] At present, the most common preparation of white light LED light source is to use InGaN as blue light chip and Y3Al5O 12 :Ce 3+ (YAG:Ce) yellow phosphor is coated to prepare the light-emitting unit; InGaN emits blue light to excite YAG:Ce to emit yellow light, which is then mixed with the unabsorbed blue light to produce white light. This combination of blue light and yellow light to obtain white light has the characteristics of simple and easy packaging process, and is the most common form of white light LED light source. However, the spectrum of the light source obtained by this combination lacks the red light band, making the white light presented by the light source cold, and the color temperature is relatively high, generally greater than 4000K, and the color rendering index (Ra) is relatively low, generally less than 80, which makes it difficult to meet the technical requirements of high color rendering lighting and high color gamut backlight sources in the display backlight field.

[0004] To solve this limitation, adding red phosphors to lighting LEDs can enhance their red light emission, lowering the color temperature of LED devices from cold white light to warm white light (less than 3000K), and significantly improving the color rendering index (above 90). 4+ 、Eu 3+ As an activator, it can be used as the luminescence center of red phosphor to meet the technical requirements of high color rendering lighting and high color gamut backlight in the display backlight field. 4+ This fluoride phosphor has a unique narrow-band emission near a wavelength of 630nm, so it has extremely high color purity and a wide color gamut in backlight displays.

[0005] Fluoride red phosphors are used in display backlight packaging devices because of their wide color gamut and high color purity, for example, Na2SiF6:Mn 4+ and K2SiF6:Mn 4+ , where Na2SiF6:

[0006] Mn 4+ Phosphor compared to K2SiF6:Mn 4+ Phosphors have shorter wavelengths (Na2SiF6:

[0007] Mn 4+ Peak wavelength 627.1nm, K2SiF6:Mn 4+ Peak wavelength 630.9nm) is closer

[0008] The human eye's sensitive area has higher visual brightness. However, due to its stability compared to K2SiF6:

[0009] Mn 4+ Poor, which is mainly due to Na2SiF6:Mn 4+ Compared with K2SiF6 in water / water vapor:

[0010] Mn 4+ It has higher solubility and is generally rod-shaped. Compared with "quasi-spherical" particles, it has a higher specific surface area and a faster dissociation rate in water / water vapor. Its phosphor is encapsulated in LED organic glue, but its long-term reliability is poor and its light efficiency is low. Therefore, the current commercial fluoride phosphor is mainly K2SiF6: Mn 4+ The existing disclosure is to improve the conventional organic / inorganic coating to make the phosphor surface lack of luminescent centers and cover the Na2SiF6:Mn 4+ Advantage of high visual brightness. Summary of the Invention

[0011] The present disclosure aims to at least solve the technical problems of unstable structure and low light efficiency in the prior art, and provides a fluoride fluorescent particle, a fluoride fluorescent powder and a preparation method, a light-emitting element and a light-emitting device.

[0012] In one aspect of the present disclosure, a fluoride fluorescent particle is provided. The chemical formula of the fluoride fluorescent particle is Na2Si (1-X) F6:Mn 4+ X , 0<x<0.1, the fluoride fluorescent particle has a polyhedral structure;

[0013] The polyhedron structure includes an upper prism, a lower prism that are symmetrically arranged, and a prism located between the upper prism and the lower prism and respectively connected to the lower bottom surface of the upper prism and the lower bottom surface of the lower prism.

[0014] Optionally, the upper prism, the lower prism and the prism have at least four sides.

[0015] Optionally, the ratio of the area of ​​the upper base of the upper prism or the upper base of the lower prism to the area of ​​the base of the prism is 0.2 to 0.8.

[0016] Optionally, the ratio of the height of the prism to the sum of the height of the upper prism and the height of the lower prism is 0.2 to 1.5.

[0017] Optionally, the polyhedral structure includes at least an icosahedral structure.

[0018] Optionally, the median particle size of the fluoride fluorescent particles is 1 μm<D50<50 μm.

[0019] In another aspect of the present disclosure, a fluoride phosphor is provided, comprising the fluoride phosphor particles described above.

[0020] Optionally, in the fluoride phosphor powder, the content of the fluoride fluorescent particles is higher than 10%.

[0021] Another aspect of the present disclosure provides a method for preparing the fluoride phosphor described above, the method comprising:

[0022] dissolving sodium fluorosilicate and sodium fluoromanganate solid powders in hydrofluoric acid, heating and stirring to obtain a first solution;

[0023] Dissolving NaHF2 solid powder in hydrofluoric acid, heating and stirring to obtain a second solution;

[0024] Adding a fluorine-containing organic sodium salt to hydrofluoric acid, placing the solution in an ice bath, and stirring to dissolve the solution to obtain a third solution;

[0025] 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 phosphor.

[0026] Optionally, the mass ratio of the sodium fluorosilicate, sodium fluoromanganate solid powder and the hydrofluoric acid is 10:1.5:500;

[0027] The mass ratio of the NaHF2 solid powder to hydrofluoric acid is 9:250;

[0028] The fluorine-containing organic sodium salt is one of sodium trifluoromethanesulfonate, sodium trifluoroacetate and sodium perfluorooctanoate;

[0029] The mass ratio of the fluorine-containing organic sodium salt to the hydrofluoric acid is (0.1-1.2):100;

[0030] The first addition speed is 50 g / min, and the second addition speed is 5-32 g / min.

[0031] In another aspect of the present disclosure, a light-emitting element is provided, comprising the fluoride phosphor described above and a light source.

[0032] In another aspect of the present disclosure, a light-emitting device is provided. The light-emitting device includes the light-emitting element described above.

[0033] The present invention discloses a fluoride fluorescent particle, a fluoride fluorescent powder, a preparation method thereof, a light-emitting element, and a light-emitting device. The chemical formula of the fluoride fluorescent particle is Na2Si (1-X) F6:Mn 4+ X , 0<X<0.1, the fluoride phosphor particles have a polyhedral structure; the polyhedral structure includes symmetrically arranged upper and lower prisms, and a prism located between the upper and lower prisms and respectively bonded to the lower bases of the upper and lower prisms. This polyhedral phosphor has the characteristics of high-intensity emission and high stability. Compared with rod-shaped and amorphous structures, it reduces the contact area with water / water vapor after LED packaging, slows the dissociation rate, and extends the service life of the LED device. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic diagram of an icosahedral morphology of a fluoride fluorescent particle according to a specific embodiment of the present disclosure;

[0035] Figure 2 This is a flowchart of a method for preparing fluoride phosphor according to a specific embodiment of the present disclosure;

[0036] Figure 3 This is a morphology diagram of the icosahedron in the fluoride phosphor prepared in Example 1 of the present disclosure;

[0037] Figure 4 The icosahedral Na2SiF6:Mn of Example 1 of the present disclosure 4+ Excitation spectrum of fluoride fluorescent particles;

[0038] Figure 5 The icosahedral Na2SiF6:Mn of Example 1 of the present disclosure 4+ Emission spectrum of fluoride fluorescent particles;

[0039] Figure 6 The icosahedral Na2SiF6:Mn of Example 1 of the present disclosure 4+ Crystalline X-ray diffraction spectrum of fluoride fluorescent particles;

[0040] Figure 7 The amorphous Na2SiF6:Mn prepared in Comparative Example 1 of the present disclosure 4+ Morphology of fluoride phosphor;

[0041] Figure 8 The rod-shaped Na2SiF6:Mn prepared in Comparative Example 2 of the present disclosure 4+ Morphology of fluoride phosphor. DETAILED DESCRIPTION

[0042] 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.

[0043] like Figure 1 As shown, in one aspect of this embodiment, a fluoride fluorescent particle Na2SiF6:Mn 4+ The fluoride fluorescent particles Na2SiF6:Mn 4+ The chemical formula is Na2Si (1-X) F6:Mn 4+ X , 0<x<0.1, the fluoride fluorescent particle has a polyhedral structure; the polyhedral structure 100 includes an upper prism 110 and a lower prism 120 symmetrically arranged, and a prism 130 located between the upper prism 110 and the lower prism 120 and respectively connected to the lower base surface of the upper prism 110 and the lower base surface of the lower prism 120.

[0044] This embodiment proposes a polyhedral structure of Na2SiF6:Mn 4+ Fluoride fluorescent particles, this polyhedral structure has a highly symmetrical and regular geometric structure compared to rod-shaped structures or amorphous structures. The ordered arrangement of atoms in this structure makes the interaction between atoms in the polyhedral structure more stable when affected by the external environment, and it is not easy to cause structural destruction or dissociation. Secondly, the three-dimensional geometric structure of the polyhedron can better couple with the excitation light source. Its multiple faces and symmetrical spatial structure can receive and scatter the excitation light from different angles, increasing the contact between the excitation light and the luminescent center inside the phosphor (such as Mn 4+ The ordered polyhedral structure can reduce the interaction probability of ions during the luminescence process, thereby improving energy transfer and excitation efficiency. This embodiment optimizes and enhances the crystal structure of the phosphor, resulting in high luminescence efficiency, high structural strength, and resistance to dissociation.

[0045] It should be understood that the upper and lower pyramids in the fluorescent particles of this embodiment are symmetrically distributed. Each of the upper and lower pyramids has multiple side faces, an upper base, and a lower base. The lower base has a relatively smaller area, while the upper base has a relatively larger area. The side faces are trapezoidal, while the upper and lower bases are polygonal. A prism, on the other hand, has multiple side faces and two bases of equal area. The side faces of the prism are quadrilaterals, and the base is polygonal. Thus, one base of the prism is bonded to the lower base of the upper pyramid, and the other base of the prism is bonded to the lower base of the lower pyramid. Of course, the polyhedron structure formed by the upper and lower pyramids, and the prism, constitutes a single, integrated structure.

[0046] In some preferred embodiments, the upper pyramid, lower pyramid, and prism have at least six sides. That is, the upper pyramid and lower pyramid are at least hexagonal pyramid structures, and the prism is at least hexagonal prism structure. For example, when the upper pyramid and lower pyramid have six sides, the polyhedral structure should be an icosahedron. Of course, the upper pyramid, lower pyramid, and prism can also have a larger number of sides to form other polyhedral structures, which are not listed here. Of course, the phosphor particles of this embodiment can include any one of these polyhedral structures, and can also include multiple polyhedral structures.

[0047] As a further preferred embodiment, the polyhedral structure is preferably an icosahedron. That is, the polyhedral structure of the fluoride fluorescent particle includes at least an icosahedral morphology, and the icosahedral structure accounts for more than 10%, and more preferably, the icosahedral structure accounts for more than 50%. This icosahedral structure has a highly symmetrical and regular geometry. The high symmetry means that its properties are more uniform in all directions. The ordered structure results in fewer internal defects, tighter atomic bonding, and greater structural stability. Secondly, the polyhedral shape of the icosahedron makes the scattering and refraction of incident light more uniform. When light enters the phosphor, it is reflected and refracted between multiple faces, increasing the probability of light interacting with the luminescent center, thereby improving light absorption efficiency and ultimately achieving stronger fluorescence emission. At the same time, the symmetry of the icosahedron makes its optical properties more uniform in all directions, which facilitates light propagation and energy transfer within the phosphor, avoids light loss caused by anisotropy of optical properties, and helps improve light efficiency.

[0048] In other preferred embodiments, please refer to Figure 1The ratio of the upper base area of ​​the upper prism 110 or the upper base area of ​​the lower prism 120 (s1) to the base area of ​​the prism (s2) is 0.2 to 0.8, and preferably 0.3 to 0.5. A reasonable area ratio helps the fluorescent particles absorb and convert the excitation light, and better matches the incident and emission paths of the excitation light. When the area ratio of the upper base of the prism to the base area of ​​the prism is within the above range, the excitation light can be more evenly distributed between the upper and lower prisms and the prism of the fluorescent particle, thereby increasing the contact between the excitation light and the luminescence center Mn. 4+ , thereby improving the light conversion efficiency and achieving stronger fluorescence emission.

[0049] In other preferred embodiments, the ratio of the prism height (h2) to the sum of the upper prism height (h1) and the lower prism height (h3) is 0.2 to 1.5, and more preferably 0.3 to 0.5. A suitable height ratio influences the propagation path length of the excitation light within the phosphor particles. This range ensures that the light travels an appropriate optical path within the upper and lower prisms and prism structure, fully absorbing the excitation light energy while effectively emitting fluorescence, thereby improving overall light efficiency.

[0050] In other preferred embodiments, the median particle size of the fluoride 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 take into account both coating process and better fluorescence conversion efficiency.

[0051] In another aspect of this embodiment, a fluoride phosphor is provided, which includes the fluoride phosphor particles described above, and the content of the fluoride phosphor particles in the powder is higher than 10%, that is, the number of phosphor particles with a polyhedral structure accounts for 10% or more of the total amount of the phosphor.

[0052] like Figure 2 As shown, another aspect of this embodiment provides a method S200 for preparing the fluoride phosphor described above, which specifically includes the following steps S210 to S240:

[0053] S210, dissolving solid powders of sodium fluorosilicate and sodium fluoromanganate in hydrofluoric acid, heating and stirring to obtain a first solution.

[0054] 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.

[0055] S220, dissolving NaHF2 solid powder in hydrofluoric acid, heating and stirring to obtain a second solution.

[0056] 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.

[0057] S230, adding a fluorine-containing organic sodium salt to hydrofluoric acid, stirring and dissolving in an ice bath to obtain a third solution.

[0058] In step S230, the mass ratio of the fluorine-containing organic sodium salt to the hydrofluoric acid is (0.1-1.2):100, and the hydrofluoric acid is also preferably 50% hydrofluoric acid.

[0059] In step S230, the fluorine-containing organic sodium salt is selected from sodium trifluoromethanesulfonate, sodium trifluoroacetate, and sodium perfluorooctanoate.

[0060] 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.

[0061] 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 3 hours, and the washing treatment includes adding HF (5%) and stirring and washing for 2 hours, and washing with ethanol twice.

[0062] During the powder synthesis process, fluorine-containing organic sodium salts were introduced to stimulate the lateral expansion growth of crystal habit, changing the Na2SiF6:Mn 4+ The crystal growth mode has evolved into a regular and more stable polyhedral structure compared to the amorphous and rod-shaped structure. This polyhedral structure phosphor has the characteristics of high-intensity emission and high stability. Compared with the rod-shaped structure, it reduces the contact area with water / water vapor after LED packaging, reduces the dissociation rate, and extends the service life of LED devices.

[0063] In another aspect of this embodiment, a light-emitting element is provided. The light-emitting element includes the fluoride phosphor described above and a light source.

[0064] In another aspect of this embodiment, a light-emitting device is provided. The light-emitting device includes the light-emitting element described above.

[0065] The preparation method of fluoride red phosphor will be further described below with reference to specific examples:

[0066] Example 1

[0067] This example provides a method for preparing a polyhedral fluoride red phosphor, including the following steps:

[0068] 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.

[0069] 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.

[0070] 3. Add 0.1 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.

[0071] 4. Place a 2000 mL Teflon beaker in an ice water bath, add the first solution and the second solution at a rate of 50 g / min, and the third solution at a rate of 25 g / min into the Teflon beaker, and stir for 3 hours to mix evenly.

[0072] 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.

[0073] like Figure 3 As shown, the Na2SiF6:Mn prepared in this embodiment 4+ The fluoride phosphor powder includes fluoride phosphor particles with a polyhedral structure and powders with other morphologies, wherein the content of the fluoride phosphor particles in the phosphor powder is greater than 10%, and the fluoride phosphor particles have an icosahedral structure. The median particle size of the fluoride phosphor particles is 30.3 μm, the ratio of the area of ​​the upper base of the upper prism or the upper base of the lower prism (s1) to the base area of ​​the prism (s2) is 0.2, and the ratio of the sum of the height of the prism (h2), the height of the upper prism (h1), and the height of the lower prism (h3) is h2 / (h1+h3)=0.5.

[0074] The following is an analysis of the prepared icosahedral phosphor as an example. The excitation spectrum, emission spectrum and crystal phase X-ray diffraction results are as follows:

[0075] like Figure 4 As shown, it belongs to Na2SiF6:Mn 4+ The characteristic excitation spectrum of the phosphor is within the wavelength range of 300-550nm, and blue light in a specific wavelength range (440-450nm) can more effectively excite the phosphor.

[0076] like Figure 5As shown, icosahedral Na2SiF6:Mn 4+ The emission spectrum of the phosphor 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.

[0077] like Figure 6 As shown, icosahedral Na2SiF6:Mn 4+ The diffraction peaks of the phosphor show that it is consistent with the hexagonal Na2SiF6 (PDF#33-1280) standard card, and has high crystallinity and no other impurities.

[0078] As shown in Table 1, the peak intensity L0 of the phosphor prepared in this embodiment is 1850.9, the intensity L1 after aging at high temperature and high humidity for 1000 hours is 1773.2, and the light decay is 4.2%.

[0079] Example 2

[0080] This example provides a method for preparing a polyhedral fluoride red phosphor, including the following steps:

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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 25g / min into the Teflon beaker respectively, and stir for 3 hours to mix evenly.

[0085] 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.

[0086] The Na2SiF6:Mn 4+The fluoride phosphor powder includes fluoride phosphor particles with a polyhedral structure and powders with other morphologies, wherein the content of the fluoride phosphor particles in the phosphor powder is greater than 10%, and the fluoride phosphor particles have an icosahedral structure. The median particle size of the fluoride phosphor particles is 30.2 μm, the ratio of the area of ​​the upper base of the upper prism or the upper base of the lower prism (s1) to the base area of ​​the prism (s2) is 0.4, and the ratio of the sum of the height of the prism (h2), the height of the upper prism (h1), and the height of the lower prism (h3) is h2 / (h1+h3)=0.5.

[0087] As shown in Table 1, the peak intensity L0 of the phosphor prepared in this embodiment is 1966.3, the intensity L1 after aging at high temperature and high humidity for 1000 hours is 1917.1, and the light decay is 2.5%.

[0088] Example 3

[0089] This example provides a method for preparing a polyhedral fluoride red phosphor, comprising the following steps:

[0090] 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.

[0091] 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.

[0092] 3. Add 1.2 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.

[0093] 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 25g / min into the Teflon beaker respectively, and stir for 3 hours to mix evenly.

[0094] 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.

[0095] The Na2SiF6:Mn 4+The fluoride phosphor powder includes fluoride phosphor particles with a polyhedral structure and powders with other morphologies, wherein the content of the fluoride phosphor particles in the phosphor powder is greater than 10%, and the fluoride phosphor particles have an icosahedral structure. The median particle size of the fluoride phosphor particles is 30.3 μm, the ratio of the area of ​​the upper base of the upper prism or the upper base of the lower prism (s1) to the base area of ​​the prism (s2) is 0.8, and the ratio of the sum of the height of the prism (h2), the height of the upper prism (h1), and the height of the lower prism (h3) is h2 / (h1+h3)=0.5.

[0096] As shown in Table 1, the peak intensity L0 of the phosphor prepared in this embodiment is 1962.2, the intensity L1 after aging at high temperature and high humidity for 1000 hours is 1905.3, and the light decay is 2.9%.

[0097] Example 4

[0098] This example provides a method for preparing a polyhedral fluoride red phosphor, comprising the following steps:

[0099] 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.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] The Na2SiF6:Mn 4+The fluoride phosphor powder includes fluoride phosphor particles with a polyhedral structure and powders with other morphologies, wherein the content of the fluoride phosphor particles in the phosphor powder is greater than 10%, and the fluoride phosphor particles have an icosahedral structure. The median particle size of the fluoride phosphor particles is 30.5 μm, the ratio of the area of ​​the upper base of the upper prism or the upper base of the lower prism (s1) to the base area of ​​the prism (s2) is 0.4, and the ratio of the sum of the height of the prism (h2), the height of the upper prism (h1), and the height of the lower prism (h3) is h2 / (h1+h3)=0.2.

[0105] As shown in Table 1, the peak intensity L0 of the phosphor prepared in this embodiment is 1957.3, the intensity L1 after aging at high temperature and high humidity for 1000 hours is 1894.7, and the light decay is 3.2%.

[0106] Example 5

[0107] This example provides a method for preparing a polyhedral fluoride red phosphor, comprising the following steps:

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] The Na2SiF6:Mn 4+The fluoride phosphor powder includes fluoride phosphor particles with a polyhedral structure and powders with other morphologies, wherein the content of the fluoride phosphor particles in the phosphor powder is greater than 10%, and the fluoride phosphor particles have an icosahedral structure. The median particle size of the fluoride phosphor particles is 30.2 μm, the ratio of the area of ​​the upper base of the upper prism or the upper base of the lower prism (s1) to the base area of ​​the prism (s2) is 0.4, and the ratio of the sum of the height of the prism (h2), the height of the upper prism (h1), and the height of the lower prism (h3) is h2 / (h1+h3)=1.5.

[0114] As shown in Table 1, the peak intensity L0 of the phosphor prepared in this embodiment is 1863.1, the intensity L1 after aging at high temperature and high humidity for 1000 hours is 1786.7, and the light decay is 4.1%.

[0115] In summary, the icosahedron s1 / s2 and h2 / (h1+h3) ratio parameters can be controlled by adjusting the concentration and feed rate of the third solution. A higher concentration results in a higher s1 / s2 ratio, and a faster feed rate results in a smaller h2 / (h1+h3) ratio.

[0116] Comparative Example 1

[0117] This example provides a method for preparing amorphous fluoride red phosphor, including the following steps:

[0118] 1. Measure 1.5 g of Na2MnF6 and dissolve it in 50 g of commercially available 10%-15% HSF to obtain the first solution.

[0119] 2. Dissolve 16.4 g of NaHF2 in 500 g of 50% hydrofluoric acid (electronic grade) to obtain a second solution.

[0120] 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.

[0121] like Figure 7 As shown, the Na2SiF6:Mn prepared in this embodiment 4+ Fluoride phosphors have an amorphous morphology.

[0122] As shown in Table 1, the peak intensity L0 of the phosphor prepared in this comparative example is 1535.8, the intensity L1 after aging at high temperature and high humidity for 1000 hours is 1346.9, and the light decay is 12.3%.

[0123] According to the results of Comparative Example 1 and Examples 1-5, when the phosphor morphology is amorphous, the peak intensity is low, and the intensity is low and the light decay is high after high temperature and high humidity aging, indicating that the luminous intensity is not high and the stability is poor.

[0124] Comparative Example 2

[0125] This example provides a method for preparing a rod-shaped fluoride red phosphor, comprising the following steps:

[0126] 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.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] like Figure 8 As shown, the Na2SiF6:Mn prepared in this embodiment 4+ Fluoride phosphors are rod-shaped structures with a certain aspect ratio.

[0131] As shown in Table 1, the peak intensity L0 of the phosphor prepared in this comparative example is 1627.1, the intensity L1 after aging at high temperature and high humidity for 1000 hours is 1474.2, and the light decay is 9.4%.

[0132] According to the results of Comparative Example 2 and Examples 1-5, when the phosphor morphology is rod-shaped, the peak intensity is low, and the intensity is low and the light decay is high after high temperature and high humidity aging, indicating that the luminous intensity is not high and the stability is also poor.

[0133] Table 1 Performance results of phosphors

[0134]

[0135] In summary, the phosphors of Examples 1-5 have an intensity L of 1773.2-1917.1 and a luminous decay of 2.5%-4.2% after aging for 1000 hours at high temperature and high humidity. The intensity of the phosphors of Examples 1-5 after aging is higher than that of the phosphors of the comparative example, and the luminous decay is significantly lower than that of the phosphors of the comparative example. This indicates that the phosphors prepared in Examples 1-5 and containing polyhedral phosphor particles have better stability and are more conducive to extending the service life of LED devices.

[0136] The present disclosure provides a fluoride fluorescent particle, a fluoride fluorescent powder, a preparation method thereof, a light-emitting element, and a light-emitting device, which have the following beneficial effects compared to the prior art:

[0137] First, the present disclosure proposes a polyhedral fluoride phosphor particle that has better stability and higher light efficiency than the currently disclosed rod-shaped or amorphous phosphors.

[0138] Second, the present invention synthesizes a Na2SiF6:Mn with icosahedral structural characteristics through a wet synthesis process. 4 + Fluoride fluorescent particles have a simple and easy-to-operate process. The relative sizes of prisms and pyramids in the polyhedral structure can be controlled by adjusting the feed rate and concentration of the solution, thereby adjusting the size of the polyhedral structure and improving the stability and light efficiency of the phosphor.

[0139] 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 fluorescent particle, characterized in that: The chemical formula of the fluoride fluorescent particles is Na2Si (1-X) F6:Mn 4 + X , 0<x<0.1, the fluoride fluorescent particle has a polyhedral structure; The polyhedron structure includes an upper prism, a lower prism that are symmetrically arranged, and a prism located between the upper prism and the lower prism and respectively connected to the lower bottom surface of the upper prism and the lower bottom surface of the lower prism.

2. The fluoride fluorescent particle according to claim 1, characterized in that The upper truncated pyramid, the lower truncated pyramid, and the prism have at least six sides.

3. The fluoride fluorescent particle according to claim 2, characterized in that: The ratio of the area of ​​the upper bottom surface of the upper prism or the upper bottom surface of the lower prism to the area of ​​the bottom surface of the prism is 0.2 to 0.

8.

4. The fluoride fluorescent particle according to claim 2, characterized in that The ratio of the sum of the height of the prism, the height of the upper prism, and the height of the lower prism is 0.2 to 1.

5.

5. The fluoride fluorescent particle according to any one of claims 1 to 4, characterized in that: The polyhedral structure includes at least an icosahedral structure.

6. The fluoride fluorescent particle according to any one of claims 1 to 4, characterized in that: The median particle size of the fluoride fluorescent particles is 1 μm<D50<50 μm.

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

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

9. A method for preparing the fluoride phosphor according to claim 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 to hydrofluoric acid, stirring and dissolving the solution 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 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 to the hydrofluoric acid is (0.1-1.2):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 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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