Fluoride phosphors and light-emitting devices

Abstract

To provide a fluoride phosphor with high brightness. [Solution] A fluoride phosphor having a composition comprising at least one element M selected from the group consisting of Group 4 elements, Group 13 elements and Group 14 elements, at least one element selected from the group consisting of alkali metals and ammonium ions, manganese, and fluorine atoms, wherein when the total number of moles of the alkali metal and ammonium ions is 2, the number of moles of manganese is greater than 0 and less than 0.2, the total number of moles of element M is greater than 0.8 and less than 1, and the number of moles of fluorine atoms is greater than 5 and less than 7, and the particle size ratio (Da / Dm) of the average particle size Da measured by the Fischer subsieve sizers method to the volume median diameter Dm measured by laser diffraction particle size distribution analysis is 0.85 or more.

Description

Technical Field

[0001] The present disclosure relates to a fluoride phosphor and a light-emitting device.

Background Art

[0002] Light-emitting devices combining a light-emitting element and a phosphor have been variously developed and are used in a wide range of fields such as lighting, vehicle-mounted lighting, displays, and backlights for liquid crystals. For example, for phosphors used in light-emitting devices for backlight applications for liquid crystals, high color purity, that is, a narrow full width at half maximum of the emission peak, is required. As a phosphor with a narrow full width at half maximum of the red emission peak, Patent Document 1 discloses, for example, a double fluoride phosphor having a composition represented by K2SiF6:Mn.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In addition to a narrow full width at half maximum of the emission peak, improvement in luminance is required for phosphors used in light-emitting devices. For example, in the double fluoride phosphor described in Patent Document 1, there is room for improvement in luminance. Therefore, one aspect of the present disclosure aims to provide a fluoride phosphor with high luminance.

Means for Solving the Problems

[0005] The first embodiment is a fluoride phosphor having a composition comprising at least one element M selected from the group consisting of Group 4 elements, Group 13 elements, and Group 14 elements, at least one element selected from the group consisting of alkali metals and ammonium ions, manganese, and fluorine atoms, wherein, when the total number of moles of the alkali metal and ammonium ions is 2, the number of moles of manganese is greater than 0 and less than 0.2, the total number of moles of element M is greater than 0.8 and less than 1, and the number of moles of fluorine atoms is greater than 5 and less than 7. The fluoride phosphor has a particle size ratio (Da / Dm) of average particle size Da measured by the Fischer subsieve sizers method to the volume median diameter Dm measured by the laser diffraction particle size distribution method, which is 0.85 or greater.

[0006] The second aspect is a method for producing a fluoride phosphor, comprising preparing fluoride particles having a specific composition and heat-treating a mixture containing the prepared fluoride particles, an alkali metal, and a liquid medium. The fluoride particles contain element M, which includes at least one element selected from the group consisting of group 4 elements, group 13 elements, and group 14 elements; at least one element selected from the group consisting of alkali metals and ammonium ions; manganese; and fluorine atoms, wherein, when the total number of moles of the alkali metal and ammonium ions is 2, the number of moles of manganese is greater than 0 and less than 0.2, the total number of moles of element M is greater than 0.8 and less than 1, and the number of moles of fluorine atoms is greater than 5 and less than 7. [Effects of the Invention]

[0007] According to one aspect of this disclosure, a fluoride phosphor with high brightness can be provided. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic cross-sectional view showing an example of a light-emitting device containing a fluoride phosphor. [Figure 2] This is an example of a scanning electron microscope (SEM) image of a fluoride phosphor according to Example 1. [Figure 3]This is an example of an SEM image of a fluoride phosphor related to Comparative Example 1. [Modes for carrying out the invention]

[0009] In this specification, the content of each component in a composition refers to the total amount of multiple substances present in the composition, unless otherwise specified, if multiple substances corresponding to each component exist in the composition. Furthermore, the upper and lower limits of the numerical ranges described herein can be arbitrarily selected and combined from the numerical values ​​exemplified as numerical ranges. In this specification, the relationship between color names and chromaticity coordinates, the relationship between the wavelength range of light and the color names of monochromatic light, etc., conform to JIS Z8110. The full width at half maximum (FWHM) of a phosphor refers to the wavelength width (FWHM) of the emission spectrum where the emission intensity is 50% of the maximum emission intensity. The volume median diameter of a phosphor is the volume-based median diameter, and in the volume-based particle size distribution, it refers to the particle size corresponding to 50% of the volume accumulation from the smallest diameter side. The particle size distribution of a phosphor is measured by laser diffraction using a laser diffraction particle size distribution analyzer. In this specification, in formulas representing the composition of a phosphor or luminescent material, multiple elements or ions separated by commas (,) mean that at least one of these multiple elements or ions is contained in the composition. Also, in formulas representing the composition of a phosphor, the element before the colon (:) represents the matrix crystal, and the element after the colon (:) represents the activating element. Embodiments of the present invention will be described in detail below. However, the embodiments shown below are illustrative of fluoride phosphors and luminescent devices for embodying the technical concept of the present invention, and the present invention is not limited to the fluoride phosphors and luminescent devices shown below.

[0010] Fluoride phosphors The fluoride phosphor has a composition comprising at least one element M selected from the group consisting of Group 4, Group 13, and Group 14 elements, at least one element selected from the group consisting of alkali metals and ammonium ions, manganese, and fluorine atoms. The composition of the fluoride phosphor may be such that, when the total number of moles of alkali metals and ammonium ions is 2, the number of moles of manganese is greater than 0 and less than 0.2, the total number of moles of element M is greater than 0.8 and less than 1, and the number of moles of fluorine atoms is greater than 5 and less than 7. The fluoride phosphor may have a particle size ratio (Da / Dm) of 0.85 or higher between the volume median diameter Dm measured by laser diffraction particle size distribution analysis and the average particle size Da measured by the Fischer subsieve sizers method (FSSS method). Fluoride phosphors with a particle size ratio (Da / Dm) of 0.85 or higher can exhibit high brightness.

[0011] The volume median diameter Dm is the particle size corresponding to the 50% cumulative frequency from the smallest diameter side in the particle size distribution measured by the laser diffraction particle size distribution method. The laser diffraction particle size distribution method is a measurement method that uses scattered light from a laser beam irradiated onto a particle to measure the particle size distribution of that particle. Therefore, when the particles being measured include primary particles and secondary particles which are aggregates of multiple primary particles, the particle size distribution is measured for the entire particle group without distinguishing between primary and secondary particles. In other words, the volume median diameter Dm is a measured value for the particle group including primary and secondary particles. On the other hand, the average particle size Da measured by the FSSS method is the Fisher Sub-Sieve Sizer's Number. The FSSS method is a type of air permeability method that uses the resistance of air flow to measure the specific surface area and mainly determines the particle size of primary particles.

[0012] Fluoride phosphors are sometimes used in the manufacture of light-emitting devices in the form of a resin composition dispersed in a resin. The closer the particle size ratio Da / Dm of the fluoride phosphor is to 1, the lower the proportion of secondary particles and the higher the proportion of primary particles in the fluoride phosphor particle group. A higher proportion of primary particles in the fluoride phosphor particle group tends to improve the dispersibility of the fluoride phosphor in the resin. Therefore, the particle size ratio Da / Dm can be used as one indicator of the dispersibility of the fluoride phosphor in the resin. Furthermore, the particle size of the fluoride phosphors contained in the resin composition used in the manufacture of light-emitting devices may be limited by the volume median diameter Dm, which affects the fluidity in the dispensing means such as syringes used to distribute the resin composition. On the other hand, the brightness of the fluoride phosphor tends to increase as the average particle size Da, which is the particle size of the primary particles, increases. Therefore, for fluoride phosphors with similar volume median diameters Dm, fluoride phosphors with a particle size ratio Da / Dm close to 1 and a larger average particle size Da tend to have higher brightness in the fluoride phosphor itself and higher luminous flux in the light-emitting devices produced from them.

[0013] The particle size ratio Da / Dm of the fluoride phosphor may be, for example, 0.85 or higher, preferably 0.87 or higher, 0.90 or higher, 0.92 or higher, 0.94 or higher, or 0.97 or higher, from the viewpoint of improving the brightness of the fluoride phosphor. The particle size ratio Da / Dm is usually 1 or lower. The particle size ratio Da / Dm of the fluoride phosphor can be set to a desired value, for example, by the method of manufacturing the fluoride phosphor described later.

[0014] The volume median diameter Dm of the fluoride phosphor may be, for example, in the range of 25 μm to 60 μm, preferably in the range of 28 μm to 55 μm, and more preferably in the range of 30 μm to 50 μm. If the volume median diameter Dm of the fluoride phosphor is within the predetermined range and the particle size ratio Da / Dm is 0.85 or higher, even when a composition containing resin and fluoride phosphor is potted onto a molded body using a syringe to form a wavelength conversion member of a light-emitting device, the fluoride phosphor can be potted in a dispersed state within the resin without clogging the syringe. This makes it easier to manufacture light-emitting devices more efficiently. In addition, the luminous flux of the resulting light-emitting device can be increased.

[0015] The fluoride phosphor may have an average particle size Da measured by the FSSS method, for example, in the range of 20 μm to 60 μm, preferably in the range of 23 μm to 55 μm or more, more preferably in the range of 25 μm to 50 μm, or 45 μm or less, or 40 μm or less. If the average particle size Da of the fluoride phosphor measured by the FSSS method is within the predetermined range and the particle size ratio Da / Dm is 0.85 or more, the resin composition containing the fluoride phosphor and resin can be potted in a state where the phosphor is dispersed in the resin without the fluoride phosphor clogging the syringe. This makes it easier to manufacture light-emitting devices more efficiently and increases the luminous flux of the resulting light-emitting devices.

[0016] The composition of the fluoride phosphor may be such that, when the total number of moles of alkali metals and ammonium ions is 2, the number of moles of Mn is, for example, greater than 0 and less than 0.2, preferably between 0.01 and 0.12. Also, when the total number of moles of alkali metals and ammonium ions is 2, the number of moles of element M may be, for example, greater than 0.8 and less than 1, preferably between 0.88 and 0.99. Furthermore, when the number of moles of alkali metals is 2, the number of moles of F may be, for example, greater than 5 and less than 7, preferably between 5.9 and 6.1. The composition of the fluoride phosphor can be analyzed, for example, by X-ray fluorescence analysis, inductively coupled plasma (ICP) emission spectroscopy, etc.

[0017] The alkali metal in the composition of the fluoride phosphor may include at least one selected from the group consisting of lithium (Li), sodium (Na), potassium (K), rubidium (Rb), and cesium (Cs). Alternatively, the alkali metal may include at least potassium (K) and at least one selected from the group consisting of lithium (Li), sodium (Na), rubidium (Rb), and cesium (Cs). The ratio of moles of K to the total number of moles of alkali metals and ammonium ions in the composition may be, for example, 0.90 or higher, preferably 0.95 or higher, or 0.97 or higher. The ratio of moles of K may be, for example, 1 or less, or 0.995 or less. In the composition of the fluoride phosphor, ammonium ions (NH4) may be used instead of alkali metals. + ) may also be included. If ammonium ions are included, the ratio of the number of moles of ammonium ions to the total number of moles of alkali metals and ammonium ions in the composition may be, for example, 0.10 or less, preferably 0.05 or less, or 0.03 or less. The lower limit of the ratio of moles of ammonium ions may be, for example, greater than 0, preferably 0.005 or more. The alkali metals in the composition of the fluoride phosphor may be alkali metal ions.

[0018] The element M in the composition of the fluoride phosphor includes at least one selected from the group consisting of Group 4 elements, Group 13 elements, and Group 14 elements. Examples of Group 4 elements include titanium (Ti), zirconium (Zr), hafnium (Hf), etc., and at least one selected from the group consisting of these elements may be included. Examples of Group 13 elements include boron (B), aluminum (Al), gallium (Ga), indium (In), thallium (Tl), etc., and at least one selected from the group consisting of these elements may be included. Examples of Group 14 elements include carbon (C), silicon (Si), germanium (Ge), tin (Sn), etc., and at least one selected from the group consisting of these elements may be included. In one embodiment, element M may include at least one of the Group 14 elements, preferably at least one of Si and Ge, and more preferably at least Si. In one embodiment, element M may include at least one element from group 13 and at least one element from group 14, preferably at least Al and at least one of Si and Ge, and more preferably at least Al and Si.

[0019] The manganese (Mn) in the composition of the fluoride phosphor may contain manganese ions, and may contain at least tetravalent manganese ions.

[0020] The composition of the fluoride phosphor may be such that the total number of moles of elements M and Mn is 0.9 to 1.1, preferably 0.95 to 1.05, or 0.97 to 1.03, relative to the total number of moles of alkali metals and ammonium ions (2).

[0021] The composition of the fluoride phosphor may be the composition represented by the following formula (1). A c [M 1-b Mn b F d (1)

[0022] In formula (1), A is Li, Na, K, Rb, Cs and NH4+ It may contain at least one selected from the group consisting of. M contains at least Si and may further contain at least one element selected from the group consisting of Group 4 elements, Group 13 elements, and Group 14 elements. Mn may be a tetravalent Mn ion. b may satisfy 0 < b < 0.2, and c is [M 1-b Mn b F d is the absolute value of the charge of the ion, and d may satisfy 5 < d < 7.

[0023] A in formula (1) contains at least K and may further contain at least one selected from the group consisting of Li, Na, Rb, Cs, and NH4 + The ratio of the number of moles of K to the total number of moles of A in the composition may be, for example, 0.90 or more, preferably 0.95 or more, or 0.97 or more. The upper limit of the ratio of the number of moles of K may be, for example, 1 or 0.995 or less.

[0024] In formula (1), b is preferably 0.005 or more and 0.15 or less, 0.01 or more and 0.12 or less, or 0.015 or more and 0.1 or less. c may be, for example, 1.8 or more and 2.2 or less, preferably 1.9 or more and 2.1 or less, or 1.95 or more and 2.05 or less. d is preferably 5.5 or more and 6.5 or less, 5.9 or more and 6.1 or less, 5.95 or more and 6.05 or less, or 5.97 or more and 6.03 or less.

[0025] The fluoride phosphor may have a theoretical composition represented by the following formula (1a). A2MF6:Mn (1a)

[0026] In formula (1a), A may contain at least one selected from the group consisting of Li, Na, K, Rb, Cs, and NH4 + M contains at least Si and may further contain at least one element selected from the group consisting of Group 4 elements, Group 13 elements, and Group 14 elements. Mn may be a tetravalent Mn ion.

[0027] In one embodiment of the composition of the fluoride phosphor, the first composition may contain at least one selected from the group consisting of Group 4 elements and Group 14 elements as element M, preferably may contain at least one selected from the group consisting of Group 14 elements, more preferably may contain at least one of Si and Ge, and still more preferably may contain at least Si. Further, in the first composition of the fluoride phosphor, the total molar number of Si, Ge, and Mn may be 0.9 or more and 1.1 or less, preferably 0.95 or more and 1.05 or less, or 0.97 or more and 1.03 or less, with respect to the total molar number 2 of alkali metal and ammonium ions.

[0028] The first composition of the fluoride phosphor may be a composition represented by the following formula (2). A 1 q [M 1 1-p Mn p F r (2)

[0029] In formula (2), A 1 may contain at least one selected from the group consisting of Li, Na, K, Rb, Cs, and NH4. M + contains at least one of Si and Ge, and may further contain at least one element selected from the group consisting of Group 4 elements and Group 14 elements. Mn may be tetravalent Mn ions. p may satisfy 0 < p < 0.2, q is the absolute value of the charge of [M 1 1 1-p p Mn r F 1 ions, and r may satisfy 5 < r < 7.

[0030] A in formula (2) 1 contains at least K, and may further contain at least one selected from the group consisting of Li, Na, Rb, Cs, and NH4. When A + contains ammonium ions, A in the composition 1 1 ​The ratio of moles of ammonium ions to the total number of moles of ammonium ions may be, for example, 0.10 or less, preferably 0.05 or less, or 0.03 or less. The lower limit of the ratio of moles of ammonium ions may be, for example, greater than 0, preferably 0.005 or more.

[0031] In formula (2), p is preferably 0.005 to 0.15, 0.01 to 0.12, or 0.015 to 0.1. q may be, for example, 1.8 to 2.2, preferably 1.9 to 2.1, or 1.95 to 2.05. r may be preferably 5.5 to 6.5, 5.9 to 6.1, 5.92 to 6.05, or 5.95 to 6.025.

[0032] The fluoride phosphor of the first composition may have a first theoretical composition represented by the following formula (2a). A 1 2M 1 F6:Mn (2a)

[0033] In formula (2a), A 1 These are Li, Na, K, Rb, Cs and NH4 + It may include at least one selected from the group consisting of M. 1 It comprises at least one of Si and Ge, and may further comprise at least one element selected from the group consisting of Group 4 and Group 14 elements. Mn may be a tetravalent Mn ion.

[0034] A second composition, which is one embodiment of the composition of the fluoride phosphor, may contain at least one selected from the group consisting of a Group 4 element and a Group 14 element as element M, and at least one Group 13 element, preferably may contain at least one selected from the group consisting of Group 14 elements and at least one Group 13 element, and more preferably may contain at least Si and Al. Further, in the second composition of the fluoride particles, the total molar number of Si, Al, and Mn may be 0.9 or more and 1.1 or less, preferably 0.95 or more and 1.05 or less, or 0.97 or more and 1.03 or less, with respect to the total molar number 2 of alkali metals and ammonium ions. Furthermore, in the second composition of the fluoride phosphor, the molar number of Al may be more than 0 and 0.1 or less, preferably more than 0 and 0.03 or less, 0.002 or more and 0.02 or less, or 0.003 or more and 0.015 or less, with respect to the total molar number 2 of alkali metals and ammonium ions.

[0035] The second composition of the fluoride phosphor may be a composition represented by the following formula (3). A 2 t [M 2 1-s Mn s F u (3)

[0036] In formula (3), A 2 may contain at least one selected from the group consisting of Li, Na, K, Rb, Cs, and NH4 + , preferably contains at least K, and may further contain at least one selected from the group consisting of Li, Na, Rb, Cs, and NH4 + . M 2 contains at least Si and Al, and may further contain at least one element selected from the group consisting of Group 4 elements, Group 13 elements, and Group 14 elements. Mn may be tetravalent Mn ions. s may satisfy 0 < s < 0.2, and t is the absolute value of the charge of the [M 2 1-s Mn s F u ion, and u may satisfy 5 < u < 7.

[0037] A in formula (3) 2 When A contains ammonium ions, A in the composition 2 The ratio of the number of moles of ammonium ions to the total number of moles of A may be, for example, 0.10 or less, preferably 0.05 or less, or 0.03 or less. The lower limit of the ratio of the number of moles of ammonium ions may be, for example, more than 0, preferably 0.005 or more.

[0038] In formula (3), s may preferably be 0.005 or more and 0.15 or less, 0.01 or more and 0.12 or less, or 0.015 or more and 0.1 or less. t may be, for example, 1.8 or more and 2.2 or less, preferably 1.9 or more and 2.1 or less, or 1.95 or more and 2.05 or less. u may preferably be 5.5 or more and 6.5 or less, 5.9 or more and 6.1 or less, 5.92 or more and 6.05 or less, or 5.95 or more and 6.025 or less.

[0039] The fluoride particles of the second composition may have a second theoretical composition represented by the following formula (3a). A 2 2Si 1-v Al v F 6-v :Mn (3a)

[0040] In formula (3a), A 2 may contain at least one selected from the group consisting of Li, Na, K, Rb, Cs and NH4 + preferably contains at least K, and may further contain at least one selected from the group consisting of Li, Na, Rb, Cs and NH4 + v may satisfy 0 < v < 1, preferably satisfy 0.005 < v < 0.03. Mn may be tetravalent Mn ions.

[0041] The fluoride phosphor is, for example, a phosphor activated with tetravalent manganese, and may absorb light in the short-wavelength region of the visible light and emit red light. The light irradiated onto the fluoride phosphor may be mainly in the blue region, and its peak wavelength may be, for example, in the wavelength range of 380 nm to 485 nm. The emission peak wavelength in the emission spectrum of the fluoride phosphor may be, for example, in the wavelength range of 610 nm to 650 nm. The full width at half maximum in the emission spectrum of the fluoride phosphor may be, for example, 10 nm or less.

[0042] Method for producing fluoride phosphors A method for producing a fluoride phosphor may include a first step of preparing fluoride particles having a specific composition, and a second step of heat-treating a mixture containing the prepared fluoride particles and a treatment solution containing an alkali metal and a liquid medium. Here, the fluoride particles having a specific composition may contain element M, which includes at least one element selected from the group consisting of group 4 elements, group 13 elements, and group 14 elements; at least one element selected from the group consisting of alkali metals and ammonium ions; manganese; and fluorine atoms, wherein, when the total number of moles of alkali metals and ammonium ions is 2, the number of moles of manganese is greater than 0 and less than 0.2, the total number of moles of element M is greater than 0.8 and less than 1, and the number of moles of fluorine atoms is greater than 5 and less than 7. The alkali metal contained in the treatment solution may contain at least potassium.

[0043] By heat-treating a mixture containing fluoride particles having a specific composition and a processing solution containing alkali metals and a liquid medium, fluoride phosphors with a particle size ratio Da / Dm close to 1 can be efficiently produced. This is thought to be because, for example, heat-treating the fluoride particles in a liquid medium containing alkali metal ions promotes recrystallization through the dissolution reaction of the fluoride particles, increasing the proportion of primary particles in the fluoride particles. The resulting fluoride phosphor has high brightness, and in a light-emitting device equipped with a wavelength conversion member containing fluoride phosphor and resin, for example, the luminous flux is improved.

[0044] In the first step, fluoride particles having a specific composition are prepared. In the first step, the fluoride particles may be prepared by receiving them or by manufacturing the desired fluoride particles. The details of the composition of the prepared fluoride particles are the same as those of the fluoride phosphors described above.

[0045] Fluoride particles can be produced, for example, as follows. If the fluoride particles have a first composition, they can be produced by a manufacturing method that includes mixing solution a, which contains a first complex ion including tetravalent manganese, a second complex ion including at least one element selected from the group consisting of group 4 and group 14 elements and a fluoride ion, and at least hydrogen fluoride, with solution b, which contains an alkali metal and at least hydrogen fluoride. Here, the alkali metal contained in the fluoride particles may include at least potassium.

[0046] Fluoride particles having the first composition can also be produced by a manufacturing method that includes, for example, mixing a first solution containing at least a first complex ion including tetravalent manganese and hydrogen fluoride, a second solution containing at least an alkali metal and hydrogen fluoride, and a third solution containing at least a second complex ion including at least one element selected from the group consisting of group 4 and group 14 elements and fluoride ions. For a method of producing fluoride particles having the first composition, see, for example, Japanese Patent Publication No. 2014-141684, Japanese Patent Publication No. 2015-143318, Japanese Patent Publication No. 2015-188075, etc.

[0047] If the fluoride particles have a second composition, the fluoride particles having the second composition can be produced by a manufacturing method that includes, for example, preparing fluoride particles having a first composition, preparing fluoride particles containing Al, alkali metals, and F, and performing a first heat treatment step in which a mixture containing these fluoride particles and the fluoride particles having the first composition is subjected to a first heat treatment at a first heat treatment temperature of 600°C to 780°C in an inert gas atmosphere. Here, the composition of the fluoride particles containing Al, alkali metals, and F may be such that the ratio of the total number of moles of alkali metals to the number of moles of Al is 1 or more and 3 or less, and the ratio of the number of moles of F is 4 or more and 6 or less. Alternatively, the ratio of the total number of moles of alkali metals to the number of moles of Al is 2 or more and 3 or less, and the ratio of the number of moles of F is 5 or more and 6 or less. For a method of producing fluoride particles having a second composition, refer to, for example, Japanese Patent Publication No. 2010-254933, Japanese Patent Publication No. 2022-099232, etc. Here, the alkali metals contained in the fluoride particles may include at least potassium.

[0048] In the second step, a mixture containing the prepared fluoride particles and a treatment solution containing alkali metals and a liquid medium is heat-treated. The alkali metals contained in the treatment solution are the same as those contained in the composition of the fluoride particles, and the alkali metals contained in the treatment solution and the alkali metals contained in the composition of the fluoride particles may be the same. The alkali metals contained in the treatment solution may be in the form of alkali metal ions. Furthermore, the alkali metals contained in the treatment solution may contain at least potassium. If the alkali metals contained in the treatment solution contain potassium, the ratio of the number of moles of potassium to the total number of moles of alkali metals in the treatment solution may be, for example, 0.90 or more, preferably 0.95 or more, or 0.97 or more, and may be, for example, 1 or 0.995 or less. If the treatment solution contains potassium, it may contain it as an inorganic salt such as potassium hydrogen fluoride (KHF2), potassium nitrate (KNO3), or potassium fluoride (KF), and the inorganic salt may be contained in a state where it is dissolved in the liquid medium.

[0049] The alkali metal content in the processing solution may be, for example, 5% by mass or more and 30% by mass or less, preferably 10% by mass or more, 12% by mass or more, 15% by mass or more, 18% by mass or more, or 20% by mass or more, for example, 28% by mass or less or 25% by mass or less.

[0050] The liquid medium is not particularly limited and can be appropriately selected from commonly used liquids depending on the purpose. Specific examples of liquid mediums include water; alcohol solvents such as methanol, ethanol, and isopropyl alcohol; ketone solvents such as acetone and male ethyl ketone; and organic solvents such as diethyl ether and diisopropyl ether. Furthermore, the liquid medium may be a substance that is a gas at normal pressure but liquefies under pressure, or a substance that is a solid at room temperature but liquefies under heating. The liquid medium preferably contains at least water, and may be substantially water. The liquid medium may be a single substance or a combination of two or more substances.

[0051] The treatment solution may further contain components that are soluble in the liquid medium. Examples of components that are soluble in the liquid medium include inorganic acids such as hydrogen fluoride (HF), hexafluorosilicic acid (H2SiF6), and nitric acid (HNO3); and peroxides such as hydrogen peroxide. The components that are soluble in the liquid medium may be used individually or in combination of two or more. The treatment solution may contain at least hydrogen fluoride. If the treatment solution contains hydrogen fluoride, the hydrogen fluoride content in the treatment solution may be, for example, 10% by mass or more and 80% by mass or less, preferably 20% by mass or more, 40% by mass or more, or 60% by mass or more, and may be 75% by mass or less, 70% by mass or less, or 65% by mass or less.

[0052] The amount of processing solution used in the mixture may be, for example, 50% by mass or more and 500% by mass or less as a mass ratio to the fluoride particles, preferably 80% by mass or more, 85% by mass or more, or 100% by mass or more, and preferably 300% by mass or less, 200% by mass or less, or 150% by mass or less. When the mass ratio of the processing solution is within the above range, there is a tendency to be able to produce a fluoride phosphor with a higher proportion of primary particles.

[0053] The temperature for the heat treatment in the second step may be, for example, 150°C or higher and less than 230°C. The heat treatment temperature may preferably be 160°C or higher, 170°C or higher, or 180°C or higher, and preferably 225°C or lower, or 220°C or lower. If the heat treatment temperature is 150°C or higher, the recrystallization by the dissolution reaction of the fluoride phosphor proceeds more smoothly, and a fluoride phosphor with a high proportion of primary particles and a particle size ratio Da / Dm close to 1 can be obtained. Also, if the heat treatment temperature is less than 230°C, the deterioration of the container used for heat treatment can be suppressed.

[0054] The heat treatment time can be appropriately selected according to the treatment conditions such as temperature. For example, the heat treatment time may be 4 hours or more and 24 hours or less, preferably 8 hours or more, 12 hours or more, or 14 hours or more, and may be 20 hours or less or 18 hours or less. A heat treatment time of 4 hours or more tends to produce a fluoride phosphor with a higher proportion of primary particles. A time of 24 hours or less is advantageous from the viewpoint of production efficiency. The atmosphere during the heat treatment is not particularly limited and may be an air atmosphere or an inert gas atmosphere.

[0055] The mixture can be heated by placing it in a pressure-resistant sealed container, such as an autoclave. By using a pressure-resistant sealed container for the heat treatment, the mixture can be subjected to pressurized heat treatment. In other words, the heat treatment of the mixture in the second step may be pressurized heat treatment of the mixture. The pressure-resistant sealed container may be made of stainless steel or the like, with its inner surface coated with a fluororesin such as polytrifluoroethylene (PTFE), or it may consist of a sample container made of fluororesin and a pressure-resistant, sealable outer cylinder enclosing the sample container.

[0056] The method for producing a fluoride phosphor may further include, after the second step, a step of recovering the fluoride phosphor obtained in the second step by solid-liquid separation, a step of drying the solid-liquid separated fluoride phosphor, a step of dispersing the dried fluoride phosphor, and so on.

[0057] Light-emitting device The light-emitting device may comprise a fluoride phosphor and a light source having an emission peak wavelength in the wavelength range of 380 nm to 485 nm. The light-emitting device may further include other components as needed. The fluoride phosphor may constitute the light-emitting device as, for example, a wavelength conversion member comprising a fluoride phosphor and a resin.

[0058] An example of a light-emitting device will be described based on the drawings. Figure 1 is a schematic cross-sectional view showing an example of a light-emitting device according to this embodiment. This light-emitting device is an example of a surface-mount type light-emitting device. The light-emitting device 100 has a light-emitting element 10, which is a light source that emits light having an emission peak wavelength in the short wavelength range of visible light (for example, in the range of 380 nm to 485 nm), and a molded body 40 on which the light-emitting element 10 is mounted. The molded body 40 has a first lead 20 and a second lead 30 and is integrally molded from a thermoplastic resin or a thermosetting resin. The molded body 40 has a recess formed therein with a bottom surface and side surfaces corresponding to a substrate, and the light-emitting element 10 is mounted on the bottom surface of the recess. The light-emitting element 10 has a pair of positive and negative electrodes, and the pair of positive and negative electrodes are electrically connected to the first lead 20 and the second lead 30 via a wire 60. The light-emitting element 10 is covered with a wavelength conversion member 50. The wavelength conversion member 50 contains a phosphor 70 including a fluoride phosphor that converts the wavelength of light from the light-emitting element 10. The phosphor 70 may further include the fluoride phosphor and a light-emitting material that emits light having an emission peak wavelength in a different wavelength range from the fluoride phosphor when excited by light from the light-emitting element 10.

[0059] The wavelength conversion member may contain a resin and a phosphor. Examples of resins constituting the wavelength conversion member include silicone resin, epoxy resin, modified silicone resin, modified epoxy resin, and acrylic resin. For example, the refractive index of the silicone resin may be between 1.35 and 1.55, and more preferably between 1.38 and 1.43. Silicone resins within these refractive index ranges exhibit excellent light transmittance and can be suitably used as resins constituting the wavelength conversion member. Here, the refractive index of the silicone resin is the refractive index after curing and is measured in accordance with JIS K7142:2008. In addition to the resin and phosphor, the wavelength conversion member may further contain a light diffusing material. By including a light diffusing material, the directivity from the light-emitting element can be reduced and the viewing angle can be increased. Examples of light diffusing materials include silicon dioxide, titanium dioxide, zinc oxide, zirconium oxide, and aluminum oxide.

[0060] The light-emitting element emits light having an emission peak wavelength in the short-wavelength region of visible light, specifically in the wavelength range of 380 nm to 485 nm. The light-emitting element may be a light source that excites a fluoride phosphor. Preferably, the light-emitting element has an emission peak wavelength in the range of 380 nm to 480 nm, more preferably in the range of 410 nm to 480 nm, and even more preferably in the range of 430 nm to 480 nm. It is preferable to use a semiconductor light-emitting element as the light source. By using a semiconductor light-emitting element as the light source, a stable light-emitting device can be obtained that is highly efficient, has high linearity of output to input, and is resistant to mechanical shock. As the semiconductor light-emitting element, for example, a semiconductor light-emitting element using a nitride-based semiconductor can be used. Preferably, the full width at half maximum of the emission peak in the emission spectrum of the light-emitting element is, for example, 30 nm or less.

[0061] The light-emitting device is composed of a fluoride phosphor. Details of the fluoride phosphor included in the light-emitting device are as previously described. The fluoride phosphor is contained, for example, in a wavelength conversion member that covers the light source. In a light-emitting device in which the light source is covered with a wavelength conversion member containing a fluoride phosphor, a portion of the light emitted from the light source is absorbed by the fluoride phosphor and emitted as red light. By using a light source that emits light having an emission peak wavelength in the range of 380 nm to 485 nm, the emitted light can be utilized more effectively, the loss of light emitted from the light-emitting device can be reduced, and a highly efficient light-emitting device can be provided.

[0062] The light-emitting device preferably further includes a light-emitting material other than a fluoride phosphor in addition to the fluoride phosphor. The light-emitting material other than the fluoride phosphor can be any material that absorbs light from a light source and converts it to light of a different wavelength than that of the fluoride phosphor. The light-emitting material can be included in a wavelength conversion member, for example, in the same way as the fluoride phosphor.

[0063] The light-emitting material may have an emission peak wavelength in the wavelength range of 495 nm or more and 573 nm or less, and is preferably at least one selected from the group consisting of β-sialon phosphors, halosilicate phosphors, silicate phosphors, rare earth aluminate phosphors, and nitride phosphors. The β-sialon phosphor may have a composition represented by, for example, the following formula (IIa). The halosilicate phosphor may have a composition represented by, for example, the following formula (IIb). The silicate phosphor may have a composition represented by, for example, the following formula (IIc). The rare earth aluminate phosphor may have a composition represented by the following formula (IId). The nitride phosphor may have a composition represented by, for example, the following formula (IIe), (IIf), or (IIg). When the wavelength conversion member includes a β-sialon phosphor as a light-emitting material other than a fluoride phosphor, a light-emitting device having a wider color reproducibility range can be obtained when the light-emitting device is used as a light source for a backlight, for example. When the wavelength conversion member includes a halosilicate phosphor, a silicate phosphor, a rare earth aluminate phosphor, or a nitride phosphor as a light-emitting material other than a fluoride phosphor, a light-emitting device having higher color rendering properties or higher luminous efficiency can be obtained when the light-emitting device is used as a light source for illumination, for example.

[0064] Si 6-x Al x O x N 8-x :Eu (IIa) (In formula (IIa), x is a number satisfying 0 < x ≤ 4.2.) (Ca,Sr,Ba)8MgSi4O 16 (F,Cl,Br)2:Eu (IIb) (Ba,Sr,Ca,Mg)2SiO4:Eu (IIc) (Y,Lu,Gd,Tb)3(Al,Ga)5O 12 :Ce (IId) (La,Y,Gd)3Si6N 11 :Ce (IIe) (Sr,Ca)LiAl3N4:Eu (IIf) (Ca,Sr)AlSiN3:Eu (IIg)

[0065] The wavelength conversion member may further include at least one type of quantum dot in addition to the fluoride phosphor. The quantum dot may absorb light from the light source and convert it to light of a different wavelength than the fluoride phosphor, or it may convert it to light of a similar wavelength. Examples of quantum dots include quantum dots having a perovskite structure with a composition such as (Cs,FA,MA)(Pb,Sn)(Cl,Br,I)3 (where FA is formamidinium and MA is methylammonium), quantum dots having a chalcopyrite structure with a composition such as (Ag,Cu,Au)(In,Ga)(S,Se,Te)2, semiconductor quantum dots such as (Cd,Zn)(Se,S), and InP-based semiconductor quantum dots, and at least one selected from the group consisting of these may be included. By including quantum dots as a light-emitting material other than the fluoride phosphor in the wavelength conversion member, a light-emitting device with a wider range of color reproduction can be made when the light-emitting device is used as a backlight, for example.

[0066] The invention relating to this disclosure may encompass, for example, the following embodiments: [1] A composition comprising at least one element M selected from the group consisting of Group 4 elements, Group 13 elements and Group 14 elements, at least one element selected from the group consisting of alkali metals and ammonium ions, manganese, and fluorine atoms, wherein when the total number of moles of the alkali metal and ammonium ions is 2, the number of moles of manganese is greater than 0 and less than 0.2, the total number of moles of element M is greater than 0.8 and less than 1, and the number of moles of fluorine atoms is greater than 5 and less than 7. A fluoride phosphor having a particle size ratio (Da / Dm) of 0.85 or higher between the volume median diameter Dm measured by laser diffraction particle size distribution analysis and the average particle size Da measured by the Fischer subsieve sizers method.

[0067] [2] The fluoride phosphor according to [1] having a composition represented by the following formula (1). A c [M 1-b Mn b Fd (1)

[0068] In formula (1), A contains at least one selected from the group consisting of Li, Na, K, Rb, Cs, and NH4 + M contains at least one element selected from the group consisting of Group 4 elements, Group 13 elements, and Group 14 elements, and contains at least Si. b satisfies 0 < b < 0.2, and c is the absolute value of the charge of the 1-b Mn b F d ion, and d satisfies 5 < d < 7.

[0069] [3] The fluoride phosphor according to [1] or [2], wherein the average particle diameter Da measured by the Fischer sub-sieve sizers method is in the range of 20 μm or more and 60 μm or less.

[0070] [4] A light-emitting device comprising the fluoride phosphor according to any one of [1] to [3] and a light source having an emission peak wavelength within the range of 380 nm or more and 485 nm or less.

[0071] [5] The light-emitting device according to [4], further comprising a light-emitting material having an emission peak wavelength within the range of 495 nm or more and 573 nm or less.

[0072] [6] Preparing fluoride particles having a composition containing at least one element M selected from the group consisting of Group 4 elements, Group 13 elements, and Group 14 elements, at least one selected from the group consisting of alkali metals and ammonium ions, manganese, and fluorine atoms, wherein when the total number of moles of the alkali metals and ammonium ions is 2, the number of moles of manganese exceeds 0 and is less than 0.2, the total number of moles of element M exceeds 0.8 and is less than 1, and the number of moles of fluorine atoms exceeds 5 and is less than 7; heat-treating a mixture containing the prepared fluoride particles and a treatment liquid containing an alkali metal and a liquid medium. A method for producing a fluoride phosphor.

[0073] [7] The method for producing a fluoride phosphor according to [6], wherein the alkali metal content in the processing solution is 10% by mass or more.

[0074] [8] The method for producing a fluoride phosphor according to [6] or [7], wherein the processing solution further comprises hydrogen fluoride.

[0075] [9] The method for producing a fluoride phosphor according to [8], wherein the processing solution contains 40% by mass or more of hydrogen fluoride.

[0076]

[10] A method for producing a fluoride phosphor according to any one of [6] to [9], wherein the temperature of the heat treatment is 180°C or higher. [Examples]

[0077] The embodiments of this disclosure will be described in detail below with reference to examples, but the embodiments of this disclosure are not limited to these examples.

[0078] Manufacturing Example 1 7029 g of KHF2 was weighed and dissolved in 37.3 L of a 55% by mass aqueous solution of hydrogen fluoride (HF) to prepare the first solution. 314.2 g of K2MnF6 was also weighed and dissolved in 6.0 L of a 55% by mass aqueous solution of HF to prepare the second solution. Next, 7.8 L of an aqueous solution containing 40% by mass of H2SiF6 was prepared to prepare the third solution. Then, the second and third solutions were added dropwise to the first solution over approximately 10 hours while stirring at 20°C. After the dropwise addition was complete, 400 ml of 35% hydrogen peroxide solution was added, and the mixture was washed with pure water. The resulting precipitate was then subjected to solid-liquid separation, washed with ethanol, and dried at 90°C for 10 hours to produce the fluoride particles P1 of Production Example 1.

[0079] The obtained fluoride particles P1 had an average particle size Da = 20.5 μm, and K2[Si 0.961 Mn 0.039 It had a composition represented by [F6].

[0080] Manufacturing Example 2 Except for weighing 7029g of KHF2 and dissolving it in 41.3L of a 55% by mass HF aqueous solution to prepare the first solution, and weighing 333.8g of K2MnF6 and dissolving it in 6.0L of a 55% by mass HF aqueous solution to prepare the second solution, fluoride particles P2 of Production Example 2 were produced in the same manner as in Production Example 1.

[0081] The obtained fluoride particles P2 had an average particle size Da = 40.0 μm, and K2[Si 0.963 Mn 0.037 It had a composition represented by [F6].

[0082] Manufacturing Example 3 Fluoride particles P3 of Production Example 3 were produced in the same manner as in Production Example 1, except that 7029g of KHF2 was weighed and dissolved in 42.0L of a 55% by mass HF aqueous solution to prepare the first solution, and 340.4g of K2MnF6 was weighed and dissolved in 6.0L of a 55% by mass HF aqueous solution to prepare the second solution.

[0083] The obtained fluoride particles P3 had an average particle size Da = 50.0 μm, and K2[Si 0.962 Mn 0.038 It had a composition represented by [F6].

[0084] Manufacturing Example 4 Fluoride particles P4 of Production Example 4 were produced in the same manner as in Production Example 1, except that 7029 g of KHF2 was weighed and dissolved in 36.5 L of a 55% by mass HF aqueous solution to prepare the first solution, and 484.4 g of K2MnF6 was weighed and dissolved in 6.0 L of a 55% by mass HF aqueous solution to prepare the second solution.

[0085] The obtained fluoride particles P4 had an average particle size Da = 18.5 μm, and K2[Si 0.941 Mn 0.059 It had a composition represented by [F6].

[0086] Manufacturing Example 5 Fluoride particles P5 of Production Example 5 were produced in the same manner as in Production Example 1, except that 7029 g of KHF2 was weighed and dissolved in 40.0 L of a 55% by mass HF aqueous solution to prepare the first solution, and 497.5 g of K2MnF6 was weighed and dissolved in 6.0 L of a 55% by mass HF aqueous solution to prepare the second solution.

[0087] The obtained fluoride particles P5 had an average particle size Da = 31.5 μm, and K2[Si 0.944 Mn 0.056 It had a composition represented by [F6].

[0088] Example 1 50 g of fluoride particles P1 produced in Production Example 1 were weighed and placed into a PTFE sample container (manufactured by San-ai Chemical Co., Ltd.: HUT-100R) with a capacity of 100 ml. Next, 75 g of a treatment solution (potassium concentration: 20% by mass) prepared by dissolving 30 g of KHF2 in 45 g of a 65% by mass HF aqueous solution was added, stirred to form a slurry, and then the container was capped. The capped sample container was placed in a stainless steel outer cylinder (manufactured by San-ai Chemical Co., Ltd.: HUS-100) and heat-treated in a 190°C constant temperature oven for 16 hours.

[0089] After the heat treatment was completed, the PTFE sample container was removed from the stainless steel outer cylinder, the precipitate obtained in the sample container was transferred to a beaker, 600 ml of 1% hydrogen peroxide solution was added and washed, solid-liquid separation was performed, followed by ethanol washing and drying at 90°C for 10 hours. After drying, a wet dispersion treatment using polyethylene beads was performed for 1 hour, solid-liquid separation was performed, followed by washing with hydrogen peroxide solution and ethanol, and drying at 90°C for 10 hours to produce the fluoride phosphor of Example 1.

[0090] Example 2 The fluoride phosphor of Example 2 was prepared in the same manner as in Example 1, except that the fluoride particles P2 produced in Production Example 2 were used.

[0091] Example 3 The fluoride phosphor of Example 3 was prepared in the same manner as in Example 1, except that the fluoride particles P3 produced in Production Example 3 were used.

[0092] Example 4 The fluoride phosphor of Example 4 was prepared in the same manner as in Example 1, except that the fluoride particles P4 produced in Production Example 4 were used.

[0093] Example 5 The fluoride phosphor of Example 5 was prepared in the same manner as in Example 5, except that the fluoride particles P5 produced in Production Example 5 were used.

[0094] Example 6 The fluoride phosphor of Example 6 was prepared in the same manner as in Example 2, except that the treatment solution used for the heat treatment was changed to a treatment solution prepared by dissolving 37.5 g of KHF2 in 37.5 g of a 65% by mass HF aqueous solution (potassium concentration: 25% by mass).

[0095] Example 7 The fluoride phosphor of Example 7 was prepared in the same manner as in Example 1, except that the treatment solution used for the heat treatment was changed to a treatment solution prepared by dissolving 15 g of KHF2 in 60 g of a 65% by mass HF aqueous solution (potassium concentration: 10% by mass).

[0096] Comparative Example 1 Comparative Example 1's fluoride phosphor was prepared by subjecting the fluoride particles P1 produced in Production Example 1 to a wet dispersion treatment using polyethylene beads for 1 hour, similar to Example 1, followed by solid-liquid separation, washing with hydrogen peroxide and ethanol, and drying at 90°C for 10 hours.

[0097] Comparative Example 2 The fluoride phosphor of Comparative Example 2 was prepared in the same manner as in Comparative Example 1, except that the fluoride particles P2 produced in Production Example 2 were used.

[0098] Comparative Example 3 The fluoride phosphor of Comparative Example 3 was prepared in the same manner as in Comparative Example 1, except that the fluoride particles P3 produced in Production Example 3 were used.

[0099] Comparative Example 4 The fluoride particles P1 produced in Production Example 1 were heat-treated in an atmosphere with a fluorine gas (F2) concentration of 20% by volume and a nitrogen gas concentration of 80% by volume, while in contact with fluorine gas, at a temperature of 500°C for a holding time of 8 hours. Next, a wet dispersion treatment using polyethylene beads was performed for 1 hour, followed by solid-liquid separation, washing with hydrogen peroxide and ethanol, and drying at 90°C for 10 hours to produce the fluoride phosphor of Comparative Example 4.

[0100] Comparative Example 5 The fluoride phosphor of Comparative Example 5 was prepared in the same manner as in Example 1, except that the treatment solution used for the heat treatment was changed to a treatment solution prepared by dissolving 10 g of KHF2 in 45 g of a 65% by mass HF aqueous solution (potassium concentration: 9% by mass).

[0101] evaluation Each of the fluoride phosphors obtained above was evaluated as follows. The results are shown in Table 1.

[0102] 1. Average particle size Da The average particle size Da was measured using the FSSS method with a Fisher Sub-Sieve Sizer Model 95 (manufactured by Fisher Scientific).

[0103] 2. Volume median diameter Dm Using a laser diffraction particle size distribution analyzer (product name: MASTER SIZER3000, manufactured by MALVERN), the volume median diameter Dm was measured, which is the particle size at which the volume accumulation frequency from the small diameter side reaches 50%.

[0104] 3. Emission spectrum and relative luminance Using a spectrofluorometer (product name: QE-2000, manufactured by Otsuka Electronics Co., Ltd.), excitation light with an emission peak wavelength of 450 nm was irradiated onto each fluoride phosphor, and the emission spectrum of each fluoride phosphor at room temperature (25°C) was measured.

[0105] From the measured emission spectrum data, the luminance of the fluoride phosphor of Comparative Example 1 was set to 100%, and the luminance of the fluoride phosphors other than Comparative Example 1 was determined as relative luminance.

[0106] 4. Mn quantity (variable b) Using an X-ray fluorescence analyzer (XRF; product name: ZSX PrimusII, manufactured by Rigaku Corporation), the Mn content was measured by X-ray fluorescence analysis, and the molar ratio of Mn in 1 mole of the composition represented by formula (I) (variable b) was determined.

[0107] 5. SEM image Scanning electron microscope (SEM) images of the fluoride phosphor were obtained using a scanning electron microscope (SEM). Figure 2 shows the SEM image of Example 1, and Figure 3 shows the SEM image of Comparative Example 1.

[0108] [Table 1]

[0109] As shown in Table 1, the fluoride phosphors of Examples 1 to 6 obtained higher relative brightness than the fluoride phosphors of the comparative examples. Furthermore, the particle size ratio Da / Dm of the fluoride phosphors of the examples was closer to 1, indicating improved dispersibility. [Explanation of Symbols]

[0110] 10: Light-emitting element, 20: First lead, 30: Second lead, 40: Molded body, 50: Fluorescent material, 60: Wire, 70: Phosphor, 100: Light-emitting device

Claims

1. The composition comprises an element M including at least one selected from the group consisting of Group 4 elements, Group 13 elements, and Group 14 elements, at least one selected from the group consisting of alkali metals and ammonium ions, manganese, and fluorine atoms, wherein, when the total number of moles of the alkali metal and ammonium ions is 2, the number of moles of manganese is greater than 0 and less than 0.2, the total number of moles of element M is greater than 0.8 and less than 1, and the number of moles of fluorine atoms is greater than 5 and less than 7. A fluoride phosphor in which the particle size ratio (Da / Dm) of the average particle size Da measured by the Fischer subsieve sizers method to the volume median diameter Dm measured by the laser diffraction particle size distribution method is 0.85 or higher.

2. A fluoride phosphor according to claim 1, having a composition represented by the following formula (1). A ｃ [M １－ｂ Mn ｂ F ｄ ] (1) (In Formula (1), A contains at least one selected from the group consisting of Li, Na, K, Rb, Cs, and NH ４ ＋ M contains at least one element selected from the group consisting of Group 4 elements, Group 13 elements, and Group 14 elements, and contains at least Si. b satisfies 0 < b < 0.2, and c is the absolute value of the charge of the １－ｂ Mn ｂ F ｄ ion, and d satisfies 5 < d < 7. )

3. The fluoride phosphor according to claim 1, wherein the average particle size Da measured by the Fischer subsieve sizers method is 20 μm or more and 60 μm or less.

4. A light-emitting device comprising a fluoride phosphor according to any one of claims 1 to 3, and a light source having an emission peak wavelength in the wavelength range of 380 nm to 485 nm.

5. The light-emitting apparatus according to claim 4, further comprising a light-emitting material having an emission peak wavelength in the wavelength range of 495 nm to 573 nm.

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