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

Abstract

The present application provides a phosphor having a good emission peak wavelength, a narrow spectral half-value width, and a high emission intensity, and a light emitting device, a lighting device, an image display device, and / or a display lamp for a vehicle having good color rendering, color reproducibility, and / or conversion efficiency. The present application relates to a phosphor having a crystal phase having a composition represented by a specific formula, and a value of Log 10 (b) is 3.5 or less, and a light emitting device having the above phosphor as a second light emitter.

Description

Technical Field

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

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

[0003] As this type of white light-emitting LED, in recent years, LEDs that use, on a blue LED chip, a nitride phosphor that emits red light by using blue light from the blue LED chip as excitation light and a phosphor that emits green light have been used. Further improvement in luminous efficiency is required for LEDs, and phosphors having excellent luminescent properties as red phosphors, and light-emitting devices including such phosphors are desired.

[0004] As red phosphors used in light-emitting devices, for example, those represented by the general formula K2(Si,Ti)F6:Mn, K2Si 1- x Na x Al x KSF phosphors represented by F6:Mn(0<x<1), S / CASN phosphors represented by the general formula (Sr,Ca)AlSiN3:Eu are known. However, for KSF phosphors, since they are highly toxic substances activated by Mn, phosphors that are more friendly to human body and environment are required. In addition, for S / CASN phosphors, the full width at half maximum of the emission spectrum (hereinafter sometimes referred to as "spectral full width at half maximum", "Afull width at half maximum" or "FWHM") is mostly about 80 nm to 90 nm, which is relatively wide, and the emission wavelength region tends to include wavelength regions with low relative visibility. Therefore, from the viewpoint of improving conversion efficiency, red phosphors with narrower spectral full width at half maximum are required.

[0005] In addition, as a red phosphor applicable to light-emitting devices in recent years, for example, Patent Document 1 discloses a phosphor represented by a composition formula of SrLiAl3N4:Eu in Examples.

[0006] Prior Art Literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent No. 6335884 Summary of the Invention

[0009] Problem to be Solved by the Invention

[0010] However, the phosphor described in Patent Document 1, by using a boron nitride crucible, may introduce boron into the phosphor, thus reducing its luminescence properties. In contrast, in recent years, there has been a demand for phosphors with better luminescence intensity and luminescence devices with better conversion efficiency, based on more refined compound designs than ever before.

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

[0012] In addition, the present invention aims to provide a light-emitting device, an illumination device, an image display device, and / or a vehicle display light with good color rendering, color reproduction, and / or conversion efficiency.

[0013] Methods for solving problems

[0014] The inventors conducted in-depth research and discovered that the above-mentioned problems could be solved by using a phosphor containing a crystal phase represented by a specific composition and adjusting the content of a specific element to a certain level, or a light-emitting device equipped with such a phosphor, thereby completing the present invention. Several non-limiting embodiments are shown below.

[0015] Embodiment 1 of the present invention is a phosphor comprising a crystalline phase having a composition represented by the following formula [1], and wherein, when the content of B (boron) is set to b (mass ppm), Log 10 (b) has a value of 3.5 or less.

[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 contains 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.)

[0018] a, b, c, d, e, and x respectively satisfy the following equations.

[0019] 0.7 ≤ a ≤ 1.3

[0020] 0.9 ≤ b ≤ 1.3

[0021] c = 3.0

[0022] 3.2≤d≤4.8

[0023] 0.0≤e≤0.2

[0024] 0.0< <x≤0.2)

[0025] Embodiment 2 of the present invention is a phosphor comprising a crystalline phase having a composition represented by the following formula [2], and wherein, when the content of B (boron) is set to b (mass ppm), Log 10 (b) has a value of 3.5 or less.

[0026] Re x MA a MB b (Al 1-y MC' y ) c D d X e [2]

[0027] (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 contains 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.)

[0028] a, b, c, d, e, x, and y respectively satisfy the following equations.

[0029] 0.7 ≤ a ≤ 1.3

[0030] 0.9 ≤ b ≤ 1.3

[0031] c = 3.0

[0032] 3.2≤d≤4.8

[0033] 0.0≤e≤0.2

[0034] 0.0 <x≤0.2

[0035] 0.0 <y≤1.0)

[0036] In embodiment 3 of the present invention, when the content of B (boron) in the phosphor of embodiment 1 or 2 is set to b (mass ppm), Log10 (b) Fluorescent particles with a value of 3.0 or less.

[0037] In the fourth embodiment of the present invention, in any of the phosphors of embodiments 1 to 3, in the above formula [1] or formula [2], 80 mol% or more of MA is a phosphor composed of one or more elements selected from the group consisting of Ca, Sr and Ba.

[0038] In embodiment 5 of the present invention, in any of the phosphors of embodiments 1 to 4, in the above formula [1] or formula [2], 80 mol% or more of MB is a Li phosphor.

[0039] In the present invention, in any of the phosphors of methods 1 and 3 to 5, the phosphor in the above formula [1] is composed of 80 mol% or more of MC consisting of one or more elements selected from the group consisting of Al and Ga.

[0040] In the present invention, in any of the phosphors of methods 1 and 3 to 6, the phosphor in formula [1] above has 80 mol% or more of MC as Al.

[0041] In embodiment 8 of the present invention, in any of embodiments 2 to 5, the phosphor in the above formula [2] is a phosphor in which 80 mol% or more of MC' is Ga.

[0042] In embodiment 9 of the present invention, in any of the phosphors of embodiments 1 to 8, 80 mol% or more of Re is a phosphor of Eu in the above formula [1] or formula [2].

[0043] The present invention, in any of the embodiments 1 to 9, is a phosphor having a crystal phase with a space group of P-1 represented by the above formula [1] or formula [2].

[0044] The present invention, in any of the phosphors of embodiments 1 to 10, is a phosphor having a peak emission wavelength in the emission spectrum in the range of 620 nm or more and 660 nm or less.

[0045] The present invention, in embodiment 12, is a phosphor of any of embodiments 1 to 11, wherein the half-width (FWHM) of the emission spectrum is less than 70 nm.

[0046] Embodiment 13 of the present invention is a light-emitting device comprising a first light-emitting body and a second light-emitting body, the second light-emitting body comprising one or more phosphors that emit visible light upon irradiation by light from the first light-emitting body, the second light-emitting body comprising a phosphor of any of embodiments 1 to 12.

[0047] In embodiment 14 of the present invention, the second light-emitting body further comprises a yellow phosphor and / or a green phosphor in the light-emitting device of embodiment 13.

[0048] In embodiment 15 of the present invention, the light-emitting device of embodiment 14 includes the aforementioned yellow phosphor and / or green phosphor, comprising one or more of the following: garnet-based phosphor, silicate-based phosphor, nitride phosphor, and oxynitride phosphor.

[0049] Embodiment 16 of the present invention is a lighting device having a light-emitting device of any one of embodiments 13 to 15 as a light source.

[0050] Embodiment 17 of the present invention is an image display device, which includes a light-emitting device of any one of embodiments 13 to 15 as a light source.

[0051] Embodiment 18 of the present invention is a vehicle indicator light, which includes a light-emitting device of any one of embodiments 13 to 15 as a light source.

[0052] Invention Effects

[0053] According to the present invention, a phosphor with good emission peak wavelength, narrow spectral half-width, and high emission intensity can be provided.

[0054] Furthermore, according to the present invention, it is possible to provide light-emitting devices, lighting devices, image display devices, and / or vehicle display lights with good color rendering, color reproduction, and / or conversion efficiency. Attached Figure Description

[0055] [ Figure 1 ] Figure 1 The Log value is calculated when the content of boron (B) in the phosphors of Comparative Example 1 and Examples 1-4 is set to b (mass ppm). 10 (b) is plotted on the horizontal axis, and the relative brightness of the phosphors of Comparative Example 1 and Examples 1 to 4 is plotted on the vertical axis when the brightness of Comparative Example 1 is set to 1.0. Detailed Implementation

[0056] The present invention will be described below with examples and embodiments, but the present invention is not limited to the following examples and embodiments, and can be implemented in any way without departing from the spirit of the present invention.

[0057] It should be noted that, in the present specification, the numerical range represented by "~" means a range including the numerical values before and after "~" as the lower limit and the upper limit. In addition, in the compositional formulas of the phosphors in the present specification, each compositional formula is separated by a顿号(、). In addition, when a plurality of elements are listed separated by commas (,), it means that one or more of the listed elements can be contained in any combination and composition. For example, the compositional formula "(Ca,Sr,Ba)Al2O4:Eu" generally represents "CaAl2O4:Eu", "SrAl2O4:Eu", "BaAl2O4:Eu", "Ca 1-x Sr x Al2O4:Eu", "Sr 1- x Ba x Al2O4:Eu", "Ca 1-x Ba x Al2O4:Eu" and "Ca 1-x-y Sr x Ba y Al2O4:Eu" (wherein, 0<x<1, 0<y<1, 0<x+y<1 in the formula).

[0058] <Phosphor>

[0059] In one embodiment, the present invention provides a phosphor comprising a crystal phase having a composition represented by the following formula [1], and when the content of B (boron) is set as b (ppm by mass), Log 10 (b) is 3.5 or less (hereinafter, sometimes referred to as "the phosphor [1] of the present embodiment").

[0060] Re x MA a MB b MC c D d X e [1]

[0061] (In the above formula [1], MA comprises one or more elements selected from the group consisting of Ca, Sr, Ba, Na, K, Y, Gd and La, MB comprises one or more elements selected from the group consisting of Li, Mg and Zn, MC comprises 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 comprises one or more elements selected from the group consisting of F, Cl, Br and I, Re comprises one or more elements selected from the group consisting of Eu, Ce, Pr, Tb and Dy,

[0062] a, b, c, d, e, and x respectively satisfy the following equations.

[0063] 0.7 ≤ a ≤ 1.3

[0064] 0.9 ≤ b ≤ 1.3

[0065] c = 3.0

[0066] 3.2≤d≤4.8

[0067] 0.0≤e≤0.2

[0068] 0.0 <x≤0.2)

[0069] In addition, the phosphor of this embodiment[1] and the phosphor of this embodiment[2] described later are sometimes collectively referred to as "the phosphor of this embodiment".

[0070] In another embodiment, the present invention is a light-emitting device having the phosphor [1] of this embodiment.

[0071] In formula [1], Re can be europium (Eu), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm) and ytterbium (Yb), etc. However, from the viewpoint of improving the emission wavelength and emission 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 has 80 mol% or more of Eu as Re, and even more preferably has Eu as Re.

[0072] 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 containing one or more elements selected from the group consisting of Ca, Sr, and Ba, and more preferably containing Sr. In addition, preferably 80 mol% or more of MA is composed of 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.

[0073] In formula [1], MB contains one or more elements selected from the group consisting of lithium (Li), magnesium (Mg) and zinc (Zn), preferably containing Li, more preferably containing 80 mol% or more of Li, and even more preferably containing Li.

[0074] 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 containing Al, Ga or Si, more preferably containing one or more elements selected from the group consisting of Al and Ga, even more preferably MC is composed of 80 mol% or more of one or more elements selected from the group consisting of Al and Ga, particularly preferably MC is composed of 90 mol% or more of one or more elements selected from the group consisting of Al and Ga, and most preferably MC is composed of one or more elements selected from the group consisting of Al and Ga.

[0075] In one embodiment, 80 mol% or more of the MC is Al, preferably 90 mol% or more, more preferably 95 mol% or more, and even more preferably 98 mol% or more of Al. By having 80 mol% or more of the MC be Al, a red phosphor can be provided that exhibits the same emission peak wavelength and emission intensity as existing red phosphors such as S / CASN, but with a narrow spectral half-width. By using such a red phosphor, a light-emitting device can be provided that maintains the same or higher level of conversion efficiency (Lm / W) as before while exhibiting excellent color rendering or color reproducibility.

[0076] In formula [1], D is one or more elements selected from the group consisting of N (nitrogen) and O (oxygen). The proportion of N (nitrogen) in D can be adjusted arbitrarily, preferably 50 mol% or more, more preferably 70 mol% or more, even more preferably 80 mol% or more, and may also be 100 mol%. By appropriately adjusting the proportion of N (nitrogen) in D, the overall charge balance of the crystal phase can be maintained, or the wavelength of the emission peak can be adjusted.

[0077] In formula [1], X contains one or more elements selected from the group consisting of fluorine (F), chlorine (Cl), bromine (Br), and iodine (I). That is, in a particular embodiment, from the viewpoint of maintaining the stability of the crystal structure and the overall charge balance of the phosphor, a portion of N in D can be replaced by the halogen element shown in X.

[0078] When the content of B (boron) in the phosphor [1] of this embodiment is set to b (mass ppm), Log 10 (b) is typically 3.5 or less, preferably 3.0 or less, more preferably 2.5 or less, and even more preferably 2.2 or less. 10 (b) has no particular lower limit on its value; a smaller value is preferred, and it can also be a negative value. 10 (b) A negative value indicates that the boron content is less than 1 ppm.

[0079] By making the above Log 10(b) values ​​below the above upper limit can improve the luminescence intensity of the phosphor.

[0080] Regarding the above Log 10 Methods with values ​​below the aforementioned upper limit are not particularly limited as long as the effects of the present invention are not lost. In specific embodiments, methods such as dispersing or attaching elements or compounds different from boron to the raw material mixture powder, coating the surface of the reaction vessel with the aforementioned elements or compounds different from boron, and using a reaction vessel made of a material containing the aforementioned elements or compounds different from boron can be employed for synthesis.

[0081] There are no limitations on the elements that are different from boron, as long as the effect of the invention can be achieved. Elements that can be used as materials for crucibles can be used. In one embodiment, one or more elements selected from the group consisting of Mo, W, Nb, Ta, Ni, Pt and Ir are included. It is preferred to include one or more elements selected from the group consisting of Mo, W, Nb, Ta and Ni. More preferably, Mo is included.

[0082] It should be noted that, in the embodiments described later, Mo was used as an example.

[0083] The reason why the phosphor of this embodiment exhibits good brightness, spectral half-width and / or luminescence intensity is not yet certain, but it is believed that a phase with poor luminescence characteristics may be generated by mixing in boron, and by preventing this situation, the luminescence characteristics are improved.

[0084] Formula [1] above and Formula [2] below may also contain ingredients other than those explicitly stated, provided that the effect of the present invention is not impaired.

[0085] Other than those explicitly stated above, the following can be cited as components: elements whose element number differs from any element in formula [1] and formula [2] described below by one or two; elements in the same group as the element to be added; another rare earth element that is different from the rare earth element to be added; halogen elements when halides are used as raw materials; and other elements that may be included as impurities in various raw materials.

[0086] In cases where components other than those explicitly described above are included, for example, elements other than those explicitly described above may be included at any of the sites MA, MB, MC, and D, as well as MC', X, and Re (described later), for the purpose of exhibiting new effects; or components other than those explicitly described above may be unavoidably or accidentally introduced during the impurity sources of the raw materials and manufacturing processes such as pulverization and synthesis. Furthermore, as trace additives, examples 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 in the phosphor, respectively. The ideal ratio for stable crystal structure is the ratio of a+x, b, c, and d+e to be 1, 1, 3, and 4, respectively. However, in reality, due to various reasons such as single-atom defects, compositional 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 ratio. However, as long as the essence of the present invention is not impaired, or as long as the effect of the present invention is not lost, the present invention does not exclude these. Specifically, the allowable numerical ranges of a, b, c, d, e, and x are described below.

[0088] The value of a is typically 0.7 or higher, preferably 0.8 or higher, more preferably 0.9 or higher, typically 1.3 or lower, preferably 1.2 or lower, more preferably 1.1 or lower.

[0089] The value of b is typically 0.7 or higher, preferably 0.8 or higher, more preferably 0.9 or higher, typically 1.3 or lower, preferably 1.2 or lower, more preferably 1.1 or lower.

[0090] The value of c is typically 2.4 or higher, preferably 2.6 or higher, more preferably 2.8 or higher, typically 3.6 or lower, preferably 3.4 or lower, more preferably 3.2 or lower. Alternatively, in one embodiment, the value of c is 3.0.

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

[0092] The value of e is not particularly limited, and is generally above 0.0, generally below 0.2, preferably below 0.1, more preferably below 0.06, further preferably below 0.04, and even more preferably below 0.02.

[0093] The value of x is typically greater than 0.0, preferably 0.0001 or more, more preferably 0.001 or more, typically 0.2 or less, preferably 0.15 or less, more preferably 0.12 or less, further preferably 0.1 or less, and even more preferably 0.08 or less. By setting the value of x to be above or greater than the aforementioned lower limit, a phosphor with good luminescence intensity can be obtained. By setting the value of x to be below the aforementioned upper limit, a phosphor in which Re readily enters the crystal and functions easily as a luminescence center can be obtained.

[0094] By keeping b, c, d, and e within the aforementioned ranges, the crystal structure is stabilized. Furthermore, the values ​​of d and e can be appropriately adjusted to maintain the overall charge balance of the phosphor.

[0095] Furthermore, by keeping the value of a within the aforementioned range, the crystal structure can be stabilized, resulting in a phosphor with fewer heterogeneous phases.

[0096] The value of b+c is typically 3.1 or higher, preferably 3.4 or higher, more preferably 3.7 or higher, typically 4.9 or lower, preferably 4.6 or lower, and more preferably 4.3 or lower. Alternatively, in one embodiment, the value of b+c is 3.9 or higher and 4.3 or lower.

[0097] By using the values ​​of b+c within the aforementioned range, the crystal structure is stabilized.

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

[0099] By using the values ​​of d+e within the aforementioned range, the crystal structure is stabilized.

[0100] From the perspective of obtaining a phosphor with good emission peak wavelength and half-width in the emission spectrum, it is preferable that any value is within the above range.

[0101] It should be noted that there are no particular limitations on the method for determining the elemental composition of the aforementioned phosphors. They can be determined by conventional methods, such as GD-MS, ICP spectrophotometry, or energy-dispersive X-ray diffraction (EDX).

[0102] In one embodiment, the present invention comprises a crystal phase having a composition represented by the following formula [2], and wherein the content of B (boron) is set to b (mass ppm) when Log 10 (b) A phosphor with a value of 3.5 or less (hereinafter, sometimes referred to as "the phosphor of this embodiment [2]").

[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 contains 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.)

[0105] a, b, c, d, e, x, and y respectively satisfy the following equations.

[0106] 0.7 ≤ a ≤ 1.3

[0107] 0.9 ≤ b ≤ 1.3

[0108] c = 3.0

[0109] 3.2≤d≤4.8

[0110] 0≤e≤0.2

[0111] 0.0 <x≤0.2

[0112] 0.0 <y≤1.0)

[0113] In another embodiment, the present invention is a light-emitting device having the phosphor [2] of this embodiment.

[0114] The types and composition of MA, MB, D, X, and Re elements in the above formula [2] can be set to be the same as those in the above formula [1].

[0115] Furthermore, regarding the aforementioned Log in the phosphor [2] of this embodiment... 10 (b) The preferred values ​​and the method of manufacturing the phosphor can also be the same as those of the phosphor in this embodiment [1] described above.

[0116] 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 is preferable to contain one or more elements selected from the group consisting of Ga and Si, and more preferably Ga.

[0117] In a further preferred embodiment, in formula [2], 80 mol% or more of MC' can be Ga, or MC' can be composed of Ga.

[0118] The values ​​and preferred ranges of a, b, c, d, e and x in the above formula [2] can be set to be the same as those in the above formula [1].

[0119] In the above formula [2], the value of y is greater than 0.0, usually greater than 0.01, preferably greater than 0.015, more preferably greater than 0.03, further preferably greater than 0.05, especially preferably greater than 0.1, usually less than 1.0, preferably less than 0.7, more preferably less than 0.5, further preferably less than 0.3, especially preferably less than 0.25.

[0120] By setting the value of y to be above or greater than the aforementioned lower limit, the emission peak wavelength of the phosphor is shortened, thus providing a light-emitting device with good color rendering or color reproducibility. Conversely, by setting the value of y to be below the aforementioned upper limit, a phosphor with good luminescence intensity can be obtained, providing a light-emitting device with good conversion efficiency. The value of y can be appropriately adjusted to obtain the preferred luminescence intensity and emission peak wavelength for the desired purpose.

[0121] [Grain size of the crystal phase]

[0122] The particle size of the phosphor phase in this embodiment is generally 2 μm or more and 35 μm or less, based on the volume median particle size. The lower limit is preferably 3 μm or more, more preferably 4 μm or more, and even more preferably 5 μm or more. In addition, the upper limit is preferably 30 μm or less, more preferably 25 μm or less, even more preferably 20 μm or less, and particularly preferably 15 μm or less.

[0123] When the central particle size (volume median particle size) of the volume reference is above the lower limit mentioned above, it is preferred from the viewpoint of improving the light-emitting characteristics of the LED package display by the crystal phase. When it is below the upper limit mentioned above, it is preferred from the viewpoint that the crystal phase can avoid nozzle clogging in the LED package manufacturing process.

[0124] The volume-based median particle size (VPS) of the crystalline phase of a phosphor can be determined using measurement techniques known to those skilled in the art, but in a preferred embodiment, it can be measured, for example, using a laser particle size analyzer. In the embodiments of this specification, the volume-based median particle size (DPS, VPS) is... 50 The particle size distribution (cumulative distribution) is defined as the particle size at which the relative particle mass of the volume reference is 50% when the particle size distribution is determined by measuring the sample using a particle size distribution measuring device based on the laser diffraction / scattering method.

[0125] {Physical properties of fluorescent particles, etc.}

[0126] [Spatial Group]

[0127] In the phosphor of this embodiment, the crystal system (space group) having a crystal phase composed of formula [1] or formula [2] is not limited as long as the inventive effect can be obtained. In one embodiment, it can be set as P42 / m of tetragonal crystal, P-1 of monoclinic crystal, 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 the repeating period of the above-mentioned length, preferably belonging to No. 2 based on "International Tables for Crystallography (Third, revised edition), Volume A Space Group Symmetry".

[0128] By narrowing the half-width (FWHM) of the emission spectrum in the aforementioned space group, phosphors with good luminescence efficiency can be obtained.

[0129] Here, the space group can be determined using conventional methods, such as electron beam diffraction, X-ray diffraction structure analysis using powder or single crystal, and neutron beam diffraction structure analysis.

[0130] [Characteristics of the emission spectrum]

[0131] The phosphor of this embodiment is excited by irradiation with light of an appropriate wavelength, emitting red light that exhibits good emission peak wavelength and spectral half-width (FWHM) in the emission spectrum. Hereinafter, the emission spectrum, excitation wavelength, emission peak wavelength, and spectral half-width (FWHM) will be described.

[0132] (Excitation wavelength)

[0133] The phosphor of this embodiment has an excitation peak in a wavelength range of typically 270 nm or higher, preferably 300 nm or higher, more preferably 320 nm or higher, even more preferably 350 nm or higher, particularly preferably 400 nm or higher, and also typically 500 nm or lower, preferably 480 nm or lower, and more preferably 460 nm or lower. That is, it is photoexcited in the near-ultraviolet to blue region.

[0134] It should be noted that the shape of the emission spectrum and the description of the emission peak wavelength and spectral half-width below are applicable regardless of the excitation wavelength, but from the point of view of improving quantum efficiency, it is preferable to irradiate light with wavelengths in the above range that have good absorption and excitation efficiency.

[0135] (Peak emission wavelength)

[0136] The phosphor of this embodiment typically has a peak wavelength of 620 nm or more in its emission spectrum, preferably 625 nm or more, and more preferably 630 nm or more. Furthermore, the peak wavelength in this emission spectrum is typically 670 nm or less, preferably 660 nm or less, and more preferably 655 nm or less. For example, the phosphor of this embodiment can have a peak emission wavelength in the range of 620 nm or more and 660 nm or less in its emission spectrum.

[0137] By setting the peak wavelength of the phosphor's emission spectrum within the aforementioned range, a good red color is achieved. Using this phosphor, a light-emitting device with good color rendering or color reproducibility can be provided. Furthermore, by setting the peak wavelength of the phosphor's emission spectrum below the aforementioned upper limit, a light-emitting device with good red visibility and a lumen equivalent (lm / W) can be provided.

[0138] In light-emitting devices, phosphors with different peak wavelengths can be used depending on the application. There are no particular limitations on the methods for obtaining phosphors with different peak wavelengths; one method is to change the composition of the MC elements.

[0139] In one embodiment, by using Al in MC in the above formula [1] and increasing the Al ratio, a phosphor with a longer emission peak wavelength can be obtained. In this embodiment, the emission peak wavelength is preferably 640 nm or more, more preferably 645 nm or more, typically 670 nm or less, and preferably 660 nm or less. By having a phosphor with an emission wavelength in this range, for example, in a light-emitting device for lighting purposes, a light-emitting device that balances luminous efficiency and color rendering can be provided, or in a light-emitting device for a backlight unit of a liquid crystal display, a light-emitting device that balances luminous efficiency and color reproduction range can be provided.

[0140] In another embodiment, by fabricating a phosphor containing a crystalline phase having the composition shown in the aforementioned formula [2] using Al and MC' elements, a phosphor with a relatively short emission peak wavelength can be obtained. In this embodiment, the emission peak wavelength is typically 615 nm or more, preferably 620 nm or more, more preferably 625 nm or more, even more preferably 630 nm or more, typically 660 nm or less, preferably 645 nm or less, and more preferably 640 nm or less. By using a phosphor with an emission wavelength in the above range, a light-emitting device with good color rendering or color reproduction can be obtained.

[0141] (Half-width of the emission spectrum)

[0142] The half-width of the emission spectrum of the phosphor in this embodiment is typically 80 nm or less, preferably 70 nm or less, more preferably 60 nm or less, even more preferably 55 nm or less, particularly preferably 50 nm or less, and typically 10 nm or more.

[0143] By using phosphors with a half-width in the emission spectrum within the aforementioned range, it is possible to expand the color reproduction range in image display devices such as liquid crystal displays without reducing color purity.

[0144] Furthermore, by setting the emission peak wavelength and spectral half-width to below the aforementioned upper limit, 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.

[0145] It should be noted that, in order to excite the aforementioned phosphor with light of approximately 450 nm, a GaN-based LED can be used as the excitation source, for example. Furthermore, the measurement of the emission spectrum of the aforementioned phosphor, as well as the calculation of its emission peak wavelength, peak relative intensity, and spectral half-width, can be performed using commercially available spectroscopic measuring devices, such as commercially available xenon lamps or other light sources with emission wavelengths of 300–400 nm, and fluorescence measuring devices equipped with general photodetectors.

[0146] <Methods for manufacturing fluorescent particles>

[0147] The phosphor of this embodiment can be synthesized by mixing and heating the raw materials that constitute the phosphor in a manner that satisfies the aforementioned formula [1] or formula [2] in the proportion of each element.

[0148] [Fluorescent material]

[0149] There are no particular limitations on the phosphor raw materials that can serve as the supply source for each element (MA, MB, MC, MC', Re). Examples include the elemental form, oxides, nitrides, hydroxides, chlorides, halides such as fluorides, sulfates, nitrates, phosphates, and organic acid salts such as acetates. Furthermore, compounds containing two or more of the aforementioned element groups can also be used. Additionally, each compound can be a hydrate, etc.

[0150] It should be noted that, in the embodiments described later, nitrides of each element are used as phosphor raw materials.

[0151] There are no particular restrictions on the methods for obtaining the raw materials of each fluorophore; commercially available substances can be purchased and used.

[0152] There are no particular restrictions on the purity of each phosphor raw material. From the viewpoint of ensuring strict element ratios and avoiding the occurrence of heterogeneous phases caused by impurities, higher purity is preferred. It is usually 90 mol% or more, preferably 95 mol% or more, more preferably 97 mol% or more, and even more preferably 99 mol% or more. There are no particular restrictions on the upper limit, but it is usually 100 mol% or less. It may also contain unavoidable impurities.

[0153] In the embodiments described later, phosphor raw materials with a purity of 95 mol% or higher were used.

[0154] Regarding oxygen (O), nitrogen (N), and halogen (X), in addition to being supplied by using oxides, nitrides, and halides as phosphor raw materials to serve as the supply source for the aforementioned elements, they can also be appropriately contained by forming an oxygen- or nitrogen-containing atmosphere during the synthesis reaction.

[0155] [Mixed Process]

[0156] There are no particular limitations on the mixing method of phosphor raw materials, and conventional methods can be used. For example, the phosphor raw materials are weighed to obtain the target composition, and then thoroughly mixed using a ball mill or the like to obtain a phosphor raw material mixture. As for the above mixing method, there are no particular limitations, but specifically, methods (a) and (b) below can be cited.

[0157] (a) Dry mixing method: The aforementioned phosphor raw materials are pulverized and mixed by combining pulverization using dry pulverizers such as hammer mills, roller mills, ball mills, jet mills, or mortars and pestles with mixing using mixers such as belt mixers, V-type mixers, Henschel mixers, or mortars and pestles.

[0158] (b) Wet mixing method: Add solvents such as water or dispersion media to the aforementioned phosphor raw materials, and mix them using, for example, a pulverizer, mortar and pestle, or an evaporating dish and stirring rod, to make a solution or slurry, and then dry it by spray drying, heat drying or natural drying.

[0159] The mixing of phosphor raw materials can be either the dry mixing method or the wet mixing method described above. To avoid contamination of the phosphor raw materials by moisture, the dry mixing method or the wet mixing method using non-water-soluble solvents is preferred.

[0160] It should be noted that in the embodiments described later, method (a) is used.

[0161] [Add an element different from boron]

[0162] In a specific embodiment, the above-described method for manufacturing phosphors may involve adding an element or compound different from boron to the resulting phosphor raw material mixture after the above-described mixing process.

[0163] There are no particular limitations on the methods for adding elements different from boron, as long as the element or its compound is dispersed or attached to the phosphor raw material mixture. Conventional methods can be used. For example, gas-phase methods or sol-gel methods can be used, or the phosphor raw material mixture can be mixed with an element or its compound different from boron and then subjected to heat treatment. Alternatively, for example, the surface of the reaction vessel can be coated with an element or its compound different from boron; furthermore, for example, a reaction vessel made of a material containing an element or its compound different from boron can be used for synthesis.

[0164] [Heating Process]

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

[0166] Regarding the pressure during the heating process, it can be either atmospheric pressure or pressurized pressure, as long as the target phosphor can be obtained. However, pressurization is preferred to prevent the volatilization of elements contained in the phosphor raw material. When pressurized, the pressure is typically 0.1 MPa or higher and 200 MPa or lower, preferably 100 MPa or lower. By keeping the pressure within this range, good reactivity of the phosphor raw material can be ensured.

[0167] There are no restrictions on the method of pressurization; for example, methods such as heating a sealed container, mechanical pressurization, or using air pressure can be used.

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

[0169] It should be noted that, in the embodiments described later, a crucible made of boron nitride or a crucible made by coating boron nitride with an element different from boron described above is used.

[0170] Heating is preferably carried out in an inactive atmosphere, and gases such as nitrogen, argon, and helium as the main components can be used.

[0171] It should be noted that, in the embodiments described later, heating is performed under a nitrogen atmosphere.

[0172] In the heating process, heating is typically performed for 10 minutes to 200 hours, preferably 1 hour to 100 hours, and more preferably 2 hours to 50 hours within the aforementioned temperature range. Furthermore, this heating process can be performed once or in multiple stages. Examples of performing the heating process in multiple stages include: an annealing process involving heating under pressure to repair defects, and a secondary heating process where secondary particles or a final product are obtained after a primary heating process to obtain primary particles or intermediates.

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

[0174] [Screening of fluorescent agents]

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

[0176] Therefore, for example, by changing several conditions to manufacture phosphors, and by screening the obtained phosphors through grading, washing, etc., and analyzing reflectance, XRD spectra, etc., phosphors that meet the requirements of the present invention can be screened, and the phosphors of the above embodiments 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 upon irradiation by light from the first light-emitting body, wherein the second light-emitting body comprises the phosphor of this embodiment [1] or the phosphor of this embodiment [2]. Here, the second light-emitting body may be used alone or in any combination and ratio of two or more types.

[0179] In the light-emitting device of this embodiment, the aforementioned second light-emitting body may further contain a phosphor that emits yellow, green or red (orange or red) fluorescence under irradiation by light from an excitation source, in addition to the phosphor of this embodiment which contains a crystalline phase having the composition shown in the aforementioned formula [1] or formula [2].

[0180] In addition, in a specific embodiment, the light-emitting device of the present invention contains a phosphor comprising a crystalline phase having the composition shown in the aforementioned formula [1] or formula [2], and further contains a yellow phosphor and / or a green phosphor.

[0181] Specifically, in the case of constituting a light-emitting device, as a yellow phosphor, it is preferable to have an emission peak in the wavelength range of 550 nm or higher and 600 nm or lower; as a green phosphor, it is preferable to have an emission peak in the wavelength range of 500 nm or higher and 560 nm or lower. Furthermore, orange or red phosphors typically have an emission peak in the wavelength range of 615 nm or higher, preferably 620 nm or higher, more preferably 625 nm or higher, further preferably 630 nm or higher and typically 660 nm or lower, preferably 650 nm or lower, more preferably 645 nm or lower, and further preferably 640 nm or lower.

[0182] By appropriately combining phosphors in the aforementioned wavelength regions, a light-emitting device exhibiting excellent color reproducibility can be provided. It should be noted that, regarding the excitation source, an excitation source having an emission peak in the wavelength range below 420 nm can be used.

[0183] Hereinafter, a light-emitting device is described in which a phosphor of this embodiment, having an emission peak in a wavelength range of 620 nm or higher and 660 nm or lower and containing a crystal phase having the composition shown in the aforementioned formula [1] or formula [2], is used as a red phosphor, and a first light-emitting element is used as a light-emitting element having an emission peak in a wavelength range of 300 nm or higher and 460 nm or lower, but this embodiment is not limited to these.

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

[0185] (A) A method of using a light emitter having a light emission peak in a wavelength range of 300 nm or more and 460 nm or less as a first light emitter, using at least one phosphor (yellow phosphor) having a light emission peak in a wavelength range of 550 nm or more and 600 nm or less, and using a phosphor of this embodiment having a crystal phase having the composition shown in the aforementioned formula [1] or formula [2] as a second light emitter.

[0186] (B) A method in which a light emitter having an emission peak in a wavelength range of 300 nm or more and 460 nm or less is used as the first light emitter, and at least one phosphor (green phosphor) having an emission peak in a wavelength range of 500 nm or more and 560 nm or less is used as the second light emitter, and a phosphor of this embodiment having a crystal phase having the composition shown in the aforementioned formula [1] or formula [2] is used as the second light emitter.

[0187] (C) The method of using a light emitter having an emission peak in a wavelength range of 300 nm or more and 460 nm or less as the first light emitter, using at least one phosphor (yellow phosphor) having an emission peak in a wavelength range of 550 nm or more and 600 nm or less, at least one phosphor (green phosphor) having an emission peak in a wavelength range of 500 nm or more and 560 nm or less, and a phosphor of the present embodiment having a crystal phase having the composition shown in the aforementioned formula [1] or formula [2] as the second light emitter.

[0188] As the green or yellow phosphor in the above-described method, commercially available products can be used, such as garnet-based phosphors, silicate-based phosphors, nitride phosphors, and oxynitride phosphors. That is, in the above-described method, the yellow phosphor and / or green phosphor can include any one or more of garnet-based phosphors, silicate-based phosphors, nitride phosphors, and oxynitride phosphors.

[0189] (Yellow fluorescent material)

[0190] Garnet-based fluorophores that can be used as yellow fluorophores include, for example, (Y, Gd, Lu, Tb, La)3(Al, Ga)5O 12 (Ce, Eu, Nd); Examples of silicate-based phosphors include (Ba, Sr, Ca, Mg)₂SiO₄:(Eu, Ce); Examples of nitride and oxide phosphors include (Ba, Ca, Mg)Si₂O₂N₂:Eu (SION phosphor) and (Li, Ca)₂(Si, Al). 12 (O, N) 16 :(Ce,Eu) (α-Ce-SiO2 phosphor), (Ca,Sr)AlSi4(O,N)7:(Ce,Eu) (1147 phosphor), (La,Ca,Y,Gd)3(Al,Si)6N 11 (Ce, Eu) (LSN phosphors), etc.

[0191] They can be used individually or in combination of two or more.

[0192] As a yellow phosphor, garnet-based phosphors are preferred among the above-mentioned phosphors, with Y3Al5O3 being the most preferred. 12 Ce represents YAG-based fluorescent cells.

[0193] (Green fluorescent agent)

[0194] Garnet-based phosphors that can be used as green phosphors include, for example, (Y, Gd, Lu, Tb, La)3(Al, Ga)5O 12 :(Ce, Eu, Nd), Ca3(Sc, Mg)2Si3O12 :(Ce,Eu) (CSMS phosphor); examples of silicate-based phosphors include (Ba,Sr,Ca,Mg)3SiO 10 :(Eu,Ce), (Ba,Sr,Ca,Mg)2SiO4:(Ce,Eu) (BSS phosphor); examples of oxide phosphors include (Ca,Sr,Ba,Mg)(Sc,Zn)2O4:(Ce,Eu) (CASO phosphor); examples of nitride phosphors and oxynitride phosphors include (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); examples of aluminate phosphors include (Ba,Sr,Ca,Mg)2Al 10 O 17 :(Eu,Mn) (GBAM-based phosphor), etc.

[0195] They may be used alone in one kind, or may be used in combination of two or more kinds.

[0196] (Red phosphor)

[0197] As the red phosphor, the phosphor of the present embodiment including a crystal phase having the composition represented by the aforementioned formula [1] or formula [2] is used, but in addition to the phosphor of the present embodiment, other orange or red phosphors such as Mn-activated fluoride phosphors, garnet-based 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 may be used.

[0198] Examples of Mn-activated fluoride phosphors include K2(Si,Ti)F6:Mn, K2Si 1-x Na x Al x F6:Mn (0<x<1) (collectively referred to as KSF phosphors); examples of sulfide phosphors include (Sr,Ca)S:Eu (CAS phosphor), La2O2S:Eu (LOS phosphor); examples of garnet-based phosphors include (Y,Lu,Gd,Tb)3Mg2AlSi2O 12:Ce; for nanoparticles, CdSe can be cited for example; for nitride or oxynitride phosphors, (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 (x in the above formulas is 0<x<1), etc.

[0199] One of them may be used alone, or two or more thereof may be used in combination.

[0200] [Structure of Light-emitting Device]

[0201] The light-emitting device according to the present embodiment may include a first luminous body (excitation light source) and use the phosphor of the present embodiment that includes at least a crystal phase having the composition represented by the aforementioned formula [1] or formula [2] as a second luminous body. The structure thereof is not limited, and any known device structure can be adopted.

[0202] As for embodiments of device structures and light-emitting devices, for example, the embodiments described in Japanese Patent Application Laid-Open No. 2007-291352 can be cited. In addition, as for the forms of the light-emitting device, bullet type, cup type, chip on board, remote phosphor and the like can be cited.

[0203] {Use of Light-emitting Device}

[0204] There is no particular limitation on the use of the light-emitting device, and it can be used in various fields where conventional light-emitting devices are used. However, the light-emitting device with high color rendering properties is particularly suitable for use as a light source for lighting devices and image display devices.

[0205] In addition, a light-emitting device including a red phosphor with a favorable emission wavelength can also be used for red vehicle display lights, or vehicle display lights using white light including red.

[0206] [Lighting Device]

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

[0208] When the aforementioned light-emitting device is applied to a lighting device, there are no limitations on the specific configuration of the lighting device, as long as the aforementioned light-emitting device is appropriately assembled into a known lighting device for use. For example, a surface-emitting lighting device in which multiple light-emitting devices are arranged on the bottom surface of the housing can be cited.

[0209] [Image display device]

[0210] In one embodiment, the present invention may be configured as an image display device having the aforementioned light-emitting device as a light source.

[0211] When the aforementioned light-emitting device is used as the light source of an image display device, there are no limitations on the specific configuration of the image display device, but it is preferable to use it in conjunction with a color filter. For example, as an image display device, in the case of a color image display device that utilizes a color liquid crystal display element, by using the aforementioned light-emitting device as a backlight source and combining a light shutter utilizing liquid crystal and a color filter having red, green, and blue pixels, an image display device can be formed.

[0212] [Vehicle indicator lights]

[0213] In one embodiment, the present invention can be configured as a vehicle indicator light having the aforementioned light-emitting device as a light source.

[0214] In a particular embodiment, the light-emitting device for vehicle indicator lights is preferably a light-emitting device that emits white light. Preferably, the deviation (duv) between the light emitted from the light-emitting device and the blackbody radiation trajectory of the light color is -0.0200 to 0.0200, and the color temperature is 5000K or higher and 30000K or lower.

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

[0216] Vehicle indicator lights include headlights, side lights, taillights, turn signals, brake lights, fog lights, etc., which are installed on the vehicle for the purpose of displaying certain information to other vehicles, people, etc.

[0217] Example

[0218] The following examples illustrate several specific embodiments of the present invention, but the present invention is not limited to the following content as long as it does not depart from its spirit.

[0219] {Determination Method}

[0220] [Determination of Fluorescent Composition]

[0221] The contents of Sr, Al, Ga, Eu, Li, and B in the fluorescent samples were determined based on JIS K0116:2014. The samples were subjected to pressurized acid hydrolysis in hydrochloric acid solution and diluted to appropriate concentrations, then measured using high-frequency inductively coupled plasma optical emission spectrometry (ICP-OES). It should be noted that the contents of Sr, Al, Ga, and Eu were determined using the intensity ratio method with a Co standard solution as an internal standard, while the contents of Li and B were determined by constructing standard curves for each element and using the intensity ratio method.

[0222] Regarding the nitrogen content in fluorophore samples, refer to JIS R1603:2007 14.1(a), JIS R2015:2007 8.2, etc., and determine it by pressure acid hydrolysis-steam distillation-neutralization titration method. It should be noted that pressure acid hydrolysis uses a solution containing sulfuric acid and hydrogen fluoride.

[0223] [Determination of Luminescence Spectroscopy]

[0224] The emission spectrum was measured using a spectrophotometer F-4500 (manufactured by Hitachi High Technology Co., Ltd.) under the following measurement conditions.

[0225] • Light source: Xenon lamp

[0226] • Excitation wavelength: 455nm

[0227] • Measurement wavelength range: 200–900 nm

[0228] • Measurement interval: 0.2 nm

[0229] The chromaticity coordinates are calculated from the emission spectrum data of 480nm to 800nm ​​using the CIE1931 XYZ equation function.

[0230] [Measurement of quantum efficiency]

[0231] The quantum efficiency is calculated based on the emission spectrum measured using the QE-2100 quantum efficiency measurement system (manufactured by Otsuka Electronics Co., Ltd.) under the following measurement conditions.

[0232] • Light source: Xenon lamp

[0233] • Excitation wavelength: 455nm

[0234] • Measurement wavelength range: 200–850 nm

[0235] • Measurement interval: 1.2–1.5 nm

[0236] <Examples 1-4>

[0237] Nitride raw materials of various elements were 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. A boron nitride (BN) crucible coated with Mo was prepared as the reaction vessel. The above phosphor raw material mixture was placed in the reaction vessel and the reaction vessel was sealed. The reaction vessel was placed in a heating furnace and fired at a maximum temperature of 845°C for 5 hours under a nitrogen atmosphere. Multiple experiments were conducted, and phosphors with different B (boron) contents were obtained. These were therefore designated as Examples 1 to 4.

[0238] <Comparative Example 1>

[0239] As the reaction vessel, a boron nitride (BN) crucible with an uncoated surface was used. Otherwise, the procedure was the same as in Example 1 to obtain the phosphor of Comparative Example 1.

[0240] <Comparative Example 2>

[0241] The highest firing temperature was set to 1000°C. Otherwise, the operation was the same as in Example 1 to obtain the phosphor of Comparative Example 2.

[0242] <Comparative Example 3>

[0243] As the reaction vessel, a molybdenum (Mo) crucible with no metal coating on its surface was used, and the maximum firing temperature was set to 1000°C. Otherwise, the operation was the same as in Example 1 to obtain the phosphor of Comparative Example 3.

[0244] [evaluate]

[0245] The crystal structure of the obtained phosphors was determined by powder X-ray diffraction. As a result, the phosphors of Examples 1-4 and Comparative Example 1 showed good agreement with the diffraction patterns of SrLiAl3N4 belonging to space group P-1.

[0246] The manufacturing conditions of the phosphors in Examples 1-4 and Comparative Examples 1-3, Log 10 The values ​​of (b), 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. Detailed results of the compositional analysis of the phosphors of Examples 1 to 4 and Comparative Examples 1 to 3 are shown in Table 2.

[0247] [Table 1]

[0248] Table 1

[0249]

[0250] [Table 2]

[0251] Table 2

[0252]

[0253] <Example 5>

[0254] The phosphor raw material mixture obtained by mixing the nitride raw materials of each element in the manner of Sr:Li:Al:Eu = 0.99:1:3.0:0.01 was used as the reaction vessel. A molybdenum (Mo) crucible with no metal coating was used. Otherwise, the operation was the same as in Example 1 to obtain the phosphor of Example 5.

[0255] <Example 6>

[0256] As the reaction vessel, a boron nitride (BN) crucible coated with Mo was used. Otherwise, the procedure was the same as in Example 5 to obtain the phosphor of Example 6.

[0257] <Comparative Examples 4-7>

[0258] As described in Table 3, the material of the crucible used for the reaction vessel, the presence or absence of a metal coating on the surface of the reaction vessel, and the maximum firing temperature were changed. Otherwise, the operation was the same as in Example 5 to obtain the phosphors of Comparative Examples 4 to 7.

[0259] [evaluate]

[0260] The manufacturing conditions of the phosphors in Examples 5-6 and Comparative Examples 4-7, Log 10 The values ​​of (b), the relative luminescence intensity with the luminescence intensity of Comparative Example 7 set to 1.00, and other luminescence characteristics are shown in Table 3. Detailed results of the compositional analysis of the phosphors of Examples 5-6 and Comparative Examples 4-7 are shown in Table 4.

[0261] [Table 3]

[0262] Table 3

[0263]

[0264] [Table 4]

[0265] Table 4

[0266]

[0267] As can be seen from Tables 1 to 4, the phosphor in this embodiment is a red phosphor with a narrow peak half width (FWHM) and high luminescence intensity.

[0268] in addition, Figure 1 The Log shows the value of boron (B) in the phosphors of Comparative Example 1 and Examples 1-4 as b (mass ppm). 10(b) is plotted on the horizontal axis, and the relative brightness of the phosphors of Comparative Example 1 and Examples 1-4 is plotted on the vertical axis when the brightness of Comparative Example 1 is set to 1.0. Figure 1 It can be seen that Log 10 (b) The phosphor of this embodiment has a high luminescence intensity of 3.5 or less.

[0269] The various embodiments have been described above, but the present invention is not limited to these examples. Obviously, those skilled in the art will be able to conceive of various modifications or alterations within the scope of the claims, and these also fall within the technical scope of the present invention. Furthermore, the constituent elements in the above embodiments can be arbitrarily combined without departing from the spirit of the invention.

[0270] It should be noted that this application is based on Japanese patent application filed on February 6, 2023 (Japanese Patent Application No. 2023-016168), the contents of which are incorporated herein by reference.

[0271] Industrial availability

[0272] The present invention can provide phosphors with good emission peak wavelength, narrow spectral half width, and / or high emission intensity. By using such phosphors, light-emitting devices with good color rendering, color reproduction and / or conversion efficiency can be provided, and therefore can be applied to lighting devices, image display devices and vehicle display lights.

Claims

1. A phosphor comprising a crystal phase having a composition represented by the following formula [1], and a value of Log (b / a) is 3.5 or less, wherein a is a content of Al, and b is a content of B, each in mass ppm. 10 (b) the value of Log (b / a) is 3.5 or less, Re x MA a MB b MC c D d X e [1] In the above formula [1], MA is Sr, MB stands for Li. MC is Ga, or Al and Ga. D is an element selected from the group consisting of N (nitrogen) and O (oxygen), and includes N (nitrogen). X is one or more elements selected from the group consisting of F, Cl, Br, and I. Re is Eu. a, b, c, d, e, and x respectively satisfy the following equations: 0.9≤a≤1.1 0.9≤b≤1.1 c=3.0 3.8≤d≤4.4 0.0≤e≤0.1 0.0<x≤0.08。 2. A phosphor comprising a crystal phase having a composition represented by the following formula [2], and a value of Log (b / a) is 3.5 or less, where b is a content of B (boron) in mass ppm, and a is a content of Al in mass ppm. 10 (b) is 3.5 or less, Re x MA a MB b (Al 1-y MC' y ) c D d X e [2] In the above formula [2], MA is Sr, MB stands for Li. MC' is Ga, D is an element selected from the group consisting of N (nitrogen) and O (oxygen), and includes N (nitrogen). X is one or more elements selected from the group consisting of F, Cl, Br, and I. Re is Eu. a, b, c, d, e, x, and y respectively satisfy the following equations: 0.9≤a≤1.1 0.9≤b≤1.1 c=3.0 3.8≤d≤4.4 0.0≤e≤0.1 0.0<x≤0.08 0.1≤y≤1.0。 3. In the phosphor according to claim 1 or 2, when the content of B, i.e., boron, is set as b, and the unit is mass ppm, Log 10 (b) has a value of 3.0 or less.

4. The phosphor according to claim 1 or 2, wherein the space group of the crystal phase having the composition represented by the formula [1] or formula [2] is P-1.

5. The phosphor according to claim 1 or 2, wherein the emission spectrum has a peak emission wavelength in the range of 620 nm or higher and 660 nm or lower.

6. The phosphor according to claim 1 or 2, wherein the half-width at half maximum (FWHM) of the emission spectrum is less than 70 nm.

7. A light-emitting device comprising a first light-emitting element and a second light-emitting element, the second light-emitting element comprising one or more phosphors that emit visible light upon irradiation by light from the first light-emitting element. The second luminescent body comprises the phosphor as described in claim 1 or 2.

8. The light-emitting device according to claim 7, wherein the second light-emitting body further comprises a yellow phosphor and / or a green phosphor.

9. The light-emitting device according to claim 8, wherein the yellow phosphor and / or green phosphor comprises any one or more of garnet-based phosphors, silicate-based phosphors, nitride phosphors, and oxynitride phosphors.

10. A lighting device comprising the light-emitting device of claim 7 as a light source.

11. An image display device comprising the light-emitting device of claim 7 as a light source.

12. A vehicle indicator light comprising the light-emitting device of claim 7 as a light source.

Images