Fluorescent glass ceramic, preparation method thereof and luminescent device

Abstract

The invention provides fluorescent glass ceramic, a preparation method thereof and a luminescent device. The fluorescent glass ceramic comprises glass powder and fluorescent powder; the fluorescent powder comprises blue-green fluorescent powder, and the emission peak wavelength of the blue-green fluorescent powder is 480-510 nm; the blue-green fluorescent powder comprises first fluorescent powder; the molecular formula of the first fluorescent powder is (Ba1-w-nAwRen) GxNyOz1Fz2, the crystal structure of the first fluorescent powder belongs to an orthogonal structure, and the first fluorescent powder is crystallized in a space group Pcca; based on the total mass of the glass powder and the fluorescent powder, the mass percentage content of the glass powder is 20%-80%, and the mass percentage content of the fluorescent powder is 20%-80%. The fluorescent glass ceramic disclosed by the invention can give consideration to the luminescent property of the fluorescent glass ceramic and the reliability and thermal stability of the luminescent property.

Description

Technical Field

[0001] This application relates to the field of luminescent materials technology, and more specifically, to a fluorescent glass ceramic, its preparation method, and a luminescent device. Background Technology

[0002] Fluorescent glass ceramics, due to their advantages such as all-inorganic structure, high thermal stability, and weather resistance, have become a key material to replace traditional resin-encapsulated fluorescent devices. They are mainly used in lighting displays, automotive electronics, and other fields, especially in the lighting display field.

[0003] However, currently, the phosphors used in fluorescent glass ceramics for lighting displays are mainly garnet-based fluorescent glass ceramics. The sintering temperature during the preparation of these ceramics is excessively high (above 800℃), leading to lattice distortion, surface corrosion, and element diffusion during sintering, thus deteriorating the material's luminescent properties. Alternatively, poor compatibility between the phosphor and glass powder can cause cracks due to thermal stress during sintering, affecting not only the overall material uniformity but also reducing the density of the fluorescent glass ceramic, further worsening its mechanical properties and fluorescence stability. Therefore, developing novel fluorescent materials is of great significance. Summary of the Invention

[0004] In view of the above problems, this application provides a fluorescent glass ceramic, a method for preparing the same, and a light-emitting device.

[0005] In one aspect, this application provides a fluorescent glass-ceramic.

[0006] The fluorescent glass-ceramic of this application includes glass powder and phosphor; based on the total mass of the glass powder and the phosphor, the mass percentage of the glass powder is A, the mass percentage of the phosphor is B, and A satisfies 20%≤A≤80%, and B satisfies 20%≤B≤80%; the phosphor includes a blue-green phosphor, and the emission peak wavelength of the blue-green phosphor is 480nm~510nm; the blue-green phosphor includes a first phosphor.

[0007] The molecular formula of the first phosphor is (Ba 1-w-n A w RE n )G x N y O z1 F z2Its crystal structure is orthorhombic and crystallized in space group Pcca; wherein, A includes at least one of Mg, Ca, Sr, and Zn; RE includes at least one of Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, and Tm; G includes at least one of tetravalent metal elements; F includes at least one of S, C, Cl, F, and Br; and (Ba 1-w-n A w RE n )G x N y O z1 E z2 The parameters w, n, x, y, z1, and z2 in the equation satisfy the following conditions: 0.001≤w≤0.3; 0.001≤n≤0.1; 1.8≤x≤2.2; 1.8≤y≤2.2; 1.8≤z1≤2.2; 0≤z2≤0.2.

[0008] In some embodiments, the blue-green phosphor further includes a second phosphor, the second phosphor having the molecular formula M a D b E c :mEu 2+ Wherein, M includes at least one of Sr, Ba, Ca, Mg, and Zn; D includes Al; E includes O; and M a D b E c :mEu 2+ The parameters a, b, c, and m satisfy the following conditions: 3.7 ≤ a ≤ 4.3, 12 ≤ b ≤ 16, 22 ≤ c ≤ 28, and 0.01 ≤ m ≤ 0.5.

[0009] In some embodiments, D further includes at least one of B, Ga, or In.

[0010] In some embodiments, E further includes at least one of F, Cl, Br, or I.

[0011] In some embodiments, the blue-green phosphor includes Sr 4-m Al 14 O 25 :mEu 2+ Where 0.02≤m≤0.3.

[0012] In some embodiments, the blue-green phosphor includes (Ba 1-w-n A w RE n )G x N y O z1The parameters w, n, x, y, and z1 satisfy the following conditions: 0.001≤w≤0.3; 0.001≤n≤0.1; 1.8≤x≤2.2; 1.8≤y≤2.2; 1.8≤z1≤2.2.

[0013] In some embodiments, when the blue-green phosphor includes both a second phosphor and a first phosphor, the mass percentage of the second phosphor is 30% to 70% and the mass percentage of the first phosphor is 30% to 70% based on the total mass of the blue-green phosphor.

[0014] In some embodiments, the glass powder comprises zinc borosilicate glass powder.

[0015] In some embodiments, the zinc borosilicate glass powder, by molar percentage, comprises the following components: 5%~30% SiO2, 10%~35% B2O3, 20%~60% ZnO, 0.1%~12% Al2O3, 0.3%~15% P2O5, 2%~20% RO, and 0.1%~15% R2O; wherein RO is selected from at least one of MgO, CaO, SrO, and BaO; and R2O is selected from at least one of Li2O, Na2O, and K2O.

[0016] In some embodiments, the phosphor further includes a green phosphor; based on the total mass of the phosphor, the mass percentage of the blue-green phosphor is 5% to 95%, and the mass percentage of the green phosphor is 5% to 95%.

[0017] In some embodiments, the green phosphor satisfies at least one of the following conditions: Condition 1, the emission peak wavelength of the green phosphor is 510 nm to 540 nm; Condition 2, the green phosphor comprises β-Sialon:Eu 2+ AlON:Mn 2+ Lu3(Al,Ga)5O 12 :Ce 3+ (Ba,Sr)2SiO4:Eu 2+ Any one of them.

[0018] In some embodiments, the phosphor surface is coated with powder, and the powder satisfies at least one of the following conditions: condition i, the powder includes any one of yttrium oxide, aluminum oxide, silicon oxide, titanium dioxide, magnesium oxide, zinc oxide, or boron nitride; condition ii, the particle size of the powder is 20 nm to 200 nm; condition iii, the powder completely coats the phosphor surface, and the coating thickness is ≥50 nm.

[0019] Secondly, this application provides a method for preparing any of the above-mentioned fluorescent glass ceramics.

[0020] The preparation method of this application includes the following steps: According to the specified ratio of glass powder and phosphor, the corresponding mass of glass powder and phosphor are mixed evenly and then pressed into a blank to obtain a green body; the green body is then sintered to obtain the fluorescent glass ceramic.

[0021] In some embodiments, the sintering satisfies at least one of the following conditions: (1) the sintering temperature is 400℃~700℃; (2) the sintering time is 10 min~2 h.

[0022] In some embodiments, the particle size of the glass powder is 1 μm to 30 μm.

[0023] In some embodiments, the particle size of the phosphor is 10 μm to 35 μm.

[0024] Thirdly, this application provides a light-emitting device.

[0025] The light-emitting device of this application includes a light source and a fluorescent glass ceramic as described in any one of the above claims; wherein the emission peak wavelength of the light source is L, wherein L satisfies 380nm≤L≤410nm, or satisfies 430nm≤L≤460nm.

[0026] In some embodiments, the color coordinates of the emitted light from the light-emitting device in the CIE 1931 chromaticity diagram are located within a quadrilateral region enclosed by points 1 (0.012, 0.495), 2 (0.200, 0.400), 3 (0.200, 0.320), and 4 (0.040, 0.320).

[0027] The embodiments of this application have at least the following beneficial effects: 1. This application uses zinc borosilicate glass powder and phosphor to create a compound, which allows the zinc borosilicate glass powder to effectively lower the sintering temperature of the fluorescent glass ceramic. The lower sintering temperature reduces the amount of fluorescent activating ions (such as Eu) in the phosphor. 2+ Volatilization or valence state changes can improve the stability of the fluorescence performance of fluorescent glass ceramics.

[0028] 2. This application satisfies the following by limiting the content of glass powder and phosphor: based on the total mass of the glass powder and the phosphor, the mass percentage of the glass powder is 20%~80%, and the mass percentage of the phosphor is 20%~80%. This is beneficial to make the content of glass powder and phosphor more suitable, and can take into account both the luminescent performance of fluorescent glass ceramics and the mechanical properties of the overall structure, which is beneficial to improving the performance stability of fluorescent glass ceramics.

[0029] 3. This application defines blue-green phosphors as including those with the molecular formula (Ba). 1-w-n A w RE n )G x N y O z1 F z2 The first phosphor can better improve the luminescence performance of the phosphor in terms of blue-green emission. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 The refined XRD pattern of the phosphor in Example 1.

[0032] Figure 2 This is a schematic diagram showing the color coordinates of azure in the CIE XYZ chromaticity diagram. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0034] In the description of this application, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings, and are used only for ease of description and simplification of operation. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. In addition, the terms "first" and "second" are used only for descriptive distinction and have no special meaning.

[0035] The technical solutions in this application will now be described clearly and in detail with reference to the accompanying drawings.

[0036] Fluorescent glass ceramics The fluorescent glass-ceramic of this application includes glass powder and fluorescent powder.

[0037] The phosphor in this application includes a blue-green phosphor, wherein the emission peak wavelength of the blue-green phosphor is 480 nm to 510 nm. The blue-green phosphor includes a first phosphor.

[0038] In this application, the molecular formula of the first phosphor is (Ba 1-w-n A w RE n )G x N y O z1 F z2 Its crystal structure is orthorhombic; wherein, A includes at least one of Mg, Ca, Sr, and Zn; RE includes at least one of Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, and Tm; G includes at least one of tetravalent metal elements; and F includes at least one of S, C, Cl, F, and Br.

[0039] It should be noted that when the first phosphor has (Ba 1-w-c A w RE c )D x N y O z1 When considering the molecular formula, it can be understood as: in G x N y N y O z1 Based on the crystal structure, elements A and RE are introduced through doping. The introduced elements A and RE can occupy BaD through co-doping. x N y O z1 Specific positions in the crystal lattice, such as principal lattice sites or interstitial sites, can also partially replace existing elements in the first phosphor. By co-doping with elements A and RE, partial replacement of Ba in the first phosphor is achieved, thereby optimizing or improving the color purity, luminous efficiency, and reliability of the first phosphor of this application.

[0040] Furthermore, this application considers that when w is greater than 0.3, it may cause a change in the symmetry of the crystal structure, such as changing from an orthorhombic structure to a monoclinic structure, or remaining an orthorhombic structure but not crystallizing in the Pcca space group; while when c is greater than 0.1, it will cause the concentration quenching of luminescence from the luminescent center, leading to a sharp drop in luminescence efficiency. Therefore, this application will (Ba 1-w-n A w RE n )G x N y O z1 F z2The parameters w, n, x, y, z1, and z2 are constrained to satisfy the following conditions: 0.001 ≤ w ≤ 0.3; 0.001 ≤ n ≤ 0.1; 1.8 ≤ x ≤ 2.2; 1.8 ≤ y ≤ 2.2; 1.8 ≤ z1 ≤ 2.2; 0 ≤ z2 ≤ 0.2. It can be understood that "0 ≤ z2 ≤ 0.2" indicates that the first phosphor may or may not contain the element F.

[0041] Based on the above scheme, it is possible to better optimize the luminous efficiency, color purity (emission peak half width at half maximum), and long-term reliability of phosphors by obtaining a crystal structure with orthogonal structure and crystallization in the Pcca space group.

[0042] In some embodiments, the emission peak wavelength of the first phosphor is 490 nm to 500 nm, and its molecular formula is (Ba 1-w-n Sr w Eu n Si₂N₂O₂, where 0.001≤w≤0.3; 0.001≤n≤0.1. Based on the above scheme, the Sr introduced by doping is... 2+ and Eu 2+ It can better control and optimize the Si2N2O2 crystal structure, thereby better improving the luminous efficiency, color purity and long-term aging performance of the first phosphor in blue-green emission.

[0043] In this application, the molecular formula of the second phosphor is M. a D b E c :mEu 2+ Wherein, M includes at least one of Sr, Ba, Ca, Mg, and Zn; D includes Al; E includes O; and M a D b E c :mEu 2+ The parameters a, b, c, and m satisfy the following conditions: 3.7 ≤ a ≤ 4.3, 12 ≤ b ≤ 16, 22 ≤ c ≤ 28, and 0.01 ≤ m ≤ 0.5. Based on the above scheme, the second phosphor can better cooperate with the first phosphor, thereby improving the luminous efficiency, color purity, and long-term aging performance of the phosphor's blue-green emission.

[0044] In some embodiments, D further includes at least one of B, Ga, or In.

[0045] In some embodiments, the F element includes at least one of F, Cl, Br, or I.

[0046] In some embodiments, the glass powder of this application includes zinc borosilicate glass powder.

[0047] It should be noted that this application takes into account the presence of ZnO in zinc borosilicate glass powder. Compared to pure silicate glass, ZnO can, to a certain extent, disrupt the network structure of silicon-oxygen tetrahedra formed by SiO2, thereby lowering the glass transition temperature and melting temperature of the glass. This effectively reduces the sintering temperature of the fluorescent glass ceramic. The lower sintering temperature can reduce the number of fluorescent activating ions (such as Eu) in the phosphor. 2+ Volatilization or valence state changes can improve the stability of the fluorescence performance of fluorescent glass ceramics.

[0048] In some embodiments, the zinc borosilicate glass powder, by molar percentage, comprises the following components: 5%~30% SiO2, 10%~35% B2O3, 20%~60% ZnO, 0.1%~12% Al2O3, 0.3%~15% P2O5, 2%~20% RO, and 0.1%~15% R2O; wherein RO is selected from at least one of MgO, CaO, SrO, and BaO; and R2O is selected from at least one of Li2O, Na2O, and K2O.

[0049] Based on the above scheme, the content of each component of zinc borosilicate glass powder is within a more suitable range, thereby enabling the fluorescent glass ceramic of this application to further reduce the sintering temperature while maintaining good glass-forming properties and transparency. Moreover, it is beneficial to make the thermal expansion coefficients of glass powder and phosphor powder more matched, further reducing the possibility of cracks caused by thermal stress during sintering, which is conducive to further improving the density of fluorescent glass ceramic and further improving the long-term reliability of fluorescent performance.

[0050] In this application, based on the total mass of the glass powder and the phosphor, the mass percentage of the glass powder is 20% to 80%, and the mass percentage of the phosphor is 20% to 80%.

[0051] Based on the above scheme, it is beneficial to make the content of glass powder and phosphor more suitable, so as to take into account both the fluorescence color rendering effect of fluorescent glass ceramics and the mechanical properties of the overall structure, and to improve the performance stability of fluorescent glass ceramics.

[0052] For example, the mass percentage of glass powder is 20%, 30%, 40%, 50%, 60%, 70%, 80%, or any two of the above values.

[0053] For example, the mass percentage of phosphor is 20%, 30%, 40%, 50%, 60%, 70%, 80%, or any two of the above values.

[0054] In some preferred embodiments, when the blue-green phosphor includes a second phosphor, the second phosphor used satisfies the following conditions: M is selected from Sr, D is selected from Al, E is selected from O, and b is 14 and c is 25, that is, the second phosphor is preferably of the molecular formula Sr. 4-m Al 14 O 25 :mEu 2+ Fluorescent powder.

[0055] It should be noted that the molecular formula Sr can be... 4-m Al 14 O 25 :mEu 2+ The second phosphor is understood to be: strontium aluminate Sr4Al 14 O 25 As a matrix, by introducing Eu into its structure 2+ , making Eu 2+ Eu is doped into the Sr site, partially replacing Sr. 2+ As the luminescent center, it enables the efficient blue-green broadband emission of the second phosphor. Here, 'm' can be understood as Eu. 2+ In terms of the molar doping concentration at the Sr site, this application controls m within the range of 0.02 ≤ m ≤ 0.3, thereby better improving the luminescence performance of the second phosphor in terms of blue-green emission.

[0056] In some preferred embodiments, when the blue-green phosphor includes a first phosphor, the first phosphor used satisfies the following conditions: z2=0, A is selected from Sr, RE is selected from Eu, and G is selected from Si, that is, the first phosphor is preferably of the molecular formula (Ba). 1-w-n Sr w Eu n Si x N y O z1 Fluorescent powder.

[0057] It should be noted that the molecular formula (Ba) can be used as an example. 1-w-n Sr w Eu n Si x N y O z1 The first phosphor is understood to be: oxynitrosilicate (BaSi) x N y O z1 Using Sr as the matrix, by simultaneously introducing Sr into its structure 2+ and Eu 2+ , making Sr 2+ and Eu 2+ All dopants are injected into the Ba sites to partially replace Ba. 2+Among them, Eu 2+ Doping with Sr can split the crystal field of oxynitrosilicates, thereby achieving broadband blue-green emission. 2+ Co-doping can further modulate the lattice field and further improve the fluorescence performance of the phosphor.

[0058] In the above scheme, w can be understood as Sr 2+ In the molar doping concentration at the Ba site, n can be understood as Eu. 2+ In terms of the molar doping concentration at the Ba site, this application controls w within the range of 0.001≤w≤0.3 and n within the range of 0.001≤n≤0.1, thereby better improving the luminescence performance of the first phosphor in terms of blue-green emission.

[0059] For example, the first phosphor is preferably of the molecular formula (Ba). 1-w-n Sr w Eu n Phosphor of Si2N2O2.

[0060] It should be noted that this application does not limit the specific preparation method of the first phosphor, as long as it can achieve the preparation of the phosphor with (Ba) of the present application. 1-w-n A w RE n )G x N y O z1 F z2 The first phosphor with the molecular formula is sufficient. For example, in some embodiments, it can be prepared by solid-state sintering.

[0061] For example, this application has (Ba 1-w-n A w RE n )G x N y O z1 F z2 The preparation method of the first phosphor with the molecular formula includes the following steps: S1, Preparation of reaction raw materials: According to the elemental composition of the inorganic substances in the first phosphor, corresponding reaction raw materials of Ba, A, G, N and O elements and RE are provided, or corresponding reaction raw materials of Ba, A, G, N, O, F and RE elements are provided.

[0062] This application does not limit the specific form in which Ba reaction raw materials are added, as long as no other impurities are introduced and the appropriate mass of Ba element is provided. For example, in some embodiments, the reaction raw materials for Ba include Ba oxides and / or carbonates.

[0063] For example, in some embodiments, the reaction feedstock for Ba is selected from barium carbonate (BaCO3).

[0064] This application does not limit the specific form in which the reaction raw material A is added, as long as no other impurities are introduced and the corresponding mass of element A is provided. For example, in some embodiments, the reaction raw material A includes oxides and / or carbonates of A.

[0065] For example, in some embodiments, A is selected from Sr, and the reaction raw materials for Sr include strontium carbonate (SrCO3).

[0066] This application does not limit the specific form in which the reaction raw materials for G are added, as long as no other impurities are introduced and the appropriate mass of G element is provided. For example, in some embodiments, the reaction raw materials for G include oxides and / or nitrides of G.

[0067] For example, in some embodiments, G is selected from Si, and the reactants for Si include silicon nitride.

[0068] This application does not limit the specific form in which the RE reaction raw materials are added, as long as no other impurities are introduced and the appropriate mass of RE elements is provided. For example, in some embodiments, the RE reaction raw materials include RE oxides and / or nitrides.

[0069] For example, in some embodiments, RE is selected from Eu, and the reactants of Eu include europium oxide.

[0070] This application does not limit the specific form in which the reactants F are added, as long as no other impurities are introduced and the corresponding mass of F element is provided. In this application, O is provided by oxides of other elements, and N is provided by nitrides of other elements.

[0071] S2, Preparation of the mixture: The reactants and flux are mixed to obtain a mixture.

[0072] This application does not limit the specific flux used, as long as it can achieve the effects described herein. For example, in some embodiments, the flux used in this application includes at least one of metal halides, NH4Cl, NH4F, H3BO3, and alkaline earth metal halides. Based on the above scheme, the added flux reduces the temperature of subsequent heat treatment, promotes grain growth and phase purification, and improves luminescence performance and batch stability. For example, the flux can form a liquid phase environment when melted at high temperature, reducing the mass transfer resistance between reactant particles, shortening the ion diffusion path, and facilitating the contact and reaction of various reactants, such as promoting the combination reaction of Ba, Si, N, and O elements.

[0073] In some embodiments, the flux content is 0.1% to 8% by mass, based on the total mass of the mixture. Based on the above scheme, the contact and reaction of the various reactants can be better promoted.

[0074] S3, first sintering: Under an inert gas atmosphere, the mixture is sintered at a temperature T1 to form a first powder cake; wherein T1 ≥ the optimal crystallization temperature of the target basic lattice, the target basic lattice being a lattice formed by Ba, elements G, N and O.

[0075] In S3 of the above scheme, an inert gas is preferred as the reaction atmosphere, and T1 is used as the reaction temperature, where T1 ≥ the optimal crystallization temperature of the target basic lattice. This avoids the possibility of oxidation side reactions or decomposition of the reactants in the mixture with air (oxygen) to produce impurities, thus forming a target basic lattice with high crystallinity. The inert gas includes nitrogen.

[0076] For example, in some embodiments, the target first phosphor has (Ba 1-w-c Sr w Eu n The general formula for Si2N2O2 corresponds to the target basic lattice BaSi2N2O2. The optimal crystallization temperature of BaSi2N2O2 is close to 1300℃. Therefore, under an inert gas atmosphere, using a reaction temperature T1≥1300℃ can avoid the potential oxidation side reaction between the reactant BaCO3 and air (oxygen), and suppress the decomposition of silicon nitride Si3N4, thereby reducing the formation of impurity phases such as BaSiN2 and SiO2. This achieves the directional formation of a pure-phase BaSi2N2O2 lattice, providing stable lattice sites for activating ions. Simultaneously, it avoids abnormal growth in the subsequent high-temperature stage due to insufficient grain development at low temperatures. Furthermore, at a temperature T1≥1300℃, it is beneficial to eliminate pores and residual gases, reducing defects such as pores and cracks inside the first powder cake, and improving powder density.

[0077] This application does not limit the specific sintering time of the first sintering, which can be adjusted according to the specific temperature T1 used. For example, in some embodiments, the sintering time of the first sintering is 3 hours to 16 hours.

[0078] S4, First Crushing: The first powder cake was crushed to obtain fluorescent powder.

[0079] Based on the above scheme, this application first pulverizes the first powder cake obtained by the first sintering and then performs a second sintering, which is beneficial for element A and element RE to be better doped into the target basic lattice during subsequent heating, so as to form the first phosphor of this application with an orthorhombic structure and crystallized in space group Pcca.

[0080] S5, second sintering: The phosphor is sintered at a temperature T2 under a nitrogen-hydrogen mixed atmosphere to form a second powder cake; wherein 1200℃≤T2 <T1。

[0081] Based on the above approach, it is beneficial to Eu 2+ It can evenly occupy Ba 2+ The optimized lattice environment helps to prevent ion occupancy disorder caused by oxidation, and at the same time, it can improve the thermal stability of the material and reduce color coordinate drift during high-temperature operation.

[0082] This application does not limit the specific sintering time of the second sintering; it can be adjusted according to the specific temperature T2 used. For example, in some embodiments, the sintering time of the second sintering is 2 hours to 10 hours.

[0083] In some embodiments, the hydrogen content in the nitrogen-hydrogen mixed atmosphere is ≥2% to better achieve Eu 3+ Restore to Eu 2+ In some embodiments, the hydrogen content in the nitrogen-hydrogen mixture atmosphere is 2% to 10%.

[0084] S6, Second Crushing: The second powder is crushed to obtain the first fluorescent powder.

[0085] In some embodiments, the second powder cake is pulverized to a size that allows it to pass through a 300-mesh sieve. Based on the above scheme, improving the uniformity of particle size distribution is beneficial to improving the color uniformity of the first phosphor.

[0086] In some embodiments, when the blue-green phosphor includes both a second phosphor and a first phosphor, the mass percentage of the second phosphor is 30% to 70% and the mass percentage of the first phosphor is 30% to 70% based on the total mass of the blue-green phosphor. Based on the above scheme, the luminescent performance of the blue-green phosphor can be further improved.

[0087] In some preferred embodiments, the phosphor further includes a green phosphor; based on the total mass of the phosphor, the mass percentage of the blue-green phosphor is 5% to 95%, and the mass percentage of the green phosphor is 5% to 95%. Based on the above scheme, by compounding green phosphor on the basis of blue-green phosphor, and by controlling the content of blue-green phosphor and green phosphor within the above range, the fluorescent glass ceramic of this application can better meet more different fluorescence requirements.

[0088] In some embodiments, the green phosphor satisfies at least one of the following conditions: Condition 1, the emission peak wavelength of the green phosphor is 510 nm to 540 nm; Condition 2, the green phosphor comprises β-Sialon:Eu 2+ AlON:Mn 2+ Lu3(Al,Ga)5O 12 :Ce 3+ (Ba,Sr)2SiO4:Eu 2+ Any one of the above methods. Based on the above scheme, the green phosphor of this application can be better combined with the blue-green phosphor, further improving the luminescence performance of the phosphor based on the blue-green phosphor.

[0089] In some embodiments, the phosphor surface is coated with a powder that satisfies at least one of the following conditions: Condition i, the powder includes any one of yttrium oxide, aluminum oxide, silicon oxide, titanium dioxide, magnesium oxide, zinc oxide, or boron nitride; Condition ii, the particle size of the powder is 50 nm to 200 nm; Condition iii, the powder completely coats the phosphor surface, and the coating thickness is ≥50 nm. Based on the above scheme, it can avoid the erosion of the phosphor particle surface by the glass matrix during the co-sintering of glass powder and phosphor, and is also conducive to further improving the thermal conductivity of fluorescent glass ceramics, thereby improving the reliability and thermal stability of fluorescent glass ceramics.

[0090] Preparation method of fluorescent glass ceramics The preparation method of this application includes the following steps: According to the ratio of glass powder and phosphor, the corresponding mass of glass powder and phosphor are mixed evenly and then pressed into a green body; the green body is sintered to obtain the fluorescent glass ceramic.

[0091] It should be noted that the glass powder in this application includes any of the zinc borosilicate glass powders described above. The phosphor in this application includes any of the phosphors described above.

[0092] In some embodiments, the preparation method of the fluorescent glass-ceramic of this application includes the following steps: Step 1, Preparation of glass powder: Weigh out the raw materials according to the following molar percentages: 5%~30% SiO2, 10%~35% B2O3, 20%~60% ZnO, 0.1%~12% Al2O3, 0.3%~15% P2O5, 2%~20% RO, and 0.1%~15% R2O. Mix the corresponding masses of SiO2, B2O3, ZnO, Al2O3, P2O5, MgO, and Na2O. Melt the mixed material to obtain molten glass. Make glass fragments from the molten glass and grind the glass fragments to obtain glass powder.

[0093] It should be noted that this application does not limit the specific method of forming glass fragments from molten glass, as long as the desired effect of this application can be achieved. For example, in some embodiments, this application obtains glass fragments by pouring molten glass into a cooling medium or rolling it through a cold roller mill, so that it can be subsequently crushed into glass powder.

[0094] This application does not limit the specific temperature and time of the melting process, but selects them according to the actual content of each component, as long as the glass powder raw material can be fully melted to form a molten glass material. For example, in some embodiments, the melting process temperature is 1100℃~1800℃ and the time is 0.5h~4h.

[0095] In some embodiments, the glass powder is ground to a particle size of 1 μm to 30 μm. It should be noted that the term "particle size" in this application refers to the average particle size.

[0096] Step 2, Preparation of phosphor: The second phosphor and the first phosphor are mixed to obtain a blue-green phosphor.

[0097] In some embodiments, when the phosphor further includes green phosphor, the green phosphor and blue-green phosphor are mixed in a certain ratio to obtain the phosphor. The blue-green phosphor accounts for 5% to 95% of the total mass of the phosphor, and the green phosphor accounts for 5% to 95% of the total mass of the phosphor.

[0098] In some embodiments, the phosphor is pulverized to a particle size of 10 μm to 35 μm.

[0099] In some embodiments, when the phosphor surface is also coated with powder, this application does not limit the specific coating method, as long as it can achieve the effect of this application. For example, in some embodiments, the coating method used includes, but is not limited to, hydrothermal / solvothermal coating and sol-gel coating.

[0100] For example, when the coated powder includes any one of alumina, silicon dioxide, and titanium dioxide, the sol-gel method is used for coating. In the sol-gel method, the phosphor is dispersed in a precursor sol corresponding to the powder (e.g., SiO2 sol generated by the hydrolysis of tetraethyl orthosilicate), and a dense coating layer is formed on the phosphor surface through sol-gelation, drying, and calcination.

[0101] For example, when the coated powder includes either titanium dioxide or zinc oxide, hydrothermal / solvothermal coating is used. In hydrothermal / solvothermal coating, the phosphor reacts with the corresponding precursor in a high-temperature, high-pressure hydrothermal reactor, generating a crystalline coating in situ, achieving a strong bond coating.

[0102] Step 3, pressing and shaping: The fluorescent powder and glass powder prepared above are mixed in a mass ratio of 20%~80%:20%~80%, placed in a mold, and pressed into shape by axial pressure to obtain a blank.

[0103] Step 4, sintering treatment: After demolding, the green body is placed in a muffle furnace and sintered in air at 550°C for 30 minutes. After naturally cooling to room temperature, fluorescent glass ceramics are obtained.

[0104] This application does not limit the specific sintering temperature, as long as the desired effect of this application can be achieved. For example, in some embodiments, the sintering temperature is 400℃~700℃.

[0105] For example, the sintering temperature is 400°C, 500°C, 600°C, 700°C or any two of the above values.

[0106] This application does not limit the specific sintering time; it can be flexibly adjusted according to the selected sintering temperature, as long as the desired effect of this application is achieved. For example, in some embodiments, the sintering time is 10 minutes to 2 hours. It is understood that when the sintering temperature is high (e.g., 700°C), the sintering time can be appropriately shortened (e.g., 10 minutes to 1 hour), and when the sintering temperature is low (e.g., 400°C), the sintering time can be appropriately extended (e.g., 1 hour to 2 hours).

[0107] For example, the sintering time is 10 min, 20 min, 30 min, 40 min, 50 min, 1 h, 1.5 h, 2 h or any two of the above values.

[0108] Light-emitting devices The light-emitting device of this application includes a light source and the fluorescent glass ceramic described in any one of the above.

[0109] In this application, the emission peak wavelength of the light source is L, where L satisfies 380nm≤L≤410nm, or 430nm≤L≤460nm.

[0110] In some embodiments, the color coordinates of the emitted light from the light-emitting device in the CIE 1931 chromaticity diagram are located within a quadrilateral region enclosed by points 1 (0.012, 0.495), 2 (0.200, 0.400), 3 (0.200, 0.320), and 4 (0.040, 0.320).

[0111] It should also be noted that the processes or related parameters not specifically described in this application are all based on conventional operations in the field, which should be known to those skilled in the art, and therefore will not be elaborated upon in this application.

[0112] Test methods (a) Luminous efficacy and color coordinate test: The luminous efficacy and color coordinates of the light-emitting device were tested using a HASS-2000 high-precision rapid spectroradiometer with a test voltage of 3V and a current of 500mA.

[0113] (ii) Long-term reliability testing: This can also be called the 1000h, dual 85 aging test: The light-emitting device is placed in a constant temperature and humidity chamber and continuously lit for 1000 hours. The temperature and humidity are set to 85℃ and 85%RH, respectively, the lighting voltage is 3V, and the current is 500mA. The long-term reliability of the light-emitting device is evaluated by testing the light decay and color drift after 1000 hours. The light decay percentage (Δφ%) and color drift percentage (Δxy) after 1000 hours are used to assess the long-term reliability of the light-emitting device. The smaller the values ​​of Δφ% and Δxy, the better the long-term reliability.

[0114] The following specific embodiments and comparative examples are provided to better illustrate this application. Unless otherwise specified, the raw materials used in the following embodiments are all from common commercially available products, and the devices or equipment used are all purchased from conventional commercial sales channels.

[0115] It should be noted that in Tables 1 to 4 below, "η" represents luminous efficiency, "T" represents color temperature, "△φ%" represents light decay, "△xy" represents color drift, and "\" indicates that it is not added or does not exist.

[0116] Example 1 This embodiment provides a fluorescent glass-ceramic, which is prepared by the following method: Step 1, Preparation of glass powder: According to the following molar percentage content: 17% SiO2, 20% B2O3, 31% ZnO, 3% Al2O3, 8% P2O5, 12% MgO, and 12% Na2O, weigh out the corresponding mass of SiO2, B2O3, ZnO, Al2O3, P2O5, MgO, and Na2O and mix them evenly. Melt the mixed material to obtain molten glass. Then pour the molten glass into a cold roller mill to roll and obtain glass fragments. Grind the glass fragments to obtain glass powder.

[0117] Step 2, phosphor Ba 0.934 Sr 0.05 Eu 0.016 Preparation of Si2N2O2: 2.1 Preparation of reaction raw materials: According to Ba 0.934 Sr 0.05 Eu 0.016 The stoichiometric ratio of Si2N2O2 is as follows: 184.71g of barium carbonate (purity ≥99.9%), and the corresponding masses of strontium carbonate (purity ≥99.9%), silicon dioxide (purity greater than 99.9%), silicon nitride (purity ≥99.9%), europium oxide (purity of 5N), and 2.65g of fluxing ammonium fluoride.

[0118] 2.2 Preparation of the mixture: The above-mentioned reactants and flux are loaded into a mixing tank and mixed evenly to obtain the mixture.

[0119] 2.3 First sintering: The above mixture is placed into a molybdenum crucible and covered, then placed in a carbon tube furnace and sintered at 1380℃ for 12 hours in high-purity nitrogen (purity ≥99.99%) to obtain the first powder cake.

[0120] 2.4 Crushing: Crush the first powder cake obtained in 2.3 above and pass it through a 100-mesh sieve to obtain fluorescent powder.

[0121] 2.5 Second sintering: The phosphor obtained in 2.4 above is loaded into a molybdenum crucible and covered. It is then placed in a carbon tube furnace and sintered at 1280°C for 6 hours in a high-purity hydrogen-nitrogen mixture (hydrogen volume content 2%) to obtain the second powder cake.

[0122] 2.6 Post-processing: The second powder cake obtained in 2.5 above is pulverized by a jaw crusher and roller crusher, passed through a 300-mesh sieve, and then washed in a 5% nitric acid solution for 30 minutes. Afterwards, it is filtered and dried to obtain the product with the molecular formula Ba. 0.934 Sr 0.05 Eu 0.016 Phosphor of Si2N2O2.

[0123] This application uses a Bruker D8 X-ray diffractometer to perform X-ray diffraction tests on the phosphor obtained in step 2 of this embodiment, and uses the GSAS-II project package to refine and solve the X-ray diffraction test results. The refined XRD pattern of the phosphor in Example 1 is shown below. Figure 1 As shown. It should be noted that, generally, when Rwp satisfies Rwp < 15%, the refinement result is considered to have converged, meaning that the calculated crystal structure matches the measurement data.

[0124] Depend on Figure 1 As can be seen from the refined XRD pattern of the phosphor in Example 1, the refined result Rwp is 10.449%, and the refined result converges, indicating that the measured data of the phosphor obtained in Example 1 matches the calculated crystal structure. This proves that the phosphor obtained in Example 1 is indeed the orthorhombic non-point space group Pcca, numbered 54 in International Crystallographic Table A, and its molecular formula is Ba. 0.934 Sr 0.05 Eu 0.016 Si2N2O2.

[0125] Step 3, pressing and shaping: The phosphor Ba prepared above 0.934 Sr 0.05 Eu 0.016 Si2N2O2 and glass powder are mixed at a mass ratio of 80%:20%, placed in a mold, and pressed into shape by axial pressure to obtain a green body. Step 4, sintering treatment: After demolding, the green body is placed in a muffle furnace and sintered in air at 550°C for 30 minutes. After naturally cooling to room temperature, fluorescent glass ceramics are obtained.

[0126] This application uses the fluorescent glass ceramic obtained in Example 1 to fabricate a light-emitting device through the following steps: The fluorescent glass ceramic obtained in Example 1 was sliced, ground, and polished to obtain a fluorescent glass ceramic substrate with a thickness of 0.15 mm. The fluorescent glass ceramic substrate was then cut to obtain a fluorescent glass ceramic sheet with a length × width of 1 mm × 1 mm. The fluorescent glass ceramic sheet was then mounted on the light-emitting surface of the optical power substrate, which helps to improve the encapsulation efficiency, and also provides uniform light emission and good weather resistance.

[0127] The optical power base is a blue LED chip with an emission peak wavelength of 450nm.

[0128] Examples 2 to 3, and Comparative Examples 1 to 3 The difference from Example 1 is as follows: Adjust the mass content of glass powder and phosphor according to the mass percentage of phosphor listed in Table 1.

[0129] The luminescence performance of the light-emitting devices prepared in Examples 1 to 3 was tested, and the test results are summarized in Table 1.

[0130] Table 1

[0131] According to the test results in Table 1, under the premise that the glass powder is zinc borosilicate glass powder and the phosphor includes at least one of the second phosphor and the first phosphor, when the mass content of the glass powder and the phosphor meets the following conditions: based on the total mass of the glass powder and the phosphor, the mass percentage of the glass powder is 20%~80% and the mass percentage of the phosphor is 20%~80%, the color point of the light-emitting device prepared by the fluorescent glass ceramic of this application can be included in the CIE1931 chromaticity diagram, and the color coordinates are located within the specific azure quadrilateral color frame area, while having excellent luminous performance and reliability.

[0132] Examples 4 to 5 The difference from Example 1 is as follows: The type of phosphor was adjusted according to the molecular formulas of the phosphors listed in Table 2. Specifically, the phosphor Sr in Examples 4 and 5... 3.98 Al 14 O 25 0.02Eu 2+ The preparation is as follows: 587.57 g of strontium carbonate (analytical grade), 713.72 g of alumina (purity greater than 99.9%), and 3.52 g of europium oxide (purity 5N) were weighed out, along with 3.11 g of ammonium chloride as a flux. The above raw materials were placed in a mixing tank and mixed evenly. Then, the mixture was placed in a molybdenum crucible, covered, and sintered in a box-type atmosphere furnace at 1400 °C for 12 hours in a nitrogen-hydrogen mixed gas atmosphere. The resulting powder cake was then passed through a jaw crusher, roller crusher, and sieve through a 300-mesh screen. It was then washed in a 5% hydrochloric acid solution for 30 minutes, filtered, and dried to obtain the molecular formula Sr. 3.98 Al 14 O 25 0.02Eu 2+ Fluorescent powder.

[0133] Table 2

[0134] According to the test results in Table 2, when the mass content of glass powder and phosphor meets the following conditions: based on the total mass of the glass powder and phosphor, the mass percentage of the glass powder is 20%~80%, and the mass percentage of the phosphor is 20%~80%, the blue-green phosphor of this application includes molecules with the molecular formula M... a Db E c :mEu 2+ The second phosphor and its molecular formula is (Ba 1-w-n A w RE n )G x N y O z1 F z2 When at least one of the first phosphors is used, the fluorescent glass-ceramic of this application exhibits excellent luminescence performance and reliability.

[0135] Examples 6 to 9 The difference from Example 1 is as follows: Based on the blue-green phosphor in Example 1, a green phosphor was further introduced. The specific type and mass content of the green phosphor were adjusted according to the molecular formulas of the phosphors listed in Table 3. Specifically, the green phosphor in Examples 6 to 8 was Lu3(Al,Ga)5O. 12 :Ce 3+ The green phosphor in Example 9 is β-Sialon:Eu. 2+ .

[0136] Table 3

[0137] According to the test results in Table 3, when the mass content of glass powder and phosphor meets the following conditions: based on the total mass of the glass powder and phosphor, the mass percentage of the glass powder is 20%~80%, and the mass percentage of the phosphor is 20%~80%, the phosphor is available in the blue-green phosphor of this application, which includes the phosphor with the molecular formula (Ba). 1-w-n A w RE n )G x N y O z1 F z2 Blue-green phosphors also include green phosphors with emission peak wavelengths of 510 nm to 540 nm, such as β-Sialon:Eu. 2+ Or Lu3(Al,Ga)5O 12 :Ce 3+ When at least one of the following conditions is met, the fluorescent glass-ceramic of this application exhibits excellent luminescence performance and reliability.

[0138] Examples 10 and 11, and Comparative Example 4 The difference from Example 1 is as follows: Based on the composition of the zinc borosilicate glass powder listed in Table 4, the content of each component in the glass powder was adjusted. Because the component content of the glass powder changed, the corresponding sintering temperature was also adjusted as listed in Table 4.

[0139] Table 4

[0140] Table 4 "T" 烧 "Indicates the sintering temperature."

[0141] According to the test results in Table 4, provided that the glass powder is zinc borosilicate glass powder within the required range, and the phosphor includes at least one of the second phosphor and the first phosphor, the color points of the light-emitting device prepared from the fluorescent glass ceramic of this application can be included under the following conditions: based on the total mass of the glass powder and the phosphor, the mass percentage of the glass powder is 20%~80%, and the mass percentage of the phosphor is 20%~80%. Figure 2 The CIE 1931 chromaticity diagram shown has chromatic coordinates within the azure quadrilateral area bounded by points 1 (0.012, 0.495), 2 (0.200, 0.400), 3 (0.200, 0.320), and 4 (0.040, 0.320), exhibiting excellent luminescence performance and reliability. However, when the glass powder composition exceeds the required range, the increased sintering temperature severely damages the phosphor during co-sintering with the glass powder, significantly reducing the reliability of the fluorescence performance of the prepared fluorescent glass-ceramic.

[0142] Obviously, the above embodiments of this application are merely examples for clear illustration and are not intended to limit the implementation of this application. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection claimed by this application.

Claims

1. A fluorescent glass-ceramic, characterized in that, Including glass powder and phosphor; The phosphor includes a blue-green phosphor, wherein the emission peak wavelength of the blue-green phosphor is 480nm~510nm; The blue-green phosphor includes a first phosphor; The molecular formula of the first phosphor is (Ba 1-w-n A w RE n )G x N y O z1 F z2 Its crystal structure is orthorhombic and crystallizes in space group Pcca; Wherein, A includes at least one of Mg, Ca, Sr, and Zn; RE includes at least one of Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, and Tm; G includes at least one of the tetravalent metal elements; F includes at least one of S, C, Cl, F, and Br; And (Ba 1-w-n A w RE n )G x N y O z1 E z2 The parameters w, n, x, y, z1, and z2 in the equation satisfy the following conditions: 0.001≤w≤0.3;0.001≤n≤0.1;1.8≤x≤2.2;1.8≤y≤2.2;1.8≤z1≤2.2;0≤z2≤0.2; Based on the total mass of the glass powder and the phosphor, the mass percentage of the glass powder is 20% to 80%, and the mass percentage of the phosphor is 20% to 80%.

2. The fluorescent glass-ceramic according to claim 1, characterized in that, The first phosphor has a peak emission wavelength of 490nm~500nm, and its molecular formula is (Ba 1-w-n Sr w Eu n Si2N2O2, where 0.001≤w≤0.3; 0.001≤n≤0.

1.

3. The fluorescent glass-ceramic according to claim 1, characterized in that, The blue-green phosphor also includes a second phosphor, the second phosphor having the molecular formula M. a D b E c :mEu 2+ ; Wherein, M includes at least one of Sr, Ba, Ca, Mg, and Zn; D includes Al; E includes O; And M a D b E c :mEu 2+ The parameters a, b, c, and m in the equation satisfy the following conditions: 3.7≤a≤4.3, 12≤b≤16, 22≤c≤28, 0.01≤m≤0.

5.

4. The fluorescent glass-ceramic according to claim 3, characterized in that, D also includes at least one of B, Ga, or In; E also includes at least one of F, Cl, Br or I.

5. The fluorescent glass-ceramic according to claim 3, characterized in that, The second phosphor includes Sr 4-m Al 14 O 25 :mEu 2+ Where 0.02≤m≤0.

3.

6. The fluorescent glass-ceramic according to claim 1, characterized in that, The first phosphor includes (Ba 1-w- n Sr w Eu n Si x N y O z1 The parameters w, n, x, y, and z1 satisfy the following conditions: 0.001≤w≤0.3;0.001≤n≤0.1;1.8≤x≤2.2;1.8≤y≤2.2;1.8≤z1≤2.2。 7. The fluorescent glass-ceramic according to claim 1, characterized in that, The glass powder includes zinc borosilicate glass powder.

8. The fluorescent glass-ceramic according to claim 7, characterized in that, According to the molar percentage, the zinc borosilicate glass powder comprises the following components: 5%~30% SiO2, 10%~35% B2O3, 20%~60% ZnO, 0.1%~12% Al2O3, 0.3%~15% P2O5, 2%~20% RO, 0.1%~15% R2O; RO includes at least one of MgO, CaO, SrO, and BaO. R2O includes at least one of Li2O, Na2O, and K2O.

9. The fluorescent glass-ceramic according to claim 1, characterized in that, The phosphor also includes a green phosphor, the emission peak wavelength of which is 510 nm to 540 nm.

10. The fluorescent glass-ceramic according to claim 9, characterized in that, Based on the total mass of the phosphors, the mass percentage of blue-green phosphors is 5% to 95%, and the mass percentage of green phosphors is 5% to 95%.

11. The fluorescent glass-ceramic according to claim 9, characterized in that, The green phosphor includes β-Sialon:Eu 2+ AlON:Mn 2+ Lu3(Al,Ga)5O 12 :Ce 3+ (Ba,Sr)2SiO4:Eu 2+ Any one of them.

12. The fluorescent glass-ceramic according to claim 1, characterized in that, The phosphor is coated with powder, and the powder satisfies at least one of the following conditions: Condition i, the powder comprises any one of yttrium oxide, aluminum oxide, silicon oxide, titanium dioxide, magnesium oxide, zinc oxide, or boron nitride; Condition ii, the particle size of the powder is 50~200nm; Condition iii: The powder completely coats the surface of the phosphor, and the coating thickness is ≥50nm.

13. A method for preparing a fluorescent glass-ceramic according to any one of claims 1 to 12, characterized in that, Includes the following steps: According to the specified ratio of glass powder and phosphor, the corresponding mass of glass powder and phosphor are mixed evenly and then pressed into a blank to obtain a green body; the green body is then sintered to obtain the fluorescent glass ceramic.

14. A light-emitting device, characterized in that, Includes a light source, and the fluorescent glass-ceramic according to any one of claims 1 to 12; The emission peak wavelength of the light source is L, where L satisfies 380nm≤L≤410nm, or 430nm≤L≤460nm.

15. The light-emitting device according to claim 14, characterized in that, The color coordinates of the emitted light from the light-emitting device in the CIE1931 chromaticity diagram are located within the quadrilateral area enclosed by points 1 (0.012, 0.495), 2 (0.200, 0.400), 3 (0.200, 0.320), and 4 (0.040, 0.320).

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