TWI808946B - Phosphor, light emitting device, lighting device and image display device - Google Patents

Abstract

The present invention is a phosphor characterized by comprising a crystal phase represented by the following formula [2]. M _m Al _a O _x Si _b N _d [2] (In the above formula [2], M represents an active element; 0<m≦0.04;a+b=3;0<a≦0.08;3.6≦d≦4.2; x < a)

Description

Phosphor, light emitting device, lighting device and image display device

The invention relates to a phosphor, a light emitting device, a lighting device and an image display device.

In recent years, due to the energy-saving trend, the demand for lighting or backlight using LEDs has increased. The LED used here is a white light-emitting LED with a phosphor disposed on an LED chip that emits blue or near-ultraviolet wavelength light. As this kind of white light-emitting LED, in recent years, a nitride phosphor that emits red light using blue light from a blue LED chip as excitation light on a blue LED chip and a phosphor that emits green light have been used. . Especially in display applications, among the three colors of blue, green and red, the human eye has a particularly high visibility of green, which is very beneficial to the overall brightness of the display, so it is particularly important compared to the other two colors , the development of green phosphors with excellent luminous properties is expected. As a phosphor emitting green light, for example, a phosphor represented by the experimental formula of Sr _2.7 Si ₁₃ Al ₃ O ₂ N ₂₁ : Eu _0.3 is disclosed (Patent Document 1); Si _6-z Al _z O _z N A phosphor represented by the experimental formula of _8-z (0<z<4.2) (Patent Document 2); and a phosphor composed of a sialon (SiAlON) crystal in which Eu is dissolved in a crystal having a β-type Si ₃ N ₄ crystal structure Photobody (Patent Document 3) and the like. [Prior Art Document] [Patent Document]

[Patent Document 1] International Publication No. 2012/124480 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-255895 [Patent Document 3] International Publication No. 2006/101095

[Problems to be Solved by the Invention] Although various phosphors as described above have been developed, phosphors excellent in light-emitting characteristics are still being sought. In view of the above problems, the present invention provides a novel phosphor which has a crystal structure different from conventional phosphors and which has good light emitting characteristics and can be effectively used for LED applications.

[Means to solve the problem] In view of the above-mentioned problems, the inventors of the present invention conducted intensive research on the novelty of phosphors, and as a result, found a novel phosphor different from conventional phosphors that can be effectively used in LED applications, and further Complete the present invention. The present invention is as follows. [1] A phosphor characterized by comprising a crystal phase represented by the following formula [2]. M _m Al _a O _x Si _b N _d [2] (In the above formula [2], M represents an active element, 0<m≦0.04 a+b=3 0<a≦0.08 3.6≦d≦4.2 x<a ) [2] A phosphor characterized by comprising a crystal phase represented by the following formula [1]. M _m Al _a Si _b N _d [1] (In the above formula [1], M represents an active element, 0<m≦0.04 a+b=3 0<a≦0.08 3.6≦d≦4.2) [3] For example The phosphor of [1] or [2], wherein the M element in the formula [1] or [2] is Eu, and the Eu in the phosphor system is dissolved in a sialon crystal having a β-type Si3N4 crystal structure crystalline structure. [4] The phosphor according to any one of [1] to [3], which has an emission peak wavelength in the range of not less than 500 nm and not more than 560 nm by irradiating excitation light having a wavelength of not less than 300 nm and not more than 460 nm . [5] A light-emitting device characterized by comprising a first luminous body and a second luminous body that emits visible light when irradiated with light from the first luminous body, and the second luminous body includes the following items [1] to [4] ] any one of the phosphor. [6] A lighting device characterized by comprising the light emitting device as described in [5] as a light source. [7] An image display device characterized by comprising the light emitting device as described in [5] as a light source.

The novel phosphor of the present invention has a crystal structure different from that of conventional phosphors, and is excellent in light emitting characteristics, so that it can be effectively used in LED applications. Therefore, the light-emitting device using the novel phosphor of the present invention has excellent color rendering. Furthermore, the lighting device and the image display device including the light emitting device of the present invention are of high quality.

Hereinafter, the present invention will be described with reference to embodiments or exemplified objects, but the present invention is not limited to the following embodiments or exemplified objects, and can be arbitrarily modified and implemented without departing from the gist of the present invention. In addition, the numerical range represented by "~" in this specification means the range which includes the numerical value described before and after "~" as a lower limit and an upper limit. Also, in the experimental formulas of the phosphors in this specification, each experimental formula is separated by commas (,). Also, when a plurality of elements are listed separated by commas (,), it means that one or more of the listed elements can be contained in any combination and composition. For example, the experimental formula of "(Ca, Sr, Ba)Al ₂ O ₄ :Eu" generally represents all of the following: "CaAl ₂ O ₄ :Eu", "SrAl ₂ O ₄ :Eu", "BaAl ₂ O ₄ : Eu", "Ca _1-x Sr _x Al ₂ O ₄ : Eu", "Sr _1-x Ba _x Al ₂ O ₄ : Eu", "Ca _1-x Ba _x Al ₂ O ₄ : Eu", "Ca _1-xy Sr _x Ba _y Al ₂ O ₄ :Eu" (wherein, in the formula, 0<x<1, 0<y<1, 0<x+y<1).

The present invention includes the phosphor of the first embodiment, the light emitting device of the second embodiment, the lighting device of the third embodiment, and the image display device of the fourth embodiment.

[Phosphor] The phosphor according to the first embodiment of the present invention includes a crystal phase represented by the following formula [1]. M _m Al _a Si _b N _d [1] (In the above formula [1], M represents an active element, 0<m≦0.04 a+b=3 0<a≦0.08 3.6≦d≦4.2)

The M element means selected from europium (Eu), manganese (Mn), cerium (Ce), 鐠 (Pr), neodymium (Nd), samarium (Sm), 鋱 (Tb), dysprosium (Dy), ¨ (Ho), More than one element of the group consisting of erbium (Er), ytterbium (Tm) and ytterbium (Yb). M preferably contains at least Eu, more preferably Eu.

Furthermore, a part of Eu may be replaced by at least one element selected from the group consisting of Ce, Pr, Sm, Tb, and Yb, and Ce is more preferred from the viewpoint of luminous quantum efficiency. That is, M is even more preferably Eu and/or Ce, more preferably Eu.

The ratio of Eu to the entire activating element is preferably at least 50 mol%, more preferably at least 70 mol%, and most preferably at least 90 mol%. Al represents aluminum. Al can also be other chemically similar trivalent elements, such as boron (B), gallium (Ga), indium (In), scandium (Sc), yttrium (Y), lanthanum (La), gadolinium (Gd), lutetium (Lu) and so on to replace a part.

Si means silicon. Si may also be partially replaced by other chemically similar tetravalent elements, such as germanium (Ge), tin (Sn), titanium (Ti), zirconium (Zr), hafnium (Hf), and the like.

In formula [1], N represents a nitrogen element. Part of N may be substituted by other elements such as oxygen (O), halogen atoms (fluorine (F), chlorine (Cl), bromine (Br), iodine (I)) and the like.

In addition, considering that oxygen may be mixed in as an impurity in the raw material metal, and may be introduced during the pulverization step, the nitriding step, etc., oxygen is an inevitable occurrence in the phosphor of this embodiment. mixed substances. In addition, in consideration of the inclusion of halogen atoms, the inclusion as impurities in the raw material metal, or the introduction of halogen atoms during the grinding process, nitriding process, etc., especially when using a halogen compound as a flux, It may be included in the phosphor. m represents the content of mobilizing element M, and its range is usually 0<m≦0.04. The lower limit is preferably 0.0001, more preferably 0.0005, even more preferably 0.001, and even more preferably 0.005. Furthermore, the upper limit is preferably 0.02, the best is 0.01, and the best is 0.005.

a represents the content of Al, and its range is usually 0<a≦0.08, the lower limit is preferably 0.0001, more preferably 0.001, and even more preferably 0.005, and the upper limit is preferably 0.06, more preferably 0.04. b represents the content of Si element. The relationship between a and b satisfies a+b=3. d represents the content of N, and its range is usually 3.6≦d≦4.2. The lower limit is preferably 3.8, more preferably 3.9, particularly preferably 3.95, and the upper limit is preferably 4.1, more preferably 4.05.

From the standpoint of good light-emitting characteristics, especially light-emitting luminance, of the obtained phosphor, it is preferable that all the contents are within the above-mentioned range.

In the phosphor of this embodiment, even when oxygen is mixed, the crystal structure can be maintained by substituting part of Si-N in the crystal structure with Al-O. When Al is made relatively more than Si, O can be introduced into the N site while maintaining the relationship of charge compensation.

On the other hand, the phosphor of this embodiment is characterized in that the composition does not contain oxygen or contains very little oxygen. In addition, in this specification, "does not contain oxygen in the composition" is synonymous with "oxygen is below the detection limit when elemental analysis is performed on phosphor powder with the following EPMA or oxygen, nitrogen and hydrogen analyzer". In the case where the oxygen content of the phosphor of this embodiment is less than that of Al, although it is not clearly defined how to compensate the charge balance, it is considered that a part of Al and Eu are paired and replaced or defects are introduced, and local maintain balance. In this case, Al/Eu is preferably at least 0.05, more preferably at least 0.10, still more preferably at least 0.2, still more preferably at least 0.5, and most preferably at least 1.0.

Another aspect of the phosphor of this embodiment is, for example, a phosphor characterized by including a crystal phase represented by the following formula [2]. M _m Al _a O _x Si _b N _d [2] (In the above formula [2], M represents an active element, 0<m≦0.04 a+b=3 0<a≦0.08 3.6≦d≦4.2 x<a )

In the formula, the values of M element, Al, Si, N, and m, a, b, and d can be considered to be the same as formula [1]. x represents the content of oxygen (O), and its range is not particularly limited, but preferably x<a. That is, the content of O is preferably less than that of Al. This means that, as described above, by introducing Al into the crystal structure in a form other than Al—O, a phosphor with reduced oxygen can be obtained. x is preferably less than 0.05, more preferably less than 0.04, more preferably less than 0.03, even more preferably less than 0.01, especially preferably based on elemental analysis using EPMA or oxygen, nitrogen and hydrogen analysis equipment, O is below the detection limit, in the experimental formula No oxygen (ie, x=0). Therefore, x is preferably 0 or more, and the case of x=0 corresponds to the above formula [1]. x/a is preferably less than 1.0, more preferably less than 0.8, more preferably less than 0.6, even more preferably less than 0.4, especially preferably less than 0.2, especially preferably the same as above, that is, according to the use of EPMA or oxygen, nitrogen and hydrogen analysis equipment For elemental analysis of , oxygen is below the limit of detection, and oxygen is not included in the experimental formula (ie, by making x=0, x/a=0). Also, when too many defects are introduced because the O content is less than that of Al, it becomes a defect-causing site (killer site) and the luminescence characteristics may be lowered. Therefore, x+d is preferably at least 3.6, more preferably at least 3.7, even more preferably at least 3.8, even more preferably at least 3.9, and most preferably at least 3.95.

{Physical properties of the phosphor} [Crystal structure] The crystal structure of the phosphor of this embodiment is preferably a crystal structure of Eu solid-dissolved in a sialon crystal having a β-Si3N4 crystal structure. As the crystal structure of Si ₃ N ₄ , α-type and β-type are generally known, but in the phosphor of this embodiment, by making it β-type, it is possible to obtain a desired emission wavelength and have a half-length. It is preferable because it has a wide luminescence peak value.

[Lattice Constant] The lattice constant of the phosphor of this embodiment varies depending on the type of elements constituting the crystal, but is within the following range. The lattice constant of the a-axis (lattice constant La) is usually in the range of 7.600Å≦La≦7.630Å, and its lower limit is preferably 7.601Å, more preferably 7.602Å, and even more preferably 7.603Å. The limit value is preferably 7.620Å, more preferably 7.615Å. In addition, the lattice constant of the b-axis (lattice constant Lb) is the same as that of the a-axis. The lattice constant of the c-axis (lattice constant Lc) is usually in the range of 2.90Å≦Lc≦2.91Å, the lower limit is preferably 2.903Å, more preferably 2.906Å, and the upper limit is preferably 2.909 Å, more preferably 2.908Å, even more preferably 2.907Å.

In addition, if all the conditions are within the above ranges, the phosphor of this embodiment can be formed stably, and the formation of impurity phases can be suppressed, so the resulting phosphor has good luminance.

[Unit cell volume] The unit cell volume (V) calculated from the lattice constant in the phosphor of this embodiment is preferably 145.30Å ³ or more, more preferably 145.35Å ³ or more, still more preferably 145.40Å ³ or more, and preferably 146.50 Å ³ or less, more preferably 146.30 Å ³ or less, still more preferably 146.10 Å ³ or less. If the unit cell volume is too large or the unit cell volume is too small, impurities of other structures may be derived due to the instability of the skeleton structure, resulting in a decrease in luminous intensity or a decrease in color purity.

[Space Group] The crystal system of the phosphor in this embodiment is hexagonal. The space group in the phosphor of this embodiment is not particularly limited as long as the statistically determined average structure shows a repetition period of the above-mentioned length within the range that can be distinguished by single crystal X-ray diffraction. It is best to belong to No. 173 (P6 ₃ ) or No. 176 (P6 ₃ /m) according to "International Tables for Crystallography (Third, revised edition), Volume A SPACE-GROUP SYMMETRY". Here, the lattice constant and space group can be obtained according to conventional methods. The lattice constant can be obtained by Rietveld analysis on the results of X-ray diffraction and neutron ray diffraction, and the space group can be obtained by electron beam diffraction.

[Luminescent color] The luminous color of the phosphor in this embodiment can be excited by light in the near ultraviolet region to blue region such as wavelength 300nm~500nm by adjusting the chemical composition, etc., to form blue, blue-green, Green, chartreuse, yellow, orange, red, etc. are expected luminous colors.

[Emission Spectrum] The phosphor according to this embodiment preferably has the following characteristics when the emission spectrum is measured under excitation with light having a wavelength of 300 nm to 460 nm (especially a wavelength of 400 nm or 450 nm). In the phosphor of this embodiment, the peak wavelength in the above-mentioned emission spectrum is usually not less than 500 nm, preferably not less than 510 nm, more preferably not less than 520 nm. Also, it is usually not more than 560 nm, preferably not more than 550 nm, more preferably not more than 545 nm. If it is in the said range, since favorable green color will be shown in the phosphor obtained, it is preferable.

[Half-value width of emission spectrum] In the phosphor of this embodiment, the half-value width of the emission peak in the above-mentioned emission spectrum is usually 70 nm or less, preferably 60 nm or less, and usually 25 nm or more, preferably 25 nm or more. 30nm or more. By setting it as the said range, it can be used for the image display apparatuses, such as a liquid crystal display. When used to expand the color reproduction range of an image display device without reducing color purity, the half-value width of the luminous peak is preferably less than 50nm, more preferably less than 48nm, further preferably less than 45nm, and most preferably less than 43nm.

[Intensity Ratio in Emission Spectrum] In the above-mentioned image display device, in the case where the phosphor of the present embodiment is used in order not to lower the color purity and to expand the color reproduction range, except for the above-mentioned half-value width range, the emission spectrum The peak ratio is preferably within the following range. When the intensity of 512nm in the luminescent spectrum is set as P1 and the intensity of 525nm is set as P2, the value of P1/P2 is usually 0.1 or more, preferably 0.3 or more, more preferably 0.5 or more, and even more preferably 0.7 or more. Preferably it is 0.9 or more, particularly preferably 1.1 or more, especially preferably 1.3 or more, usually 3.0 or less, preferably 2.5 or less.

In addition, when the phosphor of the present embodiment is excited by light having a wavelength of 400 nm, for example, a GaN-based LED can be used. Also, for example, a 150W xenon lamp can be used as an excitation light source, and a fluorescence measuring device (manufactured by JASCO Corporation) equipped with a multi-channel charge-coupled device (CCD; charge-coupled device) detector C7041 (manufactured by Hamamatsu Photonics Co., Ltd.) can be used as a spectrum measuring device , measure the luminescence spectrum of the phosphor of this embodiment, and calculate its luminescence peak wavelength, peak relative intensity and peak half value width.

[CIE Chromaticity Coordinates] The x value of the CIE chromaticity coordinates of the phosphor of this embodiment is usually 0.240 or more, preferably 0.250 or more, more preferably 0.260 or more, usually 0.420 or less, preferably 0.400 or less , more preferably less than 0.380, more preferably less than 0.360, even more preferably less than 0.340. Also, the y value of the CIE chromaticity coordinates of the phosphor of this embodiment is usually 0.575 or more, preferably 0.580 or more, more preferably 0.620 or more, still more preferably 0.640 or more, usually 0.700 or less, preferably Below 0.690. By setting the CIE chromaticity coordinates within the above-mentioned range, when used in an image display device such as a liquid crystal display, it is possible to expand the color reproduction range of the image display device without lowering the color purity.

[Temperature Characteristics (Luminous Intensity Maintenance Rate)] The phosphor of this embodiment is also excellent in temperature characteristics. Specifically, in the case of irradiating light with a wavelength of 450 nm, the ratio of the peak emission intensity value in the emission spectrum at 150°C to the peak emission intensity value in the emission spectrum at 25°C is usually 50 % or more, preferably more than 60%, and especially preferably more than 70%. In addition, since the luminous intensity of general phosphors decreases as the temperature rises, it is difficult to think that this ratio will exceed 100%, but it may exceed 100% for some reasons. However, if it exceeds 100%, there is a tendency for color shift to occur due to temperature changes. In addition, when measuring the above-mentioned temperature characteristic, it is preferable to follow a conventional method, for example, the method of Unexamined-Japanese-Patent No. 2008-138156 etc. are mentioned.

[Excitation wavelength] The phosphor of this embodiment has a wavelength of usually above 300nm, preferably above 320nm, more preferably above 400nm, and usually below 480nm, preferably below 470nm, more preferably below 460nm The scope has an excitation peak. That is, excitation can be performed with light in the near ultraviolet to blue region.

<Method for producing phosphor> The raw materials for obtaining the phosphor of the present embodiment, the method for producing the phosphor, and the like are as follows. The manufacturing method of the phosphor of this embodiment is not particularly limited, for example, it can be manufactured by the following method: the raw material of the element M (hereinafter referred to as "M source" as appropriate), the raw material of the element Al (hereinafter appropriately referred to as "Al source"), a raw material of elemental Si (hereinafter referred to as "Si source" appropriately) are mixed into the stoichiometric ratio of formula [1] (mixing step), and the resulting mixture is fired (firing step). Moreover, below, for example, the raw material of element Eu may be referred to as "Eu source" etc. in some cases.

[Phosphor raw material] Examples of the phosphor raw material (namely, M source, Al source, and Si source) used to manufacture the phosphor of this embodiment include: each of M element, Al element, and Si element. Elemental metals, alloys, imide compounds, nitrogen oxides, nitrides, oxides, hydroxides, carbonates, nitrates, sulfates, oxalates, carboxylates, halides, etc. Considering the reactivity to compound nitrogen oxides and the low amount of NOx, SOx, etc. produced during firing, it is appropriate to select appropriately from among these compounds.

(M source) Among the M sources, specific examples of the Eu source include: Eu ₂ O ₃ , Eu ₂ (SO ₄ ) ₃ , Eu ₂ (C ₂ O ₄ ) ₃ ･10H ₂ O, EuCl ₂ , EuCl _3. Eu(NO ₃ ) ₃ ･6H ₂ O, EuN, EuNH, etc. Among them, Eu ₂ O ₃ , EuN, etc. are preferable, and EuN is particularly preferable. In addition, as specific examples of raw materials for other activating elements such as Sm source, Tm source, Yb source, etc., among the compounds listed as specific examples of Eu source, compounds in which Eu is replaced by Sm, Tm, Yb, etc. .

(Al Source) Specific examples of the Al source include AlN, Al ₂ O ₃ , Al(OH) ₃ , AlOOH, Al(NO ₃ ) ₃ , and the like. Among them, AlN and Al ₂ O ₃ are preferred, and AlN is particularly preferred. In addition, AlN is preferably one having a smaller particle diameter from the viewpoint of reactivity, and one having higher purity is preferable from the viewpoint of luminous efficiency. The oxygen content in Al metal or AlN is usually not more than 100 ppm, more preferably not more than 50 ppm, and still more preferably not more than 20 ppm. Specific examples of raw materials for other trivalent elements include compounds in which Al is substituted with B, Ga, In, Sc, Y, La, Gd, Lu, etc. among the compounds listed as specific examples of the Al source above. . In addition, simple Al can also be used as an Al source.

(Si source) Specific examples of the Si source include SiO ₂ , α-type Si ₃ N ₄ , and β-type Si ₃ N ₄ , preferably α-type Si ₃ N ₄ and β-type Si ₃ N ₄ . In addition, a compound that becomes SiO ₂ may also be used. Specific examples of such compounds include SiO ₂ , H ₄ SiO ₄ , Si(OCOCH ₃ ) ₄ , and the like. In addition, as α-type Si ₃ N ₄ , a smaller particle size is preferable from the viewpoint of reactivity, and a high purity is preferable from the viewpoint of luminous efficiency. Furthermore, it is preferable that the content ratio of the carbon element which is an impurity is small. In order to reduce the oxygen contained in the product, it is preferable to use a Si source containing less oxygen. Si metal can be used, and Si ₃ N ₄ containing less oxygen can also be used. The oxygen content in α-type Si ₃ N ₄ and β-type Si ₃ N ₄ is usually less than 100 ppm, preferably less than 80 ppm, more preferably less than 60 ppm, even more preferably less than 40 ppm, most preferably less than 20 ppm. More preferably, the α-type Si ₃ N ₄ containing more oxygen is subjected to heat treatment under the conditions of 1.0MPa or less and 1600°C or higher, so as to become β-type Si ₃ N ₄ with less oxygen before use. Specific examples of raw materials of other tetravalent elements include compounds in which Si is substituted with Ge, Ti, Zr, Hf, and the like among the compounds listed as specific examples of the above-mentioned Si source. In addition, as the Si source, simple Si may be used.

In addition, only one kind of the above-mentioned M source, Al source, and Si source may be used, or two or more kinds may be used in any combination and proportion.

[Mixing process] Weigh the raw material of the phosphor so that the target composition can be obtained, mix it well using a ball mill, etc., fill it into a crucible, and fire it at a predetermined temperature in an atmosphere of gas. The fired product is pulverized and washed. Thereby, the phosphor of this embodiment can be obtained.

The above-mentioned mixing method is not particularly limited, and may be either a dry mixing method or a wet mixing method. As a dry mixing method, a ball mill etc. are mentioned, for example. As a wet mixing method, for example, there is a method in which a solvent such as water or a dispersion medium is added to the above-mentioned phosphor raw material, mixed using a mortar and pestle to form a solution or slurry, and then spray-dried, It is dried by heat drying or natural drying.

[Firing step] The obtained mixture is filled in a heat-resistant container such as a crucible or a holder made of a material having low reactivity with each phosphor raw material. The material of the heat-resistant container used for such firing is not particularly limited as long as it does not impair the effect of the present embodiment, and examples thereof include crucibles such as boron nitride.

Although the firing temperature varies depending on other conditions such as pressure, firing can generally be carried out at a temperature ranging from 1700°C to 2150°C. The maximum attained temperature in the firing step is usually 1700°C or higher, preferably 1750°C or higher, and usually 2150°C or lower, preferably 2100°C or lower. If the firing temperature is too high, there is a tendency for nitrogen to scatter to cause defects in the matrix crystals to cause coloring. If it is too low, the progress of the solid phase reaction tends to slow down, and it may be difficult to obtain the target phase as the main phase. In order to further reduce oxygen mixed into the crystal structure, firing is preferably performed at a maximum attained temperature of 1800°C or higher, more preferably 1900°C or higher, and most preferably 2000°C or higher.

Although it varies depending on the firing temperature, etc., it is usually at least 0.2 MPa, preferably at least 0.4 MPa, and usually at most 200 MPa, preferably at most 190 MPa.

In the case of firing at a pressure of 10 MPa or less in the firing step, the maximum attained temperature during firing is usually 1800°C or higher, preferably 1900°C or higher, and usually 2150°C or lower, more preferably 2100°C or higher. below °C. By firing at the above-mentioned temperature, a crystal phase with a low oxygen content can be obtained. If the firing temperature is lower than 1800° C., the solid phase reaction does not proceed, so only an impurity phase or an unreacted phase appears, and it may be difficult to obtain the target phase as the main phase.

Also, even if a very small amount of the target crystal phase is obtained, there is a possibility that the element that becomes the luminescent center in the crystal, especially the Eu element, will not diffuse, resulting in a decrease in quantum efficiency. Also, if the firing temperature is too high, the elements constituting the target phosphor crystals are likely to volatilize, and there is a high possibility of forming lattice defects or decomposing to generate other phases as impurities.

The heating rate in the firing step is usually 2°C/minute or more, preferably 5°C/minute or more, more preferably 10°C/minute or more, and usually 30°C/minute or less, preferably 5°C/minute or more. Below 25°C/min. If the rate of temperature rise is lower than this range, the firing time may become longer. Moreover, if the temperature increase rate exceeds this range, the firing apparatus, the container, etc. may be damaged.

The firing gas atmosphere in the firing step is optional as long as the phosphor of this embodiment can be obtained, but a nitrogen-containing gas atmosphere is preferable. Specific examples include: a nitrogen atmosphere, a hydrogen-containing nitrogen atmosphere, etc., among which a nitrogen atmosphere is preferred. In addition, the oxygen content of the firing gas environment is generally preferably below 10 ppm, preferably below 5 ppm.

The firing time also varies depending on the temperature and pressure during firing, but is usually at least 10 minutes, preferably at least 30 minutes, and usually at most 72 hours, preferably at most 12 hours. If the firing time is too short, the formation and growth of grains cannot be promoted, so a phosphor with good characteristics cannot be obtained. If the firing time is too long, the volatilization of the constituent elements will be promoted, so there is a problem of induced The defect in the crystal structure prevents the phosphor with good characteristics from being obtained.

In addition, the firing step can also be repeated several times according to the requirement. At this time, the firing conditions may be the same or different in the first firing and the second firing.

Repeated firing is effective in the case of firing a phosphor with high internal quantum efficiency due to uniform diffusion of atoms during generation of the phosphor, or in the case of obtaining larger particles of several micrometers.

Also, in the case of producing the phosphor of this embodiment, it is preferable to use, for example, Li ₃ N, Na ₃ N, Mg ₃ N ₂ , Ca ₃ N ₂ , Sr ₃ N ₂ , Ba ₃ N ₂ etc. are used as flux (crystal growth auxiliary agent). In addition, when the phosphor is manufactured using flux, constituent elements of the flux such as Li, Na, Mg, Ca, Sr, and Ba may be mixed into the phosphor. The flux in this embodiment preferably has the effect of reducing the ratio of oxygen in the resulting phosphor in addition to the effect of the aforementioned crystal growth aid. In addition to the effect of crystal growth, by reducing the proportion of oxygen in the phosphor, it is possible to produce a phosphor with a narrow half-value width of the emission spectrum. In addition, in order to reduce the ratio of oxygen in the resulting phosphor, Si metal, Al metal, etc. can also be used as additives.

Furthermore, in order to reduce the ratio of oxygen in the crystalline phase, for the purpose of capturing gas containing oxygen in constituent elements such as SiO generated during firing, it is preferable to use a member that adsorbs the gas. Particularly preferred is a member made of C (carbon), and it is preferable to arrange a C-made felt or a C tube near the BN crucible.

[Post-processing step] Fragmentation, pulverization and/or classification operations are combined to make the obtained fired product into a powder of a predetermined size. Here, D50 is preferably processed to be about 30 μm or less. Specific examples of processing include: classifying the compound with a sieve with a pore size of about 45 μm, and transferring the sieved powder to the next step; or using general pulverization such as a ball mill, vibrating mill, or jet mill. A method in which a machine crushes a compound into a given particle size. In the latter method, excessive pulverization not only produces fine particles that easily scatter light, but also has the possibility of causing crystal defects on the surface of the particles, resulting in a decrease in luminous efficiency.

In addition, a step of washing the phosphor (fired product) may also be provided as required. After the cleaning step, it is dried until the moisture attached to the phosphor disappears, and is ready for use. Furthermore, dispersion and classification treatment can also be carried out according to the needs so as to disperse the coagulation. In addition, the phosphor of this embodiment can also be formed by the so-called alloying method, that is, forming by alloying and nitriding constituent metal elements in advance.

{Composition Containing Phosphor} The phosphor of the first embodiment of the present invention can also be used in admixture with a liquid medium. In particular, when the phosphor according to the first embodiment of the present invention is used for a light-emitting device or the like, it is preferably used in a form dispersed in a liquid medium. The phosphor according to the first embodiment of the present invention is dispersed in a liquid medium as one embodiment of the present invention, and is appropriately called "the phosphor-containing composition according to one embodiment of the present invention", etc. .

[Phosphor] The type of the phosphor of the first embodiment of the present invention contained in the phosphor-containing composition of the present embodiment is not limited, and can be arbitrarily selected from the above-mentioned ones. In addition, the phosphor of the first embodiment of the present invention contained in the phosphor-containing composition of this embodiment may be only one kind, or two or more kinds may be used in any combination and ratio. Furthermore, the phosphor-containing composition of the present embodiment may contain phosphors other than the phosphors of the first embodiment of the present invention as long as the effects of the present embodiment are not impaired.

[Liquid Medium] The liquid medium used in the phosphor-containing composition of the present embodiment is not particularly limited as long as it is within the target range and does not impair the performance of the phosphor. For example, any inorganic material and/or organic material can be used as long as it exhibits a liquid property under the expected use conditions, so that the phosphor of the first embodiment of the present invention can be better dispersed without adverse reactions. System materials, for example: polysiloxane resin, epoxy resin, polyimide polysiloxane resin, etc.

[Content Ratio of Liquid Medium and Phosphor] The content ratios of phosphor and liquid medium in the phosphor-containing composition of this embodiment can be arbitrary as long as the effect of this embodiment is not significantly impaired. , but regarding the liquid medium, it is usually 50% by weight or more, preferably 75% by weight or more, usually 99% by weight or less, and preferably 95% by weight relative to the entire phosphor-containing composition of this embodiment the following.

[Other Components] In addition, the phosphor-containing composition of the present embodiment may contain other components in addition to the phosphor and the liquid medium, as long as the effect of the present embodiment is not significantly impaired. Moreover, only 1 type may be used for other components, and 2 or more types may be used together in arbitrary combinations and ratios.

{Light-emitting device} The second embodiment of the present invention is a light-emitting device including a first luminous body (excitation light source) and a second luminous body that emits visible light when irradiated with light from the first luminous body. The luminous body includes the phosphor of the first embodiment of the present invention. Here, as for the phosphor of the first embodiment of the present invention, any one type may be used alone, or two or more types may be used in any combination and ratio.

As the phosphor according to the first embodiment of the present invention, for example, a phosphor that emits fluorescence in a green region when irradiated with light from an excitation light source is used. Specifically, when constituting a light-emitting device, the green phosphor in the first embodiment of the present invention preferably has a light emission peak in a wavelength range of 500 nm to 560 nm.

In addition, as an excitation source, one having an emission peak in a wavelength range of less than 420 nm can also be used. In the following, it is described that "the phosphor according to the first embodiment of the present invention has a luminescence peak in the wavelength range of 500 nm to 560 nm, and the first luminous body has a luminescence peak in the wavelength range of 300 nm to 460 nm". The aspect of the light emitting device, but the embodiment is not limited thereto.

In the above cases, the light-emitting device of this embodiment can be formed, for example, in the following aspects. That is, the following aspect can be formed: using as the first luminous body one having a luminescence peak in a wavelength range of 300 nm to 460 nm, using at least one phosphor having a luminescence peak in a wavelength range of 500 nm to 560 nm (the present invention Phosphor of the first embodiment) As the first phosphor of the second luminous body, a phosphor (red phosphor) having an emission peak in the wavelength range of 580nm to 680nm is used as the second luminous body The second phosphor.

(Red Phosphor) As the red phosphor in the above aspect, for example, the following phosphors are preferably used. As Mn activated fluoride phosphors, for example: K ₂ (Si, Ti) F ₆ : Mn, K ₂ Si _1-x Na _x Al _x F6: Mn (0<x<1); Phosphors, for example: (Sr, Ca) S:Eu (CAS phosphor), La ₂ O ₂ S:Eu (LOS phosphor); As garnet-based phosphors, for example (Y, Lu, Gd, Tb) ₃ Mg ₂ AlSi ₂ O ₁₂ : Ce; as nanoparticles, such as CdSe; as nitride or oxynitride phosphor, 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), Mx (Si, Al) ₁₂ (O, N) ₁₆ : Eu (M is Ca, Sr, etc.) (α-sialon phosphor), Li (Sr, Ba) Al ₃ N ₄ : Eu (the aforementioned x is all 0<x<1), etc. Among them, when used as an image display device with a wide color reproduction range, the half-value width of the light emission spectrum of the red phosphor in the above aspect is usually 90nm or less, preferably 70nm or less, more preferably 50nm or less, and then Preferably it is 30 nm or less, usually 5 nm or more, more preferably 10 nm or more. Among the above-mentioned phosphors, it is preferable to use Mn-activated fluoride phosphors and SrLiAl ₃ N ₄ :Eu phosphors.

(Yellow Phosphor) In the above-mentioned aspects, a phosphor (yellow phosphor) having an emission peak in the range of 550-580 nm may also be used as required. As the yellow phosphor, for example, the following phosphors are preferably used. As the garnet (Garnet) phosphor, for example (Y, Gd, Lu, Tb, La) ₃ (Al, Ga) ₅ O ₁₂ : (Ce, Eu, Nd); as the orthosilicate, For example (Ba, Sr, Ca, Mg) ₂ SiO ₄ : (Eu, Ce); As (oxy)nitride phosphor, for example: (Ba, Ca, Mg) Si2O 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) ₃ (Al, Si) ₆ N ₁₁ : Ce (LSN phosphor), etc. In addition, among the above-mentioned phosphors, a garnet-based phosphor is preferable, and among them, a YAG-based phosphor represented by Y ₃ Al ₅ O ₁₂ : Ce is most preferable.

(Green Phosphor) In the above-mentioned aspect, as the green phosphor, phosphors other than the phosphor of the first embodiment of the present invention may be included, for example, the following phosphors are preferably used. Examples of garnet-based 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); Examples of silicate phosphors include: (Ba, Sr, Ca, Mg) ₃ SiO ₁₀ : (Eu, Ce), (Ba , Sr, Ca, Mg) ₂ SiO ₄ : (Ce, Eu) (BSS phosphor); Examples of oxide phosphors include (Ca, Sr, Ba, Mg) (Sc, Zn) ₂ O ₄ : (Ce, Eu) (CASO phosphor); Examples of (oxy)nitride phosphors: (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); Examples of aluminate phosphors include (Ba, Sr, Ca, Mg) ₂ Al ₁₀ O ₁₇ : (Eu, Mn) (GBAM-based phosphor), etc.

[Structure of Light-Emitting Device] The light-emitting device of this embodiment has a first luminous body (excitation light source), and at least uses the phosphor of the first embodiment of the present invention as a second luminous body. There is no limitation, and any known device configuration can be adopted. Embodiments of the device configuration and the light-emitting device include, for example, those described in Japanese Patent Application Laid-Open No. 2007-291352. In addition, examples of the form of the light-emitting device include cannonball-type, cup-type, chip-on-board, and separate phosphors.

{Application of Light-Emitting Device} The application of the light-emitting device according to the second embodiment of the present invention is not particularly limited, and it can be used in various fields where general light-emitting devices are used, but it has a wider range of color reproduction and better color rendering. From a high point of view, it is particularly suitable as a light source for an illumination device or an image display device.

[Lighting device] The third embodiment of the present invention is a lighting device characterized by including the light emitting device of the second embodiment of the present invention as a light source. When applying the light-emitting device of the second embodiment of the present invention to a lighting device, it is preferable to properly assemble the above-mentioned light-emitting device into a known lighting device for use. Examples thereof include a surface emission lighting device in which a plurality of light emitting devices are arranged on the bottom surface of a holding case, and the like.

[Image display device] The fourth embodiment of the present invention is an image display device characterized by including the light emitting device of the second embodiment of the present invention as a light source. When the light-emitting device according to the second embodiment of the present invention 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, in the case of using a color image display device using a color liquid crystal display element as an image display device, the above-mentioned light-emitting device can be used as a backlight, and a shutter using a liquid crystal and a color filter having red, green, and blue pixels can be used. The sheets are combined to form an image display device.

EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely, this invention is not limited to a following Example unless it deviates from the summary.

<Measurement method> [Emission characteristics] A sample was placed in a copper sample holder, and the excitation emission spectrum and emission spectrum were measured using a spectrofluorometer FP-6500 (manufactured by JASCO). In addition, at the time of measurement, the measurement was performed with the slit width of the light-receiving side beam splitter being 1 nm. Also, the emission peak wavelength (hereinafter sometimes referred to as "peak wavelength") and the half-value width of the emission peak are read from the obtained emission spectrum.

[Chromaticity coordinates] The chromaticity coordinates of the x, y colorimetric system (CIE1931 colorimetric system) are the data obtained from the luminescence spectrum in the wavelength region of 460nm~800nm obtained by the above method, and the JIS is calculated according to the method of JIS Z8724 The chromaticity coordinates CIEx and CIEy in the XYZ color system specified in Z8701.

[Elemental analysis by EPMA] In order to study the elements of the phosphor obtained in the first embodiment of the present invention, the following elemental analysis was carried out. Several crystals were selected under observation with a scanning electron microscope (SEM), and analyzed for each element using an electron microprobe (wavelength dispersive X-ray analyzer: EPMA) JXA-8200 (manufactured by JEOL Corporation). In addition, the detection limit value of oxygen in this device is 100 ppm.

[Elemental analysis by ICP] Quantification of Si, Al, Eu, and Mg can be replaced by the following ICP elemental analysis in addition to EPMA elemental analysis. After alkali-melting the sample, acid was added to dissolve it, and the resulting sample solution was appropriately diluted, and quantified by an inductively coupled plasmon emission analyzer iCAP7600 Duo (manufactured by Thermo Fisher Scientific). The measurement conditions are as follows. RF power (RF power): 1200W Nebulizer gas flow: 0.60L/min Refrigerant gas flow: 12L/min Auxiliary gas: 1.0L/min

[O, N quantification] In an oxygen, nitrogen and hydrogen analyzer (TCH600 manufactured by LECO), in an inert gas environment, the quantification was carried out by pulse furnace heating extraction-NIR(O) detection method/TCD(N) detection method. In addition, the detection limit value of oxygen in this device is 0.2% by weight, and about 0.1 g of samples were measured in Examples and Comparative Examples.

[Powder X-ray Diffraction Measurement] The powder X-ray diffraction system performs precise measurement with a powder X-ray diffraction device D2 PHASER (manufactured by BRUKER). The measurement conditions are as follows. Use CuKα tube X-ray output=30KV, 10mA Scanning range 2θ=5°~65° Reading width=0.025°

[Refinement of lattice constant] From the powder X-ray diffraction measurement data of each example, the peak derived from the crystal structure classified as (P63/m) in space group (Intarnational Tables for Crystallography, No.176) was selected, and the data were used The processing software TOPAS4 (manufactured by Bruker Co.) was refined to determine the lattice constant.

{Manufacture of Phosphor} [Examples 1 to 7] Using EuN, Si ₃ N ₄ , and AlN as phosphor raw materials, phosphors were produced in the following manner. The above-mentioned raw materials were weighed with an electronic balance so as to have the respective weights shown in Table 1 below, and put into an alumina mortar, pulverized and mixed until uniform. Furthermore, 1.00 g of Mg ₃ N ₂ (manufactured by SHELLAC) was added as a flux to the mixed powder, and pulverized and mixed were further implemented. These operations were carried out in a glove box filled with Ar gas.

[Table 1]

About 0.5 g was weighed from the obtained raw material mixed powder, and it filled directly into the boron nitride crucible. This crucible was placed in a vacuum pressure firing furnace (manufactured by Shimadzu Mectem Co., Ltd.). Next, after reducing the pressure to 8×10 ^-3 Pa or less, vacuum heating was performed from room temperature to 800° C. at a temperature increase rate of 20° C./min. When reaching 800° C., maintain at this temperature and introduce nitrogen gas for 5 minutes until the pressure in the furnace becomes 0.85 MPa. After introducing nitrogen, while maintaining the pressure in the furnace at 0.85 MPa, the temperature was raised to 1600° C. and maintained for 1 hour. Furthermore, it was heated to 1950° C. and maintained for 4 hours when it reached 1950° C. After firing, cool to 1200°C, then leave to cool. Afterwards, the resultant was crushed to obtain the phosphors of Examples 3-7. In addition, with respect to Examples 1-2, after the product was crushed, green crystals were selected to obtain the phosphors of Examples 1-2.

The results of SEM observation of the phosphor of Example 1 are shown in the first figure. Also, the single crystal of Example 1 was selected by SEM observation, and elemental analysis (EPMA measurement) was carried out in order to study constituent elements and their ratios. The elements detected in EPMA are Eu, Al, Si, N, magnesium and oxygen are below the detection limit. As a result of quantitative analysis, the atomic ratio of Eu:Al:Si was 0.016(1):0.048(1):2.95(2). Numbers in parentheses indicate standard deviation. It was confirmed that the oxygen mixed during firing was almost zero.

Next, the single crystal structure of Example 1 was analyzed. From the results of basic reflection considerations obtained by single crystal X-ray diffraction, the crystal system of the phosphor in Example 1 is hexagonal, and the indices of lattice constants are a=7.6265(4)Å, b=7.6265( 4) Å, c=2.9075 (2) Å, α=90°, β=90°, γ=120°. Also, the unit cell volume of the phosphor of Example 1 is 146.454 Å3.

Also, the excitation-luminescence spectrum of the phosphor of Example 1 is shown in the second figure. Excitation spectra were monitored for luminescence at 540 nm. In addition, the emission spectrum is the measurement result when excited at 450 nm. It was confirmed that the phosphor of Example 1 exhibited an emission spectrum having an emission peak wavelength of 540 nm and a half-value width of 70 nm, and exhibited green emission.

For the phosphors of Examples 2 and 3, the single crystals of Examples 2 and 3 were selected by SEM observation, and analyzed by EPMA composition. The elements detected in EPMA are the same as in Example 1, Eu, Al, Si, N, and magnesium and oxygen are below the detection limit. Also, as a result of quantitative analysis, the atomic ratio of Eu:Al:Si was 0.008(1):0.039(1):2.96(2) in Example 2, and 0.006(1):0.030(1) in Example 3. : 2.97 (2). Numbers in parentheses represent standard deviations. It was confirmed that the oxygen mixed during firing was almost zero.

For the phosphor of Example 4, composition analysis by ICP and O/N analysis by an oxygen, nitrogen and hydrogen analyzer were implemented. As a result, oxygen was below the detection limit, and the atomic ratio of Eu:Al:Si was 0.003:0.04:2.96. The powder X-ray diffraction patterns of the phosphors of Examples 3, 4, 5, and 7 are shown in the third figure. Table 2 shows the lattice constants and unit cell volumes of the phosphors of Examples 2 to 7 refined from the obtained powder X-ray diffraction patterns. In Examples 2 to 7, phosphors having the same structure as in Example 1 were obtained almost in a single phase.

[Table 2]

It can be seen that in the phosphor obtained by the first embodiment of the present invention, by changing the ratio of Eu:Al:Si in the crystal, the a-axis changes from 7.604Å to 7.6265Å, and the c-axis changes from 2.906Å to 2.908Å, together with The unit lattice volume also varies from 145.53Å3 to 146.454Å3. For the phosphors of Examples 2, 3, 5, and 7, the emission spectra when excited by light with a wavelength of 450 nm are shown in the fourth figure. Also, for the phosphors of Examples 2 to 7, the emission peak wavelength, half width, and chromaticity read from the emission spectrum when excited with light having a wavelength of 450 nm are shown in Table 3.

[table 3]

It is clearly known that the phosphor obtained by the first embodiment of the present invention can change the ratio of Eu:Al:Si in the crystal to make the luminescence peak wavelength in the luminescence spectrum from 513nm to 540nm, and to make the half-value The width varies from 40nm to 76nm. That is, light emission from blue-green to yellow-green can be obtained with any composition.

[Example 8] Using Eu ₂ O ₃ , Si ₃ N ₄ , AlN, and Al ₂ O ₃ as phosphor raw materials, phosphors were produced in the following manner. As Si ₃ N ₄ , α-type Si3N4 (manufactured by Ube Industries: SN-E10) was heat-treated at 1950° C. for 12 hours in a nitrogen atmosphere at a pressure of 0.92 MPa to convert all of the β-type Si3N4 into Si 3 N 4 . The above-mentioned raw materials were weighed with an electronic balance so as to have the respective weights shown in Table 4 below, put into an alumina mortar, pulverized and mixed in the air until uniform. In Example 8 no magnesium nitride was used. About 2.0 g of the mixed powder from the obtained raw materials was directly filled into a crucible made of boron nitride. This crucible was placed in a vacuum pressure firing furnace (manufactured by Shimadzu Mectem Co., Ltd.). Next, after the pressure was reduced to below 8×10 ^-3 Pa, it was heated from room temperature to 800°C under vacuum at a heating rate of 20°C/min. When reaching 800° C., maintain at this temperature and introduce nitrogen gas for 5 minutes until the pressure in the furnace becomes 0.85 MPa. After introducing nitrogen, while maintaining the pressure in the furnace at 0.85 MPa, the temperature was raised to 1600° C. and maintained for 1 hour. Furthermore, it was heated to 2000° C. and maintained for 4 hours when it reached 2000° C. After firing, cool to 1200°C, then leave to cool. After that, the resultant was crushed to obtain the phosphor of Example 8.

Example 8 is all β-SiAlON single phase. [Table 4]

Composition analysis by ICP and O/N analysis by an oxygen, nitrogen and hydrogen analyzer were performed on Example 8. As a result, oxygen was detected, and the atomic ratio of Eu:Al:Si:O:N was 0.003:0.05:2.95:0.04:3.91. For the phosphors of Examples 4 and 8, the emission spectra when excited by light with a wavelength of 450 nm are shown in Fig. 5 . Also, for the phosphors of Example 4 and Example 8, the emission peak wavelength, half width, and chromaticity read from the emission spectrum when excited with light having a wavelength of 450 nm are shown in Table 5. It is clearly known that by reducing the oxygen in the crystal structure, the emission peak wavelength can be shortened, and the half-value width can also be narrowed.

[table 5]

none

The first figure is an image of the phosphor obtained in Example 1 observed with a scanning electron microscope (a photograph replacing the drawing). The second graph is a graph showing the excitation-luminescence spectrum of the phosphor obtained in Example 1. The dotted line represents the excitation spectrum, and the solid line represents the emission spectrum. The third graph is a graph showing the powder X-ray diffraction (XRD) patterns of the phosphors obtained in Examples 3, 4, 5, and 7. The fourth graph is a graph showing the emission spectra of the phosphors obtained in Examples 2, 3, 5, and 7. The fifth graph is a graph showing the emission spectra of the phosphors obtained in Examples 4 and 8.

none

Claims (8)

A phosphor characterized by comprising a crystalline phase represented by the following formula [2]: M _m Al _a O _x Si _b N _d [2] (in the above formula [2], M represents an activation element) ; 0<m≦0.04;a+b=3;0<a≦0.08;3.6≦d≦4.2;x/a≦0.4); wherein the oxygen content is 0.2% by weight or less. A phosphor characterized by comprising a crystalline phase represented by the following formula [1]: M _m Al _a Si _b N _d [1] (in the above formula [1], M represents an activation element; 0<m≦0.04 ; a+b=3; 0<a≦0.08;3.6≦d≦4.2); wherein the crystal phase of the phosphor does not contain oxygen. For the phosphor of claim 1 or 2 of the scope of the patent application, wherein the M element in the formula [1] or [2] is Eu, and the Eu in the phosphor system is dissolved in a crystal with a β-type Si ₃ N ₄ crystal structure The crystal structure of SiAlON crystal. The phosphor according to claim 1 or 2 of the patent application, wherein the emission peak wavelength ranges from 500 nm to 560 nm by irradiating excitation light having a wavelength of 300 nm to 460 nm. For example, the phosphor according to claim 3 of the patent application, which has a peak emission wavelength in the range of 500nm to 560nm by irradiating excitation light with a wavelength of 300nm to 460nm. A light-emitting device, characterized by comprising a first luminous body and a second luminous body that emits visible light when irradiated with light from the first luminous body, and the second luminous body includes claims 1 to 5 of the scope of the application Phosphor according to any one of them. An illuminating device is characterized by having a light-emitting device according to Claim 6 of the scope of the patent application as a light source. An image display device is characterized in that it has a light emitting device as claimed in Claim 6 of the scope of the patent application as a light source.