JP2023090161A - Phosphor, light emitting device, and light emitting device - Google Patents

Abstract

To provide a novel phosphor.SOLUTION: A phosphor contains an inorganic compound with an element represented by M dissolved in a host crystal represented by LpAqBrXs, where L is one or two or more kinds of elements selected from Li, Na, K, Rb, and Cs, A is one or two or more kinds of elements selected from Sr, Ba, Mg, and Ca. B is one or two or more kinds of elements selected from La, Y, Ce, Gd, Sc, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, and Lu. X is O, M is Eu, p, q, r and s satisfy 14.70≤p+q+r+s≤15.30, 1.70≤p≤2.30, 0.70≤q≤1.30, 3.70≤r≤4.30, and 7.70≤s≤8.30. When the phosphor is irradiated with excitation light at a wavelength of 378 nm, the phosphor emits light having a peak wavelength in a range of 540 nm or more and 650 nm or less.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to phosphors, light-emitting elements, and light-emitting devices.

The phosphor is a fluorescent display tube (VFD (Vacuum-Fluorescent Display)), a field emission display (FED (Field Emission Display)) or an SED (Surface-Conduction Electron-Emitter Display), a plasma display panel (PDP (Plasma Disp lay panel) ), cathode-ray tubes (CRTs), light-emitting diodes (LEDs), liquid-crystal display backlights, and the like. In particular, white LEDs, in which near-ultraviolet or blue light-emitting semiconductor light-emitting elements and phosphors are combined, are generally used for applications such as liquid crystal displays and lighting fixtures.

In recent years, liquid crystal displays and LEDs for lighting applications are strongly required to have high color reproducibility, and for this reason, phosphors with a narrow half width of the emission peak are desirable. For example, in white LEDs for liquid crystal displays, there is a demand for green phosphors and red phosphors with narrow half-value widths. It has been reported.

As an example of a narrow-band green phosphor, a green phosphor obtained by using β-SiAlON as a host crystal and activating it with Eu, that is, a β-SiAlON phosphor is known (see Patent Document 1; , a crystal such as the above-mentioned β-SiAlON is referred to as a "host crystal", or simply referred to as a "host crystal" in some cases). In the β-SiAlON phosphor, it is known that the emission peak wavelength changes toward the shorter wavelength side by changing the oxygen content while maintaining the crystal structure.

Here, an element such as Eu that governs light emission is called an activating element. In general, the activating element exists in the form of ions in the phosphor, substituting a part of the element in the host crystal.

In this way, the color of light emitted from the phosphor is determined by the combination of the host crystal and the activating element substituted therefor. Furthermore, the combination of the host crystal and the activating element determines the emission characteristics such as emission spectrum and excitation spectrum, chemical stability, or thermal stability. are considered different fluorophores. Further, even if the chemical composition is the same, if the crystal structure of the host crystal is different, the luminous properties and chemical stability will be different, and thus they are regarded as different phosphors.

It is also known that Eu, which is an activating element, emits light differently depending on its valence state. For example, when Eu exists in a divalent state, an emission spectrum with a wide spectral width is observed. On the other hand, when Eu is trivalent, luminescence with a sharp spectral width is observed.

JP 2005-255895 A

From the above, it is important to find host crystals with novel crystal structures in the development of new phosphors, and to enhance fluorescence properties by activating metal ions responsible for light emission in such host crystals. By expressing it, it is possible to propose novel phosphors.

The inventors of the present invention explored novel phosphors and conducted detailed research on the properties of the obtained phosphors. A novel phosphor in which an active element is solid-dissolved has been found, and the present invention has been completed together with a manufacturing method thereof.

According to the invention,
A phosphor containing an inorganic compound in which an element represented by M is solid-dissolved in a host crystal represented by L _p A _q B _r X _s ,
The L is one or more elements selected from Li, Na, K, Rb, and Cs,
The A is one or more elements selected from Sr, Ba, Mg, and Ca,
The B is one or more elements selected from La, Y, Ce, Gd, Sc, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, and Lu,
The X is O,
The M is Eu,
wherein said p, q, r and s are
14.70≤p+q+r+s≤15.30,
1.70≤p≤2.30,
0.70≤q≤1.30,
3.70≦r≦4.30 and 7.70≦s≦8.30;
When the phosphor is irradiated with excitation light having a wavelength of 378 nm, it emits light having a peak wavelength in the range of 540 nm or more and 650 nm or less.
A phosphor is provided.

Further, according to the present invention, there is provided a light-emitting device containing the phosphor described above.
Further, according to the present invention, there is provided a light-emitting device including the light-emitting element described above.

According to the present invention, novel phosphors, light-emitting elements, and light-emitting devices are provided.

FIG. 2 is a diagram showing the crystal structure of Li ₂ BaY ₄ O ₈ crystal; FIG. 2 is a diagram showing powder X-ray diffraction using CuKα rays calculated from the crystal structure of Li ₂ BaY ₄ O ₈ crystal. 1 is a schematic diagram of a surface-mounted LED element using the phosphor of this embodiment; FIG. 1 is a diagram showing powder X-ray diffraction results of a compound synthesized in Example 1. FIG.

<1. Phosphor>
The phosphor of this embodiment will be described.
The phosphor of the present embodiment is a phosphor containing an inorganic compound in which an element represented by M is solid-dissolved in a host crystal represented by L _p A _q B _r X _s ,
The L is one or more elements selected from Li, Na, K, Rb, and Cs,
The A is one or two elements selected from Sr, Ba, Mg, and Ca,
The B is one or more elements selected from La, Y, Ce, Gd, Sc, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, and Lu,
The X is an element selected from O,
The M is an element selected from Eu,
wherein said p, q, r and s are
14.70≤p+q+r+s≤15.30,
1.70≤p≤2.30,
0.70≤q≤1.30,
3.70≦r≦4.30 and 7.70≦s≦8.30 are satisfied.

The phosphor of this embodiment is configured to emit light having a peak wavelength in the range of 540 nm or more and 650 nm or less when the phosphor is irradiated with excitation light having a wavelength of 378 nm.

In the process until the present invention was completed, the present inventors prepared a substance represented by the composition formula Li ₂ BaY ₄ O ₈ from raw materials containing Li element, Ba element, Y element and O element, respectively. As a result of intensive investigation, the synthesized substance is not a mixture, but a single crystal structure having Li ₂ BaY ₄ O ₈ as a crystal unit and a crystal structure that has not been reported before the present invention. was confirmed to be a compound of
In addition, it was confirmed that not only the Li ₂ BaY ₄ O ₈ crystal but also some or all of its elements could be replaced with other specific elements to maintain the same crystal structure as the Li ₂ BaY ₄ O ₈ crystal. . These are collectively represented by the symbols L, A, B and X, and the crystal represented by the composition formula L _p A _q B _r X _s (wherein the L is Li, Na, K, Rb, and Cs, the A is one or two elements selected from Sr, Ba, Mg, and Ca, and the B is La, Y, Ce , Gd, Sc, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, and Lu, wherein X is an element selected from O and M is an element selected from Eu.).

Furthermore, the crystal in which at least a part of the elements of _{the LpAqBrXs} crystal is substituted with M _maintains the _{same crystal structure as} the _LpAqBrXs crystal, and exhibits fluorescence emission. As a result, the present inventors have found a novel phosphor containing an inorganic compound in which an element represented by M is solid-dissolved in a host crystal represented by L _p A _q B _r X _s , leading to the completion of the present invention.

Table 1 shows the results of X-ray crystal structure analysis of the Li ₂ BaY ₄ O ₈ crystal, which led to the completion of the present invention.

In Table 1, the lattice constants a, b, and c indicate the lengths of the unit cell axes of the Li ₂ BaY ₄ O ₈ crystal, and α, β, and γ indicate the angles between the unit cell axes. Also, the atomic coordinates x, y, and z in Table 1 indicate the position of each atom in the unit cell with values between 0 and 1 in units of the unit cell. An analysis result was obtained that each atom of Li, Ba, Y, and O was present in this crystal, and that Y was present at the same two types of sites (Y(1) to Y(2)). Further, an analytical result was obtained that O exists at the same four types of sites (O(1) to O(4)).

FIG. 1 shows the crystal structure of the Li ₂ BaY ₄ O ₈ crystal.
In FIG. 1, 1 is an O atom. 2 is a Li atom. The Ba atom of 3 takes a cubic eight-coordinated structure with the Y atom of 4.
That is, the Li ₂ BaY ₄ O ₈ crystal belongs to the monoclinic system and belongs to the space group C2/m.
In this crystal, Eu as an activating element responsible for light emission is incorporated into the crystal in the form of substituting a part of Ba and/or Y.

The _above results were not known as publicly _known technical information prior to the _discovery of the _phosphor of the present invention. A phosphor containing a solid-dissolved inorganic compound is a novel phosphor.

Furthermore, a crystal whose composition formula is represented by L _p A _q B _r X _s , that is, a part or all of the elements of the Li ₂ BaY ₄ O ₈ crystal may be replaced with other elements, or Eu may be added as described later. A crystal with further substitution as an active element varies from the lattice constant of the Li ₂ BaY ₄ O ₈ crystal shown in Table 1, but the basic crystal structure does not change.

In this embodiment, "even if not only the Li ₂ BaY ₄ O ₈ crystal but also some or all of its elements are replaced with other specific elements, the same crystal structure as the Li ₂ BaY ₄ O ₈ crystal can be maintained. "" refers to a crystal whose composition formula is represented by L _p A _q B _r X _s , the lattice constant obtained by Rietveld analysis of the results of X-ray diffraction or neutron diffraction in the space group of C2 / m , and the chemical bond lengths between A and X and between B and X calculated from the atomic coordinates (nearest interatomic distances) are the lattice constants of the Li ₂ BaY ₄ O ₈ crystal shown in Table 1 above. is within ±5% of the chemical bond length calculated from the atomic coordinates. The chemical bond lengths cannot vary by more than ±5% compared to the Li ₂ BaY ₄ O ₈ crystal, resulting in a different crystal structure in such cases.

In the L _p A _q B _r X _s crystal according to the present embodiment, for example, in the Li ₂ BaY ₄ O ₈ crystal shown in FIG. An element represented by the symbol A can enter the site, an element represented by the symbol B can enter the site where Y enters, and an element represented by the symbol X can enter the site where O enters. With this regularity, the ratio of the number of atoms of A and B in total to 5 and X in total of 8 to L is 2 while maintaining the crystal structure of L _p A _q B _r X _s can be done. Also, an activating element such as Eu can enter the site where Ba and/or Y enter. However, it is desirable that the elements cancel each other out and the electrical neutrality of the entire crystal is maintained.

FIG. 2 shows a powder X-ray diffraction pattern using CuKα rays calculated from the crystal structure of the Li ₂ BaY ₄ O ₈ crystal based on the numerical values shown in Table 1.

As a simple method for determining whether or not a crystal whose crystal structure is unknown has the same crystal structure as the Li ₂ BaY ₄ O ₈ crystal, the following method can be preferably used. That is, for a crystal whose crystal structure is an object of determination, when the measured X-ray diffraction peak position (2θ) and the diffraction peak position shown in FIG. This is a method of determining that the crystal structure of a crystal having the same structure, ie, an unknown crystal structure, has the same crystal structure as the Li ₂ BaY ₄ O ₈ crystal. As the main peaks, 10 peaks with high diffraction intensity should be determined. In this embodiment, this determination method was used in Examples.

As described above, the phosphor of the present embodiment contains an _inorganic compound in which at _{least part of the host crystal represented by LpAqBrXs is} substituted with M,
The L is one or more elements selected from Li, Na, K, Rb, and Cs,
The A is one or two elements selected from Sr, Ba, Mg, and Ca,
The B is one or more elements selected from La, Y, Ce, Gd, Sc, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, and Lu,
The X is an element selected from O,
The M may be an element selected from Eu.
Among these, the L is preferably one or two or more elements selected from Li, Na, and K, and the A is preferably one or two elements selected from Sr, Ba, and Ca. The B is preferably one or more elements selected from La, Y, Ce, Gd, Sc, Eu, and Lu.

The host crystal related to the phosphor of the present embodiment and having a composition formula represented by L _p A _q B _r X _s can be represented by a composition formula with any combination of the above elements. It is preferably a host crystal more specifically shown in the composition formula. That is, the host crystal of the present embodiment is, for example, Li ₂ SrLa ₄ O ₈ , Li ₂ SrY ₄ O ₈ , Li ₂ SrCe ₄ O ₈ , Li ₂ SrGd ₄ O ₈ , Li ₂ SrSc ₄ O ₈ , Li ₂ SrEu _{4O8 , Li2SrLu4O8 , Li2BaLa4O8 , Li2BaY4O8 , Li2BaCe4O8 , Li2BaGd4O8 , Li2BaSc4O8 , Li2BaEu4 _ _ _ _ _ _ _ O8 , Li2BaLu4O8 , Li2CaLa4O8 , Li2CaY4O8 , Li2CaCe4O8 , Li2CaGd4O8 , Li2CaSc4O8 , Li2CaEu4O _ _ _ _ _ _ 8 , Li2CaLu4O8 , Na2SrLa4O8 , Na2SrY4O8 , Na2SrCe4O8 , Na2SrGd4O8 , Na2SrSc4O8 , Na2SrEu4O8 _ _ _ _ _ _ _ , Na2SrLu4O8 , Na2BaLa4O8 , Na2BaY4O8 , Na2BaCe4O8 , Na2BaGd4O8 , Na2BaSc4O8 , Na2BaEu4O8 , _ _ _ _ _ _ Na2BaLu4O8 , Na2CaLa4O8 , Na2CaY4O8 , Na2CaCe4O8 , Na2CaGd4O8 , Na2CaSc4O8 , Na2CaEu4O8 , Na _ _ _ _ _ _ 2CaLu4O8 , K2SrLa4O8 , K2SrY4O8 , K2SrCe4O8 , K2SrGd4O8 , K2SrSc4O8 , K2SrEu4O8 , K2 _ _ _ _ _ _ _ SrLu4O8 , K2BaLa4O8 , K2BaY4O8 , K2BaCe4O8 , K2BaGd4O8 , K2BaSc4O8 , K2BaEu4O8 , K2BaLu _ _ _ _ _ _ 4O8 , K2CaLa4O8 , K2CaY4O8 , K2CaCe4O8 , K2CaGd4O8 , K2CaSc4O8 , K2CaEu4O8 , K2CaLu4 _ _ _ _ _ _ _ O8} is preferred. When it is desired to change the emission intensity of the phosphor or to control the color tone, it is possible to appropriately select from phosphor host crystals represented by these compositional formulas.

In order to obtain a phosphor with a higher emission intensity, it is preferable that host crystals represented by M _p (L, A) _q X _r are stably generated. Candidates for host crystals for obtaining such phosphors include Li ₂ SrLa ₄ O ₈ , Li ₂ SrY ₄ O ₈ , Li ₂ SrCe ₄ O ₈ , Li ₂ SrGd ₄ O ₈ , Li ₂ SrSc ₄ O ₈ , _{Li2SrEu4O8 , Li2SrLu4O8 , Li2BaLa4O8 , Li2BaY4O8 , Li2BaCe4O8 , Li2BaGd4O8 , Li2BaSc4O8 , Li _ _ _ _ _ _ 2} BaEu ₄ O ₈ and Li ₂ BaLu ₄ O ₈ .

In addition, in the phosphor of the present embodiment, the host crystal may be a monoclinic crystal, and may be a crystal belonging to the space group C2/m.

Further, in the phosphor of the present embodiment, the lattice constants a, b and c of the host crystal are
a=1.3213±0.1 nm,
b=0.3520±0.1 nm, and c=0.9538±0.1 nm,
is preferably satisfied.

Furthermore, in the phosphor of this embodiment,
having a composition represented by the general formula L _e A _f B _g X _h : M _i ,
The composition ratios e, f, g, h and i are
e+f+g+h+i=15.00,
1.70≦e≦2.30,
0.70≦f≦1.30,
3.70≤g≤4.30,
It is preferable to satisfy 7.70≦h≦8.30 and 0.00<i≦0.20.
Such a composition ratio is considered to stably generate host crystals, and a phosphor with higher emission intensity can be obtained.

The composition ratio e is a parameter representing the composition ratio of Li and the like.
The composition ratio f is a parameter representing the composition ratio of Ba and the like, and when it is 0.70 or more and 1.30 or less, the crystal structure does not become unstable, and a decrease in emission intensity can be suppressed.
The composition ratio g is a parameter representing the composition ratio of Y and the like, and when it is 3.70 or more and 4.30 or less, the crystal structure does not become unstable, and a decrease in emission intensity can be suppressed.
The composition ratio h is a parameter representing the composition ratio of O. When the composition ratio h is 7.70 or more and 8.30 or less, the crystal structure of the phosphor does not become unstable, and a decrease in emission intensity can be suppressed.
The composition ratio i is a parameter representing the composition ratio of the activating element M in Eu, and if i exceeds 0.00, it is possible to suppress a decrease in luminance due to lack of the activating element. When i is less than 1.30, it is possible to sufficiently maintain the structure of the host crystal. If it is 1.30 or more, the structure of the host crystal may become unstable. Moreover, if i is further reduced to 0.20 or less, it is possible to suppress the decrease in emission intensity due to the concentration quenching phenomenon caused by the interaction between the activating elements, which is preferable.

Further, when irradiated with excitation light having a wavelength of 378 nm, the phosphor of the present embodiment can emit fluorescence having a light intensity peak in a wavelength range of, for example, 540 nm or more and 650 nm or less, preferably 545 nm or more and 640 nm or less.

When the phosphor of the present embodiment is irradiated with excitation light having a wavelength of 378 nm, the half width at the peak wavelength of light including the light intensity peak in the wavelength range of 540 nm or more and 650 nm or less is, for example, 40 nm or more and 70 nm or less, preferably 45 nm or more and 65 nm. It can fluoresce as follows.

The phosphor of this embodiment is a phosphor in which the host crystal is substituted with Eu as an activating element. A phosphor containing Eu as an activating element is a phosphor with high emission intensity, and a phosphor emitting fluorescence of 540 nm or more and 650 nm or less can be obtained with a specific composition.

Further, in the phosphor of the present embodiment, the host crystal represented by L _p A _q B _r X _s is partially or wholly Ba element,
Part or all of the B is at least one of La element, Gd element and Y element,
is preferred.

The phosphor of this embodiment is a phosphor that emits light by absorbing the energy of vacuum ultraviolet rays, ultraviolet rays, visible light, or radiation having a wavelength of, for example, 100 nm or more and 500 nm or less. Examples of radiation include, but are not limited to, X-rays, α-rays, β-rays, γ-rays, electron beams, and neutron beams. By using an excitation source having an emission wavelength within this range, the phosphor of this embodiment can be caused to emit light efficiently.

The phosphor of the present embodiment is preferably single crystal particles of the phosphor of the present embodiment, particles in which single crystals of the phosphor of the present embodiment are aggregated, or a mixture thereof.
It is desirable that the phosphor of the present embodiment has a purity as high as possible. May be included as long as it is not damaged.

For example, impurity elements such as Fe, Co, and Ni contained in the raw material and the firing vessel may reduce the emission intensity of the phosphor. In this case, by setting the total amount of these impurity elements in the phosphor to 500 ppm or less, the effect on the decrease in emission intensity is reduced.

In addition, when the phosphor of this embodiment is produced, a compound having a crystalline phase or amorphous phase (also referred to as a subphase) other than the phosphor of this embodiment may be produced at the same time. The subphase does not necessarily have the same composition as the phosphor of this embodiment. The phosphor of the present embodiment preferably contains no subphase as much as possible, but may contain a subphase as long as the emission of the phosphor is not impaired.

That is, as one of the embodiments of the present invention, the phosphor of the present embodiment uses the crystal represented by the above-described _LpAqBrXs as a host crystal, and an Eu activating _element is added in _an ion _state to the host crystal. It is a mixture of a substituted inorganic compound and another crystal phase such as a subphase different from the inorganic compound, and the content of the inorganic compound is, for example, 50% by mass or more, preferably 70% by mass or more, more preferably is 90% by mass or more.

When the desired characteristics cannot be obtained with a single crystal phosphor represented by L _p A _q B _r X _s , the above embodiment may be used. The content of the host crystal represented by L _p A _q B _r X _s may be adjusted according to the desired properties, but if it is 20% by mass or more, the emission intensity will be sufficient. From this point of view, it is preferable that 20 mass % or more of the inorganic compound is the main component in the phosphor of the present embodiment. Such a phosphor can emit fluorescence having a peak in the wavelength range of 540 nm or more and 650 nm or less when it is irradiated with excitation light having a wavelength of 378 nm.

The shape of the phosphor of the present embodiment is not particularly limited, but when used as dispersed particles, for example, single crystal particles having an average particle size of 0.1 μm or more and 50 μm or less, or aggregated single crystals Particles are preferred. When the particle diameter is controlled within this range, the luminous efficiency is high, and the operability when mounted on the LED is good.
The average particle diameter is a volume-based median diameter calculated from a particle size distribution (cumulative distribution) measured using a particle size distribution measuring apparatus based on a laser diffraction/scattering method, which is defined in JIS Z882 5:2013. ( _d50 ). It is also possible to sinter the phosphor of this embodiment and use it in the form of non-particles. In particular, a plate-shaped sintered body containing a phosphor is generally called a phosphor plate, and can be preferably used as a light-emitting member of a light-emitting element, for example.

<2. Method for producing phosphor>
A method for manufacturing the phosphor of this embodiment will be described.
An example of a method for producing a phosphor is one or two or more elements selected from Li, Na, K, Rb, and Cs, and one or two elements selected from L, Sr, Ba, Mg, and Ca. selected from one or more elements B and O selected from A, La, Y, Ce, Gd, Sc, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, and Lu; and an element M selected from Eu, comprising: a mixing step of obtaining a raw material mixture containing each element constituting the composition; and a firing step of firing the raw material mixture. ,including.

As an example of the mixing step, a raw material containing the element L, a raw material containing the element A, a raw material containing the element B, a raw material containing the element X, and a raw material containing the element M are mixed. , a raw material mixture may be obtained.
When the source substance is a compound, one compound may contain a plurality of elements selected from among L, A, B, X and M, and the source substance may be composed of a single element, that is, a single element. good.

The raw material containing element L is a metal, oxide, carbonate, hydroxide, oxynitride, or nitride containing one or more elements selected from Li, Na, K, Rb, and Cs. , hydrides, fluorides and chlorides, or a mixture of two or more of them. Specifically, oxides are preferably used.

Source materials containing element A are metals, oxides, carbonates, hydroxides, oxynitrides, nitrides, hydrogen containing one or more elements selected from Sr, Ba, Mg, and Ca. It is a single substance or a mixture of two or more kinds selected from a compound, a fluoride and a chloride, and specifically an oxide is preferably used.

The raw material containing element B is one or more selected from La, Y, Ce, Gd, Sc, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, and Lu. A single substance or a mixture of two or more selected from metals containing elements, oxides, carbonates, hydroxides, oxynitrides, nitrides, hydrides, fluorides and chlorides, specifically oxides is preferably used.

The raw material containing the element M is a single substance or a mixture of two or more selected from Eu-containing alloys, oxides, nitrides, fluorides and chlorides. Specifically, europium oxide is preferably used. Each source material is preferably in powder form.

For example, to produce an Eu-activated Li ₂ BaY ₄ O ₈ phosphor, europium oxide, nitride, or fluoride, lithium oxide, nitride, or fluoride, and barium oxide It is preferable to use a compound containing yttrium oxide, nitride, or fluoride and yttrium oxide, nitride, or fluoride as the raw material mixture. In particular, europium oxide, lithium oxide, barium oxide, and yttrium oxide are more preferably used.

In the method for producing the phosphor of the present embodiment, a compound containing an element other than the elements constituting the phosphor, which forms a liquid phase at a temperature equal to or lower than the firing temperature during firing for synthesizing the phosphor of the present embodiment, is used. It may be added and fired. A compound that generates such a liquid phase acts as a flux and functions to promote synthesis reaction and grain growth of the phosphor, so that stable crystals can be obtained and the emission intensity of the phosphor can be improved. .

The compound that forms a liquid phase at a temperature below the firing temperature is selected from Mg, Ca, Sr, Ba, Zn, Li, Na, K, Al, Ga, B, In, Sc, Y, La and Si. There are one or more mixtures of fluorides, chlorides, iodides, bromides and phosphates of one or more elements. Since these compounds have different melting points, they should be used according to the synthesis temperature. These compounds that generate a liquid phase are also included in the raw materials for convenience in the present embodiment.

For producing phosphors in powder or aggregate form, each source material is preferably powder. Further, since the synthesis reaction of the phosphor starts from the contact portion between the raw material powders, it is preferable to set the average particle size of the raw material powder to 500 μm or less, because the contact portion of the raw material powder increases and the reactivity improves.

(Mixing method)
In the method for producing the phosphor of the present embodiment, the method of mixing each raw material to form a raw material mixture is not particularly limited, and a known mixing method is used. That is, in addition to the dry mixing method, the raw materials can be mixed by wet mixing in an inert solvent that does not substantially react with each raw material, and then removing the solvent. As a mixing device, a V-type mixer, a rocking mixer, a ball mill, a vibrating mill, etc. are preferably used.

(Firing container)
In sintering the raw material mixture, various heat-resistant materials can be used as a sintering container for holding the raw material mixture. A container, a carbon container such as a carbon sintered body, a container made of molybdenum, tungsten, or tantalum metal can be used.

(firing temperature)
In the method for manufacturing the phosphor of the present embodiment, the firing temperature of the raw material mixture can be set as appropriate, and may be, for example, 700° C. or higher and 1200° C. or lower. By setting the firing temperature to 700° C. or higher, the crystal growth of the phosphor can be facilitated and sufficient fluorescence properties can be obtained. Also, by setting the firing temperature to 1200° C. or less, decomposition of the phosphor can be suppressed, and deterioration of the fluorescence properties can be suppressed. Although the firing time varies depending on the firing temperature, it is usually about 1 to 10 hours. There are no particular restrictions on the time-dependent pattern of heating, temperature maintenance, and cooling during firing, and raw materials may be added as needed during firing.

(firing atmosphere)
The sintering step is preferably performed in a reducing sintering atmosphere capable of reducing at least part of Eu ³⁺ in the raw material mixture to the state of Eu ²⁺ . The firing atmosphere may include, for example, neutral gases such as NH ₃ and N ₂ and reducing gases such as H ₂ and CH ₄ . These may be used alone or in combination of two or more. Among these, from the viewpoint of emission intensity, NH ₃ , N ₂ or H ₂ may be used, preferably NH ₃ or N ₂ may be used.
The gas in the firing atmosphere may be composed of, for example, NH ₃ or N ₂ as a main component. The purity of NH ₃ or N ₂ at 200° C. is, for example, 98% by volume or more, preferably 99% by volume or more.
Furnace materials such as heat insulators and heaters include graphite resistance heating electric furnaces made of carbon, all-metal furnaces made of molybdenum and tungsten, tubular furnaces that heat alumina and quartz furnace core tubes with heaters, A corrosive furnace may be used. Appropriate gas species may be used depending on the furnace material.

(firing pressure)
As for the pressure range during firing, an atmosphere pressurized as much as possible is preferable because thermal decomposition of the raw material mixture and the product phosphor can be suppressed. Specifically, 0.01 MPa or more is preferable. In addition, the oxygen partial pressure in the atmosphere during firing is preferably 0.0001% or less in order to suppress oxidation of each raw material and phosphor during firing.

(Baking times)
The number of times of the firing process described above may be one time, but may be a plurality of times.
The number of firing steps refers to the number of repetitions of the steps of controlling the firing temperature and firing pressure of the raw material mixture, holding the raw material mixture at the firing temperature, releasing control of the firing pressure, and cooling to room temperature.

(Annealing treatment after firing)
Heat treatment (also referred to as annealing) at a temperature of 600° C. or more and 1200° C. or less for the phosphor obtained by firing, the phosphor powder after pulverizing it, and the phosphor powder after adjusting the particle size. can also This operation may restore defects and crushing damage contained in the phosphor. Defects and damages may cause a decrease in emission intensity, and the heat treatment may restore the emission intensity.

Further, the phosphor after firing or annealing may be washed with a solvent or an acidic or basic solution. By this operation, the content of the compound that forms a liquid phase at a temperature lower than the firing temperature and the subphase can be reduced. As a result, the emission intensity of the phosphor may increase.

Thus, the phosphor of this embodiment emits light having a peak wavelength in the range of 540 nm or more and 650 nm or less when it is irradiated with excitation light having a wavelength of 378 nm.
Due to such emission characteristics, the phosphor of this embodiment is further useful as a material for constructing a light-emitting element using the phosphor of this embodiment or a phosphor plate containing the phosphor of this embodiment. Furthermore, lighting fixtures and image display devices using the light-emitting element are also suitable, and the phosphor of the present embodiment is also suitable for pigments and ultraviolet absorbers. The phosphor of the present embodiment is not only used alone, but is also used as a fluorescent molding, a fluorescent sheet, or a fluorescent film obtained by molding a composition obtained by mixing various materials containing the phosphor of the present embodiment with a resin or the like. It is possible to provide such a molded body. In addition, the phosphor of the present embodiment is excellent in heat resistance because it does not deteriorate even when exposed to high temperatures, and has the advantage of being excellent in long-term stability in an oxidizing atmosphere and a moisture environment. It can provide products with excellent durability.

<3. Light emitting element>
The phosphor of this embodiment can be used for various purposes, and a light-emitting device containing the phosphor of this embodiment is also one aspect of the present invention. The shape of the phosphor of the present embodiment contained in the light-emitting element may be particulate, or may be obtained by sintering particulate phosphor. A plate obtained by sintering a particulate phosphor again is sometimes called a phosphor plate. Further, the light-emitting element referred to here generally includes a phosphor and an excitation source.

When the phosphor of the present embodiment is used to form a light-emitting device generally called a light-emitting diode (also referred to as an LED), for example, the phosphor of the present embodiment is placed in a resin or glass (collectively referred to as a solid medium). is generally preferably employed in a form in which the phosphor-containing composition in which is dispersed is arranged so that the excitation light from the excitation source is applied to the phosphor. At this time, the phosphor-containing composition can also contain a phosphor other than the phosphor of the present embodiment.

The resin that can be used as the solid medium of the phosphor-containing composition exhibits liquid properties before molding or when the phosphor is dispersed, and causes unfavorable reactions and the like for the phosphor and the light-emitting device of the present embodiment. If not, any resin can be selected depending on the purpose. Examples of resins include addition reaction type silicone resins, condensation reaction type silicone resins, modified silicone resins, epoxy resins, polyvinyl resins, polyethylene resins, polypropylene resins, polyester resins, and the like. One type of these resins may be used alone, or two or more types may be used together in any combination and ratio. When the resin is a thermosetting resin, it is cured to obtain the phosphor-containing composition in which the phosphor of the present embodiment is dispersed.

The use ratio of the solid medium is not particularly limited, and may be appropriately adjusted according to the application. is in the range of 5% by mass or more, and usually 30% by mass or less, preferably 15% by mass or less. By making it equal to or higher than the above lower limit, the emission intensity of the phosphor can be improved. Aggregation of the phosphor can be suppressed by making it equal to or less than the above upper limit.

In addition to the phosphor and solid medium of the present invention, the phosphor-containing composition of this embodiment may contain other components according to its use. Other ingredients include diffusing agents, thickeners, bulking agents, interfering agents, and the like. Specific examples include silica-based fine powder such as Aerosil, alumina, and the like.

Phosphors other than the phosphor of this embodiment include BAM phosphor, α-sialon phosphor, β-sialon phosphor, Sr ₂ Si ₅ N ₈ phosphor, and (Sr, Ba) ₂ Si ₅ N ₈ phosphor. _CaAlSiN3 phosphor, (Ca,Sr) _AlSiN3 phosphor, _K2SiF6 phosphor _, YAG phosphor, and ( _Ca ,Sr,Ba) _{Si2O2N2 .} The above phosphor may be further included.

As one embodiment of the light-emitting element, in addition to the phosphor of the present embodiment, a blue phosphor that emits light with a peak wavelength of 420 nm or more and 500 nm or less by a light emitter or light source can be included. Such blue phosphors include AlN: (Eu, Si), BAM: Eu, SrSi ₉ Al ₁₉ ON ₃₁ : Eu, LaSi ₉ Al ₁₉ N ₃₂ : Eu, α-sialon: Ce, JEM: Ce, etc. There is

Further, as one embodiment of the light-emitting device, in addition to the phosphor of this embodiment, a green phosphor that emits light with a peak wavelength of 500 nm or more and 550 nm or less by a light emitter or light source can be included. Examples of such green phosphors include β-sialon: Eu, (Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu, (Ca, Sr, Ba) Si ₂ O ₂ N ₂ : Eu. .

Furthermore, as one embodiment of the light-emitting device, in addition to the phosphor of this embodiment, a yellow phosphor that emits light with a peak wavelength of 550 nm or more and 600 nm or less by a light emitter or light source can be included. Such yellow phosphors include YAG:Ce, α-sialon:Eu, CaAlSiN ₃ :Ce, La ₃ Si ₆ N11:Ce, and the like.

Furthermore, as one embodiment of the light-emitting device, in addition to the phosphor of this embodiment, a red phosphor that emits light with a peak wavelength of 600 nm or more and 700 nm or less by a light emitter or light source can be included. Such red phosphors include CaAlSiN ₃ :Eu, (Ca,Sr)AlSiN ₃ :Eu, Ca ₂ Si ₅ N ₈ :Eu, Sr ₂ Si ₅ N ₈ :Eu, KSF:Mn and the like.

When the phosphor of the present embodiment is included in the light-emitting element of the present embodiment in the form of a phosphor plate, the phosphor plate refers to the particulate phosphor of the present embodiment after molding into a desired shape. , which is sintered under heat. However, the phosphor plate of this embodiment may contain phosphors other than the phosphor of this embodiment and other components. Examples of other components here include glass as a medium, a binder resin, a dispersant, and a sintering aid. Additives such as the binder resin, dispersant, and sintering aid are not particularly limited, but substances known in the art that are generally decomposed and removed at the same time as heating and sintering can be preferably used.

The average particle diameter of the phosphor particles used in manufacturing the phosphor plate is not particularly limited, but the addition amount of the binder resin that imparts moldability is adjusted according to the specific surface area of the phosphor particles. , for example, those having an average particle diameter of 0.1 μm or more and 30 μm or less can be preferably used.

The phosphor plate can be manufactured by a known method. For example, additives such as a binder resin, a dispersant, and a sintering aid are added to the powdered phosphor of the present embodiment, and a dispersion medium is added and wet-mixed to adjust the viscosity of the resulting slurry. It is then heated and baked to decompose and remove the additive, thereby obtaining the phosphor sheet of the present embodiment. The temperature, time, and atmosphere of the heat firing may be appropriately changed to known conditions depending on the material used. In addition, it is also effective to add glass powder having a lower melting point than the phosphor of this embodiment, mold the mixture, and then bake it to produce a phosphor plate.

The excitation source included in the light-emitting device of this embodiment emits excitation energy for exciting the phosphor of this embodiment and other types of phosphors to emit light, and is, for example, a light source. The phosphor of this embodiment emits light even when irradiated with vacuum ultraviolet rays of 100 to 190 nm, ultraviolet rays of 190 to 380 nm, electron beams, or the like, and a preferable excitation source is, for example, a blue semiconductor light emitting device. The phosphor of this embodiment also emits light by the light from this excitation source, and functions as a light-emitting element. Note that the light-emitting element of this embodiment need not be a single element, and may be an integrated element in which a plurality of light-emitting elements are combined.

As one form of the light emitting element of this embodiment, the light emitter or light emitting source emits ultraviolet or visible light with a peak wavelength of 300 to 500 nm, preferably 300 to 470 nm, and the phosphor of this embodiment emits blue light to yellowish green light. There is a light-emitting element that emits white light or light other than white light by mixing red light (for example, 435 nm to 570 nm to 750 nm) and light with a wavelength of 450 nm or more emitted by another phosphor of the present embodiment.

Note that the above-described embodiment of the light-emitting element is an example, and in addition to the phosphor of the present embodiment, a blue phosphor, a green phosphor, a yellow phosphor, or a red phosphor is appropriately combined to obtain a desired color. It goes without saying that a high white light can be achieved.

Furthermore, as one of the embodiments of the light-emitting element, the use of an LED emitting light with a wavelength of 280 to 500 nm as a light-emitting body or a light-emitting source results in high light-emitting efficiency, so that a highly efficient light-emitting device can be constructed. In addition, the light from the excitation source to be used is not particularly limited to monochromatic light, and may be bichromatic light.

FIG. 3 shows an outline of a light-emitting device (surface-mounted LED) using the phosphor of this embodiment.

A surface-mounted white light emitting diode lamp (11) will be described. Two lead wires (12, 13) are fixed to a white alumina ceramics substrate (19) with high reflectance of visible light. It is an electrode that is soldered when mounted on an electric board. A blue light-emitting diode element (14) having an emission peak wavelength of 450 nm is mounted and fixed to one end of one of the lead wires (13) so as to be located in the center of the substrate. The lower electrode of the blue light emitting diode element (14) and the lower lead wire are electrically connected by a conductive paste, and the upper electrode and another lead wire (12) are connected by bonding wires ( 15) are electrically connected.

A mixture of the first resin (16) and the phosphor (17) mixed with the phosphor of the above embodiment is mounted in the vicinity of the light emitting diode element. The first resin in which the phosphor is dispersed is transparent and covers the entire blue light emitting diode element (14). A wall member (20) having a hole in the center is fixed on the ceramic substrate. The wall surface member (20) has a hole in the center thereof for receiving the blue light emitting diode element (14) and the first resin (16) in which the phosphor (17) is dispersed, and the portion facing the center. is sloped. This slope is a reflecting surface for extracting light forward, and the curved shape of the slope is determined in consideration of the direction of light reflection. In addition, at least the surface constituting the reflecting surface is a surface having high visible light reflectance with white or metallic luster. In the light emitting device, the wall surface member (20) is made of white silicone resin. The hole in the center of the wall member forms a recess as the final shape of the chip-type light-emitting diode lamp. 16) is filled with a transparent second resin (18) so as to seal all of them. In the light emitting device, the same epoxy resin can be used for the first resin (16) and the second resin (18). The same light-emitting element emits white light.

<4. Light-emitting device>
Furthermore, a light-emitting device including the light-emitting element of the aspect described above is also one aspect of the present invention. Specific examples of light-emitting devices include lighting fixtures, backlights for liquid crystal panels, and various display devices.

<5. Image display device>
Furthermore, an image display device including the light-emitting element of the aspect described above is also one aspect of the present invention. Specific examples of image display devices include vacuum fluorescent display (VFD), field emission display (FED), plasma display panel (PDP), cathode ray tube (CRT), and liquid crystal display (LCD).

<6. Pigment>
The phosphor of this embodiment can also be used as a constituent material of a pigment, for example, by utilizing its function. That is, when the phosphor of this embodiment is irradiated with illumination such as sunlight or a fluorescent lamp, a white object color is observed. Phosphors can be suitably used for inorganic pigments, for example. Therefore, when used as a paint, ink, paint, glaze, or pigment added to plastic products, it can maintain a good white color for a long period of time.

<7. UV absorber>
The phosphor of the present embodiment is not used alone, but can be used as a constituent material of, for example, an ultraviolet absorber by utilizing its function. That is, when the ultraviolet absorber containing the phosphor of this embodiment is kneaded into plastic products or coatings, or applied to the surface of plastic products, they can be effectively protected from deterioration by ultraviolet rays.

<8. Phosphor sheet>
The phosphor of the present embodiment is mixed with, for example, a resin to form a composition, and phosphor moldings, phosphor films, and phosphor sheets obtained by molding the composition are also cited as preferred examples of the use of the phosphor of the present embodiment. be done. For example, the phosphor sheet of this embodiment is a sheet in which the phosphor of this embodiment is uniformly dispersed in a medium. Although the material of the medium is not particularly limited, it is preferably a material that is transparent and capable of maintaining a sheet-like shape, such as a resin. Specifically, silicone resins, epoxy resins, polyarylate resins, PET-modified polyarylate resins, polycarbonate resins, cyclic olefins, polyethylene terephthalate resins, polymethyl methacrylate resins, polypropylene resins, modified acrylics, polystyrene resins and acrylonitrile styrene. A copolymer resin and the like are included. In the phosphor sheet of this embodiment, a silicone resin or an epoxy resin is preferably used from the viewpoint of transparency. Considering heat resistance, a silicone resin is preferably used.

Additives can be added to the phosphor sheet of the present embodiment as necessary. For example, a leveling agent during film formation, a dispersant that promotes dispersion of the phosphor, and an adhesion aid such as a silane coupling agent as a modifier of the sheet surface may be added as necessary during film formation. . Inorganic particles such as silicone fine particles may also be added as a phosphor sedimentation inhibitor.

The film thickness of the phosphor sheet of the present embodiment is not particularly limited, but is preferably determined based on the phosphor content and desired optical properties. From the viewpoint of phosphor content, workability, optical properties, and heat resistance, the film thickness is, for example, 10 μm or more and 3 mm or less, more preferably 50 μm or more and 1 mm or less.

The method for manufacturing the phosphor sheet of this embodiment is not particularly limited, and a known method can be used. The phosphor sheet of the present embodiment only needs to contain the phosphor of the present embodiment, and may be a single-layer sheet or a multi-layer sheet, and the entire sheet need not be uniform. It is also possible to provide a substrate layer on one or both surfaces of the sheet, or on the interior. The material of the substrate layer is also not particularly limited, and for example, known metals, films, glass, ceramics, paper and the like can be used. Specifically, metal plates and foils such as aluminum (including aluminum alloys), zinc, copper, and iron, cellulose acetate, polyethylene terephthalate (PET), polyethylene, polyester, polyamide, polyimide, polyphenylene sulfide, polystyrene, polypropylene, and polycarbonate. , polyvinyl acetal, plastic film such as aramid, paper laminated with the plastic, paper coated with the plastic, paper laminated or vapor-deposited with the metal, plastic film laminated or vapor-deposited with the metal, etc. mentioned. When the substrate is a metal plate, the surface may be plated with chromium, nickel, or the like, or ceramic-treated. In particular, it is preferable that the base material is flexible and in the form of a film having high strength. Therefore, for example, a resin film is preferable, and specific examples include a PET film, a polyimide film, and the like.

Although the embodiments of the present invention have been described above, these are examples of the present invention, and various configurations other than those described above can be adopted. Moreover, the present invention is not limited to the above-described embodiments, and includes modifications, improvements, etc. within the scope of achieving the object of the present invention.

EXAMPLES The present invention will be described in detail below with reference to Examples, but the present invention is not limited to the description of these Examples.

(Reference example)
First, Li ₂ BaY ₄ O ₈ was synthesized as a reference example.

<Raw materials>
Lithium oxide (Li ₂ O, manufactured by Kojundo Chemical Co., Ltd.) _powder , barium oxide (BaO, _manufactured by Kojundo Chemical Co., Ltd.) powder, yttrium oxide ( _{Y 2} O ₃ , Kojundo Chemical Co., Ltd.) powder and europium oxide (Eu ₂ O ₃ , purity 99.9%, Shin-Etsu Chemical Co., Ltd.) powder were used.

Lithium oxide (Li ₂ O), barium oxide (BaO), and yttrium oxide (Y ₂ O ₃ ) were placed in a glove box filled with dry N ₂ gas so that the atomic ratio of Li, Ba, and Y was 2. : 1:4, and mixed for 10 minutes using a silicon nitride sintered pestle and mortar. Next, the raw material mixed powder thus obtained was filled in an alumina crucible.

The crucible filled with the mixed raw material powder was set in a tubular furnace. The firing procedure of the mixed powder was as follows. First, the firing atmosphere was once reduced to 10 Pa or less by a rotary pump, NH ₃ with a purity of 99.999% by volume was introduced to set the pressure in the furnace to atmospheric pressure, and the NH ₃ gas flow rate was controlled to 1 L / min. , the temperature was raised from room temperature to 1000° C. at a rate of 7° C./min, and the temperature was maintained for 4 hours. Then, after cooling to 400° C., the NH ₃ gas was switched to N 2 gas, and the flow rate was controlled to 1 L/min to cool to room temperature.

The fired raw material mixture powder (herein also referred to as “composite”) was taken out from the crucible and pulverized into powder using a pestle and mortar made of silicon nitride sintered body. Elemental analysis by ICP emission spectrometry was performed on this powdery composite, and the atomic ratio (analysis value) of Li:Ba:Y was 2.0:1.0:4.0, and the firing It was confirmed that there was no change in composition between before and after.

The powdery composite was observed with an optical microscope, and crystal particles with a size of 8 μm×6 μm×4 μm were collected and fixed to the tip of a glass fiber with an organic adhesive. Using a single-crystal X-ray diffractometer (SMART APEX II Ultra, manufactured by Bruker AXS) equipped with a MoKα ray rotating anticathode, the X-ray diffraction was measured under the conditions that the output of the X-ray source was 50 kV and 50 mA. did As a result, it was confirmed that this crystal grain was a single crystal.

The crystal structure was determined from the X-ray diffraction measurement results using single crystal structure analysis software (APEX2, manufactured by Bruker AXS). The crystal structure data obtained are shown in Table 1 above. Also, the crystal structure is shown in FIG. Table 1 describes the crystal system, space group, lattice constants, types of atoms, and atomic positions, and this data is used to determine the shape of the unit cell and the arrangement of atoms in the cell. be able to.

The crystal belongs to the monoclinic system, the space group C2/m,12, the lattice constants a, b, c and the angles α, β, γ are each a=1.3213 nm.
b = 0.3520 nm
c = 0.9538 nm
α=90.000°
β=119.746°
γ=90.000°
Met.

The atomic positions were as shown in Table 1 above.

From the crystal structure data shown in Table 1, it was confirmed that the Li ₂ BaY ₄ O ₈ crystal is a novel substance that has not been reported so far. Also, the powder X-ray diffraction pattern was calculated from the crystal structure data. FIG. 2 shows powder X-ray diffraction using CuKα rays calculated from the crystal structure of the Li ₂ BaY ₄ O ₈ crystal. From now on, powder X-ray diffraction measurement of the composite was performed, and if the measured powder X-ray diffraction pattern was the same as that of FIG. 2, it was determined that the Li ₂ BaY ₄ O ₈ crystal shown in FIG. 1 was produced.

Furthermore, with respect to _{the LpAqBrXs} crystal _, when _{a crystal} having _the same _{crystal structure} as the _Li2BaY4O8 crystal excluding the _Li2BaY4O8 crystal was examined, it was _{found that Li2BaY4O8} It has been found that the crystal can be partially or entirely replaced with La and Gd while retaining the crystal structure. That is, the crystal of Li _{2 BaBrO 8} (B is one, two or a mixture of Y, La and Gd) has the same crystal structure as the Li ₂ BaY ₄ O ₈ crystal.

A Li ₂ BaY ₄ O ₈ crystal in which the lattice constant and the like have changed while maintaining the crystal structure was also analyzed by powder X-ray diffraction analysis based on the lattice constant value obtained by the powder X-ray diffraction measurement and the crystal structure data in Table 1 above. patterns can be calculated. Therefore, by comparing the calculated powder X-ray diffraction pattern and the measured powder X-ray diffraction pattern, it can be determined whether it is a Li ₂ BaY ₄ O ₈ crystal.

(Example 1)
In a glove box filled with dry _N2 gas, according to the design composition (atomic ratio) in Example 1 shown in Table 2 below, the powdered raw material was mixed with the raw material mixture composition (mass ratio) shown in Table 3 below. Weighed to be
The weighed mixed raw material powder was mixed for 10 minutes using a silicon nitride sintered pestle and a mortar. After that, the mixed powder was filled in an alumina crucible.

The crucible filled with the mixed raw material powder was set in a tubular furnace. The firing procedure of the mixed powder was as follows. First, the firing atmosphere was once reduced to 10 Pa or less by a rotary pump, NH ₃ with a purity of 99.999% by volume was introduced to set the pressure in the furnace to atmospheric pressure, and the NH ₃ gas flow rate was controlled to 1 L / min. , the temperature was raised from room temperature to 1000° C. at a rate of 7° C./min, and the temperature was maintained for 4 hours. Then, after cooling to 400° C., the NH ₃ gas was switched to N 2 gas, and the flow rate was controlled to 1 L/min to cool to room temperature.

The fired product was taken out from the crucible and pulverized using an alumina pestle and mortar to obtain a powdery composite (phosphor of Example 1). When elemental analysis was performed on the powdered composite by ICP emission spectrometry, the atomic ratio (analysis value) of Li:Ba:Y was 2.0:1.0:4.0, and before and after firing It was confirmed that there was no change in composition.

(Example 2)
A phosphor (powder composite) of Example 2 was produced in the same manner as in Example 1 according to the design composition in Table 2 and the raw material mixture composition in Table 3, except that the powder raw materials to be mixed were different.

(Example 3)
A phosphor (powder composite) of Example 3 was produced in the same manner as in Example 1 according to the design composition in Table 2 and the raw material mixture composition in Table 3, except that the powder raw materials to be mixed were different.

The X-ray diffraction pattern of the composite in FIG. 4 shows good agreement with the X-ray diffraction pattern calculated from the Li ₂ BaY ₄ O ₈ crystal shown in FIG. 2, and has the same crystal structure as the Li ₂ BaY ₄ O ₈ crystal. It was confirmed to be a crystal.
For example, 2θ in FIG. ° and 51.84°, respectively, showing good agreement.

From the above, it was confirmed that the synthesized product of Example 1 was an inorganic compound in which the Li ₂ BaY ₄ O ₈ crystal was substituted with Eu. Although not shown, in Examples 2 and 3, X-ray diffraction patterns similar to those in Example 1 were obtained. The results of comparing the X-ray diffraction patterns of Examples 2 and 3 with the major peaks in FIG.

From the above, it was confirmed that the synthesized products of Examples 1 to 3 contained, as main components, novel inorganic compounds in which Eu activating ions were substituted for Li ₂ BaY ₄ O ₈ crystals.

[Luminous properties]
Regarding the powders of the composites of each example and comparative example, using a multichannel spectrometer (MCPD-9800 manufactured by Otsuka Electronics Co., Ltd.), monochromatic light separated from the emission light source at a wavelength of 378 nm was used as an excitation source. The sample was irradiated and the fluorescence spectrum measurement of the sample was performed.

[Luminous properties]
In Example 1, luminescence having a maximum emission intensity at 550 nm was observed. The full width at half maximum of the emission spectrum was 54 nm. In Example 2, luminescence with a maximum emission intensity at 550 nm was observed. The full width at half maximum of the emission spectrum was 65 nm. In Example 3, luminescence with a maximum emission intensity at 627 nm was observed.
On the other hand, in Comparative Example 1, emission having a maximum emission intensity at 611 nm was observed.

1 O atom 2 Li atom 3 B1 atom 4 Y atom 11 Surface mount type white light emitting diode lamp 12, 13 Lead wire 14 Blue light emitting diode element 16 First resin 17 Phosphor 18 Second resin 19 Alumina ceramic substrate 20 Wall member

Claims (10)

A phosphor containing an inorganic compound in which an element represented by M is solid-dissolved in a host crystal represented by L _p A _q B _r X _s ,
The L is one or more elements selected from Li, Na, K, Rb, and Cs,
The A is one or more elements selected from Sr, Ba, Mg, and Ca,
The B is one or more elements selected from La, Y, Ce, Gd, Sc, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, and Lu,
The X is O,
The M is Eu,
wherein said p, q, r and s are
14.70≤p+q+r+s≤15.30,
1.70≤p≤2.30,
0.70≤q≤1.30,
3.70≦r≦4.30 and 7.70≦s≦8.30;
When the phosphor is irradiated with excitation light having a wavelength of 378 nm, it emits light having a peak wavelength in the range of 540 nm or more and 650 nm or less.
Phosphor. The phosphor according to claim 1,
The phosphor, wherein the half width of the peak wavelength of the light is 40 nm or more and 70 nm or less. The phosphor according to claim 1 or 2,
The L is one or more elements selected from Li, Na, and K,
The A is one or two elements selected from Sr, Ba, and Ca,
The phosphor, wherein B is one or more elements selected from La, Y, Ce, Gd, Sc, Eu, and Lu. The phosphor according to any one of claims 1 to 3,
Part or all of the A is Ba element,
A phosphor in which part or all of B is at least one of La element, Gd element and Y element. The phosphor according to any one of claims 1 to 4,
The phosphor, wherein the host crystal is a monoclinic crystal. The phosphor according to any one of claims 1 to 5,
A phosphor, wherein the crystal structure of the host crystal belongs to the space group C2/m. The phosphor according to any one of claims 1 to 6,
The lattice constants a, b and c of the host crystal are
a=1.3213±0.1 nm,
A phosphor that satisfies b=0.3520±0.1 nm and c=0.9538±0.1 nm. The phosphor according to any one of claims 1 to 7,
The phosphor has a composition represented by the general formula L _e A _f B _g X _h : _Mi ,
The composition ratios e, f, g, h and i are
e+f+g+h+i=15.00,
1.70≦e≦2.30,
0.70≦f≦1.30,
3.70≤g≤4.30,
7. A phosphor satisfying 70≦h≦8.30 and 0.00<i≦0.20. A light emitting device comprising the phosphor according to any one of claims 1 to 8. A light-emitting device comprising the light-emitting element according to claim 9 .

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