Beta-sialon phosphor, method for producing the same, and light emitting member and light emitting device

Abstract

The present invention relates to a β-sialon phosphor and a manufacturing method thereof, and a light emitting member and a light emitting device. A β-sialon phosphor containing Eu as a luminescent center, with β-sialon as a matrix crystal, wherein the chemical states of Eu are divided into Eu 2+ , Eu 3+ , and an intermediate state thereof (denoted as Eu m ), and the existence ratio thereof satisfies the relationship of 0.1 < Eu m / (Eu 2+ + Eu 3+ + Eu m ) < 0.4 and Eu 2+ / (Eu 2+ + Eu 3+ ) > 0.7.

Description

Technical Field

[0001] This invention relates to a β-type silon phosphor that can be effectively excited by ultraviolet to blue light to emit green light, a method for manufacturing the same, and a light-emitting component and device using the β-type silon phosphor. Background Technology

[0002] Eu ions exist in both divalent and trivalent states, and function as activators of fluorophores in both. This is especially true for divalent Eu ions. 2+ Because it can effectively absorb excitation energy through the absorption band of the 4f-5d allowed transition and emit light, it can produce phosphors with good efficiency. Among the matrix crystals such as orthosilicates, α- and β-type silanes, M2Si5N8, and MAlSiN3 (M: alkaline earth element), Eu... 2+ Activated phosphors, which can be effectively excited by blue light and emit green to red fluorescence with high efficiency, are widely used as phosphors for white light-emitting diodes (white LEDs).

[0003] Most of the Eu present in the aforementioned fluorophores, except for the target Eu, 2+ In addition, Eu also coexists 3+ To obtain high fluorescence properties, it is desirable to improve Eu 2+ The proportion of existence. Eu 2+ With Eu 3+ The quantitative ratio can be calculated, for example, by measuring the XANES spectrum at the Eu-L3 absorber. XANES is short for X-ray Absorption Near Edge Structure, a spectroscopic method in X-ray Absorption Fine Structure (XAFS) determination. It is known that the energy of the strong absorption peaks appearing in the L3 absorber XANES spectrum of rare earth elements is determined by the valence of the rare earth element. In the case of Eu, Eu... 2+ It appears around 6970 eV, Eu 3+ It appears around 6980 eV, so the two peaks can be separated for quantification.

[0004] For fluorophores presumed to contain Eu of various valences, Eu is calculated using XAFS. 2+ With Eu 3+ The ratio, and discuss the fluorescence properties with Eu 2+ / Eu 3+ The correlation between the ratios. For example, it is shown that for β-silon phosphors activated with Eu, Eu... 2+ / (Eu 2+ +Eu 3+ The value is above 0.8 and the brightness is high (Patent Document 1).

[0005] Eu-activated β-type silon phosphors not only possess excellent heat resistance and durability, and exhibit minimal brightness changes with increasing temperature, but also emit green light with a peak in the 520–550 nm wavelength region when excited by a wide range of wavelengths from ultraviolet to blue. Therefore, they have been put into practical use as phosphors useful for white LEDs. As mentioned earlier, although by increasing Eu... 2+ / (Eu 2+ +Eu 3+ While the brightness of β-type silon phosphors may increase, the urgent desire for further increases in brightness is strong. However, the situation is that simply increasing Eu... 2+ / (Eu 2+ +Eu 3+ It is difficult to further improve the brightness of β-type silon phosphors.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent No. 5368557 Summary of the Invention

[0009] The problem the invention aims to solve

[0010] The present invention was made to solve the problems mentioned above, and its object is to provide a β-type silon phosphor with high brightness, a method for manufacturing the same, and a light-emitting component and light-emitting device using the β-type silon phosphor with the same characteristics.

[0011] Solution for solving the problem

[0012] The inventors have conducted repeated and in-depth studies on the presence state of Eu in β-type silon phosphors, and have obtained the following insights: The presence of Eu in the phosphor is related to the presence of Eu... 2+ and Eu 3+ Different intermediate chemical states allow the brightness of the phosphor to increase when Eu in the intermediate state exists within a fixed range, thus completing this invention.

[0013] That is, the present invention is a β-type silane phosphor, which uses β-type silane as the matrix crystal and contains Eu as the luminescent center, wherein the chemical state of Eu is divided into Eu... 2+ Eu 3+ and their intermediate states (hereafter referred to as Eu) m When these three are present, their ratio satisfies 0.1. <Eu m / (Eu 2+ +Eu 3+ +Eu m )<0.4 and Eu 2+ / (Eu 2+ +Eu 3+ The relationship is greater than 0.7.

[0014] Furthermore, the present invention provides a method for manufacturing the aforementioned β-type silon phosphor, comprising the following steps: a first calcination step, wherein a mixed powder comprising at least silicon nitride, aluminum nitride, and a Eu compound is calcined in a nitrogen atmosphere at 1550–2100°C to obtain calcined powder; a second calcination step, wherein one or more powders selected from silicon nitride, silicon oxide, aluminum nitride, aluminum oxide, and europium oxide are added to the aforementioned calcined powder, and calcined in a nitrogen atmosphere at 1900–2100°C to obtain a calcined product; an annealing step, wherein the aforementioned calcined product is heated in a non-oxidizing atmosphere other than pure nitrogen at a temperature below the second calcination temperature; and an acid treatment step, wherein the annealed powder is acid-treated.

[0015] In addition, the present invention is a light-emitting component comprising: a light-emitting element; one or more β-type silon phosphors, which absorb light emitted by the light-emitting element and emit light with a wavelength longer than that emitted by the light-emitting element; and a sealing material containing a β-type silon phosphor, wherein the aforementioned β-type silon phosphor is the β-type silon phosphor of the present invention.

[0016] In addition, the present invention is a light-emitting device that uses the aforementioned light-emitting component of the present invention.

[0017] The effects of the invention

[0018] According to the present invention, it is possible to provide a β-type silon phosphor that displays high brightness, a method for manufacturing the same, and a light-emitting component and device using the β-type silon phosphor having the same properties. Attached Figure Description

[0019] Figure 1 An explanatory diagram showing the XANES spectrum of the β-type silon phosphor obtained in Example 1.

[0020] Figure 2 An explanatory diagram showing the XANES spectrum of the β-type silon phosphor obtained in Comparative Example 1. Detailed Implementation

[0021] The β-type silon phosphor of the present invention is a β-type silon phosphor that uses β-type silon as a matrix crystal and contains Eu as a luminescent center, wherein the chemical state of the Eu is classified as Eu... 2+ Eu 3+ and their intermediate states (Eu) m When these three are present, their ratio satisfies 0.1. <Eu m / (Eu 2+ +Eu 3+ +Eum )<0.4 and Eu 2+ / (Eu 2+ +Eu 3+ The relationship is greater than 0.7.

[0022] Previously, Eu existed in the chemical state of Eu. 2+ and Eu 3+ These two methods separate the XANES spectra obtained by XAFS measurement into Eu. 2+ and Eu 3+ Calculate the ratio of these two peaks. In XANES spectra, Eu absorbs at specific energy positions corresponding to its valence number; therefore, Eu... 2+ With Eu 3+ The energy difference between the absorption peaks should be constant. However, measurements and analyses of the state of Eu in various β-type silon phosphors revealed the following: the aforementioned energy difference is not constant and varies depending on the sample. This indicates that in Eu... 2+ With Eu 3+ There is an Eu peak between them 2+ With Eu 3+ intermediate state (Eu) m In XANES spectra, using Eu 2+ The peak is higher than Eu 3+ The peak appears at an energy level of approximately 8 eV, from which the value of Eu can be calculated. 2+ Eu 3+ And Eu which exists among them m The presence ratio. The green luminescence of the β-type silon phosphor is accompanied by Eu dissolved in the β-type silon crystal. 2+ Electron transition, Eu m It does not directly contribute to luminescence. Eu can be considered... m It exists at grain boundaries or particle interfaces. Eu m It is formed during the crystal growth process of β-type cyrone, Eu m The presence of Eu can be considered a highly correlated indicator of the crystallinity of β-type silon. m / (Eu 2+ +Eu 3+ +Eu m When the α value is below 0.1, the crystallinity of β-silicon is low, thus the brightness of the phosphor decreases. m / (Eu 2+ +Eu 3+ +Eu m When the value is 0.4 or higher, the proportion of non-β-type silron crystals that do not contribute to luminescence in the phosphor becomes higher, so it is not preferred.

[0023] In addition, regarding the previous Eu2+ With Eu 3+ An analytical method for peak energy differences that are not fixed, Eu m More as Eu 3+ Judging from the composition, it contains Eu m In the case of Eu 2+ The proportion is tended to be underestimated. This was achieved by adding the aforementioned Eu... m The correct three-component analysis of Eu 2+ With Eu 3+ The presence of a variable ratio is clear; in the β-type silon phosphor of the present invention, Eu, which does not contribute to luminescence at all, is preferred. 3+ Ideally, it should not exist; specifically, Eu is preferred. 2+ / (Eu 2+ +Eu 3+ () greater than 0.7.

[0024] For the β-type silron phosphor matrix crystal of the present invention, β-type silron is a solid solution of β-type silicon nitride (Si3N4) in which the Si positions are partially replaced by Al and the N positions are partially replaced by O, and is composed of the general formula Si 6-z Al z O z N 8-z The z-value, representing the compositional parameter that maintains the crystal structure of β-cyrone, ranges from 0 to 4.2. This z-value affects the coordination environment of Eu ions dissolved in the β-cyrone crystal, significantly influencing fluorescence properties. For obtaining a high-brightness green phosphor, a z-value in the range of 0.005 to 1 is preferred.

[0025] Furthermore, the amount of Eu contained in the β-type silon phosphor of the present invention is preferably 0.1 to 2% by mass. If the Eu content is less than 0.1% by mass, the number of Eu ions associated with luminescence as β-type silon decreases, and sufficient brightness cannot be obtained, which is therefore not preferred. If the Eu content is greater than 2% by mass, concentration quenching will occur, and heterogeneous phases such as α-type silon, in which Eu not dissolved in the β-type silon crystal absorbs visible light, will form, resulting in lower brightness, which is also not preferred.

[0026] The following illustrates an example of a method for manufacturing the β-type silon phosphor of the present invention. However, the method for obtaining the phosphor of the present invention is not limited thereto; conventionally known methods or suitable combinations thereof may also be used if the presence of Eu in the β-type silon phosphor can be within the scope of the present invention.

[0027] For the raw materials, a mixed powder containing silicon nitride (Si3N4), aluminum nitride (AlN), and Eu compounds may be used. The Eu compound can be selected from metals, oxides, carbonates, halides, nitrides, and oxynitrides of Eu. These Eu compounds can be used alone or in combination of two or more. The calcination is performed in two stages, with the specified raw materials mixed in such a way that the final composition of the β-type silon phosphor is achieved in both calcinations. At this time, the amount of oxides contained in the silicon nitride powder and aluminum nitride powder is also taken into consideration. For the purpose of adjusting the oxygen content derived from the raw materials, silicon oxide (SiO2), aluminum oxide (Al2O3), metallic silicon, and metallic aluminum may also be mixed.

[0028] When mixing the aforementioned raw materials, methods such as dry mixing or wet mixing in a non-reactive solvent that does not substantially react with the components of the raw materials followed by solvent removal can be used. As mixing equipment, V-type mixers, rocker mixers, ball mills, vibratory mills, etc., can be appropriately used.

[0029] The above-mentioned raw material powder mixture is filled into a container such as a crucible, where at least the surface in contact with the raw material is formed of boron nitride. The mixture is heated in a nitrogen atmosphere at a temperature of 1550–2100°C to carry out a reaction within the raw material powder. The key point of this stage is to achieve high dispersion of Eu within the sample through the reaction; even partial formation of β-silicon is acceptable at this stage, regardless of the formation rate. Eu is highly dispersed by diffusion into the liquid phase generated when the oxides contained in the raw material are heated to a high temperature. If the calcination temperature is below 1550°C, this liquid phase is absent or insufficient, resulting in inadequate diffusion of Eu, which is undesirable. If the calcination temperature exceeds 2100°C, very high nitrogen pressure is required to suppress the decomposition of β-silicon, which is not industrially desirable.

[0030] The sample (calcined powder) obtained in the first calcination process is in powder or block form, depending on the raw material composition and calcination temperature. Furthermore, it may be pulverized or crushed as needed to produce a powder, for example, one that passes entirely through a sieve with an opening of 45 μm.

[0031] Next, one or more of silicon nitride, silicon oxide, aluminum nitride, aluminum oxide, and europium oxide are added to the calcined powder. The mixture is then mixed, filled into a container, and subjected to a second calcination process in a nitrogen atmosphere at a temperature of 1900–2100°C to obtain the calcined product. This calcined product is a β-type silane with Eu dissolved in it. In the second calcination, a calcination temperature of 1900°C or higher is preferred to increase the formation rate of the β-type silane. Since the sample (calcined product) after the second calcination is in block form, it is pulverized and crushed to produce a powder.

[0032] The β-type silane containing Eu synthesized by the above method is subjected to annealing treatment in a non-oxidizing atmosphere other than pure nitrogen at a temperature below the second calcination temperature to convert the Eu in the Eu to Eu. 2+ The annealing process aims to achieve a state where the proportion of Eu is increased and the Eu that hinders fluorescence emission can be dissolved and removed through acid treatment in the next step. A rare gas or a reducing gas is preferred as the atmosphere for the annealing process. Rare gases include, for example, gases of Group 18 elements such as argon and helium. Reducing gases include, for example, gases with reducing power such as ammonia, carbon dioxide, carbon monoxide, and hydrogen. The reducing gas can be used in elemental form or as a mixture with neutral gases such as nitrogen and rare gases.

[0033] The appropriate temperature range for annealing varies depending on the atmosphere used. If the temperature is too low, the state change of Eu will not proceed and its properties will not improve; if the temperature is too high, β-silicon will decompose, making this undesirable. The appropriate temperature range for annealing in rare gas atmospheres such as argon and helium is 1350–1600 °C.

[0034] Next, the annealed powder (annealed powder) is subjected to acid treatment. The acid used in the acid treatment can be one or more acids selected from hydrofluoric acid, sulfuric acid, phosphoric acid, hydrochloric acid, and nitric acid, used in the form of an aqueous solution containing these acids. The main purpose of this acid treatment is to remove compounds that hinder fluorescence emission generated during the annealing process; a mixture of hydrofluoric acid and nitric acid is preferred. The acid treatment process is carried out as follows: the annealed β-type silon phosphor is dispersed in an aqueous solution containing the aforementioned acid, and stirred for several minutes to several hours (e.g., 10 minutes to 3 hours) to allow it to react with the acid. The acid temperature can be room temperature, but since the reaction proceeds more easily at higher temperatures, 50–80°C is preferred. After acid treatment, it is preferable to wash with water after separating the phosphor particles and acid using a filter or the like.

[0035] The β-type silon phosphor of the present invention is excited over a wide wavelength range from ultraviolet to visible light and emits green light with high fluorescence efficiency, making it an excellent green phosphor. This β-type silon phosphor exhibits minimal brightness variation relative to changes in the operating environment and can be used alone or in combination with other phosphors in various light-emitting elements, particularly white LEDs using ultraviolet or blue LEDs as the light source.

[0036] The light-emitting component of the present invention comprises: a light-emitting element; one or more β-type silron phosphors, which absorb light emitted by the light-emitting element and emit light with a wavelength longer than that emitted by the light-emitting element; and a sealing material containing a β-type silron phosphor, wherein the β-type silron phosphor is the aforementioned β-type silron phosphor. Because the light-emitting component of the present invention uses the aforementioned β-type silron phosphor, it exhibits minimal brightness reduction, long lifespan, and high brightness even when used at high temperatures.

[0037] Therefore, the present invention is a light-emitting device using this light-emitting component. Because it is a light-emitting device using the aforementioned β-type silron phosphor, the brightness reduction and color shift are small, resulting in a long lifespan.

[0038] [Example]

[0039] The present invention will be described in more detail below with examples and comparative examples, but the present invention is not limited to these.

[0040] (Example 1)

[0041] 95.43% by mass of α-type silicon nitride powder (SN-E10 grade, oxygen content 1.0% by mass) manufactured by Ube Industries, Ltd., 3.04% by mass of aluminum nitride powder (F grade, oxygen content 0.8% by mass) manufactured by Tokuyama Corporation, 0.74% by mass of alumina powder (TM-DAR grade) manufactured by Daimei Chemical Industry Co., Ltd., and 0.79% by mass of europium oxide powder (RU grade) manufactured by Shin-Etsu Chemical Industry Co., Ltd. were mixed using a V-type mixer (S-3 manufactured by Tsutsui Rikikaku Equipment Co., Ltd.), and all of them were passed through a 250 μm sieve to remove agglomerates, resulting in a mixed powder. The mixing ratio here (first formulation composition (% by mass)) is based on the general formula Si of β-type silane. 6-z Al z O z N 8-z In the design, excluding europium oxide, z = 0.25 is calculated from the Si / Al ratio.

[0042] 200g of the raw material mixture powder with the aforementioned first formulation was filled into a covered cylindrical boron nitride container (manufactured by Denka Co., Ltd., N-1 grade) with an inner diameter of 10cm and a height of 10cm. The container was then subjected to a heat treatment (first calcination step) at 1800°C for 4 hours in an electric furnace with a carbon heater under a pressurized nitrogen atmosphere of 0.8MPa. The heat-treated powder was then passed through a sieve with an opening of 45μm. It should be noted that all the powder passed through the sieve. The first calcination step involves mixing the sieved powder (also called calcined powder) with the raw material mixture powder having the aforementioned first formulation composition at a mass ratio of 1:1 (second formulation composition (mass %)). This mixing is performed using the same method as described above. 200g of this mixed powder is then filled into a covered cylindrical boron nitride container with an inner diameter of 10cm and a height of 10cm. The container is then heated in an electric furnace with a carbon heater at 2000°C under a pressurized nitrogen atmosphere of 0.8MPa for 12 hours (second calcination step). The heated sample, having formed slowly agglomerated lumps, is coarsely crushed with a hammer and then pulverized using a Supersonic JetMill (manufactured by Nippon Pneumatic Mfg. Co., Ltd., PJM-80SP). The pulverization conditions are: sample feed rate set to 50g / min and pulverizing air pressure set to 0.3MPa. The pulverized powder is then passed through a sieve with an opening of 45μm. It should be noted that the sieve has a throughput of 95%.

[0043] The second calcination process involved filling a covered cylindrical boron nitride container (5 cm inner diameter, 3.5 cm height) with 20 g of pulverized powder (passed through a 45 μm sieve) into a furnace with a carbon heater at 1500 °C for 8 hours under an atmospheric pressure argon atmosphere. The annealed powder was then immersed in a 1:1 mixture of 50% hydrofluoric acid and 70% nitric acid at 75 °C for 30 minutes. This process of directly precipitating the acid-treated powder and removing the supernatant and fine powder was repeated until the pH of the solution was above 5 and the supernatant became transparent. The final precipitate was filtered and dried to obtain the β-type silane phosphor powder of Example 1. Powder X-ray diffraction analysis showed that the existing crystalline phase was a single β-type silane phase. ICP emission spectroscopy analysis revealed Si, Al, and Eu contents of 57.7%, 2.29%, and 0.62% by mass, respectively. The z-value calculated from the Si and Al content is 0.24. The first and second formulation compositions of Example 1 are recorded in Table 1.

[0044] (Comparative Example 1)

[0045] 200g of a raw material mixed powder, prepared with the same composition as the first formulation of Example 1, was filled into a covered cylindrical boron nitride container (manufactured by Denka Co., Ltd., N-1 grade) with an inner diameter of 10cm and a height of 10cm, in the same manner as the first calcination step of Example 1. However, the heat treatment equivalent to the first calcination step of Example 1 was not performed; instead, heat treatment was performed under the same conditions as the second calcination step of Example 1. The sample obtained by heat treatment was subjected to pulverization, annealing, and acid treatment using the same method and conditions as in Example 1 to obtain the β-type silon phosphor powder of Comparative Example 1. After powder X-ray diffraction analysis, the results showed that the existing crystalline phase was a single β-type silon phase. ICP emission spectroscopy analysis showed that the contents of Si, Al, and Eu were 57.3%, 2.23%, and 0.56% by mass, respectively. The z-value calculated from the Si and Al contents was 0.23. It should be noted that the formulation composition of the raw material mixed powder of Comparative Example 1 is recorded in the second formulation composition column of Table 1.

[0046] (Evaluation of fluorescence properties)

[0047] The fluorescence characteristics of the β-type silon phosphor were determined using a spectrophotometer (Hitachi High-Technologies Corporation, F-7000) calibrated with Rhodamine B and a standard light source. The phosphor powder was filled into a dedicated solid sample holder, and the fluorescence spectrum was measured when irradiated with excitation light at a wavelength of 455 nm. The peak intensity and peak wavelength were then determined. It should be noted that since peak intensity varies depending on the measuring device and conditions, the units are arbitrary. The β-type silon phosphors of Example 1 and Comparative Example 1 were measured and compared under the same conditions, with consecutive measurements. When the peak intensity of the β-type silon phosphor in Comparative Example 1 was set to 100%, the peak intensity of the phosphor in Example 1 was 112%. The peak wavelength for both Example 1 and Comparative Example 1 was 542 nm.

[0048] (XAFS assay)

[0049] XAFS spectra of the Eu-L3 absorption end of the β-type silron phosphor were measured using a Si(111)2 crystal monochromator in the XAFS measurement apparatus set up at Beam line BL11 or BL15 of the Saga Prefectural Kyushu Synchrotron Radiation Research Center (SAGA-LS). For X-ray energy correction, Eu-L3 absorption end XANES measurements of europium oxide were performed before sample measurement, with an absorption peak energy of 6980 eV. For the sample used for measurement, approximately 50 mg of phosphor powder and approximately 120 mg of boron nitride as a diluent were mixed in an agate mortar until homogeneous, and then granulated into objects with a diameter of 10 mm and a thickness of 1 mm using a mold. For incident X-ray energy, scans were performed in the range of 6800–7100 eV, particularly near the Eu-L3 absorption end (6980 eV) at intervals of approximately 0.4 eV. For incident X-ray intensity I0, an ionization chamber with an electrode length of 17 cm and a He / N2 = 50 / 50 mixed gas flowing in was used. For transmitted X-ray intensity, an ionization chamber with an electrode length of 31 cm and N2 gas flowing in was used. The measurements were taken by the transmission method.

[0050] For the obtained XANES spectrum of the Eu-L3 absorption end, normalization was performed by subtracting the background from the lower energy side (front region) of the absorption peak and setting the background intensity of the higher energy side (back edge region) of the absorption peak to 1. The portion of the normalized spectrum corresponding to the step-like absorption was then normalized using the arctangent function and Eu... 2+ and Eu 3+ The corresponding peaks are related to the Lorentz function and Eu. m The corresponding peaks were modeled using Gaussian functions. The initial values ​​of the peak positions of each component were set to the portions corresponding to the step-like absorption, Eu. 2+ 6971 eV, and Eu 3+ The corresponding peak is 6978 eV, and it is similar to Eu. m The corresponding peak was 6975 eV, and a fitting was performed. These analyses used the XAFS data analysis software "Athena" as shown in the following literature.

[0051] B. Ravel and M. Newville, J. Synchrotoron Rad. (2005) 12, p.537-541

[0052] Defined as: the XANES spectrum model of the Eu-L3 absorption end of the β-silicon fluorophore, obtained as the fitting result, and related to Eu... 2+ Let the area of ​​the corresponding Lorentz function be S[Eu] 2+ ]、and Eu 3+ Let the area of ​​the corresponding Lorentz function be S[Eu] 3+ ]、and Eum Let the area of ​​the corresponding Gaussian function be S[Eu] m When ], S[Eu 2+ ]、S[Eu 3+ ]、S[Eu m The relative proportions of Eu 2+ Eu 3+ Eu m The proportions of their existence correspond to each other. (By...) Figure 1 Eu obtained from the XANES spectrum of Example 1 m / (Eu 2+ +Eu 3+ +Eu m ) is 0.34, Eu 2+ / (Eu 2+ +Eu 3+ The value is 0.82, which is derived from Comparative Example 1. Figure 2 Eu obtained m / (Eu 2+ +Eu 3+ +Eu m ) is 0.05, Eu 2+ / (Eu 2+ +Eu 3+ The value is 0.86.

[0053] (Examples 2-4, Comparative Examples 2 and 3)

[0054] In Examples 2-4 and Comparative Example 2, the same raw materials as in Example 1 were used. A raw material mixture powder was prepared using the first formulation shown in Table 1. The calcination conditions were set at 1900°C for 4 hours. Except for this, the first calcination process was performed using the same method as in Example 1. It should be noted that the heated sample became a slowly agglomerated block; therefore, the block was coarsely crushed with a hammer and then pulverized using a supersonic airflow mill. The pulverization conditions were a sample feed rate of 50 g / min and a pulverizing air pressure of 0.3 MPa. The pulverized powder was passed through a sieve with an opening of 45 μm, and all of it passed. The second formulation, using these powders (calcined powder) and the same raw materials as in Example 1, was mixed separately. It should be noted that for both the first and second formulations, the general formula Si in β-type silane was used. 6- z Al z O z N 8-z The design excludes europium oxide and uses the method of calculating z = 0.1 based on the Si / Al ratio.

[0055] [Table 1]

[0056]

[0057] For the raw material mixture powders prepared from the second formulation in Examples 2-4 and Comparative Example 2, heat treatment was performed under the same conditions as the second calcination step in Example 1 (2000°C × 12 h, pressurized nitrogen atmosphere at 0.8 MPa). Since the heat-treated samples were hard lumps, they were coarsely crushed with a hammer and repeatedly pulverized using a roller crusher (MAKINO Corporation, MRCA-0, alumina roller) until all samples passed through a 150 μm sieve. The pulverized powder was then pulverized using a supersonic airflow mill (sample feed rate: 50 g / min, pulverizing air pressure: 0.3 MPa). The pulverized powder was then annealed and acid-treated under the same argon atmosphere as in Example 1 to obtain the β-type silon phosphors of Examples 2-4 and Comparative Example 2.

[0058] In Comparative Example 3, a raw material mixture powder with the same composition as the first formulation of Example 2 was used, and subjected to heat treatment, pulverization, annealing, and acid treatment under the same conditions as the second calcination process of Example 2 to obtain the β-type silon phosphor of Comparative Example 3. It should be noted that the formulation composition of Comparative Example 3 is recorded in the second formulation composition column of Table 1 in the same way as that of Comparative Example 1.

[0059] Powder X-ray diffraction (PXRD) analysis of the β-type silron phosphors of Examples 2-4 and Comparative Examples 2 and 3 revealed that the crystalline phase present in all cases was a single β-type silron phase. The Si, Al, and Eu contents of the phosphors, the z-value calculated from the Si / Al ratio, the fluorescence peak intensity (relative value when Comparative Example 2 was set to 100) and peak wavelength at 455 nm light excitation, and the Eu content obtained by XAFS analysis were also analyzed. m / (Eu 2+ +Eu 3+ +Eu m Eu 2+ / (Eu 2+ +Eu 3+ (See Table 2.)

[0060] [Table 2]

[0061]

[0062] The examples, through their correction, are high-brightness β-type silon phosphors compared to the comparative examples.

[0063] Industrial availability

[0064] The β-type silon phosphor of the present invention is excited by a wide range of wavelengths from ultraviolet to blue light and exhibits high-brightness green emission, thus making it suitable for use as a phosphor for white LEDs that use blue or ultraviolet light as a light source.

Claims

1. A β-type silane phosphor, comprising β-type silane as the matrix crystal and containing Eu as the luminescent center, wherein the Eu content is 0.1~2% by mass, wherein... The chemical states of Eu are divided into Eu 2+ Eu 3+ and their intermediate state Eu m When these three conditions are met, their proportion satisfies 0.

1. <Eu m / (Eu) 2+ +Eu 3+ +Eu m ) < 0.4 and Eu 2+ / (Eu) 2+ +Eu 3+ The relationship is greater than 0.

7. The Eu 2+ Eu 3+ and their intermediate state Eu m The following is obtained: The XANES spectrum of the Eu-L3 absorption end of the β-type silane phosphor was measured. For the XANES spectrum of the Eu-L3 absorption end, normalization was performed by subtracting the background from the lower energy side (front region) of the absorption peak and setting the background intensity of the higher energy side (back edge region) of the absorption peak to 1. The portion of the normalized spectrum corresponding to the step-like absorption was then subjected to an arctangent function and compared with the Eu-L3 absorption end. 2+ and Eu 3+ The corresponding peaks are related to the Lorentz function and Eu. m The corresponding peaks were modeled using Gaussian functions, with the initial values ​​of the peak positions of each component set to the portions corresponding to the step-like absorption, Eu. 2+ 6971 eV, and Eu 3+ The corresponding peak is 6978 eV, and it is similar to Eu. m The corresponding peak is 6975 eV. A fitting was performed. Defined as: the XANES spectrum model of the Eu-L3 absorption end of the β-silicon fluorophore, obtained as the fitting result, and related to Eu... 2+ Let the area of ​​the corresponding Lorentz function be S[Eu] 2+ ]、and Eu 3+ Let the area of ​​the corresponding Lorentz function be S[Eu] 3+ ]、and Eu m Let the area of ​​the corresponding Gaussian function be S[Eu] m When ], S[Eu 2+ ]、S[Eu 3+ ]、S[Eu m The relative proportions of Eu 2+ Eu 3+ Eu m The proportions of existence correspond to, β-type cyrone, as the matrix crystal, is composed of the general formula Si. 6-z Al z O z N 8-z This indicates that the z-value is greater than or equal to 0.005 and less than or equal to 1. The β-type silon phosphor is obtained by a manufacturing method comprising the following steps: In the first roasting process, a mixed powder containing at least silicon nitride, aluminum nitride and europium oxide is roasted in a nitrogen atmosphere at 1550~2100°C, and then pulverized and crushed to obtain roasted powder. In the second calcination step, two or more powders selected from silicon nitride, silicon oxide, aluminum nitride, aluminum oxide, and europium oxide are added to the calcination powder, including aluminum nitride and europium oxide. The powder is then calcined in a nitrogen atmosphere at 1900~2100°C, pulverized, and crushed to obtain the calcined product. The annealing process involves heating the calcined material at 1350-1600°C in a non-oxidizing atmosphere other than pure nitrogen; and The acid treatment process involves acid treatment of the annealed powder. The acid used in the acid treatment is selected from one or more acids, namely hydrofluoric acid, sulfuric acid, phosphoric acid, hydrochloric acid, and nitric acid, and is used in the form of an aqueous solution containing these acids for 10 minutes to 3 hours at a temperature of 50 to 80°C. In the post-processing step, the phosphor particles and acid are separated and then washed with water.

2. A light-emitting component comprising: a light-emitting element; one or more β-type silon phosphors, wherein the β-type silon phosphors absorb light emitted by the light-emitting element and emit light with a wavelength longer than that emitted by the light-emitting element; and a sealing material containing the β-type silon phosphor. The β-type silon phosphor is the β-type silon phosphor as described in claim 1.

3. A light-emitting device that uses the light-emitting component as described in claim 2.

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