Phosphor, light-emitting device, lighting device, image display device, and vehicle display lamp

Abstract

The present invention addresses the problem of providing a phosphor having a good emission peak wavelength, a narrow spectral half-value width, and a high emission intensity, and providing a light-emitting device, an illumination device, an image display device, and / or a vehicle display lamp having good color rendering properties, color reproducibility, and / or conversion efficiency. The present invention relates to a phosphor and a light-emitting device provided with the phosphor as a second light-emitting body, the phosphor containing a crystal phase having a composition represented by a specific formula and containing an element Z, the content of the element Z being 1000 mass ppm or less, and the element Z containing one or more elements selected from the group consisting of Mo, W, Nb, Ta, Ni, Pt, and Ir.

Description

Technical Field

[0001] The present invention relates to a phosphor, a light-emitting device, a lighting device, an image display device, and a vehicle display lamp. Background Art

[0002] In recent years, due to the trend of energy conservation, the demand for lighting and backlights using LEDs has increased. The LEDs used here are white light-emitting LEDs in which a phosphor is disposed on an LED chip that emits light having a blue or near-ultraviolet wavelength.

[0003] As such a white light-emitting LED, in recent years, an LED that uses a nitride phosphor that emits red light using blue light from a blue LED chip as excitation light and a phosphor that emits green light on a blue LED chip has been used. As an LED, further luminous efficiency is required, and a phosphor having excellent luminous characteristics as a red phosphor and a light-emitting device including such a phosphor are desired.

[0004] As a red phosphor used in a light-emitting device, for example, a KSF phosphor represented by the general formula K2(Si,Ti)F6:Mn, K2Si

[0009] x Na x Al x F6:Mn (0 < x < 1), an S / CASN phosphor represented by the general formula (Sr,Ca)AlSiN3:Eu, etc. are known. However, for the KSF phosphor, since it is a highly toxic substance activated by Mn, a phosphor more friendly to the human body and the environment is required. In addition, regarding the S / CASN phosphor, in most cases, the full width at half maximum (hereinafter, sometimes referred to as "spectral half width" or "A full width at half maximum", "FWHM") in the emission spectrum is relatively wide, about 80 nm to 90 nm, and the emission wavelength region easily includes a wavelength region with relatively low visibility. Therefore, from the viewpoint of improving the conversion efficiency, a red phosphor having a narrower spectral half width is required.

[0005] In addition, as a red phosphor that can be applied to recent light-emitting devices, for example, a phosphor represented by the compositional formula SrLiAl3N4:Eu is disclosed in Example in Patent Document 1.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Patent No. 6335884 Gazette [[ID=3​​​​​However, the luminous intensity of the phosphor described in Patent Document 1 is unclear, and a phosphor with higher luminous intensity and a light-emitting device with higher conversion efficiency are desired.

[0011] In view of the above problems, an object of the present invention is to provide a phosphor having a good emission peak wavelength, a narrow spectral half-value width, and a high emission intensity.

[0012] Another object of the present invention is to provide a light emitting device, an illumination device, an image display device, and / or a vehicle indicator lamp with excellent color rendering properties, color reproducibility, and / or conversion efficiency.

[0013] Means for solving problems

[0014] The present inventors conducted intensive research and discovered that the above-mentioned problems can be solved by using a phosphor containing a crystal phase represented by a specific composition and containing a specific element in a certain amount or more, or a light-emitting device including such a phosphor, thereby completing the present invention. Several non-limiting embodiments are described below.

[0015] Aspect 1 of the present invention is a phosphor comprising a crystal phase having a composition represented by the following formula [1] and comprising element Z, wherein the content of the element Z is 1000 ppm by mass or less, and the element Z comprises one or more elements selected from the group consisting of Mo, W, Nb, Ta, Ni, Pt, and Ir.

[0016] Re x MA a MB b MC c D d X e [1]

[0017] (In the above formula [1], MA contains one or more elements selected from the group consisting of Ca, Sr, Ba, Na, K, Y, Gd and La, MB contains one or more elements selected from the group consisting of Li, Mg and Zn, MC contains one or more elements selected from the group consisting of Al, Si, Ga, In and Sc, D is one or more elements selected from the group consisting of N (nitrogen) and O (oxygen), X contains one or more elements selected from the group consisting of F, Cl, Br and I, Re contains one or more elements selected from the group consisting of Eu, Ce, Pr, Tb and Dy, and a, b, c, d, e, and x each satisfy the following formula.

[0018] 0.7≤a≤1.3

[0019] 0.7≤b≤1.3

[0020] 2.4≤c≤3.6

[0021] 3.2≤d≤4.8

[0022] 0.0≤e≤0.2

[0023] 0.0 <x≤0.2)

[0024] A second embodiment of the present invention is a phosphor comprising a crystal phase having a composition represented by the following formula [2] and comprising element Z, wherein the content of the element Z is 1000 ppm by mass or less, and the element Z comprises one or more elements selected from the group consisting of Mo, W, Nb, Ta, Ni, Pt, and Ir.

[0025] Re x MA a MB b (Al 1-y MC' y ) c D d X e [2]

[0026] (In the above formula [2], MA contains one or more elements selected from the group consisting of Ca, Sr, Ba, Na, K, Y, Gd and La, MB contains one or more elements selected from the group consisting of Li, Mg and Zn, MC' contains one or more elements selected from the group consisting of Si, Ga, In and Sc, D is one or more elements selected from the group consisting of N (nitrogen) and O (oxygen), X contains one or more elements selected from the group consisting of F, Cl, Br and I, Re contains one or more elements selected from the group consisting of Eu, Ce, Pr, Tb and Dy, and a, b, c, d, e, x, y each satisfy the following formula.

[0027] 0.7≤a≤1.3

[0028] 0.7≤b≤1.3

[0029] 2.4≤c≤3.6

[0030] 3.2≤d≤4.8

[0031] 0.0≤e≤0.2

[0032] 0.0 <x≤0.2

[0033] 0.0 <y≤1.0)

[0034] A third aspect of the present invention is the phosphor according to the first or second aspect, wherein the phosphor contains 1.0 mass ppm or more of the element Z.

[0035] A fourth aspect of the present invention is the phosphor according to any one of aspects 1 to 3, wherein the element Z contains one or more elements selected from the group consisting of Mo, W, Nb, Ta, and Ni.

[0036] A fifth aspect of the present invention is the phosphor according to any one of aspects 1 to 4, wherein in the formula [1] or [2], 80 mol % or more of MA is one or more elements selected from the group consisting of Ca, Sr, and Ba.

[0037] A sixth aspect of the present invention is the phosphor according to any one of aspects 1 to 5, wherein in the above formula [1] or [2], 80 mol % or more of MB is Li.

[0038] A seventh aspect of the present invention is the phosphor according to any one of aspects 1 and 3 to 6, wherein in the formula [1], 80 mol % or more of MC contains one or more elements selected from the group consisting of Al and Ga.

[0039] Aspect 8 of the present invention is the phosphor according to any one of aspects 1 and 3 to 7, wherein in the formula [1], 80 mol % or more of MC is Al.

[0040] A ninth aspect of the present invention is the phosphor according to any one of aspects 2 to 6, wherein in the formula [2], 80 mol % or more of MC' is Ga.

[0041] A tenth aspect of the present invention is the phosphor according to any one of aspects 1 to 9, wherein in the formula [1] or [2], 80 mol % or more of Re is Eu.

[0042] Aspect 11 of the present invention is the phosphor according to any one of aspects 1 to 10, wherein the space group of the crystal phase having the composition represented by the above formula [1] or [2] is P-1.

[0043] Aspect 12 of the present invention is the phosphor according to any one of aspects 1 to 11, wherein the phosphor has a light emission peak wavelength in a range of 620 nm to 660 nm in a light emission spectrum.

[0044] Aspect 13 of the present invention is the phosphor according to any one of aspects 1 to 12, wherein the full width at half maximum (FWHM) in the emission spectrum is 70 nm or less.

[0045] A fourteenth embodiment of the present invention is a light-emitting device comprising a first light-emitting body and a second light-emitting body, wherein the second light-emitting body includes one or more phosphors that emit visible light when irradiated with light from the first light-emitting body, and the second light-emitting body includes the phosphor according to any one of embodiments 1 to 13.

[0046] A fifteenth aspect of the present invention is the light-emitting device according to the fourteenth aspect, wherein the second light-emitting body further includes a yellow phosphor and / or a green phosphor.

[0047] Mode 16 of the present invention is a light-emitting device according to Mode 15, wherein the yellow phosphor and / or green phosphor includes one or more of a garnet-based phosphor, a silicate-based phosphor, a nitride phosphor, and a nitrogen oxide phosphor.

[0048] A seventeenth aspect of the present invention is a lighting device including the light-emitting device according to any one of aspects 14 to 16 as a light source.

[0049] An eighteenth aspect of the present invention is an image display device including the light-emitting device according to any one of aspects 14 to 16 as a light source.

[0050] A nineteenth aspect of the present invention is a vehicle indicator lamp including the light emitting device according to any one of the fourteenth to sixteenth aspects as a light source.

[0051] Effects of the Invention

[0052] According to the present invention, it is possible to provide a phosphor having a good emission peak wavelength, a narrow spectral half-value width, and high emission intensity.

[0053] Furthermore, according to the present invention, a light emitting device, an illumination device, an image display device, and / or a vehicle indicator lamp having excellent color rendering properties, color reproducibility, and / or conversion efficiency can be provided. DETAILED DESCRIPTION

[0054] Hereinafter, the present invention will be described with reference to the embodiments and examples. However, the present invention is not limited to the following embodiments and examples, and can be implemented with arbitrary modifications within the scope of the present invention.

[0055] It should be noted that the numerical range indicated by “~” in this specification refers to the range that includes the numerical values ​​recorded before and after “~” as the lower limit and upper limit. In addition, in the composition formula of the phosphor in this specification, the division of each composition formula is represented by a comma (,). In addition, when multiple elements are listed and separated by a comma (,), it means that one or more of the listed elements can be contained in any combination and composition. For example, a composition formula such as “(Ca, Sr, Ba)Al2O4:Eu” indicates that it includes “CaAl2O4:Eu”, “SrAl2O4:Eu”, “BaAl2O4:Eu”, “Ca 1-x Sr x Al2O4:Eu", "Sr 1- x Ba x Al2O4:Eu", "Ca 1-x Bax "Al2O4:Eu" and "Ca" 1-x-y Sr x Ba y All of "(Al2O4:Eu)" (where, in the formula, 0 < x < 1, 0 < y < 1, 0 < x + y < 1).

[0056] <Phosphor>

[0057] In one embodiment, the present invention is a phosphor that includes a crystal phase having a composition represented by the following formula [1], the phosphor includes an element Z, and the aforementioned element Z includes one or more elements selected from the group consisting of Mo, W, Nb, Ta, Ni, Pt, and Ir (hereinafter sometimes referred to as "phosphor [1] of the present embodiment").

[0058] Re x MA a MB b MC c D d X e [1]

[0059] (In the above formula [1], MA includes one or more elements selected from the group consisting of Ca, Sr, Ba, Na, K, Y, Gd, and La, MB includes one or more elements selected from the group consisting of Li, Mg, and Zn, MC includes one or more elements selected from the group consisting of Al, Si, Ga, In, and Sc, D is one or more elements selected from the group consisting of N (nitrogen) and O (oxygen), X includes one or more elements selected from the group consisting of F, Cl, Br, and I, Re includes one or more elements selected from the group consisting of Eu, Ce, Pr, Tb, and Dy, and a, b, c, d, e, and x respectively satisfy the following formulas.)

[0060] 0.7 ≤ a ≤ 1.3 <http: / / www.wipo.int / portal / index.html.en

[0061] 0.7 ≤ b ≤ 1.3

[0062] 2.4 ≤ c ≤ 3.6

[0063] 3.2 ≤ d ≤ 4.8

[0064] 0.0 ≤ e ≤ 0.2

[0065] (0.0 < x ≤ 0.2)

[0066] In addition, the phosphor [1] of the present embodiment and the phosphor [2] of the present embodiment described later are sometimes collectively referred to as "phosphors of the present embodiment".

[0067] In another embodiment, the present invention is a light-emitting device including the phosphor [1] of the present embodiment.

[0068] In formula [1], europium (Eu), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm) and ytterbium (Yb) can be used as Re. From the viewpoint of improving the emission wavelength and the luminescence quantum efficiency, Re preferably contains one or more elements selected from the group consisting of Eu, Ce, Pr, Tb and Dy, more preferably contains Eu, further preferably 80 mol% or more of Re is Eu, and further preferably Re is Eu.

[0069] In formula [1], MA contains one or more elements selected from the group consisting of calcium (Ca), strontium (Sr), barium (Ba), sodium (Na), potassium (K), yttrium (Y), gadolinium (Gd), and lanthanum (La), preferably contains one or more elements selected from the group consisting of Ca, Sr, and Ba, and more preferably contains Sr. In addition, preferably, 80 mol% or more of MA is one or more elements selected from the group consisting of Ca, Sr, and Ba, and more preferably, MA is composed of one or more elements selected from the group consisting of Ca, Sr, and Ba.

[0070] In formula [1], MB contains one or more elements selected from the group consisting of lithium (Li), magnesium (Mg) and zinc (Zn), preferably contains Li, more preferably 80 mol % or more of MB is Li, and even more preferably MB is Li.

[0071] In formula [1], MC contains one or more elements selected from the group consisting of aluminum (Al), silicon (Si), gallium (Ga), indium (In) and scandium (Sc), preferably contains Al, Ga or Si, more preferably contains one or more elements selected from the group consisting of Al and Ga, further preferably 80 mol% or more of MC consists of one or more elements selected from the group consisting of Al and Ga, particularly preferably 90 mol% or more of MC consists of one or more elements selected from the group consisting of Al and Ga, and most preferably MC consists of one or more elements selected from the group consisting of Al and Ga.

[0072] In one embodiment, MC comprises at least 80 mol% Al, preferably at least 90 mol%, more preferably at least 95 mol%, and even more preferably at least 98 mol%. By comprising at least 80 mol% Al, a red phosphor can be provided that exhibits emission peak wavelength and emission intensity comparable to existing red phosphors such as S / CASN, while having a narrow spectral half-value width. By using such a red phosphor, a light-emitting device can be provided that maintains conversion efficiency (Lm / W) comparable to or greater than conventional ones, while also exhibiting excellent color rendering or color reproducibility.

[0073] In formula [1], D is one or more elements selected from the group consisting of N (nitrogen) and O (oxygen). The ratio of N (nitrogen) in D can be adjusted arbitrarily, preferably 50 mol% or more, more preferably 70 mol% or more, further preferably 80 mol% or more, and may be 100 mol%. By appropriately adjusting the ratio of N (nitrogen) in D, the charge balance of the entire crystal phase can be maintained or the emission peak wavelength can be adjusted.

[0074] In formula [1], X includes one or more elements selected from the group consisting of fluorine (F), chlorine (Cl), bromine (Br), and iodine (I). That is, in a specific embodiment, from the perspective of maintaining crystal structure stability and charge balance of the entire phosphor, a portion of the N in D may be substituted with the halogen element represented by X.

[0075] The content of the element Z in the phosphor [1] of this embodiment is not limited as long as the effects of the present invention are not lost. In a specific embodiment, the amount of the element Z contained in the phosphor is usually 1.0 mass ppm or more, preferably 1.5 mass ppm or more, more preferably 2.0 mass ppm or more, further preferably 5.0 mass ppm or more, particularly preferably 10 mass ppm or more, most preferably 20 mass ppm or more, and can be 50 mass ppm or more, 100 mass ppm or more, 150 mass ppm or more, 200 mass ppm or more, 250 mass ppm or more, or 300 mass ppm or more.

[0076] Element Z is contained in the phosphor in a very small amount as an impurity in raw materials such as AlN, and thus may be contained in the phosphor in an amount of about 1 to several ppm. Since the comparative examples described below did not achieve the effects of the present invention, it is considered that in order to fully achieve the effects of the present invention, it is preferable to contain a significant amount of element Z, for example, preferably 10 mass ppm or more of element Z.

[0077] The content of element Z is not limited unless the effects of the invention are lost, and is usually 10,000 mass ppm or less, and can be 5,000 mass ppm or less, 2,000 mass ppm or less, or 1,000 mass ppm or less.

[0078] In a specific embodiment, the content of element Z is 1000 mass ppm or less, preferably 800 mass ppm or less, more preferably 700 mass ppm or less, and can be 600 mass ppm or less, 500 mass ppm or less, or 400 mass ppm or less.

[0079] The element Z generally contains one or more elements selected from the group consisting of Mo, W, Nb, Ta, Ni, Pt, and Ir.

[0080] The element Z preferably includes one or more elements selected from the group consisting of Mo, W, Nb, Ta, and Ni, and more preferably includes Mo.

[0081] In addition, in a specific embodiment, the aforementioned element Z is composed of one or more elements selected from the group consisting of Mo, W, Nb, Ta, Ni, Pt and Ir, preferably composed of one or more elements selected from the group consisting of Mo, W, Nb, Ta and Ni, and more preferably composed of Mo.

[0082] The method for incorporating the element Z into the phosphor is not particularly limited, provided that the effects of the present invention are not impaired. In certain embodiments, methods such as dispersing or adhering element Z or its compound to the raw material mixed powder, coating the surface of a reaction vessel with element Z or its compound, and synthesizing the element Z using a reaction vessel made of a material containing element Z or its compound can be employed. Due to the localization of element Z in the phosphor, "element Z" is sometimes referred to as "added element Z."

[0083] The reason why the phosphor of this embodiment shows good brightness, spectral half-width and / or luminous intensity is still uncertain. For example, the following possibilities can be listed: by the presence of element Z or a compound of Z between the phosphor and the reaction container, components that hinder luminescence can be prevented from adhering to, reacting or dissolving in the phosphor, and a high-brightness phosphor can be obtained.

[0084] The aforementioned formula [1] and the formula [2] described later may contain components other than those explicitly described unless the effects of the present invention are impaired.

[0085] As components other than those explicitly described above, there may be mentioned: an element having an element number different by one or two from that of any element constituting formula [1] and formula [2] described later, an element of the same group as an intentionally added element, a rare earth element different from the intentionally added rare earth element, a halogen element when a halide is used as a raw material, and elements that may be generally contained as impurities in various other raw materials.

[0086] Examples of components other than those explicitly mentioned above that are included include, for example, the inclusion of an element other than those explicitly mentioned above at any of MA, MB, MC, and D, as well as MC', X, and Re described later, for the purpose of developing new effects; and the unavoidable or unintentional introduction of components other than those explicitly mentioned above due to impurity sources in the raw materials, or during manufacturing processes such as pulverization and synthesis. Examples of trace components include reaction aids and components derived from the raw materials.

[0087] In the above formula [1], a, b, c, d, e, and x represent the molar contents of MA, MB, MC, D, X, and Re contained in the phosphor, respectively. The ideal ratios for a stable crystal structure are when the ratios of a+x, b, c, and d+e are 1, 1, 3, and 4, respectively. However, in reality, due to various reasons such as single-atom defects, composition changes caused by oxidation of the phosphor surface, heterogeneity, and charge compensation, the values ​​of a+x, b, c, and d+e may vary slightly from the ideal ratios. However, as long as the essence of the present invention is not impaired or the effects of the present invention are not lost, the present invention does not exclude these. Specifically, the following describes the permissible numerical ranges of a, b, c, d, e, and x.

[0088] The value of a is usually 0.7 or more, preferably 0.8 or more, more preferably 0.9 or more, and is usually 1.3 or less, preferably 1.2 or less, more preferably 1.1 or less.

[0089] The value of b is usually 0.7 or more, preferably 0.8 or more, more preferably 0.9 or more, and usually 1.3 or less, preferably 1.2 or less, more preferably 1.1 or less.

[0090] The value of c is usually 2.4 or more, preferably 2.6 or more, more preferably 2.8 or more, and is usually 3.6 or less, preferably 3.4 or less, more preferably 3.2 or less.

[0091] The value of d is usually 3.2 or more, preferably 3.4 or more, more preferably 3.6 or more, and even more preferably 3.8 or more, and is usually 4.8 or less, preferably 4.6 or less, more preferably 4.4 or less, and even more preferably 4.2 or less.

[0092] The value of e is not particularly limited, but is usually 0.0 or more and usually 0.2 or less, preferably 0.1 or less, more preferably 0.06 or less, further preferably 0.04 or less, and even more preferably 0.02 or less.

[0093] The value of x is usually greater than 0.0, preferably greater than 0.0001, more preferably greater than 0.001, and usually less than 0.2, preferably less than 0.15, more preferably less than 0.12, even more preferably less than 0.1, and even more preferably less than 0.08. By setting the value of x to be greater than or equal to the above lower limit, a phosphor with excellent luminescence intensity can be obtained. By setting the value of x to be less than or equal to the above upper limit, a phosphor with Re well incorporated into the crystal can be obtained, which facilitates the phosphor to function as a luminescence center.

[0094] By setting b, c, d, and e within the above ranges, the crystal structure is stabilized. In addition, the values ​​of d and e can be appropriately adjusted to maintain the charge balance of the entire phosphor.

[0095] Furthermore, by setting the value of a within the above range, the crystal structure is stabilized, and a phosphor with fewer heterophases can be obtained.

[0096] The value of b+c is usually 3.1 or more, preferably 3.4 or more, more preferably 3.7 or more, and usually 4.9 or less, preferably 4.6 or less, more preferably 4.3 or less.

[0097] By setting the value of b+c within the above range, the crystal structure is stabilized.

[0098] The value of d+e is usually 3.2 or more, preferably 3.4 or more, more preferably 3.7 or more, and is usually 5.0 or less, preferably 4.6 or less, more preferably 4.3 or less.

[0099] When the value of d+e is within the above range, the crystal structure is stabilized.

[0100] If any of the values ​​are within the above range, it is preferable in that the emission peak wavelength and the half-value width in the emission spectrum of the obtained phosphor are good.

[0101] It should be noted that the method for determining the elemental composition of the aforementioned phosphor is not particularly limited and can be determined by conventional methods, for example, using GD-MS, ICP spectroscopy or energy dispersive X-ray analysis (EDX).

[0102] In one embodiment, the present invention is a phosphor comprising a crystalline phase having a composition represented by the following formula [2] (hereinafter sometimes referred to as "phosphor [2] of this embodiment"), comprising an element Z, wherein the element Z comprises one or more elements selected from the group consisting of Mo, W, Nb, Ta, Ni, Pt and Ir.

[0103] Re x MA a MB b (Al 1-y MC' y ) c D d X e [2]

[0104] (In the above formula [2], MA contains one or more elements selected from the group consisting of Ca, Sr, Ba, Na, K, Y, Gd and La, MB contains one or more elements selected from the group consisting of Li, Mg and Zn, MC' contains one or more elements selected from the group consisting of Si, Ga, In and Sc, D is one or more elements selected from the group consisting of N (nitrogen) and O (oxygen), X contains one or more elements selected from the group consisting of F, Cl, Br and I, Re contains one or more elements selected from the group consisting of Eu, Ce, Pr, Tb and Dy, and a, b, c, d, e, x, y each satisfy the following formula.

[0105] 0.7≤a≤1.3

[0106] 0.7≤b≤1.3

[0107] 2.4≤c≤3.6

[0108] 3.2≤d≤4.8

[0109] 0.0≤e≤0.2

[0110] 0.0 <x≤0.2

[0111] 0.0 <y≤1.0)

[0112] In another embodiment, the present invention is a light-emitting device including the phosphor [2] of this embodiment.

[0113] The types and compositions of the elements MA, MB, D, X, and Re in the above formula [2] may be the same as those in the above formula [1].

[0114] In addition, the type and content of the element Z in the phosphor [2] of this embodiment, and the method for producing the phosphor containing the element Z can also be the same as those of the phosphor [1] of the above-mentioned embodiment.

[0115] In formula [2], MC' contains one or more elements selected from the group consisting of Si, Ga, In and Sc. From the viewpoint of improving crystal stability and luminescence intensity, it preferably contains one or more elements selected from the group consisting of Ga and Si, and more preferably contains Ga.

[0116] In a more preferred specific embodiment, in formula [2], 80 mol % or more of MC' may be Ga, or MC' may be composed of Ga.

[0117] The values ​​and preferred ranges of a, b, c, d, e, and x in the aforementioned formula [2] may be the same as those in the aforementioned formula [1].

[0118] The value of y in the above formula [2] is greater than 0.0, usually 0.01 or more, preferably 0.015 or more, more preferably 0.03 or more, further preferably 0.05 or more, particularly preferably 0.1 or more, and usually 1.0 or less, preferably 0.7 or less, more preferably 0.5 or less, further preferably 0.3 or less, and particularly preferably 0.25 or less.

[0119] By setting the value of y to a value greater than or equal to the aforementioned lower limit, the peak emission wavelength of the phosphor is shortened. Using such a phosphor, a light-emitting device with excellent color rendering or color reproducibility can be provided. Furthermore, by setting the value of y to a value less than or equal to the aforementioned upper limit, a phosphor with excellent emission intensity can be obtained. Using such a phosphor, a light-emitting device with excellent conversion efficiency can be provided. The value of y can be appropriately adjusted to achieve the desired emission intensity and peak emission wavelength depending on the intended purpose.

[0120] [Particle size of crystal phase]

[0121] The particle size of the crystal phase of the phosphor of this embodiment is usually greater than 2 μm and less than 35 μm in terms of the volume-based central particle size (volume median particle size), and the lower limit is preferably greater than 3 μm, more preferably greater than 4 μm, and further preferably greater than 5 μm. In addition, the upper limit is preferably less than 30 μm, more preferably less than 25 μm, further preferably less than 20 μm, and particularly preferably less than 15 μm.

[0122] When the volume-based central particle size (volume median particle size) is above the above lower limit, it is preferred from the perspective of the crystal phase improving the luminescent properties displayed in the LED package. When it is below the above upper limit, it is preferred from the perspective of the crystal phase being able to avoid nozzle clogging in the manufacturing process of the LED package.

[0123] The volume-based central particle diameter (volume median particle diameter) of the crystalline phase of the phosphor can be measured using a measurement technique known to those skilled in the art. In a preferred embodiment, for example, it can be measured using a laser particle size analyzer. In the examples of this specification, the volume-based central particle diameter (volume median particle diameter, (d 50 )) is defined as the particle size at which the relative particle amount on a volume basis becomes 50% when a sample is measured using a particle size distribution measuring apparatus based on the laser diffraction scattering method to determine the particle size distribution (cumulative distribution).

[0124] {Physical properties of phosphors, etc.}

[0125] [Space Group]

[0126] In the phosphor of this embodiment, the crystalline system (space group) of the crystalline phase having the composition represented by formula [1] or formula [2] is not limited as long as the effects of the invention can be obtained. In one embodiment, it can be tetragonal P42 / m, monoclinic P-1, etc., preferably P-1. Regarding the space group in the phosphor of this embodiment, there is no particular limitation as long as the average structure statistically considered within the range that can be distinguished by powder X-ray diffraction or single crystal X-ray diffraction shows a repetition period of the above length. It is preferably No. 2 based on "International Tables for Crystallography (Third, revised edition), Volume A Space-Group Symmetry".

[0127] By using the above-mentioned space group, the full width at half maximum (FWHM) in the emission spectrum becomes narrow, and a phosphor with good emission efficiency can be obtained.

[0128] Here, the space group can be determined by conventional methods, for example, electron diffraction, X-ray diffraction structure analysis using powder or single crystal, neutron diffraction structure analysis, etc.

[0129] [Characteristics of Luminescence Spectra]

[0130] The phosphor of this embodiment is excited by irradiation with light of an appropriate wavelength and emits red light with a favorable peak wavelength and full width at half maximum (FWHM) in its emission spectrum. The emission spectrum, excitation wavelength, peak wavelength, and full width at half maximum (FWHM) are described below.

[0131] (Excitation wavelength)

[0132] The phosphor of this embodiment has an excitation peak in a wavelength range of generally 270 nm or more, preferably 300 nm or more, more preferably 320 nm or more, further preferably 350 nm or more, particularly preferably 400 nm or more, and generally 500 nm or less, preferably 480 nm or less, and more preferably 460 nm or less. That is, it is excited by light in the near-ultraviolet to blue region.

[0133] It should be noted that the shape of the luminescence spectrum and the description of the luminescence peak wavelength and spectral half-value width described below can be applied independently of the excitation wavelength, but from the perspective of improving quantum efficiency, it is preferred to irradiate light with a wavelength in the above-mentioned range that has good absorption and excitation efficiency.

[0134] (Emission peak wavelength)

[0135] The peak wavelength in the luminescence spectrum of the fluor of present embodiment is usually more than 620nm, preferably more than 625nm, more preferably more than 630nm. In addition, the peak wavelength in this luminescence spectrum is usually below 670nm, preferably below 660nm, more preferably below 655nm. The fluor of present embodiment can, for example, have a luminescence peak wavelength in the range of more than 620nm and less than 660nm in the luminescence spectrum.

[0136] By setting the peak wavelength in the phosphor's emission spectrum within the above range, the luminescent color becomes a good red. Using this phosphor, it is possible to provide a light-emitting device with excellent color rendering or color reproducibility. Furthermore, by setting the peak wavelength in the phosphor's emission spectrum below the above upper limit, it is possible to provide a light-emitting device with good red visibility and a good lumen equivalent of 1m / W.

[0137] In a light-emitting device, phosphors with different peak wavelengths can be used depending on the application. The method for obtaining phosphors with different peak wavelengths is not particularly limited, and one method can be achieved by changing the composition of the MC element.

[0138] In one embodiment, in the aforementioned formula [1], by using Al as MC and increasing the Al ratio, a phosphor having a relatively long emission peak wavelength can be obtained. In this embodiment, the emission peak wavelength is preferably 640 nm or greater, more preferably 645 nm or greater, and typically 670 nm or less, preferably 660 nm or less. By having a phosphor having an emission wavelength within this range, for example, a light-emitting device for lighting applications can be provided that achieves both luminous efficiency and color rendering properties, or a light-emitting device for a backlight unit of a liquid crystal display can be provided that achieves both luminous efficiency and a color reproduction range.

[0139] In another embodiment, a phosphor having a relatively short peak emission wavelength can be obtained by using Al and MC' elements and including a crystal phase having a composition represented by the aforementioned formula [2]. In this embodiment, the peak emission wavelength is typically 615 nm or greater, preferably 620 nm or greater, more preferably 625 nm or greater, and even more preferably 630 nm or greater, and typically 660 nm or less, preferably 645 nm or less, and more preferably 640 nm or less. By using a phosphor having an emission wavelength within this range, a light-emitting device with excellent color rendering properties or color reproducibility can be obtained.

[0140] (Full width at half maximum of the luminescence spectrum)

[0141] The half-value width in the emission spectrum of the phosphor of this embodiment is usually 80 nm or less, preferably 70 nm or less, more preferably 60 nm or less, further preferably 55 nm or less, particularly preferably 50 nm or less, and is usually 10 nm or more.

[0142] By using a phosphor having a half-value width in an emission spectrum within the above-mentioned range, it is possible to expand the color reproduction range without reducing color purity in an image display device such as a liquid crystal display.

[0143] In addition, by making the emission peak wavelength and spectral half-value width below the above upper limits, a phosphor with relatively high visibility in the emission wavelength region can be provided. By using such a phosphor in a light-emitting device, a light-emitting device with high conversion efficiency can be provided.

[0144] It should be noted that to excite the phosphor with light having a wavelength of approximately 450 nm, a GaN-based LED can be used as the excitation light source. Furthermore, the measurement of the phosphor's emission spectrum and the calculation of its peak wavelength, peak relative intensity, and spectral half-value width can be performed using a commercially available spectrometer, such as a xenon lamp, with an emission wavelength of 300 to 400 nm and a fluorescence measurement device equipped with a conventional photodetector.

[0145] <Method for producing phosphor>

[0146] The phosphor of this embodiment can be synthesized by mixing raw materials of the elements constituting the phosphor so that the ratio of the elements satisfies the above-mentioned formula [1] or formula [2] and heating the mixture.

[0147] [Phosphor raw materials]

[0148] The phosphor raw materials that serve as the source of each element (MA, MB, MC, MC', Re) are not particularly limited, and examples thereof include simple substances of each element, halides such as oxides, nitrides, hydroxides, chlorides, and fluorides, inorganic salts such as sulfates, nitrates, and phosphates, and organic acid salts such as acetates. Furthermore, compounds containing two or more of the aforementioned element groups may also be used. Furthermore, each compound may be in the form of a hydrate, etc.

[0149] It should be noted that in the examples described below, nitrides of various elements are used as phosphor raw materials.

[0150] The method for obtaining each phosphor raw material is not particularly limited, and commercially available phosphor raw materials can be purchased and used.

[0151] There is no particular restriction on the purity of each phosphor raw material. From the perspective of strictly controlling the element ratio and avoiding the appearance of heterogeneous phases caused by impurities, the higher the purity, the better. It is usually 90 mol% or more, preferably 95 mol% or more, more preferably 97 mol% or more, and further preferably 99 mol% or more. There is no particular restriction on the upper limit, but it is usually 100 mol% or less. Impurities that are inevitably mixed in may also be included.

[0152] In the examples described below, a phosphor raw material having a purity of 95 mol % or higher was used.

[0153] Regarding oxygen (O), nitrogen (N) and halogen (X), in addition to being supplied by using oxides, nitrides and halides as phosphor raw materials that serve as supply sources of the aforementioned elements, they can also be appropriately contained by forming an oxygen-containing or nitrogen-containing atmosphere during the synthesis reaction.

[0154] [Mixing process]

[0155] The method for mixing the phosphor raw materials is not particularly limited, and conventional methods can be used. For example, the phosphor raw materials are weighed to obtain the desired composition and thoroughly mixed using a ball mill or the like to obtain a phosphor raw material mixture. The mixing method is not particularly limited, but specifically includes the following methods (a) and (b).

[0156] (a) Dry mixing method: The phosphor raw materials are ground and mixed by combining grinding using a dry grinding machine such as a hammer mill, roller mill, ball mill, jet mill, or mortar and pestle, and mixing using a mixer such as a ribbon blender, V-type blender, Henschel mixer, or mortar and pestle.

[0157] (b) Wet mixing method: A solvent or dispersion medium such as water is added to the aforementioned phosphor raw material, and the mixture is mixed using, for example, a grinder, a mortar and pestle, or an evaporating dish and a stirring rod to form a solution or slurry, and then dried by spray drying, heat drying, or natural drying.

[0158] The phosphor raw materials may be mixed by either the dry mixing method or the wet mixing method. In order to avoid contamination of the phosphor raw materials by water, the dry mixing method or the wet mixing method using a non-water-soluble solvent is preferred.

[0159] It should be noted that in the examples described below, method (a) was adopted.

[0160] [Method containing element Z]

[0161] In a specific embodiment, the method for producing the phosphor may include adding element Z or a compound of Z to the obtained phosphor raw material mixture after the mixing step.

[0162] The method for adding element Z is not particularly limited as long as element Z or its compound is dispersed or attached to the phosphor raw material mixture, and conventional methods can be used. For example, a vapor phase method or a sol-gel method using a solution containing element Z or its compound and a solvent can be used. Alternatively, the phosphor raw material mixture and element Z or its compound can be mixed and then heated.

[0163] Furthermore, as described in the heating step described later, a crucible composed of element Z may be used, or the surface of the crucible may be coated with element Z or a compound containing element Z.

[0164] [Heating process]

[0165] In the heating step, for example, the phosphor raw material mixture obtained in the mixing step is placed in a crucible and then heated at a temperature of 500°C to 1200°C, preferably 600°C to 1100°C.

[0166] The heating process pressure can be either normal pressure or pressurized, as long as the desired phosphor is obtained. However, pressurization is preferred to prevent volatilization of elements contained in the phosphor raw material. During pressurization, the pressure is typically between 0.1 MPa and 200 MPa, preferably 100 MPa or less. By maintaining the pressure within this range, good reactivity of the phosphor raw material can be ensured.

[0167] The pressurization method is not limited, and for example, a method of heating a sealed container, a method of mechanical pressurization, a method of using air pressure, etc. can be used.

[0168] The material of the crucible is preferably a material that does not react with the phosphor raw material or reactant, and examples include ceramics such as alumina, quartz, boron nitride, silicon carbide, silicon nitride, metals such as nickel (Ni), platinum (Pt), molybdenum (Mo), tungsten (W), tantalum (Ta), niobium (Nb), iridium (Ir), rhodium (Rh), or alloys with these as the main components.

[0169] In addition, in the Examples described below, a crucible made of boron nitride or a crucible made of boron nitride coated with element Z was used.

[0170] Heating is preferably performed in an inert atmosphere, and a gas mainly composed of nitrogen, argon, helium, etc. can be used.

[0171] In addition, in the Examples described below, heating was performed under a nitrogen atmosphere.

[0172] In the heating process, heating is generally performed in the above-mentioned temperature range for 10 minutes to 200 hours, preferably 1 hour to 100 hours, and more preferably 2 hours to 50 hours. In addition, the heating process can be performed once or multiple times. As a method of performing the heating process multiple times, there can be mentioned a method including an annealing process of heating under pressure to repair defects, a method of performing a secondary heating to obtain secondary particles or a final product after a primary heating to obtain a primary particle or an intermediate, etc.

[0173] In this way, the phosphor of this embodiment can be obtained.

[0174] [Screening of phosphors]

[0175] The phosphor of this embodiment can be roughly obtained by the above method. However, due to minute differences such as tiny attachments in the reaction container, impurities in each reagent, and batches of each raw material reagent, the obtained phosphor sometimes contains particles that slightly deviate from the scope of the requirements of the present invention. In addition, substances with large particle sizes and small substances, phosphors with different reflectivities, etc. are sometimes mixed.

[0176] Therefore, for example, by changing several conditions to manufacture a phosphor, screening the obtained phosphor by grading, cleaning, etc., analyzing the reflectivity, XRD spectrum, etc., and screening the phosphor that meets the requirements of the present invention, the phosphor of the above embodiment can be reliably obtained.

[0177] <Light-emitting device>

[0178] In one embodiment, the present invention is a light-emitting device comprising: a first light-emitting body (excitation light source); and a second light-emitting body comprising one or more phosphors that emit visible light when irradiated with light from the first light-emitting body, wherein the second light-emitting body comprises phosphor [1] of this embodiment or phosphor [2] of this embodiment. The second light-emitting body may be used alone or in combination of two or more in any combination and ratio.

[0179] In the light-emitting device of this embodiment, the second light-emitting body may further contain a phosphor that emits fluorescence in a yellow, green or red region (orange or red) when irradiated with light from an excitation light source, in addition to the phosphor of this embodiment having a crystal phase having a composition represented by the aforementioned formula [1] or formula [2].

[0180] In a specific embodiment, in the light-emitting device of the present invention, the second light-emitting body includes a phosphor having a crystal phase having a composition represented by the formula [1] or [2], and further includes a yellow phosphor and / or a green phosphor.

[0181] Specifically, when constituting a light-emitting device, a yellow phosphor preferably has a luminescence peak in a wavelength range of 550 nm to 600 nm, and a green phosphor preferably has a luminescence peak in a wavelength range of 500 nm to 560 nm. Furthermore, an orange or red phosphor typically has a luminescence peak in a wavelength range of 615 nm to 620 nm, more preferably 625 nm to 630 nm, and typically 660 nm to 650 nm, more preferably 645 nm to 640 nm, and even more preferably 640 nm to 660 nm.

[0182] By appropriately combining the phosphors in the above wavelength regions, a light-emitting device exhibiting excellent color reproducibility can be provided. It should be noted that as the excitation light source, an excitation light source having a luminescence peak in a wavelength range of less than 420 nm can be used.

[0183] Below, a method of a light-emitting device is described in which the phosphor of this embodiment having a light-emitting peak in a wavelength range of not less than 620 nm and not more than 660 nm and containing a crystal phase having a composition represented by the aforementioned formula [1] or formula [2] is used as a red phosphor, and a light-emitting body having a light-emitting peak in a wavelength range of not less than 300 nm and not more than 460 nm is used as the first light-emitting body, but this embodiment is not limited to these.

[0184] In the above case, the light-emitting device of this embodiment can be configured as the following (A), (B), or (C), for example.

[0185] (A) A method of using a light-emitting body having a luminescence peak in a wavelength range of greater than 300 nm and less than 460 nm as a first light-emitting body, and using at least one phosphor (yellow phosphor) having a luminescence peak in a wavelength range of greater than 550 nm and less than 600 nm, and a phosphor of this embodiment comprising a crystal phase having a composition represented by the aforementioned formula [1] or formula [2] as a second light-emitting body.

[0186] (B) A method of using a light-emitting body having a luminescence peak in a wavelength range of greater than 300 nm and less than 460 nm as a first light-emitting body, and using at least one phosphor (green phosphor) having a luminescence peak in a wavelength range of greater than 500 nm and less than 560 nm, and a phosphor of this embodiment comprising a crystal phase having a composition represented by the aforementioned formula [1] or formula [2] as a second light-emitting body.

[0187] (C) A method of using a luminescent body having a luminescent peak in a wavelength range of not less than 300 nm and not more than 460 nm as a first luminescent body, at least one phosphor (yellow phosphor) having a luminescent peak in a wavelength range of not less than 550 nm and not more than 600 nm, at least one phosphor (green phosphor) having a luminescent peak in a wavelength range of not less than 500 nm and not more than 560 nm, and the phosphor of this embodiment comprising a crystal phase having a composition represented by the aforementioned formula [1] or formula [2] as a second luminescent body.

[0188] As the green phosphor or yellow phosphor in the above embodiment, commercially available products can be used, for example, garnet-based phosphors, silicate-based phosphors, nitride phosphors, oxynitride phosphors, etc. That is, in the above embodiment, the yellow phosphor and / or green phosphor can include any one or more of a garnet-based phosphor, a silicate-based phosphor, a nitride phosphor, and a oxynitride phosphor.

[0189] (yellow phosphor)

[0190] Examples of garnet-based phosphors that can be used as yellow phosphors include (Y, Gd, Lu, Tb, La)3(Al, Ga)5O 12 :(Ce, Eu, Nd); as silicate phosphors, for example, (Ba, Sr, Ca, Mg)2SiO4:(Eu, Ce); as nitride phosphors and oxynitride phosphors, for example, (Ba, Ca, Mg)Si2O2N2:Eu (SION phosphors), (Li, Ca)2(Si, Al) 12 (O, N) 16 :(Ce, Eu)(α-sialon phosphor),(Ca, Sr)AlSi4(O, N)7:(Ce, Eu)(1147 phosphor),(La, Ca, Y, Gd)3(Al, Si)6N 11 :(Ce, Eu)(LSN phosphor), etc.

[0191] These may be used alone or in combination of two or more.

[0192] As the yellow phosphor, garnet-based phosphors are preferred among the above phosphors, and among them, Y3Al5O 12 : YAG-based phosphor represented by Ce.

[0193] (Green phosphor)

[0194] Examples of garnet-based phosphors that can be used as green phosphors include (Y, Gd, Lu, Tb, La)3(Al, Ga)5O 12 :(Ce, Eu, Nd), Ca3(Sc, Mg)2Si3O12 :(Ce, Eu) (CSMS phosphor); As a silicate phosphor, for example, (Ba, Sr, Ca, Mg)3SiO 10 :(Eu, Ce), (Ba, Sr, Ca, Mg)2SiO4:(Ce, Eu) (BSS phosphor); As an oxide phosphor, for example, (Ca, Sr, Ba, Mg)(Sc, Zn)2O4:(Ce, Eu) (CASO phosphor); As a nitride phosphor and a oxynitride phosphor, for example, (Ba, Sr, Ca, Mg)Si2O2N2:(Eu, Ce), Si 6-z Al z O z N 8-z :(Eu, Ce) (β - sialon phosphor) (0 < z ≤ 1), (Ba, Sr, Ca, Mg, La)3(Si, Al)6O 12 N2:(Eu, Ce) (BSON phosphor); As an aluminate phosphor, for example, (Ba, Sr, Ca, Mg)2Al 10 O 17 :(Eu, Mn) (GBAM - type phosphor), etc.

[0195] They can be used individually, or two or more of them can be used in combination.

[0196] (Red phosphor)

[0197] As the red phosphor, the phosphor of the present embodiment including the crystal phase having the composition shown in the aforementioned formula [1] or formula [2] is used. However, in addition to the phosphor of the present embodiment, other orange or red phosphors such as Mn - activated fluoride phosphors, garnet - type phosphors, sulfide phosphors, nanoparticle phosphors, nitride phosphors, and oxynitride phosphors can also be used. As other orange or red phosphors, for example, the following phosphors can be used.

[0198] As the Mn - activated fluoride phosphor, for example, K2(Si, Ti)F6:Mn, K2Si 1-x Na x Al x F6:Mn (0 < x < 1) (collectively referred to as KSF phosphor); As the sulfide phosphor, for example, (Sr, Ca)S:Eu (CAS phosphor), La2O2S:Eu (LOS phosphor); As the garnet - type phosphor, for example, (Y, Lu, Gd, Tb)3Mg2AlSi2O 12:Ce; As nanoparticles, for example, CdSe can be cited; As nitride or oxynitride phosphors, for example, (Sr, Ca)AlSiN3:Eu (S / CASN phosphor), (CaAlSiN3) 1-x ·(SiO2N2) x :Eu (CASON phosphor), (La, Ca)3(Al, Si)6N 11 :Eu (LSN phosphor), (Ca, Sr, Ba)2Si5(N, O)8:Eu (258 phosphor), (Sr, Ca)Al 1+x Si 4-x O x N 7-x :Eu (1147 phosphor), M x (Si, Al) 12 (O, N) 16 :Eu (M is Ca, Sr, etc.) (α-sialon phosphor), Li(Sr, Ba)Al3N4:Eu (where x is 0 < x < 1 for the above) etc.

[0199] They can be used alone or in combination of two or more.

[0200] [Structure of the light-emitting device]

[0201] The light-emitting device of the present embodiment can have a first light-emitting body (excitation light source) and use the phosphor of the present embodiment containing at least a crystal phase having the composition shown in the foregoing formula [1] or formula [2] as the second light-emitting body, and its structure is not limited, and any well-known device structure can be adopted arbitrarily.

[0202] As an example of the device structure and an embodiment of the light-emitting device, for example, the embodiment described in Japanese Patent Application Laid-Open No. 2007-291352 can be cited. In addition, as the form of the light-emitting device, a bullet type, a cup type, a chip-on-board, a remote phosphor, etc. can be cited.

[0203] {Uses of the light-emitting device}

[0204] The uses of the light-emitting device are not particularly limited and can be used in various fields where ordinary light-emitting devices are used, but a light-emitting device with high color rendering property can be particularly suitable as a light source for a lighting device or an image display device.

[0205] In addition, a light-emitting device having a red phosphor with good emission wavelength can also be used for a red vehicle display lamp or a vehicle display lamp including the red white light.

[0206] [Lighting device]

[0207] In one embodiment, the present invention can be configured as a lighting device having the foregoing light-emitting device as a light source.

[0208] When the aforementioned light-emitting device is used in a lighting device, the specific configuration of the lighting device is not limited, and the aforementioned light-emitting device can be appropriately incorporated into a known lighting device for use. For example, a surface-emitting lighting device having a plurality of light-emitting devices arranged on the bottom surface of a retaining housing can be used.

[0209] [Image Display Device]

[0210] In one embodiment, the present invention may be provided as an image display device including the above-described light-emitting device as a light source.

[0211] When the aforementioned light-emitting device is used as a light source for an image display device, the specific configuration of the image display device is not limited, but it is preferably used in conjunction with a color filter. For example, in the case of a color image display device utilizing a color liquid crystal display element, the image display device can be formed by combining the aforementioned light-emitting device as a backlight, a light shutter utilizing liquid crystal, and a color filter having red, green, and blue pixels.

[0212] [Vehicle indicator lights]

[0213] In one embodiment, the present invention may be provided as a vehicle indicator lamp including the aforementioned light emitting device as a light source.

[0214] In a specific embodiment, the light-emitting device used in the vehicle indicator light is preferably a light-emitting device that emits white light. A light-emitting device that emits white light preferably has a deviation duv (also referred to as Δuv) of the light emitted from the light-emitting device from the blackbody radiation locus of the light color of -0.0200 to 0.0200, and a color temperature of 5000K to 30000K.

[0215] In a specific embodiment, the light emitting device for the vehicle indicator light is preferably a light emitting device that emits red light. In this embodiment, for example, the light emitting device can absorb blue light emitted from a blue LED chip and emit red light, thereby serving as a red light vehicle indicator light.

[0216] Vehicle indicator lights include headlights, sidelights, taillights, turn signals, brake lights, fog lights, and other lighting installed on a vehicle for the purpose of providing some kind of indication to other vehicles, people, etc.

[0217] Example

[0218] Hereinafter, several specific embodiments of the present invention will be described by way of examples. However, the present invention is not limited to the following contents unless it departs from the gist of the present invention.

[0219] {Measurement method}

[0220] [Measurement of phosphor composition]

[0221] The Sr, Al, Ga, Eu, Li, and Mo contents in phosphor samples were determined in accordance with JIS K0116:2014 by pressurized acid hydrolysis in a hydrochloric acid solution, followed by dilution to an appropriate concentration, and then by high-frequency inductively coupled plasma optical emission spectrometry (ICP-OES). It should be noted that the Sr, Al, Ga, and Eu contents were determined using the luminescence intensity ratio method using a Co standard solution as an internal standard, while the Li and Mo contents were determined by preparing calibration curves for each element and then using the luminescence intensity method.

[0222] Note that for the trace amount of Mo, two to several measurements were performed for each sample, and the average value was used as the measured value. The measurement error of Mo was confirmed to be about 1 / 100 of the measured value, that is, about 1 to 10 mass ppm.

[0223] The N content in the phosphor sample was measured by pressure acid hydrolysis-steam distillation separation-neutralization titration method with reference to 14.1(a) of JIS R1603:2007 and 8.2 of JIS R2015:2007. The pressure acid hydrolysis used a solution containing sulfuric acid and hydrogen fluoride.

[0224] [Measurement of Luminescence Spectrum]

[0225] The emission spectrum was measured using a spectrofluorometer F-4500 (manufactured by Hitachi High-Technologies Corporation) under the following measurement conditions.

[0226] Light source: Xenon lamp

[0227] Excitation wavelength: 455nm

[0228] Measurement wavelength range: 200~900nm

[0229] ·Measurement interval: 0.2nm

[0230] The chromaticity coordinates are calculated from the emission spectrum data from 480 nm to 800 nm using the CIE 1931 XYZ equation function.

[0231] [Quantum Efficiency Measurement]

[0232] The quantum efficiency was calculated based on the emission spectrum measured using a quantum efficiency measurement system QE-2100 (manufactured by Otsuka Electronics Co., Ltd.) under the following measurement conditions.

[0233] Light source: Xenon lamp

[0234] Excitation wavelength: 455nm

[0235] Measurement wavelength range: 200~850nm

[0236] Measurement interval: 1.2 to 1.5 nm

[0237] <Examples 1-2>

[0238] The nitride raw materials of each element are mixed in the manner of Sr:Li:Al:Ga:Eu=0.99:1:2.3:0.7:0.01 to obtain a phosphor raw material mixture. As a reaction container, a boron nitride (BN) crucible with a surface coated with Mo is prepared. The above-mentioned phosphor raw material mixture is placed in the reaction container and the reaction container is sealed. The reaction container is placed in a heating furnace and sintered at a maximum temperature of 845°C for 5 hours under a nitrogen atmosphere. Multiple experiments are carried out, and as a result, phosphors with different Mo contents are obtained, which are respectively used as phosphors of Examples 1 to 2.

[0239] <Comparative Example 1>

[0240] The phosphor of Comparative Example 1 was obtained in the same manner as in Example 1 except that a boron nitride (BN) crucible whose surface was not coated with metal was used as the reaction container.

[0241] <Comparative Example 2>

[0242] A phosphor of Comparative Example 2 was obtained in the same manner as in Example 1 except that the maximum firing temperature was set to 1000°C.

[0243] [evaluate]

[0244] The crystal structure of the obtained phosphor was determined by powder X-ray diffraction. As a result, the phosphors of Examples 1 and 2 and Comparative Example 1 showed a diffraction pattern that was well consistent with that of SrLiAl 3 N 4 .

[0245] The manufacturing conditions of the phosphors of Examples 1 to 2 and Comparative Examples 1 to 2, the relative luminescence intensity with the luminescence intensity of Comparative Example 1 set to 1.00, and other luminescence characteristics are shown in Table 1, and the detailed results of the composition analysis of the main elements of the phosphors of Examples 1 to 2 and Comparative Examples 1 to 2 are shown in Table 2.

[0246] The content of element Z (Mo) in Comparative Example 1, Example 1, Example 2, and Comparative Example 2 was below the detection limit (2.0 mass ppm or less), 120 mass ppm, 300 mass ppm, and 1200 mass ppm, respectively.

[0247] [Table 1]

[0248]

[0249] [Table 2]

[0250]

[0251] As can be seen from Table 1, the phosphor of this embodiment contains an appropriate amount of element Z, thereby becoming a red phosphor having a narrow full width at half maximum (FWHM) and high emission intensity.

[0252] This result is considered to be achieved by preventing the formation of a phase with poor luminescence properties due to the incorporation of boron.

[0253] <Example 3>

[0254] The phosphor of Example 3 was obtained in the same manner as in Example 1 except that a phosphor raw material mixture in which nitride raw materials of the respective elements were mixed at Sr:Li:Al:Eu=0.99:1:3.0:0.01 was used.

[0255] <Example 4>

[0256] The phosphor of Example 4 was obtained in the same manner as in Example 3 except that a crucible made of molybdenum (Mo) whose surface was not coated with metal was used as the reaction container.

[0257] <Comparative Example 3>

[0258] A phosphor of Comparative Example 3 was obtained in the same manner as in Example 3 except that a boron nitride (BN) crucible whose surface was not coated with metal was used as a reaction container and the maximum firing temperature was set to 1000°C.

[0259] <Comparative Example 4>

[0260] The phosphor of Comparative Example 4 was obtained in the same manner as in Example 3 except that a boron nitride (BN) crucible whose surface was not coated with metal was used as the reaction container.

[0261] <Comparative Example 5>

[0262] The phosphor of Comparative Example 5 was obtained in the same manner as in Comparative Example 3 except that a crucible made of boron nitride (BN) whose surface was coated with metal was used as a reaction container.

[0263] [evaluate]

[0264] The crystal structure of the obtained phosphor was determined by powder X-ray diffraction. The results showed that the phosphors of Examples 3 to 4 and Comparative Examples 3 to 5 all showed a diffraction pattern that was well consistent with that of SrLiAl 3 N 4 .

[0265] The manufacturing conditions of the phosphors of Examples 3 to 4 and Comparative Examples 3 to 5, the relative luminescence intensity with the luminescence intensity of Comparative Example 5 set to 1.00, and other luminescence characteristics are shown in Table 3, and the detailed results of the composition analysis of the main elements of the phosphors of Examples 3 to 4 and Comparative Examples 3 to 5 are shown in Table 4.

[0266] It should be noted that the content of element Z (Mo) in Comparative Example 5, Example 3, and Example 4 was 1040 mass ppm, 560 mass ppm, and 420 mass ppm, respectively.

[0267] [Table 3]

[0268]

[0269] [Table 4]

[0270]

[0271] As can be seen from Table 3, the same effect can be expected in a phosphor including a crystal phase having a composition represented by formula [1] or formula [2].

[0272] As described above, according to this embodiment, a phosphor having a good emission peak wavelength, a narrow spectral half-width, and / or high emission intensity can be provided. In addition, by including this phosphor, a light-emitting device, a lighting device, an image display device, and / or a vehicle indicator lamp having good color rendering properties or color reproducibility and good conversion efficiency can be provided.

[0273] While various embodiments have been described above, the present invention is not limited to these examples. It is obvious that those skilled in the art will be able to devise various variations or modifications within the scope of the claims, and such variations or modifications naturally fall within the technical scope of the present invention. Furthermore, the various components of the above embodiments may be arbitrarily combined without departing from the spirit of the invention.

[0274] It should be noted that this application is based on the Japanese patent application (Japanese Patent Application No. 2023-016167) filed on February 6, 2023, the contents of which are incorporated herein by reference.

[0275] Industrial Application Possibilities

[0276] The phosphor of the present invention can provide a light-emitting device having excellent color rendering properties, color reproducibility, and / or conversion efficiency, and thus can be applied to lighting devices, image display devices, and vehicle indicator lamps.

Claims

1. A phosphor comprising a crystal phase having a composition represented by the following formula [1], and Contains element Z, the content of element Z is 1000 mass ppm or less, The element Z includes one or more elements selected from the group consisting of Mo, W, Nb, Ta, Ni, Pt and Ir, Re x MA a MB b MC c D d X e [1] In the above formula [1], MA contains one or more elements selected from the group consisting of Ca, Sr, Ba, Na, K, Y, Gd and La, MB contains one or more elements selected from the group consisting of Li, Mg, and Zn, MC contains one or more elements selected from the group consisting of Al, Si, Ga, In and Sc, D is one or more elements selected from the group consisting of N, i.e., nitrogen, and O, i.e., oxygen. X contains one or more elements selected from the group consisting of F, Cl, Br and I, Re contains one or more elements selected from the group consisting of Eu, Ce, Pr, Tb and Dy, a, b, c, d, e, and x satisfy the following formulas respectively: 0.7≤a≤1.3 0.7≤b≤1.3 2.4≤c≤3.6 3.2≤d≤4.8 0.0≤e≤0.2 0.0<x≤0.2。 2. A phosphor comprising a crystal phase having a composition represented by the following formula [2], and Contains element Z, the content of element Z is 1000 mass ppm or less, The element Z includes one or more elements selected from the group consisting of Mo, W, Nb, Ta, Ni, Pt and Ir, Re x MA a MB b (Al 1-y MC' y ) c D d X e [2] In the above formula [2], MA contains one or more elements selected from the group consisting of Ca, Sr, Ba, Na, K, Y, Gd and La, MB contains one or more elements selected from the group consisting of Li, Mg, and Zn, MC' contains one or more elements selected from the group consisting of Si, Ga, In and Sc, D is one or more elements selected from the group consisting of N, i.e., nitrogen, and O, i.e., oxygen. X contains one or more elements selected from the group consisting of F, Cl, Br and I, Re contains one or more elements selected from the group consisting of Eu, Ce, Pr, Tb and Dy, a, b, c, d, e, x, and y satisfy the following formulas respectively: 0.7≤a≤1.3 0.7≤b≤1.3 2.4≤c≤3.6 3.2≤d≤4.8 0.0≤e≤0.2 0.0<x≤0.2 0.0<y≤1.0。 The phosphor according to claim 1 or 2, comprising 1.0 mass ppm or more of the element Z. The phosphor according to claim 1 or 2, wherein the element Z contains one or more elements selected from the group consisting of Mo, W, Nb, Ta, and Ni. 5 . The phosphor according to claim 1 , wherein in the formula [1] or [2], 80 mol % or more of MA is one or more elements selected from the group consisting of Ca, Sr, and Ba. 6 . The phosphor according to claim 1 , wherein in the formula [1] or [2], 80 mol % or more of MB is Li. 7 . The phosphor according to claim 1 , wherein in the formula [1], 80 mol % or more of MC is composed of one or more elements selected from the group consisting of Al and Ga. 8 . The phosphor according to claim 1 , wherein in the formula [1], 80 mol % or more of MC is Al. 9 . The phosphor according to claim 2 , wherein in the formula [2], 80 mol % or more of MC′ is Ga. 10 . The phosphor according to claim 1 , wherein in the formula [1] or [2], 80 mol % or more of Re is Eu. 11 . The phosphor according to claim 1 , wherein the space group of the crystal phase having the composition represented by the formula [1] or [2] is P-1. 12 . The phosphor according to claim 1 , having a light emission peak wavelength in a range of 620 nm to 660 nm in a light emission spectrum. The phosphor according to claim 1 or 2, wherein the full width at half maximum (FWHM) in the emission spectrum is 70 nm or less.

14. A light-emitting device comprising: a first light-emitting body, and a second luminous body including one or more phosphors that emit visible light when irradiated with light from the first luminous body; The second luminous body comprises the phosphor according to claim 1 or 2. The light-emitting device according to claim 14 , wherein the second light-emitting body further comprises a yellow phosphor and / or a green phosphor. 16 . The light-emitting device according to claim 15 , wherein the yellow phosphor and / or the green phosphor comprises at least one of a garnet-based phosphor, a silicate-based phosphor, a nitride phosphor, and a nitride oxide phosphor.

17. A lighting device comprising the light-emitting device according to claim 14 as a light source.

18. An image display device comprising the light-emitting device according to claim 14 as a light source.

19. A vehicle indicator lamp comprising the light emitting device according to claim 14 as a light source.

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