JP7253214B1 - Light-emitting device, lighting device, image display device, and vehicle indicator light - Google Patents

Abstract

A light-emitting device, a lighting device, a screen display device, and a vehicle indicator lamp having good color rendering properties are provided. A light-emitting device including a phosphor. The phosphor contains a crystal phase having a composition represented by the following formula [1], and the peak intensity appearing in the region of 2θ = 38 to 39 degrees in the powder X-ray diffraction spectrum of the phosphor is Ix, 2θ = Ix/Iy is 0.140 or less, where Iy is the peak intensity appearing in the region of 37 to 38 degrees. RexMAaMBbMCcNdXe: Formula [1] (MA is one or more of Sr, Ca, Ba, Na, K, Y, Gd and La; MB is one or more of Li, Mg and Zn; MC is Al, Si, Ga, In , Sc X is one or more of F, Cl, Br and I. Re is one or more of Eu, Ce, Pr, Tb and Dy.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) [Selection diagram] FIG.

Description

The present invention relates to a light-emitting device, a lighting device, an image display device, and a vehicle indicator lamp.

In recent years, the demand for illumination and backlights using LEDs has increased in response to the trend toward energy conservation. The LEDs used here are white-emitting LEDs in which a phosphor is placed on an LED chip that emits light in blue or near-ultraviolet wavelengths.

As such a type of white-light-emitting LED, there has recently been one in which a red-light-emitting nitride phosphor and a green-light-emitting phosphor are used on a blue LED chip by using blue light from the blue LED chip as excitation light. used. LEDs are required to have higher luminous efficiency, and there is a demand for a light-emitting device including a red phosphor having excellent luminous properties.

Red phosphors used in light-emitting devices are represented, for example, by the general formulas K ₂ (Si, Ti) F ₆ :Mn and K ₂ Si _1-x Na _x Al _x F ₆ :Mn (0<x<1). KSF phosphor, S/CASN phosphor represented by the general formula (Sr, Ca)AlSiN ₃ :Eu, etc. are known. There is a demand for environmentally friendly phosphors. In addition, many of the S/CASN phosphors have a relatively large full width at half maximum (FWHM) of about 80 nm to 90 nm, and the emission wavelength band tends to include a wavelength band with low relative luminosity. , a red phosphor with a smaller half-value width is desired.

In addition, as a red phosphor that can be applied to recent light emitting devices, for example, Patent Document 1 discloses a phosphor represented by a composition formula of SrLiAl ₃ N ₄ :Eu and a light emitting device using the same as an example. Are listed.

Japanese Patent No. 6335884

However, the emission intensity of the phosphor described in Patent Document 1 is unknown, and a phosphor with good emission intensity and a light emitting device with good conversion efficiency are in demand.

In view of the above problems, it is an object of the present invention to provide a light-emitting device, a lighting device, an image display device, and a vehicle indicator lamp that have good color rendering properties or color reproducibility and good conversion efficiency.

As a result of intensive studies by the present inventors, it was found that a light-emitting device comprising a phosphor, wherein the phosphor contains a crystal phase represented by a specific composition, and 2θ falls within a specific region in the powder X-ray diffraction spectrum. The above problem can be solved by using a phosphor in which the ratio of the intensity of a peak corresponding to a different phase and the intensity of a peak corresponding to a crystal phase represented by the specific composition in another specific region is a predetermined value or less. The present invention was completed by finding that. That is, the present invention includes the following.

<1> A light-emitting device comprising a phosphor,
The phosphor contains a crystal phase having a composition represented by the following formula [1], and
When the peak intensity appearing in the region of 2θ = 38 to 39 degrees in the powder X-ray diffraction spectrum of the phosphor is Ix, and the peak intensity appearing in the region of 2θ = 37 to 38 degrees is Iy, the relative intensity of Ix to Iy Ix/Iy is 0.140 or less.
Re _x MA _a MB _b MC _c N _d X _e [1]
(in the above formula [1],
MA contains one or more elements selected from the group consisting of Sr, Ca, 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; 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 each satisfy the following formula.
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> The light-emitting device according to <1>, wherein 80 mol % or more of MA in formula [1] is at least one element selected from the group consisting of Sr, Ca and Ba.

<3> The light-emitting device according to any one of <1> to <2>, wherein in formula [1], 80 mol % or more of MB is Li.

<4> The light-emitting device according to any one of <1> to <3>, wherein in formula [1], 80 mol % or more of MC is composed of one or more elements selected from the group consisting of Al and Ga.

<5> The light-emitting device according to any one of <1> to <4>, wherein in formula [1], 80 mol % or more of MC is Al.

<6> The light-emitting device according to any one of <1> to <5>, wherein in formula [1], 80 mol % or more of Re is Eu.

<7> The light-emitting device according to any one of <1> to <6>, wherein the space group of the crystal phase having the composition represented by formula [1] is P-1.

<8> The light-emitting device according to any one of <1> to <7>, wherein the phosphor has an emission peak wavelength in the range of 620 nm or more and 660 nm or less in the emission spectrum.

<9> The light-emitting device according to any one of <1> to <8>, wherein the phosphor has an emission spectrum with a full width at half maximum (FWHM) of 70 nm or less.

<10> The light-emitting device according to any one of <1> to <9>, further comprising a yellow phosphor and/or a green phosphor.

<11> The description in <10>, wherein the yellow phosphor and/or the green phosphor includes any one or more of a garnet phosphor, a silicate phosphor, a nitride phosphor, and an oxynitride phosphor. luminous device.

<12> A first luminous body and a second luminous body that emits visible light by being irradiated with light from the first luminous body, wherein the second luminous body is represented by the above formula [1] The light-emitting device according to any one of <1> to <11>, comprising a phosphor containing a crystal phase having a composition.

<13> A lighting device comprising the light emitting device according to <12> as a light source.

<14> An image display device comprising the light emitting device according to <12> as a light source.

<15> A vehicle indicator light comprising the light emitting device according to <12> as a light source.

<16> A light-emitting device comprising a phosphor,
The phosphor contains a crystal phase having a composition represented by the following formula [2], and
When the peak intensity appearing in the region of 2θ = 38 to 39 degrees in the powder X-ray diffraction spectrum of the phosphor is Ix, and the peak intensity appearing in the region of 2θ = 37 to 38 degrees is Iy, the relative intensity of Ix to Iy Ix/Iy is 0.140 or less.
Re _x MA _a MB _b (MC′ _1-y MD _y ) _c N _d X _e [2]
(in the above formula [2],
MA contains one or more elements selected from the group consisting of Sr, Ca, Ba, Na, K, Y, Gd, and La,
MB contains one or more elements selected from the group consisting of Li, Mg, and Zn,
MC' is Al;
MD contains one or more elements selected from the group consisting of Si, Ga, In, and Sc,
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 each satisfy the following formula.
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)

<17> The light-emitting device according to <16>, wherein 80 mol % or more of MA in formula [2] is at least one element selected from the group consisting of Sr, Ca and Ba.

<18> The light-emitting device according to any one of <16> to <17>, wherein in the formula [2], 80 mol % or more of MB is Li.

<19> The light-emitting device according to any one of <16> to <18>, wherein Ga accounts for 80 mol % or more of MD in formula [2].

<20> The light-emitting device according to any one of <16> to <19>, wherein in formula [2], 80 mol % or more of Re is Eu.

<21> The light-emitting device according to any one of <16> to <20>, wherein the space group of the crystal phase having the composition represented by formula [2] is P-1.

<22> The light-emitting device according to any one of <16> to <21>, wherein the phosphor has an emission peak wavelength in the range of 620 nm or more and 660 nm or less in the emission spectrum.

<23> The light-emitting device according to any one of <16> to <22>, wherein the phosphor has an emission spectrum with a full width at half maximum (FWHM) of 70 nm or less.

<24> The light-emitting device according to any one of <16> to <23>, further comprising a yellow phosphor and/or a green phosphor.

<25> The description in <24>, wherein the yellow phosphor and/or the green phosphor include any one or more of a garnet phosphor, a silicate phosphor, a nitride phosphor, and an oxynitride phosphor. luminous device.

<26> A first light-emitting body and a second light-emitting body that emits visible light when irradiated with light from the first light-emitting body, wherein the second light-emitting body is represented by the above formula [2] The light-emitting device according to any one of <16> to <25>, comprising a phosphor containing a crystal phase having a composition.

<27> A lighting device comprising the light emitting device according to <26> as a light source.

<28> An image display device comprising the light emitting device according to <26> as a light source.

<29> A vehicle indicator light comprising the light emitting device according to <26> as a light source.

According to the present invention, it is possible to provide a light-emitting device, a lighting device, an image display device, and a vehicle indicator lamp that have good color rendering properties or color reproducibility and good conversion efficiency.

4 shows XRD patterns of Sample 5 and Comparative Sample 1 in Example. 4 shows emission spectra of Sample 5 and Comparative Sample 1 in Example. It is the XRD patterns of samples 3 and 7 to 11 in the example. 3 shows emission spectra of Samples 3, 5, 7 to 11 in Examples and Comparative Sample 1. FIG. 2 shows normalized emission spectra of Samples 3, 7, 11 and Reference Sample 1 in Examples. The reflectance spectrum of each sample in the example is shown. The reflectance spectrum of each sample in the example is shown. The reflectance spectrum of each sample in the example is shown. FIG. 4 is a diagram showing the relationship between the minimum value of reflectance and emission intensity in a specific wavelength band of each sample, and the relationship between the difference or ratio between reflectances and emission intensity in a plurality of specific wavelength bands in an example. 4 is a chart showing light emission characteristics of a light emitting device simulated in Examples.

Hereinafter, the present invention will be described with reference to embodiments and examples, but the present invention is not limited to the following embodiments and examples, and can be arbitrarily modified without departing from the scope of the present invention. can be implemented.

In this specification, the numerical range represented by "-" means a range including the numerical values before and after "-" as lower and upper limits. In addition, in the compositional formulas of the phosphors in this specification, each compositional formula is delimited by a comma (,). In addition, when a plurality of elements are listed separated by commas (,), it indicates that one or more of the listed elements may be contained in any combination and composition. For example, the composition formula “(Ca, Sr, Ba) Al ₂ O ₄ :Eu” is composed of “CaAl ₂ O ₄ :Eu”, “SrAl ₂ O ₄ :Eu” and “BaAl ₂ O ₄ :Eu”. and "Ca _1-x Sr _x Al ₂ O ₄ :Eu", "Sr _1-x Ba _x Al ₂ O ₄ : Eu", and "Ca _1-x Ba _x Al ₂ O ₄ : Eu", "Ca _1-xy Sr _{x Bay} Al ₂ O ₄ :Eu" (where 0<x<1, 0<y<1, 0<x+y<1) and all inclusive shall be as shown in

<Phosphor>
In one embodiment of the present invention, a light-emitting device comprising a phosphor, the phosphor includes a crystal phase having a composition represented by the following formula [1], and powder X-ray diffraction spectrum of the phosphor When the peak intensity appearing in the region of 2θ = 38 to 39 degrees is Ix, and the peak intensity appearing in the region of 2θ = 37 to 38 degrees is Iy, Ix/Iy, which is the relative intensity of Ix to Iy, is 0.140 or less. (hereinafter sometimes referred to as "the phosphor of the present embodiment").
Re _x MA _a MB _b MC _c N _d X _e [1]
(in the above formula [1],
MA contains one or more elements selected from the group consisting of Sr, Ca, 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,
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 each satisfy the following formula.
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)

In formula [1], Re includes 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. It contains one or more elements selected from the group, preferably contains Eu, more preferably 80 mol % or more of Re is Eu, and still more preferably Re is Eu.

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

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 of MB % or more is Li, more preferably MB is Li.

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 Al , Ga or Si, more preferably one or more elements selected from the group consisting of Al and Ga, more preferably 80 mol% or more of MC contains one or more elements selected from the group consisting of Al and Ga Especially preferably 90 mol% or more of MC consists of one or more elements selected from the group consisting of Al and Ga, most preferably MC consists of one or more elements selected from the group consisting of Al and Ga consists of

In one embodiment, 80 mol % or more of the MC is Al, preferably 90 mol % or more, more preferably 95 mol % or more, even more preferably 98 mol % or more. Since 80 mol % or more of MC is Al, it is possible to provide a red phosphor that exhibits an emission peak wavelength and emission intensity comparable to those of existing red phosphors such as S/CASN and has a small half-value width. By using such a red phosphor, it is possible to provide a light-emitting device having excellent color rendering properties or color reproducibility while maintaining conversion efficiency (Lm/W) comparable to or higher than conventional ones. can.

In formula [1], N represents nitrogen. A portion of N may be substituted with oxygen (O) in order to maintain the charge balance of the entire crystal phase or adjust the emission peak wavelength.

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 certain embodiments, N may be partially substituted with the halogen element represented by X, from the viewpoint of stabilizing the crystal structure and maintaining the charge balance of the phosphor as a whole.

The above formula [1] includes the case where components other than those specified are contained in a trace amount unavoidably, unintentionally, or due to trace addition components or the like.
Ingredients other than those specified include an element whose element number is one different from that of the intentionally added element, a homologous element of the intentionally added element, an intentionally added rare earth element and another rare earth element, and a halogen in the Re raw material. Examples include halogen elements when using a compound, and other elements that can be generally contained as impurities in various raw materials.
Examples of the unavoidable or unintentional inclusion of components other than those specified include, for example, those derived from impurities in raw materials, and those introduced in manufacturing processes such as pulverization and synthesis steps. In addition, a reaction aid, a Re raw material, and the like can be cited as the trace addition component.

In the above formula [1], a, b, c, d, e and x represent the molar contents of MA, MB, MC, N, X and Re contained in the phosphor, respectively.

The value of a is usually 0.6 or more, preferably 0.7 or more, more preferably 0.8 or more, still more preferably 0.9 or more, and usually 1.4 or less, preferably 1.3 or less, or more It is preferably 1.2 or less, more preferably 1.1 or less.
The value of b is usually 0.6 or more, preferably 0.7 or more, more preferably 0.8 or more, still more preferably 0.9 or more, and usually 1.4 or less, preferably 1.3 or less, or more It is preferably 1.2 or less, more preferably 1.1 or less.
The value of c is usually 2.1 or more, preferably 2.4 or more, more preferably 2.6 or more, still more preferably 2.8 or more, and usually 3.9 or less, preferably 3.6 or less, or more It is preferably 3.4 or less, more preferably 3.2 or less.
The value of d is usually 3 or more, preferably 3.2 or more, more preferably 3.4 or more, still more preferably 3.6 or more, still more preferably 3.8 or more, and usually 5 or less, preferably 4 0.8 or less, more preferably 4.6 or less, even more preferably 4.4 or less, and even more preferably 4.2 or less.
The value of e is not particularly limited, but is usually 0 or more and usually 0.2 or less, preferably 0.1 or less, more preferably 0.06 or less, still more preferably 0.04 or less, still more preferably 0.04 or less. 02 or less.
The value of x is usually greater than 0, preferably 0.0001 or more, more preferably 0.001 or more, and usually 0.2 or less, preferably 0.15 or less, more preferably 0.12 or less. , more preferably 0.1 or less, and still more preferably 0.08 or less. When the value of x is at least the above lower limit or is greater than the above lower limit, a phosphor with a good emission intensity can be obtained. It is possible to obtain a phosphor that is easily incorporated and functions as a luminescence center.

The crystal structure is stabilized when b, c, d, and e are within the above ranges. Also, the values of d and e can be appropriately adjusted for the purpose of balancing the charge of the entire phosphor.

Further, when the value of a is within the above range, the crystal structure is stabilized, and a phosphor with less heterogeneous phases can be obtained.

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. .
When the value of b+c is within the above range, the crystal structure is stabilized.

The value of d+e is usually 3.2 or more, preferably 3.4 or more, more preferably 3.7 or more, and usually 5.0 or less, preferably 4.6 or less, more preferably 4.3 or less. .
When the value of d+e is within the above range, the crystal structure is stabilized.

It is preferable that both values are within the above-described ranges, because the emission peak wavelength and the half-value width in the emission spectrum of the obtained phosphor are favorable.

The method for specifying the elemental composition of the phosphor is not particularly limited, and can be determined by a conventional method, such as GD-MS, ICP spectroscopic analysis, or energy dispersive X-ray spectrometry (EDX). .

In one embodiment of the present invention, a light-emitting device comprising a phosphor, the phosphor includes a crystal phase having a composition represented by the following formula [2], and powder X-ray diffraction spectrum of the phosphor When the peak intensity appearing in the region of 2θ = 38 to 39 degrees is Ix, and the peak intensity appearing in the region of 2θ = 37 to 38 degrees is Iy, Ix/Iy, which is the relative intensity of Ix to Iy, is 0.140 or less. is a light-emitting device.
Re _x MA _a MB _b (MC′ _1-y MD _y ) _c N _d X _e [2]
(in the above formula [2],
MA contains one or more elements selected from the group consisting of Sr, Ca, Ba, Na, K, Y, Gd, and La,
MB contains one or more elements selected from the group consisting of Li, Mg, and Zn,
MC' is Al;
MD contains one or more elements selected from the group consisting of Si, Ga, In, and Sc,
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 each satisfy the following formula.
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 types and configurations of the MA, MB, N, X, and Re elements in the formula [2] can be the same as in the formula [1].
The MC' is Al.
The MD contains one or more elements selected from the group consisting of Si, Ga, In, and Sc, and preferably one or more elements selected from the group consisting of Ga and Si from the viewpoint of crystal stability and emission intensity. element, more preferably Ga.

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

The value of y in the formula [2] is greater than 0.0, usually 0.01 or more, preferably 0.015 or more, more preferably 0.03 or more, still more preferably 0.05 or more, particularly preferably 0 0.10 or more, and usually 1.00 or less, preferably 0.70 or less, more preferably 0.50 or less, still more preferably 0.30 or less, and particularly preferably 0.25 or less.

When the value of y is equal to or greater than the above lower limit, the emission peak wavelength of the phosphor is shortened. By using such a phosphor, a light-emitting device with good color rendering or color reproducibility can be provided. Further, when the value of y is equal to or less than the above upper limit, it is possible to obtain a phosphor with good emission intensity, and by using such a phosphor, it is possible to provide a light emitting device with good conversion efficiency. The value of y can be appropriately adjusted in order to obtain a preferable emission intensity and emission peak wavelength depending on the purpose.

[Particle size of crystal phase]
The grain size of the crystal phase of the phosphor is usually 2 μm or more and 35 μm or less in terms of volume-based average grain size. , preferably 30 μm or less, more preferably 25 μm or less, even more preferably 20 μm, particularly preferably 15 μm.
When the volume-based average particle diameter is at least the above lower limit, the crystalline phase is preferable from the viewpoint of light emission characteristics exhibited in the LED package, and when it is at most the above upper limit, the crystalline phase can avoid clogging of the nozzle in the manufacturing process of the LED package. preferred from
The volume-based average particle diameter of the crystalline phase of the phosphor can be measured with a laser granulometer. Here, the volume-based average particle size is the volume-based relative particle size when the sample is measured and the particle size distribution (cumulative distribution) is obtained using a particle size distribution measuring device that uses the laser diffraction/scattering method as the measurement principle. Defined as the particle size at which the volume reaches 50% (d ₅₀ ).

{Physical properties of phosphor, etc.}
[Space group]
More preferably, the crystal system (space group) in the phosphor is P-1. The space group in the phosphor is not particularly limited as long as the average structure considered statistically in the range that can be distinguished by powder X-ray diffraction or single crystal X-ray diffraction shows a repeating period of the above length, It preferably belongs to No. 2 based on "International Tables for Crystallography (Third, revised edition), Volume A SPACE-GROUP SYMMETRY".
With the above space group, the full width at half maximum (FWHM) in the emission spectrum becomes small, and a phosphor with good luminous efficiency can be obtained.
Here, the space group can be obtained by a conventional method, for example, by electron beam diffraction, X-ray diffraction structure analysis using powder or single crystal, neutron beam diffraction structure analysis, or the like.

In the powder X-ray diffraction spectrum of the phosphor, the intensity of the peak appearing in the region of 2θ = 38 to 39 degrees is Ix, and the intensity of the peak appearing in the region of 2θ = 37 to 38 degrees is Iy. Ix/Iy, which is the relative intensity of Ix, is preferably 0.140 or less, more preferably 0.120 or less, still more preferably 0.110 or less, still more preferably 0.080 or less, and particularly preferably 0.080 or less. 060 or less, particularly preferably 0.040 or less, and usually 0 or more, but the smaller the better.

The peak in the region of 2θ = 37 to 38 degrees is one of the characteristic peaks observed when the crystal system (space group) is P-1. A phosphor with a high phase purity of 1 can be obtained. When Ix/Iy is equal to or less than the above upper limit, the phosphor has a high phase purity and a small full width at half maximum (FWHM), so that the luminous efficiency of the light emitting device is improved.

[Reflectance in specific wavelength band]
In one embodiment, the phosphor has a minimum reflectance (hereinafter sometimes referred to as A%) of 20% or more in a predetermined wavelength region, and the predetermined wavelength region is the It is the region from the emission peak wavelength of the phosphor to 800 nm. The minimum value of the reflectance is preferably 25% or more, more preferably 30% or more, still more preferably 35% or more, particularly preferably 50% or more, particularly preferably 60% or more, and extremely preferably 70% or more. .
The upper limit of the reflectance is not particularly limited, and the higher the better, but it is usually 100% or less. A red phosphor with excellent emission intensity or quantum efficiency can be provided by having a reflectance of at least the above lower limit, and a light-emitting device with good conversion efficiency can be provided by using such a phosphor.

In one embodiment, the predetermined wavelength range related to the reflectance A (%) of the phosphor is the wavelength range from the emission peak wavelength to 800 nm. The reason for selecting the above wavelength band in defining the reflectance of the phosphor will be described below.

The inventors obtained the following findings;
1. Some of the phosphors having a crystal phase represented by the formula [1] or [2] are not excited, and when the body color of the powdered phosphor is visually confirmed under natural light, appear grayish. In this specification, this condition is sometimes expressed as "dull" or "dull".
2. Among the phosphors having a crystalline phase represented by the above formula [1] or [2], the phosphors with less "dullness" are excellent in emission intensity or quantum efficiency, and by using such phosphors, conversion A light-emitting device with good efficiency can be provided.
3. Among the phosphors having a crystalline phase represented by the above formula [1] or [2], phosphors with little "dullness" tend to have high reflectance as a whole, especially light in a specific wavelength band or by an index including the reflectance for light in the specific wavelength band.

Said specific wavelength band is preferably a wavelength belonging to a wavelength band different from the normal excitation spectral region.
From one point of view, the specific wavelength band is preferably a wavelength in a wavelength region equal to or higher than the emission peak wavelength and equal to or lower than the long-wave end of the emission spectrum.
In a specific embodiment, the specific wavelength band can generally be selected from wavelengths equal to or greater than the emission peak wavelength and 900 nm or less, and the upper limit is preferably 800 nm or less, more preferably 780 nm or less. The wavelength region can take any wavelength band from the lower limit to the upper limit, if necessary.

The excitation spectral region of the phosphor is mainly from 300 nm to 520 nm, but absorption may also occur around 600 nm. Here, when the reflectance of the wavelength in the excitation spectrum region is measured, the incident light is absorbed by the phosphor, and the reflectance is affected by the absorptance. It is not suitable for specifying the body color of phosphors.

From the above point of view, in defining the phosphor suitable for use in the light-emitting device or the like according to the present invention by the reflectance, the reflectance of the wavelength band less affected by the absorption of the phosphor or the reflectance is related. The body color of the phosphor can be defined accurately by using the index to measure.

In one embodiment, the phosphor has a reflectance A ( %) is preferably -1.5 points or more, more preferably 0.0 points or more, still more preferably 3.0 points or more, and particularly preferably 4.0 points or more. is. Although the upper limit of [A - B] is not particularly limited, it is usually 50.0 points or less.
When the value of [AB] is equal to or higher than the above lower limit, a phosphor with high emission intensity can be obtained, and by using such a phosphor, a light emitting device with high conversion efficiency can be provided.

It is not clear why a phosphor with a high emission intensity can be obtained when the value of [AB] is high. Since there is no light absorption by the Re element (activator element), it is considered desirable that the absorptance is low and the reflectance is high. Since the higher the absorptance, the lower the reflectance, the higher the value of [A−B], the higher the absorption of light that contributes to the light emission by the activator element, and thus the higher the emission intensity. There is a possibility that it will be In this case, since the wavelength regions related to the reflectances A (%) and B (%) are continuous, there is a high possibility that A (%) and B (%) will have relatively close values. It is considered preferable to define by comparing A (%) and B (%) instead of B (%) alone.

In one embodiment, when the phosphor has a minimum value of reflectance in the wavelength range of 400 nm to 550 nm as C%, the difference [AC] from the reflectance A (%) is preferably is 0.0 points or more, more preferably 2.0 points or more, still more preferably 5.0 points or more, particularly preferably 10.0 points or more, particularly preferably 15.0 points or more, and extremely preferably 20.0 points or more. 0 points or more. Although the upper limit of [A- C ] is not particularly limited, it is usually 50.0 points or less.
When the value of [AC] is equal to or higher than the above lower limit, a phosphor with high emission intensity can be obtained, and by using such a phosphor, a light emitting device with high conversion efficiency can be provided.

In one embodiment, the phosphor preferably has a ratio C/A of 1 to the reflectance A (%), where C% is the minimum value of the reflectance in the wavelength region from 400 nm to 550 nm. 0.05 or less, more preferably 1.00 or less, still more preferably 0.90 or less, particularly preferably 0.80 or less, and most preferably 0.75 or less. Although the lower limit of C/A is not particularly limited, it is usually 0.0 or more.
When the value of C/A is equal to or less than the above upper limit, a phosphor with high emission intensity can be obtained, and by using such a phosphor, a light emitting device with high conversion efficiency can be provided.

It is not clear why a phosphor with a high emission intensity can be obtained when the value of [AC] is large or the value of C/A is small. Since there is not much absorption of light that contributes to light emission in the wavelength band of C, it is considered desirable that the absorptance is low and the reflectance is high. is a wavelength band that is often used, and the higher the absorptance, the lower the reflectance, so a phosphor with a low reflectance C (%) has a high absorption of excitation light that contributes to light emission. can be obtained.
As can be seen in the examples described later, phosphors with large absorption that do not contribute to light emission due to impurities tend to have a general decrease in reflectance in a wide wavelength band. When specifying, it is considered preferable to define by comparing A (%) and C (%) instead of C (%) alone.

[Characteristics of emission spectrum]
The phosphor is excited by irradiation with light having an appropriate wavelength, and emits red light exhibiting a good emission peak wavelength and full width at half maximum (FWHM) in the emission spectrum. The emission spectrum and the excitation wavelength, emission peak wavelength and half width (FWHM) for the measurement are described below.

(excitation wavelength)
The phosphor usually has a wavelength of 270 nm or more, preferably 300 nm or more, more preferably 320 nm or more, still more preferably 350 nm or more, particularly preferably 400 nm or more, and usually 500 nm or less, preferably 480 nm or less, more preferably 460 nm or less. It has an excitation peak in the range. That is, they are excited by light in the near-ultraviolet to blue region.
The shape of the emission spectrum and the description of the emission peak wavelength and half width below can be applied regardless of the excitation wavelength, but from the viewpoint of improving the quantum efficiency, light having a wavelength in the above range with good absorption and excitation efficiency is preferably irradiated.

(Emission peak wavelength)
The phosphor generally has a peak wavelength of 620 nm or more, preferably 625 nm or more, more preferably 630 nm or more in the emission spectrum. Also, the peak wavelength in this emission spectrum is usually 670 nm or less, preferably 660 nm or less, more preferably 655 nm or less.

When the peak wavelength in the emission spectrum of the phosphor is within the above range, the luminescent color is good red, and by using this, a light emitting device with good color rendering or color reproducibility can be provided. Further, by setting the peak wavelength in the emission spectrum of the phosphor to the above upper limit or less, it is possible to provide a light-emitting device with good red luminosity and good lumen equivalent lm/W.

In the light-emitting device, phosphors with different peak wavelengths can be used depending on the application. Although the method of obtaining phosphors with different peak wavelengths is not particularly limited, one method can be realized by changing the composition of the MC elements.

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

In another embodiment, by providing a phosphor containing a crystal phase having a composition represented by the above formula [2] using MC' (Al) and MD elements, fluorescence with a relatively short emission peak wavelength you can get a body In this embodiment, the emission peak wavelength is usually 615 nm or more, preferably 620 nm or more, more preferably 625 nm or more, still more preferably 630 nm or more, and usually 660 nm or less, preferably 645 nm or less, more preferably 640 nm or less. . By providing a phosphor having an emission wavelength within the above range, it is possible to obtain a light-emitting device with good color rendering properties or color reproducibility.

(Half width of emission spectrum)
The phosphor has an emission peak half width of usually 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 usually 10 nm or more. .
Since the half width of the emission peak is within the above range, the color reproduction range of the image display device can be widened without lowering the color purity when used in an image display device such as a liquid crystal display.
In addition, since the emission peak wavelength and the half-value width are equal to or less than the above upper limits, it is possible to provide a phosphor with relatively high visibility in the emission wavelength region. An expensive light-emitting device can be provided.

For example, a GaN-based LED can be used to excite the phosphor with light having a wavelength of about 450 nm. In addition, the measurement of the emission spectrum of the phosphor and the calculation of its emission peak wavelength, peak relative intensity and peak half-value width are performed using a light source having an emission wavelength of 300 to 400 nm such as a commercially available xenon lamp and general light. It can be performed using a commercially available spectrometer such as a fluorometer equipped with a detector.

<Manufacturing method of phosphor>
The phosphor can be synthesized by mixing raw materials of each element constituting the phosphor so that the ratio of each element satisfies the above formula [1] or [2] and heating.

[material]
Raw materials for each element (MA, MB, MC, MC′, MD, Re) are not particularly limited, but for example, each element alone, oxide, nitride, hydroxide, chloride, fluoride, halide, sulfuric acid, etc. salts, inorganic salts such as nitrates and phosphates, and organic acid salts such as acetates; In addition, a compound containing two or more of the above element groups may be used. Also, each compound may be a hydrate or the like.
In the examples described later, Sr ₃ N ₂ , Li ₃ N, AlN, GaN, and EuF ₃ or Eu ₂ O ₃ were used as starting materials.

The method of obtaining each raw material is not particularly limited, and commercially available products can be purchased and used.
The purity of each raw material is not particularly limited, but from the viewpoint of making the element ratio strict and avoiding the appearance of heterogeneous phases due to impurities, the higher the purity, the more preferable it is, usually 90 mol% or more, preferably 95 mol% or more, and more preferably. is 97 mol % or more, more preferably 99 mol % or more, and although the upper limit is not particularly limited, it is usually 100 mol % or less, and may contain unavoidably mixed impurities.
In all of the examples described later, raw materials with a purity of 95 mol % or more were used.

Elemental oxygen (O), elemental nitrogen (N), and elemental halogen (X) can be supplied by using oxides, nitrides, halides, and the like as raw materials for the above elements. Alternatively, it can be included as appropriate by creating a nitrogen-containing atmosphere.

[Mixing process]
A method of mixing the raw materials is not particularly limited, and a conventional method can be used. For example, phosphor raw materials are weighed so as to obtain a desired composition, and sufficiently mixed using a ball mill or the like to obtain a phosphor raw material mixture. The mixing method is not particularly limited, but specific examples include the following methods (a) and (b).
(a) Dry pulverizers such as hammer mills, roll mills, ball mills and jet mills, or pulverization using a mortar and pestle, and mixers such as ribbon blenders, V-type blenders and Henschel mixers, or mortar and pestle A dry mixing method of pulverizing and mixing the phosphor raw materials described above.
(b) A solvent such as water or a dispersion medium is added to the phosphor raw material described above, and the mixture is mixed using, for example, a grinder, mortar and pestle, or an evaporating dish and a stirring rod to form a solution or slurry, A wet mixing method in which the material is dried by spray drying, heat drying, or natural drying.

The phosphor raw materials may be mixed by either the dry mixing method or the wet mixing method, but a dry mixing method or a wet mixing method using a water-insoluble solvent is preferable in order to avoid contamination of the phosphor raw materials by moisture.
The method (a) was adopted in the examples described later.

[Heating process]
In the heating step, for example, the phosphor raw material mixture obtained in the mixing step is placed in a crucible, and subsequently heated to a temperature of 500°C to 1200°C, preferably 600°C to 1000°C, more preferably 700°C to 950°C. to heat.

The material of the crucible is preferably one that does not react with the phosphor raw material or reactant. Ceramics such as alumina, quartz, boron nitride, silicon carbide, and silicon nitride, metals such as nickel, platinum, molybdenum, tungsten, tantalum, niobium, iridium, and rhodium. , or alloys containing them as main components.
Note that crucibles made of boron nitride were used in the examples described later.

Heating is preferably performed in an inert atmosphere, and a gas containing nitrogen, argon, helium, or the like as a main component can be used.
In addition, in the examples described later, heating was performed in a nitrogen atmosphere.

In the heating step, the heating is carried out in the above temperature range, usually for 10 minutes to 200 hours, preferably 1 hour to 100 hours, more preferably 3 to 50 hours. In addition, the main heating step may be performed once or may be performed in multiple steps. As an embodiment performed in multiple stages, an embodiment in which annealing is performed by heating under pressure to repair defects, primary heating to obtain primary particles or intermediates, secondary heating to obtain secondary particles or final products and the like.
Thereby, the phosphor of the present embodiment is obtained.

[Sorting of Phosphor]
Although the phosphor according to the present embodiment can be generally obtained by the above method, the characteristics of the phosphor vary depending on minute differences such as fine deposits in the reaction vessel, impurities in each reagent , lot of each raw material reagent, etc. In addition to cases where the range of requirements is slightly deviated, substances with large and small particle sizes, phosphors with different reflectance, etc. may be mixed.
For this reason, for example, phosphors are manufactured by changing some conditions, the obtained phosphors are sorted by classification, washing, etc., and the reflectance, XRD spectrum, etc. are analyzed, and phosphors satisfying the requirements of the present invention are selected. can reliably obtain the phosphor of the present embodiment.

<Light emitting device>
In one embodiment of the present invention, a light-emitting device including a first light-emitting body (excitation light source) and a second light-emitting body that emits visible light when irradiated with light from the first light-emitting body, The light-emitting device includes, as a second light-emitting body, the phosphor of the present embodiment including the crystal phase having the composition represented by the above formula [1] or [2]. Here, the second luminous body may be used singly, or two or more of them may be used in any combination and ratio.

The light-emitting device in this embodiment includes, as the second light-emitting body, the phosphor of this embodiment containing a crystal phase having a composition represented by the above formula [1] or [2], and further, an excitation light source Phosphors that emit fluorescence in the yellow, green, or red region (orange to red) under irradiation with light from a light source can be used. Specifically, when constructing a light-emitting device, the yellow phosphor preferably has an emission peak in the wavelength range of 550 nm or more and 600 nm or less, and the green phosphor preferably has an emission peak in the wavelength range of 500 nm or more and 560 nm or less. Those having an emission peak are preferred. In addition, the orange to red phosphor is usually 615 nm or more, preferably 620 nm or more, more preferably 625 nm or more, still more preferably 630 nm or more, and usually 660 nm or less, preferably 650 nm or less, more preferably 645 nm or less, more preferably 640 nm or less. It has emission peaks in the following wavelength ranges.
A light-emitting device exhibiting excellent color reproducibility can be provided by appropriately combining phosphors in the above wavelength band. As for the excitation source, one having an emission peak in a wavelength range of less than 420 nm may be used.

Hereinafter, as the red phosphor, the phosphor of the present embodiment, which has an emission peak in the wavelength range of 620 nm or more and 660 nm or less and contains a crystal phase having a composition represented by the above formula [1] or [2], and Modes of the light-emitting device in which the first light-emitting body has an emission peak in the wavelength range of 300 nm or more and 460 nm or less will be described, but the present embodiment is not limited to these.

In the above case, the light-emitting device of this embodiment can have, for example, the following modes (A), (B), or (C).
(A) As the first luminous body, one having an emission peak in the wavelength range of 300 nm or more and 460 nm or less is used, and as the second luminous body, at least one kind of fluorescence having an emission peak in the wavelength range of 550 nm or more and 600 nm or less (yellow phosphor) and the phosphor of the present embodiment containing a crystal phase having the composition represented by the above [1] or [2].
(B) As the first luminous body, one having an emission peak in a wavelength range of 300 nm or more and 460 nm or less is used, and as the second luminous body, at least one kind of fluorescence having an emission peak in a wavelength range of 500 nm or more and 560 nm or less and a crystal phase having the composition represented by [1] or [2] above.
(C) As the first luminous body, one having an emission peak in a wavelength range of 300 nm or more and 460 nm or less is used, and as the second luminous body, at least one kind of fluorescence having an emission peak in a wavelength range of 550 nm or more and 600 nm or less (yellow phosphor), at least one phosphor (green phosphor) having an emission peak in the wavelength range of 500 nm or more and 560 nm or less, and a crystal phase having the composition represented by [1] or [2] above. A mode using the phosphor of the present embodiment containing.

Commercially available green or yellow phosphors can be used as the green or yellow phosphor in the above embodiment, and for example, garnet-based phosphors, silicate-based phosphors, nitride phosphors, oxynitride phosphors, and the like can be used.

(yellow phosphor)
Garnet-based phosphors that can be used for the yellow phosphor include, for example, (Y, Gd, Lu, Tb, La) ₃ (Al, Ga) ₅ O ₁₂ : (Ce, Eu, Nd), silicate-based phosphors For example, (Ba, Sr, Ca, Mg) ₂ SiO ₄ : (Eu, Ce), and for the nitride phosphor and oxynitride phosphor, for example, (Ba, Ca, Mg)Si ₂ O ₂ N ₂ : Eu (SION phosphor), (Li, Ca) ₂ (Si, Al) ₁₂ (O, N) ₁₆ : (Ce, Eu) (α-sialon phosphor), (Ca, Sr) AlSi ₄ (O, N) ₇ : (Ce, Eu) (1147 phosphor), (La, Ca, Y, Gd) ₃ (Al, Si) ₆ N ₁₁ : (Ce, Eu) (LSN phosphor), etc. be done.
These may be used individually by 1 type, and may be used in combination of 2 or more type.
Among the above phosphors, the yellow phosphor is preferably a garnet phosphor, and most preferably a YAG phosphor represented by Y ₃ Al ₅ O ₁₂ :Ce.

(green phosphor)
Examples of garnet-based phosphors that can be used as green phosphors include (Y, Gd, Lu, Tb, La) ₃ (Al, Ga) ₅ O ₁₂ : (Ce, Eu, Nd), Ca ₃ (Sc , Mg) _{2 Si 3} O ₁₂ : ₍ Ce, Eu) (CSMS phosphor). , Sr, Ca, Mg) ₂ SiO ₄ : (Ce, Eu) (BSS phosphor), and oxide phosphors such as (Ca, Sr, Ba, Mg) (Sc, Zn) ₂ O ₄ : ( Ce, Eu) (CASO phosphor), nitride phosphors and oxynitride phosphors include, for example, (Ba, Sr, Ca, Mg) Si ₂ O ₂ N ₂ : (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) ₆ O ₁₂ N ₂ : (Eu, Ce) (BSON phosphor), aluminate phosphor, for example, (Ba, Sr, Ca, Mg) ₂ Al ₁₀ O ₁₇ : (Eu, Mn) (GBAM phosphor), etc. is mentioned.
These may be used individually by 1 type, and may be used in combination of 2 or more type.

(red phosphor)
As the red phosphor, the phosphor of the present embodiment containing the crystal phase having the composition represented by the formula [1] or [2] is used. In addition to the phosphor of the present embodiment, for example, Mn-activated Other orange to red phosphors can be used, such as fluoride phosphors, garnet-based phosphors, sulfide phosphors, nanoparticle phosphors, nitride phosphors, oxynitride phosphors, and the like. As other orange to red phosphors, for example, the following phosphors can be used.
Examples of Mn-activated fluoride phosphors include K ₂ (Si, Ti) F ₆ :Mn, K ₂ Si _1-x Na _x Al _x F ₆ : Mn (0<x<1) (collectively, KSF fluorescence (Sr,Ca)S:Eu (CAS phosphor) and La ₂ O ₂ S:Eu (LOS phosphor) as sulfide phosphors, and as garnet-based phosphors (Y , Lu, Gd, Tb) ₃ Mg ₂ AlSi ₂ O ₁₂ :Ce, nanoparticles such as CdSe, and nitride or oxynitride phosphors such as (Sr, Ca)AlSiN ₃ :Eu(S /CASN phosphor), (CaAlSiN ₃ ) _1-x ·(SiO ₂ N ₂ ) _x : Eu (CASON phosphor), (La, Ca) ₃ (Al, Si) ₆ N ₁₁ : Eu (LSN phosphor) , (Ca, Sr, Ba) ₂ Si ₅ (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)Al ₃ N ₄ :Eu (the above x is 0<x<1) and the like.
These may be used individually by 1 type, and may be used in combination of 2 or more type.

[Structure of Light Emitting Device]
The light-emitting device according to this embodiment has a first light-emitting body (excitation light source), and a crystal phase having a composition represented by at least the above formula [1] or [2] as a second light-emitting body. It is possible to use the phosphor of the present embodiment containing the phosphor, the configuration is not limited, and any known device configuration can be used.
Embodiments of the device configuration and the light-emitting device include, for example, those described in Japanese Patent Application Laid-Open No. 2007-291352. Other forms of the light-emitting device include shell-type, cup-type, chip-on-board, remote phosphor, and the like.

{Use of light-emitting device}
The application of the light-emitting device is not particularly limited, and it can be used in various fields where ordinary light-emitting devices are used. can be used for
In addition, since it includes a red phosphor having a favorable emission wavelength, it can be used for a red vehicle indicator lamp or a white vehicle indicator lamp containing the red color.

[Lighting device]
In one embodiment, the present invention can be a lighting device including the light emitting device as a light source.
When the light-emitting device is applied to a lighting device, the specific configuration of the lighting device is not limited, and the light-emitting device as described above may be used by appropriately incorporating it into a known lighting device. For example, a surface-emitting lighting device in which a large number of light-emitting devices are arranged on the bottom surface of a holding case can be used.

[Image display device]
In one embodiment, the present invention can be an image display device including the light emitting device as a light source.
When the light emitting device is used as a light source of an image display device, the specific configuration of the image display device is not limited, but it is preferably used together with a color filter. For example, when the image display device is a color image display device using a color liquid crystal display element, the light emitting device is used as a backlight, and an optical shutter using liquid crystal and a color filter having red, green, and blue pixels are used. can be combined to form an image display device.

[Vehicle indicator light]
In one embodiment, the present invention can be a vehicle indicator lamp including the light emitting device.
The light-emitting device used in the vehicle indicator light is preferably a light-emitting device that emits white light in certain embodiments. A light-emitting device that emits white light has a deviation duv of -0.0200 to 0.0200 from the blackbody radiation locus of light color and a color temperature of 5000 K or more and 30000 K or less. is preferably
The light-emitting device used in the vehicle indicator light is preferably a light-emitting device that emits red light in certain embodiments. In this embodiment, for example, the light-emitting device may absorb blue light emitted from a blue LED chip and emit red light, thereby providing a red-light vehicular indicator lamp.
The vehicular indicator lamps include lights provided in a vehicle for the purpose of giving some kind of indication to other vehicles, people, etc., such as headlamps, side lamps, back lamps, turn signals, brake lamps, and fog lamps of the vehicle.

Hereinafter, the present invention will be described in more detail with experimental examples that replace the examples of the present invention, but the present invention is not limited to the following as long as it does not deviate from the gist of the present invention.

{Measuring method}
[Powder X-ray diffraction measurement]
Powder X-ray diffraction (XRD) was precisely measured with a powder X-ray diffractometer SmartLab 3 (manufactured by Rigaku).
The measurement conditions are as follows.
X-ray output using CuKα tube = 45 kV, 200 mA
Divergence slit = automatic detector = fast one-dimensional X-ray detector (D/teX Ultra 250)
Search range 2θ = 5 to 95 degrees Reading width = 0.02 degrees

[Measurement of reflectance]
The reflectance spectrum was measured with an ultraviolet-visible spectrophotometer (manufactured by JASCO Corporation, V-560) under the following measurement conditions. As for the reflectance, the minimum value of the reflectance in the wavelength range of 800 nm from the emission peak wavelength was obtained with the standard reflector made of foamed resin made of PTFE (Spectralon standard reflector manufactured by Labsfair) as 100%.
Light source: deuterium discharge tube (190-350 nm)
: Tungsten iodine lamp (330-900 nm)
Measurement wavelength range: 200-800nm
Measurement interval: 0.5 nm

[Measurement of emission spectrum]
The emission spectrum was measured using a spectrofluorophotometer F-4500 (manufactured by Hitachi High Technology) under the following measurement conditions.
Light source: xenon lamp Excitation wavelength: 455 nm
Measurement wavelength range: 200-800nm
Measurement interval: 0.2 nm

[Measurement of quantum efficiency]
Quantum efficiency was measured using a quantum efficiency measurement system QE-2100 (manufactured by Otsuka Electronics Co., Ltd.) under the following measurement conditions.
Light source: xenon lamp Excitation wavelength: 455 nm
Measurement wavelength range: 200-850nm
Measurement interval: 0.5 nm

<Characteristic evaluation of phosphor>
By producing a phosphor according to the above-described phosphor production method, and selecting a phosphor whose ratio of Ix and Iy in the XRD pattern satisfies the requirements of the present invention, the formula [1] or [2] is obtained. were prepared. Further, as a comparison target with the present invention, a comparative sample 1 having the Ix/Iy of 0.145 was prepared.
As a reference sample 1 showing an example of an existing phosphor, a commercially available CASN phosphor (BR-101/J, manufactured by Mitsubishi Chemical Corporation) having a composition represented by CaAlSiN ₃ :Eu was prepared. The space group of Reference Sample 1 was Cmc2 ₁ , the emission peak wavelength was 646 nm, and the half width was 87 nm.
The composition, the Ix/Iy, the emission peak wavelength, the half width, the relative emission intensity when the emission intensity of Comparative Sample 1 is set to 1, and the internal quantum efficiency (iQE) of each sample were measured. Table 1 shows the results. Table 2 shows the minimum values of the reflectance in the predetermined reflection regions and the differences or ratios between the minimum values in each region.
The space group of all samples 1 to 11 was P-1.
The XRD patterns and emission spectra of Sample 5 and Comparative Sample 1 are shown in FIGS. 1 and 2, respectively.
Reference sample 1 is an example of an existing phosphor, and is a commercially available CASN phosphor (BR-101/J, manufactured by Mitsubishi Chemical Corporation) having a composition represented by CaAlSiN ₃ :Eu. The space group of Reference Sample 1 was Cmc2 ₁ , the emission peak wavelength was 646 nm, and the half width was 87 nm.

Each sample has a very small half-value width compared to Reference Sample 1, and it can be seen that by using such a phosphor, it is possible to provide a light-emitting device having both good color rendering properties or color reproducibility and good conversion efficiency.

In addition, focusing on samples 5 and 6, which are similar in composition to comparative sample 1, both samples 5 and 6 have the same good emission peak wavelength and half-value width as compared to comparative sample 1, but the emission intensity, Both iQE are greatly improved, and it can be seen that when applied to a light-emitting device, a light-emitting device with good conversion efficiency can be obtained.

The XRD patterns of samples 3, 5, 7-11 are shown in FIG. The emission spectra of Samples 3, 5, 7-11 and Comparative Sample 1 are shown in FIG. The normalized emission spectra of Samples 3, 7, 11 and Reference Sample 1 are shown in FIG.
The reflectance spectra of each sample are shown in Figures 6A-C.
7A to 7C show the relationship between the relative emission intensity of each sample and AB, AC, and C/A according to the reflectances A to C. FIG.

As can be seen from each sample, the phosphor included in the light emitting device according to the present invention can realize various emission peak wavelengths depending on the application by adjusting the composition. In addition, each sample showed a very high luminescence intensity as compared with the comparative sample 1.
In addition, each sample has a very small half-value width compared to Reference Sample 1, and by using such a phosphor, it is possible to provide a light-emitting device with good color rendering properties or color reproducibility and good conversion efficiency.

Next, the results of simulations S1 to S9 regarding the characteristics of the light emitting device including the phosphor will be described.

SCASN phosphor (Mitsubishi Chemical Co., Ltd., BR-102/D) with an emission peak wavelength of 620 nm as the first red phosphor, and the phosphors of the samples shown in Table 2 below as the second red phosphor, or light emission Assuming that a CASN phosphor (Mitsubishi Chemical Co., BR-101/J) with a peak wavelength of 646 nm and a LuAG phosphor (Mitsubishi Chemical Co., BG-801/B4) as a green phosphor are used, each phosphor Based on information such as the emission spectrum and internal quantum efficiency (iQE), the emission spectrum of the white LED provided with each phosphor was derived. All simulations were performed assuming a blue LED chip emitting light at 449 nm. Further, the amounts of the green phosphor and the first and second red phosphors are adjusted so that the color rendering index Ra is 90 or more and the chromaticity coordinates match the coordinates of 3000K white light on the Planck curve. adjusted and compared. The results are shown in Figures 8A-G. Table 3 shows the results obtained from each spectrum for the color rendering index Ra, the red color rendering index R9, and the conversion efficiency (LER).
In addition, "phosphor mass relative value" in Table 3 is the mass ratio of each phosphor when the total mass of each phosphor is 100%, "green" is the LuAG phosphor, "red 1 ' is the first red phosphor, and 'Red 2' is the second red phosphor.

As shown in Table 3, the light-emitting device using each sample has a dramatically improved color reproducibility Ra compared to the case of using the phosphor of Comparative Sample 1, and compared to the case of using Reference Sample 1, It can be seen that LER and/or R9 are improved, and both conversion efficiency and color rendering or color reproducibility are excellent. In the example in which Comparative Sample 1 was used as the second red phosphor, Ra, which is an index of color rendering properties, was low. was very low and could not be evaluated accurately.

As shown above, in the powder X-ray diffraction spectrum, the intensity of the peak corresponding to the heterophase having the composition represented by the above formula [1] or [2] and having 2θ in a specific region, A phosphor whose ratio to the intensity of the peak corresponding to the crystal phase represented by the specific composition in the specific region is equal to or less than a predetermined value has a wavelength preferable for red color, an excellent half-value width and an emission intensity. By using a light-emitting device that includes a phosphor, it is possible to provide a light-emitting device, a lighting device, an image display device, a vehicle indicator lamp, and the like that have excellent color rendering properties or color reproducibility and high conversion efficiency.

Claims (9)

A light-emitting device comprising a phosphor,
The phosphor contains a crystal phase having a composition represented by the following formula [2], and
When the peak intensity appearing in the region of 2θ = 38 to 39 degrees in the powder X-ray diffraction spectrum of the phosphor is Ix, and the peak intensity appearing in the region of 2θ = 37 to 38 degrees is Iy, the relative intensity of Ix to Iy Ix/Iy is 0.140 or less,
A light-emitting device, wherein the phosphor has an emission peak wavelength of 620 nm or more and 645 nm or less in the emission spectrum.
RexMAaMBb(MC'1-yMDy)cNdXe [2]
(in the above formula [2],
MA is Sr;
MB is Li;
MC' is Al;
MD is Ga;
X contains 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 each satisfy the following formula.
0.7≤a≤1.3
0.7≤b≤1.3
2.4≤c≤3.6
3.2≤d≤4.8
e = 0
0.0<x≦0.2
0.0<y≦1.0) 2. The light-emitting device according to claim 1 , wherein the space group of the crystal phase having the composition represented by formula [2] is P-1. 3. The light-emitting device according to claim 1, wherein the phosphor has an emission spectrum with a full width at half maximum (FWHM) of 70 nm or less. The light-emitting device according to any one of claims 1 to 3 , further comprising a yellow phosphor and/or a green phosphor. 5. The light-emitting device according to claim 4 , wherein said yellow phosphor and/or green phosphor includes any one or more of garnet-based phosphor, silicate-based phosphor, nitride phosphor, and oxynitride phosphor. . A first light emitter and a second light emitter that emits visible light when irradiated with light from the first light emitter, and the second light emitter has a composition represented by the formula [2] The light-emitting device according to any one of claims 1 to 5 , comprising a phosphor containing a crystalline phase having A lighting device comprising the light emitting device according to claim 6 as a light source. An image display device comprising the light emitting device according to claim 6 as a light source. A vehicle indicator lamp comprising the light emitting device according to claim 6 as a light source.

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