Oxide phosphor, light-emitting device, and method for producing oxide phosphor

Abstract

To provide an oxide phosphor, a light-emitting device, and a method for producing an oxide phosphor.SOLUTION: An oxide phosphor comprises: phosphor particles that comprise a host crystal containing Ga and oxygen, and an activating element; and first compound particles disposed on the surface of the phosphor particles. The first compound particle comprises oxide particles. The oxide particle comprises at least one first element selected from the group consisting of Group 4 elements, Group 5 elements, Group 14 elements, and Group 15 elements.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to an oxide phosphor, a light-emitting device, and a method for producing the oxide phosphor. [Background technology]

[0002] Light-emitting devices having an emission intensity in the wavelength range from red light to near-infrared light are desired for use in, for example, infrared cameras, infrared communications, light sources for plant growth and cultivation, vein authentication which is a type of biometric authentication, food component analyzers that non-destructively measure the sugar content of agricultural products such as fruits and vegetables or foods, analytical instruments that non-destructively measure the presence of foreign matter in pharmaceuticals, etc. Light-emitting devices that emit light in the wavelength range from red light to near-infrared light as well as in the visible light range are also desired.

[0003] Such a light emitting device may be a light emitting device that combines a light emitting diode (LED) and a phosphor. Furthermore, examples of phosphors that can be combined with light emitting devices include phosphors that have a relatively large emission spectrum with a high emission intensity in the wavelength range from red light to near-infrared light (hereinafter also referred to as "near-infrared light emitting phosphors").

[0004] Patent Document 1 describes a near-infrared emitting phosphor having an emission peak wavelength in the range of 680 nm to 760 nm, and a composition of, for example, CaYAlO4:Mn 4+ The phosphor represented by the formula: [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2020-528486 Summary of the Invention [Problem to be solved by the invention]

[0006] In order to be suitable for the above-mentioned applications, there may be a demand for a near-infrared emitting phosphor having an emission spectrum with a wider full width at half maximum and an emission peak wavelength in a longer wavelength range. An object of the present disclosure is to provide an oxide phosphor having an emission peak wavelength in the wavelength range from red light to near-infrared light and having high emission intensity, a light-emitting device, and a method for producing the oxide phosphor. [Means for solving the problem]

[0007] The first aspect is an oxide phosphor comprising phosphor particles including a host crystal containing Ga and oxygen, and an activator element, and first compound particles arranged on the surfaces of the phosphor particles, wherein the first compound particles include oxide particles, and the oxide particles include at least one first element selected from the group consisting of Group 4 elements, Group 5 elements, Group 14 elements, and Group 15 elements.

[0008] A second aspect is a light emitting device comprising the oxide phosphor and a light emitting element having an emission peak wavelength in the range of 365 nm to 650 nm, and irradiating the oxide phosphor with excitation light.

[0009] The third aspect is a method for producing a raw material mixture containing a compound containing Ga and a compound containing Cr as an activator element; preparing a first flux containing an oxide containing at least one first element selected from the group consisting of Group 4 elements, Group 5 elements, Group 14 elements, and Group 15 elements; mixing the raw material mixture and the first flux to obtain a mixture; and heat-treating the mixture to obtain an oxide phosphor comprising phosphor particles and first compound particles containing the first element arranged on the surfaces of the phosphor particles.

[0010] A fourth aspect of the present invention is to prepare a raw material mixture containing a compound containing Ga and a compound containing Cr as an activator element; preparing a first flux containing an oxide containing at least one first element selected from the group consisting of Group 4 elements, Group 5 elements, Group 14 elements, and Group 15 elements; preparing a second flux containing a compound containing at least one second element selected from the group consisting of alkali metal elements and alkaline earth metal elements; mixing the raw material mixture, the first flux, and the second flux to obtain a mixture; and heat-treating the mixture to obtain an oxide phosphor comprising phosphor particles, first compound particles containing the first element and disposed on the surfaces of the phosphor particles, and second compound particles containing the second element and disposed on the surfaces of the phosphor particles. [Effects of the Invention]

[0011] According to the present disclosure, it is possible to provide an oxide phosphor having an emission peak wavelength in the wavelength range from red light to near-infrared light and having high emission intensity, a light-emitting device, and a method for producing the oxide phosphor. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic cross-sectional view showing an example of a first configuration example of a light emitting device. [Figure 2] FIG. 4 is a schematic cross-sectional view showing another example of the first configuration example of the light emitting device. [Figure 3] FIG. 10 is a schematic plan view showing a second configuration example of the light emitting device. [Figure 4] FIG. 10 is a schematic cross-sectional view showing a second configuration example of the light emitting device. [Figure 5] 1 is a diagram showing the emission spectra of oxide phosphors according to Examples 1 and 2 and an oxide phosphor according to Comparative Example 1. FIG. [Figure 6] FIG. 1 is a diagram showing the emission spectra of oxide phosphors according to Examples 3 to 5. [Figure 7] FIG. 1 is a diagram showing the emission spectra of oxide phosphors according to Examples 6 to 8. [Figure 8]FIG. 10 is a diagram showing the emission spectra of oxide phosphors according to Examples 9 and 10. [Figure 9] FIG. 1 is a diagram showing the emission spectra of oxide phosphors according to Examples 11 and 12. [Figure 10] 1 is a SEM photograph of an oxide phosphor according to Example 1. [Figure 11] 10 is a SEM photograph of the surface of the oxide phosphor according to Example 4. [Figure 12] 10 is an SEM photograph showing the distribution of the first element (Nb) contained in oxide particles, which are first compound particles, by EDX analysis of the surface of the oxide phosphor according to Example 4. [Figure 13] 10 is an SEM photograph showing the distribution of the second element (Na) contained in the second compound particles by EDX analysis of the surface of the oxide phosphor according to Example 4. [Figure 14] 1 is a SEM photograph of an oxide phosphor according to Comparative Example 1. [Figure 15] 1 shows an X-ray diffraction pattern of the oxide phosphor according to Example 12, and powder X-ray diffraction patterns showing the crystal structures of β-Ga2O3, Na13Nb35O94, and Na(NbO3). [Figure 16] FIG. 1 is a diagram showing the emission spectra of oxide phosphors according to Examples 13 to 15. [Figure 17] FIG. 1 is a diagram showing the emission spectra of oxide phosphors according to Examples 16 to 18. [Figure 18] FIG. 10 is a diagram showing the emission spectra of oxide phosphors according to Examples 19 and 20. [Figure 19] FIG. 1 is a diagram showing the emission spectra of oxide phosphors according to Examples 21 to 24. [Figure 20] FIG. 10 is a diagram showing the emission spectra of oxide phosphors according to Examples 25 to 28. [Figure 21] FIG. 1 is a diagram showing the emission spectra of the oxide phosphors according to Examples 29 to 31 and the oxide phosphor according to Comparative Example 2. [Figure 22] FIG. 10 is a diagram showing the emission spectra of the oxide phosphor according to Example 32 and the oxide phosphor according to Comparative Example 3. [Figure 23]FIG. 10 is a diagram showing the emission spectra of the oxide phosphor according to Example 33 and the oxide phosphor according to Comparative Example 4. [Figure 24] FIG. 10 is a diagram showing the emission spectra of the oxide phosphor according to Example 34 and the oxide phosphor according to Comparative Example 5. [Figure 25] FIG. 10 is a diagram showing the emission spectra of the oxide phosphor according to Example 35 and the oxide phosphor according to Comparative Example 6. [Figure 26] FIG. 10 is a diagram showing the emission spectra of the oxide phosphor of Example 36 and the oxide phosphor of Comparative Example 7. DETAILED DESCRIPTION OF THE INVENTION

[0013] The oxide phosphor, light-emitting device, and method for manufacturing the oxide phosphor according to the present disclosure will be described below. However, the embodiments shown below are merely examples for embodying the technical concept of the present invention, and the present invention is not limited to the oxide phosphor, light-emitting device, and method for manufacturing the oxide phosphor described below. Note that, for visible light, the relationship between color names and chromaticity coordinates, the relationship between light wavelength ranges and color names of monochromatic light, etc., conforms to JIS Z8110.

[0014] Light-emitting devices using phosphors are required to emit light in an optimal wavelength range depending on the visual target and usage conditions. For example, in medical settings, it is sometimes necessary to easily obtain information inside a living body. The living body contains light absorbers such as water, hemoglobin, and melanin. For example, hemoglobin has a high absorption rate for light in the visible wavelength range of less than 650 nm. Therefore, light-emitting devices that emit light in the visible wavelength range have difficulty transmitting light in the visible wavelength range inside the living body, making it difficult to obtain information inside the living body. If light in a wavelength range where absorption and scattering of light in biological tissue are reduced can be irradiated, it will be easier to obtain information deep inside the living body. Therefore, there is a demand for light-emitting devices that can emit light in a wavelength range known as the "biological window," which allows light to easily penetrate inside the living body. The wavelength range of approximately 650 nm to 950 nm is sometimes referred to as the "first biological window," the wavelength range of approximately 1000 nm to 1350 nm is sometimes referred to as the "second biological window," and the wavelength range of approximately 1500 nm to 1800 nm is sometimes referred to as the "third biological window." If it were possible to irradiate light in a wavelength range where the absorption and scattering of light by in vivo tissues is reduced, it would be easier to obtain information about deep tissues within the body. For example, if it were possible to measure increases or decreases in the oxygen concentration in blood by measuring the increase or decrease in light absorption by hemoglobin, which binds to oxygen, it would be possible to easily obtain information about deep tissues within the body by irradiating light from a light-emitting device. Furthermore, if information about deep tissues within the body could be obtained by irradiating light from a phosphor and a light-emitting element rather than by irradiation with X-rays or other radiation, it would be possible to obtain information about the body more safely. Therefore, phosphors used in light-emitting devices may be required to have a peak emission wavelength in the red to near-infrared wavelength range. The phosphor used in the light-emitting device may be a phosphor having an emission peak wavelength in the range of 680 nm to 1000 nm, preferably 700 nm to 1000 nm, or 1100 nm to 1400 nm, when excited by light from a light-emitting element that irradiates light having an emission peak wavelength in the range of 365 nm to 650 nm. Recently, there has been a demand for light-emitting devices that emit light in the wavelength range from red light to near-infrared light, which is highly safe and enables clearer visualization of deep areas inside a living body.Furthermore, in a light-emitting device including a light-emitting element and a phosphor, if the device is equipped with a phosphor with high luminescence intensity that can emit high-power light, detection capabilities can be further improved, making it easier to obtain information inside the living body.

[0015] In the agricultural and food industries, there is a demand for nondestructive sugar content meters that can nondestructively measure the sugar content of agricultural produce and fruits and vegetables, as well as measuring instruments (e.g., Taste Meter (registered trademark)) that can nondestructively test the taste of, for example, rice. Near-infrared spectroscopy is sometimes used as a nondestructive method for measuring the internal quality of fruits and vegetables, such as sugar content, acidity, ripeness, and internal damage, as well as the surface quality, such as abnormal dryness, that appears on the surface of the fruit and vegetable peel or the surface layer near the surface. Near-infrared spectroscopy irradiates fruits and vegetables with light in the near-infrared wavelength range, receives the transmitted light that penetrates the fruit and vegetables, and receives the reflected light that is reflected by the fruit and vegetable, and measures the quality of the fruit and vegetable based on the decrease in light intensity (light absorption). Near-infrared spectroscopy analytical devices used in such food industries use light sources such as tungsten lamps and xenon lamps. JIS K0134, General Rules for Near-Infrared Spectroscopic Analysis, states that near-infrared refers to the wavelength range from 700 nm to 2500 nm.

[0016] Furthermore, amid environmental changes such as climate change, there is a need for a stable supply of vegetables and other plants and for increased plant production efficiency. Plant factories, which allow for artificial management, can steadily supply safe vegetables to the market and are expected to be a next-generation industry. Such plant factories require light-emitting devices that can irradiate light that promotes plant growth. Plant responses to light can be divided into photosynthesis and photomorphogenesis. Photosynthesis, which utilizes light energy to split water, generate oxygen, and fix carbon dioxide into organic matter, is necessary for plant growth. Photomorphogenesis is a morphological response that uses light as a signal to germinate seeds, differentiate (germination, leaf formation, etc.), move (stomatal opening and closing, chloroplast movement), and refraction light. It has been shown that light in the wavelength range of 690 nm to 800 nm affects plant photoreceptors during photomorphogenesis. Therefore, light-emitting devices used in plant factories and the like are sometimes required to be able to emit light in a wavelength range that affects plant photoreceptors (chlorophyll a, chlorophyll b, carotenoids, phytochromes, cryptochromes, phototropins) and promotes plant growth.

[0017] Regarding the near-infrared light-emitting phosphors mentioned above, when a light-emitting element such as a light-emitting diode (LED) or laser diode (LD) that emits violet to blue light is used as an excitation light source to form a light-emitting device, a phosphor with high emission intensity is required so that emission suitable for the application can be achieved and detection can be performed with higher accuracy.

[0018] In addition, there are cases where light emitting devices that emit light in the wavelength range of 365 nm to less than 700 nm are required, in addition to emitting light in the wavelength range from red light to near-infrared light. For example, there are cases where emission in the wavelength range of visible light is required not only to obtain internal information about living organisms or fruits and vegetables, but also to improve the visibility of the target object.

[0019] The oxide phosphor includes phosphor particles containing a host crystal containing Ga and oxygen, an activator element, and first compound particles arranged on the surfaces of the phosphor particles, the first compound particles including oxide particles, and the oxide particles including at least one first element selected from the group consisting of Group 4 elements, Group 5 elements, Group 14 elements, and Group 15 elements.

[0020] The oxide phosphor is obtained by heat-treating a raw material mixture containing a host crystal containing Ga and oxygen for the oxide phosphor and a compound containing an element that serves as an activator element, together with a first flux containing an oxide containing at least one first element selected from the group consisting of Group 4 elements, Group 5 elements, Group 14 elements, and Group 15 elements. The first flux, which is heat-treated together with the raw material mixture, adheres to the surface of the resulting phosphor particles as first compound particles containing the first element or a film-like first compound containing the first element. The first compound particles containing the first element or the film-like first compound containing the first element that adhere to the surface of the phosphor particles are also referred to as the first compound. The first compound particles include oxide particles.

[0021] The particle size of the first compound particles attached to the surface of the phosphor particles is smaller than that of the phosphor particles. The attachment of the first compound particles to the surface of the phosphor particles can be confirmed, for example, by SEM images taken with a scanning electron microscope (SEM). The oxide phosphor can also be analyzed with an energy dispersive X-ray analyzer (EDX) to confirm the presence of the first compound particles on the surface of the phosphor particles. SEM or EDX can be measured using, for example, an SEM-EDX device (e.g., Model No. SU8230, manufactured by Shimadzu Corporation, and a silicon drift detector, manufactured by Horiba, Ltd.). The particle size of the first compound particles attached to the surface of the phosphor particles is also confirmed to be smaller than that of the phosphor particles from images obtained by SEM or EDX analysis. The film-like first compound attached to the surface of the phosphor particles can also be confirmed by analyzing the obtained phosphor with, for example, an energy dispersive X-ray analyzer (EDX).

[0022] The amount of the first element contained in the first compound particles is preferably in the range of 0.05% to 80% by mass, when the total amount of the oxide phosphor is taken as 100% by mass. The amount of the first element contained in the first compound particles is more preferably in the range of 0.05% to 75% by mass, even more preferably in the range of 0.08% to 70% by mass, and particularly preferably in the range of 0.10% to 70% by mass, and may be 60% to 50% by mass, 30% to 20% by mass, or even less. When the amount of the first element contained in the first compound particles is in the range of 0.05% to 80% by mass, when the total amount of the oxide phosphor is taken as 100% by mass, the flux containing the first element promotes crystal growth of the phosphor particles, resulting in phosphor particles of large particle size and high luminescence intensity. The amount (mass %) of the first element contained in the first compound particles can be measured, for example, by completely dissolving the first compound particles or phosphor particles having a film-like first compound attached to their surfaces (i.e., oxide phosphor) in a mixed solution of sulfuric acid and nitric acid, and then calculating the amount (mass %) of the element derived from the first compound by inductively coupled plasma atomic emission spectrometry (ICP-AES). When the same element derived from the first compound is contained in the phosphor particles, the amount (mass %) of the first element measured by ICP-AES also includes the amount (mass %) of the same element as the first element contained in the oxide phosphor. Even when the same element derived from the first compound is contained in the phosphor particles, the flux containing the first element promotes crystal growth of the phosphor particles as long as the amount (mass %) of the first element is within the range of 0.05% to 80% by mass, assuming the total amount of the oxide phosphor as 100% by mass.

[0023] The at least one first element selected from the group consisting of Group 4 elements, Group 5 elements, Group 14 elements, and Group 15 elements is preferably at least one selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Si, Ge, Sn, Pb, P, As, Sb, and Bi. The first element is more preferably at least one selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Si, Ge, Sn, P, and Bi. The first element is even more preferably at least one selected from the group consisting of Ti, Zr, Hf, Nb, Ta, Si, Ge, and P. The first element may be a single element or two or more elements.

[0024] The first compound particles include oxide particles, and the oxide particles are oxide particles containing a first element. The first compound particles may contain an oxide salt in which an element contained in the phosphor particles is bonded to an oxide. The oxide particles preferably contain an oxide contained in the first flux, which will be described later. When the first element is phosphorus (P), the first compound particles may be in the form of a phosphate. For example, ammonium phosphate ((NH4)3PO4), diammonium hydrogen phosphate ((NH4)2HPO4), or ammonium dihydrogen phosphate (NH4H2PO4) may be used.

[0025] The oxide phosphor preferably further comprises second compound particles arranged on the surface of the phosphor particle, and the second compound particles preferably comprise at least one second element selected from the group consisting of alkali metal elements and alkaline earth metal elements. The oxide phosphor preferably comprises first compound particles and second compound particles arranged on the surface of the phosphor particle.

[0026] The oxide phosphor is obtained by heat-treating a raw material mixture containing a compound containing Ga and a compound containing an element that serves as an activator, together with a first flux containing a compound containing a first element and / or a second flux containing a compound containing at least one second element selected from the group consisting of alkali metal elements and alkaline earth metal elements. The first flux and / or the second flux, which are heat-treated together with the raw material mixture, become first compound particles and / or second compound particles and adhere to the surface of the resulting phosphor particles. The first flux and / or the second flux, which are heat-treated together with the raw material mixture, may also adhere to the surface of the phosphor particles as a partial film-like first compound containing the first element or a film-like second compound containing the second element. The oxide phosphor can be obtained by heat-treating a raw material mixture containing a compound containing Ga and a compound containing an element that serves as an activator, a first flux containing a compound containing a first element, and a second flux containing a compound containing at least one second element selected from the group consisting of alkali metal elements and alkaline earth metal elements, to obtain phosphor particles with a larger particle size and higher luminescence intensity. The second compound particles containing the second element or the film-like second compound containing the second element that adhere to the surface of the phosphor particles are also referred to as the second compound.

[0027] The amount of the second element contained in the second compound particles is preferably in the range of 0.01% to 80% by mass, based on 100% by mass of the total amount of the oxide phosphor. The amount of the second element contained in the second compound particles is more preferably in the range of 0.02% to 60% by mass, even more preferably in the range of 0.03% to 50% by mass, even more preferably in the range of 0.05% to 40% by mass, and particularly preferably in the range of 0.10% to 30% by mass, and may be 20% or less, or even 15% or less by mass. When the amount of the second element contained in the second compound particles is in the range of 0.01% to 80% by mass, based on 100% by mass of the total amount of the oxide phosphor, the flux containing the second element promotes crystal growth of the phosphor particles, resulting in phosphor particles with larger particle sizes and higher luminescence intensity. The amount (mass %) of the second element contained in the second compound can be measured, for example, by completely dissolving second compound particles or phosphor particles having a film-like second compound attached to their surfaces (i.e., oxide phosphor) in a mixed solution of sulfuric acid and nitric acid, and then calculating the amount (mass %) of the element derived from the second compound using inductively coupled plasma atomic emission spectrometry (ICP-AES). If the phosphor particles contain the same element as the second element derived from the second compound, the amount (mass %) of the second element measured by ICP-AES also includes the amount (mass %) of the same element as the second element contained in the phosphor particles. Even if the phosphor particles contain the same element as the second element derived from the second compound, the flux containing the first element will promote crystal growth of the phosphor particles as long as the amount (mass %) of the first element is within the range of 0.05% to 80% by mass, assuming the total amount of the oxide phosphor as 100% by mass.

[0028] When the oxide phosphor has first compound particles or a film-like first compound and second compound particles or a film-like second compound attached to the surface of the phosphor particles, the amount of the first element is preferably greater than the amount of the second element. When the amount of the first element is greater than the amount of the second element, this indicates that the first flux is greater than the second flux in the first and second fluxes that are heat-treated together with the raw material mixture. When the amount of the first flux is greater than the second flux, crystal growth is promoted, resulting in phosphor particles of an oxide phosphor with larger particle size and higher luminescence intensity. The reason why crystal growth is promoted when the amount of the first flux is greater than the amount of the second flux is unclear, but the oxide containing the first element contained in the first flux often has a higher melting point than the compound containing the second element contained in the second flux. It is presumed that when a flux containing a larger amount of the first flux than the second flux is heat-treated together with the raw material mixture, the temperature at which the liquid phase of the product formed by the reaction between the compound used as the flux and part of the raw material mixture is formed is lower and closer to the heat treatment temperature for obtaining phosphor particles, which is presumed to further promote the reaction of the compounds contained in the raw material mixture.

[0029] The second element is at least one selected from the group consisting of alkali metal elements and alkaline earth metal elements. The second element is preferably at least one selected from the group consisting of Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, and Ba. The second element is more preferably at least one selected from the group consisting of Li, Na, K, Rb, Mg, Ca, Sr, and Ba. The second element is further preferably at least one selected from the group consisting of Li, Na, K, Rb, Mg, Ca, Sr, and Ba, and even more preferably at least one selected from the group consisting of Li, Na, K, Rb, Sr, and Ba. The second element may be one type alone or two or more types.

[0030] The oxide phosphor preferably has a volume average particle size at 50% cumulative concentration in a volume-based particle size distribution measured by laser diffraction particle size distribution measurement within the range of 10 μm to 50 μm. Laser diffraction particle size distribution measurement is a measurement method for distributing particle sizes without distinguishing between primary and secondary particles by utilizing scattered light from laser light irradiated onto particles. The volume median diameter Dm measured by laser diffraction particle size distribution measurement is the volume median diameter at 50% cumulative frequency from the small diameter side in the volume-based particle size distribution. By heat-treating the oxide phosphor with the first flux, the oxide phosphor contains a first element, and the volume average particle size measured by laser diffraction particle size distribution measurement increases to within the range of 10 μm to 48 μm. The volume average particle size of the oxide phosphor in a volume-based particle size distribution measured by laser diffraction particle size distribution measurement is more preferably within the range of 15 μm to 45 μm, and even more preferably within the range of 20 μm to 45 μm.

[0031] The phosphor particles of the oxide phosphor may contain a host crystal containing Ga and oxygen and an activator element, and preferably have a composition represented by the following formula (1), a composition represented by the following formula (2), or a composition represented by the following formula (3). (Ga 1-V1 M 1 V1 )2O3:Cr x1 (1) (In the above formula (1), M 1 is at least one element selected from the group consisting of Al, In, and rare earth elements, and v1 and x1 satisfy 0≦v1≦1.0 and 0.02≦x1≦0.3, respectively. (Mg 1-t2 M 2 t2 ) u2 (Ga 1-v2-x2 M 3 v2 )2O w2 :Cr 2x2 ,M 4 y2 (2) (In the above formula (2), M 2is at least one element selected from the group consisting of Ca, Sr, Ba, Ni, and Zn, and is M 3 is at least one element selected from the group consisting of B, Al, In, and Sc, and is M 4 is at least one element selected from the group consisting of Eu, Ce, Tb, Pr, Nd, Sm, Yb, Ho, Er, Tm, and Mn, and t2, u2, v2, w2, x2, and y2 satisfy 0 ≦ t2 ≦ 0.8, 0.7 ≦ u2 ≦ 1.3, 0 ≦ v2 ≦ 0.8, 3.7 ≦ w2 ≦ 4.3, 0.01 < x2 ≦ 0.15, 0 ≦ y2 ≦ 0.2, and y2 < 2x2 respectively, where "2x2" in the formula (2) is the product of 2 and the variable x2.) (Li 1-t3 M 5 t3 ) u3 (Ga 1-v3-x3-z3 M 6 v3 )5O w3 :Cr 5x3 ,Ni y3 ,M 7 5z3 (3) (In the formula (3), M 5 is at least one element selected from the group consisting of Na, K, Rb, and Cs, M<000003​​​​​​​​​​​​t3 ) u3 (Ga 1-v3-x3-z3 M 6 v3 )5O w3 :Cr 5x3 ,Ni y3 (3') (In the above formula (3'), M 5 is at least one element selected from the group consisting of Na, K, Rb and Cs, and M 6 is at least one element selected from the group consisting of B, Al, In, and rare earth elements, and t3, u3, v3, w3, x3, and y3 satisfy the following conditions: 0≦t3≦1.0, 0.7≦u3≦1.6, 0≦v3<1.0, 7.85≦w3≦11.5, 0.01≦x3≦0.24, 0≦y3≦0.5, 0.25<5x3+y3≦1.2, y3<5x3. In the formula (3'), "5x3" is the product of 5 and the variable x3.

[0033] In the oxide phosphor having the composition represented by the formula (1), M 1 is preferably at least one element selected from the group consisting of Al, In and rare earth elements, and may contain two or more elements. Rare earth elements include Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. The oxide phosphor having the composition represented by the formula (1) has a M in 1 mol of the composition. 1 The molar ratio of is expressed as the product of 2 and the variable v1, and the variable v1 is preferably in the range of 0 to 1.0 (0≦v1≦1.0), and may be in the range of 0.1 to 0.9 (0.1≦v1≦0.9). The oxide phosphor having the composition represented by the formula (1) is 1 may not be included, and v1 may be 0 (v1 = 0). In the oxide phosphor having the composition represented by formula (1), the variable x1, which represents the molar ratio of Cr, an activator element, per mole of the composition, is preferably within the range of 0.02 to 0.3 (0.02≦x1≦0.3), more preferably within the range of 0.02 to 0.2 (0.02≦x1≦0.2), and even more preferably within the range of 0.03 to 0.1 (0.03≦x1≦0.1).

[0034] It is preferable that the oxide phosphor has a composition represented by the following formula (1-1), and in a powder X-ray diffraction pattern measured using CuKα radiation, the oxide phosphor has a first peak P1 with the highest intensity within a Bragg angle 2θ range of 34° to 36°, a second peak P2 with the lowest peak top intensity within a Bragg angle 2θ range of 31° to 33°, and the peak intensity ratio (P1 / P2) of the first peak P1 to the second peak P2 is within a range of 5 to 100. When the peak intensity ratio (P1 / P2) of the first peak P1 with the highest intensity within a Bragg angle 2θ range of 34° to 36° to the second peak P2 with the lowest peak top intensity within a Bragg angle 2θ range of 31° to 33° is within a range of 5 to 100, the average particle size of the oxide phosphor having a composition represented by the following formula (1-1) becomes large. The oxide phosphor includes first compound particles containing a first element contained in a first flux, and crystals grow due to the action of the first flux. The oxide phosphor has a composition represented by the following formula (1-1), and in its powder X-ray diffraction pattern, the peak intensity ratio (P1 / P2) of the first peak P1 to the second peak P2 is in the range of 5 to 100. In the powder X-ray diffraction pattern, the oxide phosphor may have a peak intensity ratio (P1 / P2) of the first peak P1 to the second peak P2 in the range of 5 to 80, or in the range of 5 to 60. Ga2O3:Cr x1 (1-1) (In the formula (1-1), x1 satisfies 0.02≦x1≦0.3.)

[0035] The oxide phosphor having the composition represented by formula (1) preferably has a peak emission wavelength in the range of 680 nm to 1600 nm in the emission spectrum of the oxide phosphor when irradiated with excitation light. The excitation light may be light having a peak emission wavelength in the range of 365 nm to 650 nm. When irradiated with light having a peak emission wavelength in the range of 365 nm to 650 nm, the oxide phosphor preferably has a peak emission wavelength in the range of 680 nm to 1600 nm, may have a peak emission wavelength in the range of 680 nm to 1000 nm, may have a peak emission wavelength in the range of 690 nm to 900 nm, or may have a peak emission wavelength in the range of 700 nm to 800 nm. When irradiated with light having a peak emission wavelength in the range of 365 nm to 650 nm, the oxide phosphor preferably has a peak emission wavelength in the range of 680 nm to 1600 nm in the emission spectrum of the oxide phosphor when irradiated with light having a peak emission wavelength in the range of 365 nm to 650 nm.

[0036] The oxide phosphor having the composition represented by formula (1) preferably has a full width at half maximum (FWHM) in the emission spectrum of the oxide phosphor, ranging from 5 nm to 200 nm, more preferably from 50 nm to 180 nm, and even more preferably from 100 nm to 160 nm. In this specification, the FWHM refers to the wavelength width in the emission spectrum where the emission intensity is 50% of the emission intensity at the emission peak wavelength showing the maximum emission intensity. Light is absorbed and scattered in vivo, and to measure subtle changes in the propagation behavior of light in blood, it is preferable to irradiate light with an emission peak having a wide FWHM. Furthermore, even when measuring foods such as fruits, vegetables, and rice nondestructively, it is preferable to irradiate light with an emission spectrum having a wide FWHM in order to obtain information about the interior of the food. Furthermore, regarding the appearance of the color of an object when irradiated with light (hereinafter also referred to as "color rendering"), it is desirable for the emission spectrum to have a wide wavelength range, and a wider FWHM translates to light with superior color rendering. For example, when used in a work place such as a factory, it may be required to emit light that does not disrupt the spectral balance of light so that workers can work easily.

[0037] The oxide phosphor having the composition represented by formula (2) preferably has a peak emission wavelength in the range of 680 nm to 1600 nm when irradiated with excitation light having a peak emission wavelength in the range of 365 nm to 650 nm, and more preferably has a peak emission wavelength in the range of 800 nm to 1600 nm in the emission spectrum of the oxide phosphor. When irradiated with light having a peak emission wavelength in the range of 365 nm to 650 nm, the oxide phosphor may have a peak emission wavelength in the range of 810 nm to 1500 nm, or may have a peak emission wavelength in the range of 820 nm to 1400 nm, or may have a peak emission wavelength in the range of 820 nm to 1350 nm in the emission spectrum of the oxide phosphor. When irradiated with light having a peak emission wavelength in the range of 365 nm to 650 nm, the oxide phosphor preferably has a peak emission wavelength in the range of 800 nm to 1600 nm in the emission spectrum of the oxide phosphor.

[0038] The oxide phosphor having the composition represented by formula (2) preferably has a full width at half maximum in the emission spectrum of 150 nm to 350 nm, in order to easily obtain information about the inside of a living body or food and to emit light that does not disrupt the spectral balance of the light. The oxide phosphor having the composition represented by formula (2) may have a full width at half maximum in the range of 160 nm to 340 nm, or in the range of 170 nm to 330 nm. When the oxide phosphor having the composition represented by formula (2) has an emission peak wavelength in the range of 800 nm to 1600 nm, the full width at half maximum of the emission spectrum is preferably 150 nm to 250 nm, and more preferably 160 nm to 245 nm. The full width at half maximum of the emission spectrum of the oxide phosphor may be 160 nm or more, 170 nm or more, 180 nm or more, or 190 nm or more. When the oxide phosphor having the composition represented by the formula (2) has an emission peak wavelength in the range of more than 1000 nm to 1600 nm, for example, in the range of 1001 nm to 1600 nm, in the emission spectrum of the oxide phosphor, the full width at half maximum of the emission spectrum is preferably 150 nm to 350 nm, more preferably 180 nm to 340 nm, even more preferably 200 nm to 330 nm, and even more preferably 205 nm to 330 nm.

[0039] When irradiated with excitation light, the oxide phosphor having the composition represented by formula (3) preferably has a peak emission wavelength in the range of 680 nm to 1600 nm, more preferably in the range of 690 nm to 1500 nm, and even more preferably in the range of 700 nm to 1300 nm in its emission spectrum. The excitation light preferably has a peak emission wavelength in the range of 365 nm to 650 nm. When the oxide phosphor having the composition represented by formula (3) does not contain Ni, i.e., when y3 = 0, when irradiated with excitation light, the oxide phosphor preferably has a peak emission wavelength in the range of 700 nm to 900 nm, more preferably in the range of 710 nm to 850 nm in its emission spectrum.

[0040] The oxide phosphor having a composition included in the composition formula represented by formula (3) makes it easy to obtain information about the inside of a living body or food, and in order to irradiate light that does not disrupt the spectral balance of the light, the full width at half maximum in the emission spectrum of the oxide phosphor is preferably in the range of 150 nm to 250 nm, more preferably 155 nm or more, and may be 240 nm or less, or may be 235 nm or less.

[0041] The light emitting device includes the oxide phosphor and a light emitting element having an emission peak wavelength in the range of 365 nm to 650 nm and irradiating the oxide phosphor with excitation light. The oxide phosphor is preferably contained in a wavelength conversion member, and the wavelength conversion member may include a light-transmitting material.

[0042] A semiconductor element can be used as a light-emitting element that irradiates an oxide phosphor with excitation light. For example, nitride semiconductors can be selected as materials for light-emitting elements that emit green and blue light. In is used as a material for the semiconductor structure that constitutes the light-emitting element. X Al Y Ga 1-X-YN (0≦X≦1, 0≦Y≦1, X+Y≦1), etc. can be used. As a material for the light-emitting element that emits red light, for example, a gallium-aluminum-arsenic-based semiconductor or an aluminum-indium-gallium-phosphorus-based semiconductor can be selected. As the light-emitting element, it is preferable to use, for example, an LED chip or an LD chip.

[0043] The light-emitting element may have an emission peak wavelength in the range of 365 nm to 650 nm, or may have an emission peak wavelength in the range of 365 nm to 500 nm, or may have an emission peak wavelength in the range of 370 nm to 490 nm, or may have an emission peak wavelength in the range of 375 nm to 480 nm. The light-emitting element may also have an emission peak wavelength in the range of more than 500 nm to 650 nm, or may have an emission peak wavelength in the range of 510 nm to 650 nm, or may have an emission peak wavelength in the range of 520 nm to 650 nm. By using the light-emitting element as an excitation light source for the oxide phosphor, it is possible to construct a light-emitting device that emits a mixed color light of the light from the light-emitting element and the fluorescence from the phosphor containing the oxide phosphor in a desired wavelength range. The full width at half maximum of the emission peak in the emission spectrum of the light-emitting element can be, for example, 30 nm or less. It is preferable to use a light-emitting element using, for example, a nitride-based semiconductor. By using a light emitting element using a nitride semiconductor as an excitation light source, it is possible to obtain a light emitting device that is highly efficient, has high linearity of output relative to input, and is resistant to mechanical shocks.

[0044] The light emitting device essentially comprises a first phosphor containing the oxide phosphor described above, and may further comprise a phosphor having a different composition. In addition to the first phosphor, the light emitting device preferably comprises at least one phosphor selected from the group consisting of a second phosphor having a peak emission wavelength in the range of 455 nm or more and less than 495 nm, a third phosphor having a peak emission wavelength in the range of 495 nm or more and less than 610 nm, a fourth phosphor having a peak emission wavelength in the range of 610 nm or more and less than 700 nm, and a fifth phosphor having a peak emission wavelength in the range of 700 nm or more and less than 1600 nm, in the emission spectrum of each phosphor. The light emitting device comprises a light emitting element and the first phosphor containing the oxide phosphor described above, and at least one phosphor selected from the group consisting of the second phosphor, the third phosphor, the fourth phosphor, and the fifth phosphor, and thus can be used as a light source that emits light having an emission spectrum in a wavelength range that includes visible light to a portion of near-infrared light. The light-emitting device has an emission spectrum similar to that of conventionally used tungsten lamps and xenon lamps, and can be used as a light source that can be made smaller than tungsten lamps or xenon lamps. The compact light-emitting device can be installed in small mobile devices such as smartphones and smartwatches, and the information obtained from within the body can be used for health management, etc. The light emitting device can be used, for example, in a reflectance spectroscopic measuring device or a lighting device that is required to be capable of non-destructively measuring the inside of a living body or fruits and vegetables and that also has excellent color rendering properties.

[0045] The second phosphor, which has a different composition from the first phosphor containing the oxide phosphor described above, preferably contains at least one phosphor selected from the group consisting of a phosphate phosphor having a composition represented by the following formula (4a), an aluminate phosphor having a composition represented by the following formula (4b), and an aluminate phosphor having a composition represented by the following formula (4c), and may contain two or more phosphors. (Ca, Sr, Ba, Mg) 10 (PO4)6(F,Cl,Br,I)2:Eu (4a) (Ba,Sr,Ca)MgAl 10 O 17:Eu (4b) Sr4Al 14 O 25 :Eu (4c) In this specification, when a plurality of elements are separated by a comma (,) in a composition formula, it means that at least one of these elements is contained in the composition.

[0046] The third phosphor preferably contains at least one phosphor selected from the group consisting of a silicate phosphor having a composition represented by the following formula (5a), an aluminate phosphor or gallate phosphor having a composition represented by the following formula (5b), a β-sialon phosphor having a composition represented by the following formula (5c), a cesium lead halide phosphor having a composition represented by the following formula (5d), and a nitride phosphor having a composition represented by the following formula (5e), ​​and may contain two or more phosphors. When the third phosphor contains two or more phosphors, it is preferable that each of the two or more third phosphors be a phosphor having a different emission peak wavelength in the range of 495 nm or more and less than 610 nm. (Ca,Sr,Ba)8MgSiO 16 (F,Cl,Br)2:Eu (5a) (Lu,Y,Gd,Tb)3(Al,Ga)5O 12 :Ce (5b) Si 6-z Al z O z N 8-z :Eu (0 <z≦4.2) (5c) CsPb(F,Cl,Br)3(5d) (La,Y,Gd)3Si6N 11 :Ce (5e)

[0047] The fourth phosphor preferably contains at least one phosphor selected from the group consisting of a nitride phosphor having a composition represented by the following formula (6a), a fluorogermanate phosphor having a composition represented by the following formula (6b), an oxynitride phosphor having a composition represented by the following formula (6c), a fluoride phosphor having a composition represented by the following formula (6d), a fluoride phosphor having a composition represented by the following formula (6e), a nitride phosphor having a composition represented by the following formula (6f), and a nitride phosphor having a composition represented by the following formula (6g), and may contain two or more phosphors. When the fourth phosphor contains two or more phosphors, it is preferable that each of the two or more fourth phosphors is a phosphor having an emission peak wavelength in a different range within the range of 610 nm or more and less than 700 nm. (Sr,Ca)AlSiN3:Eu (6a) 3.5MgO·0.5MgF2·GeO2:Mn (6b) (Ca,Sr,Mg) k Si 12-(m+n) Al m+n O n N 16-n :Eu (6c) (In the formula (6c), k, m, and n satisfy 0 < k ≤ 2.0, 2.0 ≤ m ≤ 6.0, and 0 ≤ n ≤ 2.0.) A 1 c1 [M 6 1-b1 Mn 4+ b1 F d1 (6d) (In the formula (6d), A 1 is at least one selected from the group consisting of K + , Li + , Na + , Rb + , Cs + and NH4<000008​​​​​​​​4+ b1 F d1 is the absolute value of the charge of the ion, and d1 satisfies 5 < d1 < 7.) A 2 c2 [M 7 1-b2 Mn 4+ b2 F d2 (6e) (In the formula (6e), A 2 is at least one selected from the group consisting of K + , Li + , Na + , Rb + , Cs + and NH4 + , and among them, K + is preferred. M 7 includes group 13 elements, and may further include at least one element selected from the group consisting of group 4 elements and group 14 elements. The group 13 element is preferably Al, and the group 14 element is preferably Si. b2 satisfies 0 < b2 < 0.2, and c2 is [M 7 1-b2 Mn 4+ b2 F d2 is the absolute value of the charge of the ion, and d2 satisfies 5 < d2 < 7.) (Ba,Sr,Ca)2Si5N8:Eu (6f) (Sr,Ca)Li(Al,Ga)3N4:Eu (6g)

[0048] The fifth phosphor preferably contains at least one phosphor selected from the group consisting of a gallate phosphor having a composition represented by the following formula (7a), an aluminate phosphor having a composition represented by the following formula (7b), and a phosphor having a composition represented by the following formula (7c) which is different in composition from the oxide phosphor, a phosphor having a composition represented by the following formula (7d) which is different in composition from the oxide phosphor, a phosphor having a composition represented by the following formula (7e) which is different in composition from the oxide phosphor, a phosphor having a composition represented by the following formula (7f) which is different in composition from the oxide phosphor, a phosphor having a composition represented by the following formula (7g) which is different in composition from the oxide phosphor, a phosphor having a composition represented by the following formula (7h) which is different in composition from the oxide phosphor, a phosphor having a composition represented by the following formula (7i) which is different in composition from the oxide phosphor, a phosphor having a composition represented by the following formula (7j) which is different in composition from the oxide phosphor, and a phosphor having a composition represented by the following formula (7k) which is different in composition from the oxide phosphor, and may contain two or more phosphors.

[0049] ZnGa2O4:Cr (7a) (Lu,Y,Gd,Tb)3(Al,Ga)5O 12 :Ce,Cr (7b)

[0050] M 8 g M 9 h M 10 i M 11 5O j :Cr e , M 12 f (7c) (In the above formula (7c), M 8 is at least one element selected from the group consisting of Li, Na, K, Rb, and Cs, and M 9 is at least one element selected from the group consisting of Mg, Ca, Sr, Ba, and Zn, and M 10 is at least one element selected from the group consisting of Ba, Al, Ga, In and rare earth elements, and M 11is at least one element selected from the group consisting of Si, Ti, Ge, Zr, Sn, Hf, and Pb, and is M 12 is at least one element selected from the group consisting of Eu, Ce, Tb, Pr, Nd, Sm, Yb, Ho, Er, Tm, Ni, and Mn, and e, f, g, h, i, and j satisfy 0 < e ≦ 0.2, 0 ≦ f ≦ 0.1, f < e, 0.7 ≦ g ≦ 1.3, 1.5 ≦ h ≦ 2.5, 0.7 ≦ i ≦ 1.3, 12.9 ≦ j ≦ 15.1.)

[0051] (Ga 1-u4 M 13 u4 )2(Ge 1-v4 M 14 v4 ) w4 O x4 :Cr y4 ,M 15 <​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​is at least one element selected from the group consisting of Ca, Sr, Ba, and Zn, and M 17 is at least one element selected from the group consisting of Ga, Sc, and In, and M 18 is at least one element selected from the group consisting of Si, Ti, Zr, Sn and Hf, and M 19 is at least one element selected from the group consisting of Ni, Ce, Eu, Fe, Mn, Nd, Tm, Ho, Er, and Yb, and s5, t5, u5, v5, w5, x5, y5, and z5 satisfy the following relationships: 0≦s5≦1.0, 0≦t5≦1.0, 1.5≦u5≦2.5, 0≦v5≦0.5, 3.0≦w5≦6.0, 11.0≦x5≦17.0, 0.005≦y5≦1.0, and 0≦z5≦0.5, respectively.

[0053] M 20 x6 (Al 1-y6 M 21 y6 ) z6 O x6+3 / 2z6 :Cr v6 ,M 22 w6 (7f) (In the above formula (7f), M 20 is at least one element selected from the group consisting of alkaline earth metal elements, and M 21 is at least one element selected from the group consisting of Group 13 elements excluding Al, and M 22 is at least one element selected from the group consisting of Mn, Eu, Ce, Tb, Pr, Nd, Sm, Yb, Ho, Er, and Tm, and v5, w5, x5, y5, and z5 satisfy the following relationships: 0.004≦v6≦0.8, 0≦w6≦0.4, 0.004≦v6+w6≦0.8, 1.0≦x6≦4.0, 0≦y6≦0.7, and 4.0≦z6≦1.50, respectively.

[0054] M 23 t7 M 24 u7 (Ge 1-v7 M 25 v7 )6O w7 :Cr x7 ,M26 y7 (7g) (In the formula (7g), M 23 is at least one element selected from the group consisting of Li, Na, K, Rb, and Cs, and M 24 is at least one element selected from the group consisting of Ca, Sr, Mg, Ba, and Zn, and M 25 is at least one element selected from the group consisting of Si, Ti, Zr, Sn, Hf, and Pb, and M 26 is at least one element selected from the group consisting of Eu, Ce, Tb, Pr, Nd, Sm, Yb, Ho, Er, Tm, Ni, and Mn, and t7, u7, v7, w7, x7, and y7 satisfy 1.5 ≤ t7 ≤ 2.5, 0.7 ≤ u7 ≤ 1.3, 0 ≤ v7 ≤ 0.4, 12.9 ≤ w7 ≤ 15.1, 0 < x7 ≤ 0.2, 0 ≤ y7 ≤ 0.10, and y7 < x7 respectively.)

[0055] (Li 1-u8 M 27 u8 )4(Ge 1-v8 M 28 v8 ) w8 O x8 :Cr y8 [[ID=३२]] 29 z8 27 (7h) (In the formula (7h), M 27 is at least one element selected from the group consisting of Na, K, Rb, and Cs, and M[[ID=४०]] 28 is at least one element selected from the group consisting of Si, Ti, Zr, Sn, and Hf, and M 29 is at least one element selected from the group consisting of Ni, Eu, Fe, Mn, Nd, Tm, Ho, Er, and Yb, and u8, v8, w8, x8, y8, and z8 satisfy 0 ≤ u8 ≤ 0.3, 0 ≤ v8 ≤ 0.5, 3.5 ≤ w8 ≤ 15, 9 ≤ x8 ≤ 32, 0.005 ≤ y8 ≤ 1.0, and 0 ≤ z8 ≤ 0.5 respectively.)

[0056] (Li 1-u9 M 30 u9 )2M 31 v9M 32 w9 O x9 :Cr y9 ,M 33 z9 (7i) (In the above formula (7i), M 30 is at least one element selected from the group consisting of Na, K, Rb and Cs, and M 31 is at least one element selected from the group consisting of Mg, Ca, Sr, Ba, and Zn, and M 32 is at least one element selected from the group consisting of Si, Ge, Ti, Zr, Sn and Hf, and M 33 is at least one element selected from the group consisting of Ni, Eu, Fe, Mn, Nd, Tm, Ho, Er, and Yb, and u9, v9, w9, x9, y9, and z9 satisfy the following relationships: 0≦u9≦1.0, 0.8≦v9≦3.0, 1.8≦w9≦6, 5.4≦x9≦16, 0.005≦y9≦1.0, and 0≦z9≦0.5, respectively.

[0057] (Mg 1-p10 M 34 p10 ) q10 (Li 1-r10 M 35 r10 ) s10 (In 1-t10 M 36 t10 ) u10 (Ge 1-v10 M 37 v10 ) w10 O x10 :Cr y10 ,M 38 z10 (7j) (In the above formula (7j), M 34 is at least one element selected from the group consisting of Ca, Sr, Ba, and Zn, and M 35 is at least one element selected from the group consisting of Na, K, Rb and Cs, and M 36 is at least one element selected from the group consisting of Al, Ga, and Sc, and M 37is at least one element selected from the group consisting of Si, Ti, Zr, Sn and Hf, and M 38 is at least one element selected from the group consisting of Ni, Ce, Eu, Fe, Mn, Nd, Tm, Ho, Er, and Yb, and p10, q10, r10, s10, t10, u10, v10, w10, x10, y10, and z10 satisfy the following relationships: 0≦p10≦1.0, 0.1≦q10≦0.9, 0≦r10≦1.0, 0.05≦s10≦0.45, 0≦t10≦0.5, 0.05≦u10≦0.45, 0≦v10≦1.0, 0.8≦w10≦1.3, 2.6≦x10≦3.6, 0.02≦y10≦0.5, 0≦z10≦0.3, 0.9≦q10+s10+u10≦1.2, respectively.

[0058] (Li 1-q11 M 39 q11 ) r11 (Mg 1-s11 M 40 s11 ) t11 (Ta 1-u11-v11 Nb u11 M 41 v11 ) w11 O x11 :Cr y11 ,M 42 z11 (7k) (In the above formula (7k), M 39 is at least one element selected from the group consisting of Na, K, Rb and Cs, and M 40 is at least one element selected from the group consisting of Zn, Ca, Sr and Ba, and M 41 is at least one element selected from the group consisting of P, V, Sb and Bi, and M 42is at least one element selected from the group consisting of Ni, Ce, Eu, Fe, Mn, Nd, Tm, Ho, Er, and Yb, and q11, r11, s11, t11, u11, v11, w11, x11, y11, and z11 satisfy the following relationships: 0≦q11≦0.5, 0.5≦r11≦3.5, 0≦s11≦0.5, 1.8≦t11≦3.2, 0≦u11≦1.0, 0≦v11≦0.3, 0≦u11+v11≦1.0, 0.8≦w11≦1.2, 5.1≦x11≦6.9, 0.002≦y11≦0.5, and 0≦z11≦0.3, respectively.

[0059] An example of a light emitting device will be described with reference to the drawings. Fig. 1 is a schematic cross-sectional view showing an example of a first configuration example of a light emitting device. Fig. 2 is a schematic cross-sectional view showing another example of the first configuration example of a light emitting device.

[0060] As shown in FIG. 1 , the light emitting device 100 includes a molded body 40 having a recess, a light emitting element 10 serving as an excitation light source, and a wavelength conversion member 50 covering the light emitting element 10. The molded body 40 is formed by integrally molding a first lead 20, a second lead 30, and a resin portion 42 containing a thermoplastic resin or a thermosetting resin. In the molded body 40, at least the first lead 20 and the second lead 30 form the bottom surface of the recess, and at least the resin portion 42 forms the side surface of the recess. The light emitting element 10 is placed on the bottom surface of the recess of the molded body 40. The light emitting element 10 has a pair of positive and negative electrodes, which are electrically connected to the first lead 20 and the second lead 30 via wires 60, respectively. The light emitting element 10 is covered with the wavelength conversion member 50. The wavelength conversion member 50 preferably includes a phosphor 70 that converts the wavelength of light emitted from the light emitting element 10 and a translucent material. Phosphor 70 essentially includes first phosphor 71 containing an oxide phosphor. The oxide phosphor included in first phosphor 71 contains at least one type of phosphor particle selected from the group consisting of phosphor particles having a composition represented by formula (1), phosphor particles having a composition represented by formula (2), and phosphor particles having a composition represented by formula (3). The oxide phosphor included in the first phosphor may include two or more types of oxide phosphors, each containing phosphor particles having a different composition. Phosphor 70 may include a phosphor having an emission peak wavelength in a wavelength range different from the emission peak wavelength of first phosphor 71 and having a different composition from that of first phosphor 71. As shown in FIG. 2, phosphor 70 preferably includes at least one type of phosphor selected from the group consisting of second phosphor 72, third phosphor 73, fourth phosphor 74, and fifth phosphor 75, each of which is described above, and may include two or more types. The phosphor 70 essentially contains a first phosphor 71, and may also contain a second phosphor 72, a third phosphor 73, a fourth phosphor 74, and a fifth phosphor 75. The wavelength conversion member 50 also functions as a member for protecting the light emitting element 10, the wire 60, the phosphor 70, etc. from the external environment. The light emitting device 100 emits light upon receiving a supply of power from an external source via the first lead 20 and the second lead 30.

[0061] 3 and 4 show a second configuration example of a light-emitting device. FIG. 3 is a schematic plan view of the light-emitting device 200. FIG. 4 is a schematic cross-sectional view of the light-emitting device 200 shown in FIG. 3 taken along line III-III'. The light-emitting device 200 includes a light-emitting element 10 having an emission peak wavelength in the range of 365 nm to 650 nm, and a wavelength conversion member 51. The wavelength conversion member 51 includes a wavelength converter 52 containing a first phosphor 71 that emits light upon excitation by light from the light-emitting element 10, and a light-transmitting member 53 disposed on the emission surface side of the wavelength converter 52. The light-emitting element 10 is flip-chip mounted on the substrate 12 via bumps that are conductive members 61. The wavelength converter 52 of the wavelength conversion member 51 is disposed on the light-emitting surface of the light-emitting element 10 via an adhesive layer 80. The light-emitting element 10 and the wavelength conversion member 51 have their side surfaces covered with a light-reflective covering member 90. The wavelength converter 52 essentially includes a first phosphor 71 containing an oxide phosphor that is excited by light from the light-emitting element 10 and includes phosphor particles containing a host crystal containing Ga and oxygen, an activator element, and first compound particles and / or second compound particles disposed on the surfaces of the phosphor particles. The oxide phosphor contained in the first phosphor 71 contains at least one type of phosphor particle selected from the group consisting of phosphor particles having a composition represented by formula (1), phosphor particles having a composition represented by formula (2), and phosphor particles having a composition represented by formula (3). The oxide phosphor contained in the first phosphor may include two or more types of oxide phosphors, each containing phosphor particles having a different composition. The wavelength converter 52 may include at least one type selected from the group consisting of a second phosphor, a third phosphor, a fourth phosphor, and a fifth phosphor. The light-emitting element 10 can receive power from outside the light-emitting device 200 via wiring and a conductive member 61 formed on the substrate 12, causing the light-emitting device 200 to emit light. The light emitting device 200 may include a semiconductor element 11 such as a protective element for protecting the light emitting element 10 from being destroyed by application of an excessive voltage. The semiconductor element 11 may be mounted on a substrate 12 via a conductive member 61. A covering member 90 is disposed so as to cover the semiconductor element 11, for example. Each member used in the light emitting device will be described below. For details, the disclosure of JP 2014-112635 A can be referenced, for example.

[0062] The translucent material constituting the wavelength converter together with the phosphor may be at least one selected from the group consisting of resin, glass, and inorganic materials. The resin may be at least one selected from the group consisting of silicone resin, epoxy resin, phenolic resin, polycarbonate resin, acrylic resin, and modified resins thereof. Silicone resin and modified silicone resin are preferred because of their excellent heat resistance and light resistance. In addition to the phosphor and the translucent material, the wavelength converter may contain a filler, a colorant, and a light diffusing material as needed. Examples of fillers include silicon oxide, barium titanate, titanium oxide, and aluminum oxide.

[0063] The light-transmitting body can be a plate-shaped body made of a light-transmitting material such as glass or resin. Examples of glass include borosilicate glass and quartz glass. Examples of resin include silicone resin and epoxy resin. When the wavelength conversion member includes a substrate, the substrate is preferably made of an insulating material that is difficult to transmit light from the light-emitting element and external light. Examples of materials for the substrate include ceramics such as aluminum oxide and aluminum nitride, and resins such as phenolic resin, epoxy resin, polyimide resin, bismaleimide triazine resin (BT resin), and polyphthalamide (PPA) resin. When an adhesive layer is interposed between the light-emitting element and the wavelength conversion member, the adhesive constituting the adhesive layer is preferably made of a material that can optically connect the light-emitting element and the wavelength conversion member. The material constituting the adhesive layer is preferably at least one resin selected from the group consisting of epoxy resin, silicone resin, phenolic resin, and polyimide resin. The light-transmitting body does not have to be disposed in the wavelength conversion member.

[0064] Examples of semiconductor elements that may be provided in a light-emitting device as needed include transistors for controlling light-emitting elements and protective elements for preventing damage to light-emitting elements or performance degradation due to excessive voltage application. Zener diodes are examples of protective elements. When a light-emitting device includes a covering member, it is preferable to use an insulating material for the covering member. More specifically, examples include phenolic resin, epoxy resin, bismaleimide triazine resin (BT resin), polyphthalamide (PPA) resin, and silicone resin. Colorants, phosphors, and fillers may be added to the covering member as needed. The light-emitting device may use bumps as conductive members. Examples of materials for the bumps include Au or its alloys, and other conductive materials include eutectic solder (Au-Sn), Pb-Sn, and lead-free solder.

[0065] An example of a method for manufacturing the light emitting device of the first configuration example will be described. For details, see, for example, the disclosure of Japanese Patent Application Laid-Open No. 2010-062272. The method for manufacturing the light emitting device preferably includes a molded body preparation step, a light emitting element arrangement step, a wavelength conversion member forming composition arrangement step, and a resin package formation step. When an aggregate molded body having a plurality of recesses is used as the molded body, the resin package formation step may be followed by a singulation step of separating the molded body into individual resin packages of each unit area.

[0066] In the step of preparing a molded body, a plurality of leads are integrally molded using a thermosetting resin or a thermoplastic resin to prepare a molded body having a recess with side and bottom surfaces. The molded body may be a molded body made of an aggregate base including a plurality of recesses.

[0067] In the light-emitting element placement step, the light-emitting element is placed on the bottom surface of the recess in the molded body, and the positive and negative electrodes of the light-emitting element are connected to the first lead and the second lead by wires.

[0068] In the step of placing the composition for forming a wavelength conversion member, the composition for forming a wavelength conversion member is placed in the recess of the molded body.

[0069] In the resin package molding step, the wavelength conversion member-forming composition placed in the recesses of the molded body is cured to form a resin package, thereby manufacturing a light emitting device. When a molded body made of an aggregate substrate having multiple recesses is used, after the resin package formation step, the aggregate substrate having multiple recesses is separated into individual resin packages in each unit area in a singulation step, thereby manufacturing individual light emitting devices. In this manner, the light emitting device shown in FIG. 1 or 2 can be manufactured.

[0070] An example of a method for manufacturing the light emitting device of the second configuration example will be described. For details, reference can be made to the disclosures of, for example, Japanese Patent Application Laid-Open No. 2014-112635 or Japanese Patent Application Laid-Open No. 2017-117912. The method for manufacturing the light emitting device preferably includes a step of arranging a light emitting element, a step of arranging a semiconductor element as needed, a step of forming a wavelength conversion member including a wavelength converter, a step of bonding the light emitting element and the wavelength conversion member, and a step of forming a covering member.

[0071] For example, in the step of arranging the light-emitting element, the light-emitting element is arranged on a substrate. The light-emitting element and the semiconductor element are, for example, flip-chip mounted on the substrate. Next, in the step of forming a wavelength conversion member containing a wavelength converter, the wavelength converter may be obtained by forming a plate-shaped, sheet-shaped, or layer-shaped wavelength converter on one surface of a translucent body using a printing method, an adhesive method, a compression molding method, or an electrodeposition method. For example, a printing method can be used to print a wavelength conversion member containing a phosphor and a resin serving as a binder or solvent on one surface of a translucent body to form a wavelength conversion member containing a wavelength converter. Next, in the step of adhering the light-emitting element and the wavelength conversion member, the wavelength conversion member is placed opposite the light-emitting surface of the light-emitting element and bonded to the light-emitting element with an adhesive layer. Next, in the step of forming a covering member, the side surfaces of the light-emitting element and the wavelength conversion member are covered with a covering member composition. This covering member is intended to reflect light emitted from the light-emitting element. If the light-emitting device also includes a semiconductor element, it is preferable that the semiconductor element be embedded in the covering member. In this manner, the light-emitting device shown in Figures 3 and 4 can be manufactured.

[0072] A method for producing an oxide phosphor includes the steps of preparing a raw material mixture containing a compound containing Ga and a compound containing Cr as an activator element, preparing a first flux containing an oxide containing at least one first element selected from the group consisting of Group 4 elements, Group 5 elements, Group 14 elements, and Group 15 elements, mixing the raw material mixture with the first flux to obtain a mixture, and heat-treating the mixture to obtain an oxide phosphor including phosphor particles and first compound particles containing the first element arranged on the surfaces of the phosphor particles. In the method for producing an oxide phosphor, the raw material mixture may include a compound containing an element other than Cr as an activator element.

[0073] The method for producing an oxide phosphor involves heat-treating a mixture of a raw material mixture and a first flux containing an oxide containing at least one first element selected from the group consisting of Group 4 elements, Group 5 elements, Group 14 elements, and Group 15 elements, thereby accelerating the reaction of the compounds contained in the raw material mixture, causing crystal growth and resulting in the production of an oxide phosphor with a large particle size. The oxide containing the first element contained in the first flux adheres to the surface of the oxide phosphor particles in the form of particles or a film. The oxide phosphor with a large particle size from which crystals have grown can enhance the emission intensity.

[0074] A method for producing an oxide phosphor includes: preparing a raw material mixture containing a compound containing Ga and a compound containing Cr as an activator element; preparing a first flux containing an oxide containing at least one first element selected from the group consisting of Group 4 elements, Group 5 elements, Group 14 elements, and Group 15 elements; preparing a second flux containing a compound containing at least one second element selected from the group consisting of alkali metal elements and alkaline earth metal elements; mixing the raw material mixture with the first flux and the second flux to obtain a mixture; and heat-treating the mixture to obtain an oxide phosphor containing phosphor particles, first compound particles containing the first element arranged on the surfaces of the phosphor particles, and second compound particles arranged on the surfaces of the phosphor particles. In the method for producing an oxide phosphor, the raw material mixture may include a compound containing an element other than Cr as an activator element. The first compound particles include oxide particles.

[0075] A method for producing an oxide phosphor includes heat-treating a mixture of a raw material mixture, a first flux containing an oxide containing at least one first element selected from the group consisting of Group 4, Group 5, Group 14, and Group 15 elements, and a second flux containing a compound containing at least one second element selected from the group consisting of alkali metals and alkaline earth metals. This heat-treating the mixture promotes the reaction of the compounds contained in the raw material mixture, resulting in crystal growth and the production of an oxide phosphor with a large particle size. The oxide containing the first element contained in the first flux and the compound containing the second element contained in the second flux adhere to the surface of the oxide phosphor particles as second compound particles containing the second element or a film-like second compound containing the second element. Increasing the particle size of the oxide phosphor can increase the luminescence intensity. The compound containing the first element contained in the first flux and the first compound particles containing the first element or the film-like first compound containing the first element disposed on the surface of the phosphor particles may be the same compound or different compounds. The compound containing the second element contained in the second flux and the second compound particles containing the second element disposed on the surfaces of the phosphor particles may be the same compound or different compounds.

[0076] The raw material mixture may contain, in addition to a compound containing Ga that constitutes the host crystal of the phosphor particles and a compound containing Cr that serves as an activator element, a compound containing an element other than Ga and oxygen that constitutes the host crystal of the phosphor particles, and / or a compound containing an element other than Cr that serves as an activator element, as necessary.A method for producing an oxide phosphor may include preparing a raw material mixture containing a compound containing Ga, a compound containing Cr that serves as an activator element, a compound containing an element other than Ga and oxygen that constitutes the host crystal of the phosphor particles, as necessary, and a compound containing an element other than Cr that serves as an activator element, as necessary.

[0077] When producing phosphor particles having a composition represented by the formula (1), the element M in the composition represented by the formula (1) is an element that constitutes the host crystal of the phosphor particles having the composition represented by the formula (1), and is an element other than Ga and oxygen. 1 When producing phosphor particles having the composition represented by the formula (1), a compound containing Ga, a compound containing Cr as an activator element, and, if necessary, an element M other than Ga and oxygen that constitutes the host crystal of the phosphor particles are added. 1 When producing phosphor particles having the composition represented by formula (1), it is preferable to prepare a raw material mixture containing: 1 is at least one element selected from the group consisting of Al, In, and rare earth elements. When producing phosphor particles having the composition represented by formula (1), the compound containing elements other than Ga and oxygen that is optionally contained in the raw material mixture may contain, in addition to the compound containing Ga, an element M which is at least one element selected from the group consisting of Al, In, and rare earth elements. 1 Examples of compounds include compounds containing:

[0078] When producing phosphor particles having a composition represented by the formula (2), the elements constituting the host crystal of the phosphor particles having a composition represented by the formula (2), other than Ga and oxygen, are Mg, element M 2 , element M 3In the phosphor particles having the composition represented by the formula (2), the element serving as an activator other than Cr is the element M. 4 When producing phosphor particles having the composition represented by the formula (2), a compound containing Ga, a compound containing Cr as an activator element, and, if necessary, a compound containing Mg, which is an element other than Ga and oxygen that constitutes the host crystal of the phosphor particles, are used as essential components, and, if necessary, the element M 2 Compounds containing element M 3 and optionally an element M 4 When producing phosphor particles having a composition represented by the formula (2), it is preferable to prepare a raw material mixture containing: 2 is at least one element selected from the group consisting of Ca, Sr, Ba, Ni and Zn. When producing phosphor particles having the composition represented by formula (2), elements M other than Ga and oxygen may be included as needed. 3 is at least one element selected from the group consisting of B, Al, In and Sc. When producing phosphor particles having the composition represented by formula (2), element M, which serves as an activator element other than Cr, may be included as needed. 4 is at least one element selected from the group consisting of Eu, Ce, Tb, Pr, Nd, Sm, Yb, Ho, Er, Tm and Mn. When producing phosphor particles having the composition represented by formula (2), the compound containing elements other than Ga and oxygen that is optionally contained in the raw material mixture is a compound containing Mg, at least one element M selected from the group consisting of Ca, Sr, Ba, Ni and Zn. 2 a compound containing at least one element M selected from the group consisting of B, Al, In and Sc; 3 When producing phosphor particles having the composition represented by formula (2), the compound containing an element other than Cr as an activator element that is optionally contained in the raw material mixture includes at least one element M selected from the group consisting of Eu, Ce, Tb, Pr, Nd, Sm, Yb, Ho, Er, Tm, and Mn. 4 Examples of compounds include compounds containing:

[0079] When producing phosphor particles having a composition represented by the formula (3), the elements constituting the host crystal of the phosphor particles having the composition represented by the formula (3), other than Ga and oxygen, include Li, element M 5 , element M 6 , element M 7 When producing phosphor particles having the composition represented by the formula (3), a compound containing Ga, a compound containing Cr as an activator element, and an element other than Ga and oxygen that constitutes the host crystal of the phosphor particles, if necessary, a compound containing Li, an element M 5 Compounds containing element M 6 and optionally an element M 7 When producing phosphor particles having a composition represented by formula (3), it is preferable to prepare a raw material mixture containing: 5 is at least one element selected from the group consisting of Na, K, Rb and Cs. When producing phosphor particles having the composition represented by formula (3), elements M other than Ga and oxygen may be included as needed. 6 is at least one element selected from the group consisting of B, Al, In, and rare earth elements. The rare earth elements include Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. The element M, which is optionally contained when producing phosphor particles having the composition represented by formula (3), 7 is at least one element selected from the group consisting of Si, Ge, Sn, Ti, Zr, Hf, Bi, V, Nb, and Ta. When producing phosphor particles having the composition represented by formula (3), the compound containing elements other than Ga and oxygen that is optionally contained in the raw material mixture is at least one element M selected from the group consisting of a compound containing Li, Na, K, Rb, and Cs. 5 a compound containing at least one element M selected from the group consisting of B, Al, In and rare earth elements; 6a compound containing at least one element M selected from the group consisting of Si, Ge, Sn, Ti, Zr, Hf, Bi, V, Nb and Ta; 7 Examples of compounds include compounds containing:

[0080] The Ga-containing compound, the Cr-containing compound, the optional compound containing elements other than Ga and oxygen that constitute the host crystal, and the optional compound containing an element other than Cr as an activator element are oxides or stable compounds that easily become oxides. Specific examples of the compounds contained in the raw material mixture include oxides, carbonates, chlorides, and hydrates thereof. The Ga-containing compound may be at least one selected from the group consisting of Ga2O3, GaCl2, and GaCl3. The Cr-containing compound may be at least one selected from the group consisting of Cr2O3, Cr2(CO3)3, CrCl2, and CrCl3.

[0081] The Ga-containing compound, the Cr-containing compound, the compound containing elements other than Ga and oxygen that constitute the host crystal, and the compound containing an element other than Cr that serves as an activator element, which is used as needed, can be weighed and mixed to satisfy the composition represented by formula (1), the composition represented by formula (2), or the composition represented by formula (3), to obtain a raw material mixture. The compounds may be mixed using a mixer. The mixer may be a ball mill, which is commonly used industrially, or a vibration mill, a roll mill, a jet mill, or the like.

[0082] In preparing the first flux, the first flux includes an oxide containing at least one first element selected from the group consisting of Group 4 elements, Group 5 elements, Group 14 elements, and Group 15 elements. In preparing the first flux, the first element is preferably at least one selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Si, Ge, Sn, P, and Bi. Examples of oxides containing the first element include TiO2, ZrO2, HfO2, VO5, Nb2O5, Ta2O5, SiO2, GeO2, SnO2, (NH4)3PO4, (NH4)2HPO4, NH4H2PO4, Sb2O3, and Bi2O3. The oxide containing the first element is preferably at least one selected from the group consisting of TiO2, ZrO2, HfO2, Nb2O5, Ta2O5, SiO2, GeO2, (NH4)3PO4, (NH4)2HPO4, and NH4H2PO4.

[0083] The first flux promotes the reaction of the compounds contained in the raw material mixture and allows the solid-phase reaction to proceed more uniformly, thereby enabling the production of phosphor particles with large particle sizes and high luminescence intensity in the oxide phosphor manufacturing method. The oxide contained in the first flux adheres to the surface of the resulting phosphor particles in the form of particles or a film. It is believed that the flux promotes the reaction of the compounds contained in the raw material mixture when the temperature at which the liquid phase of the product formed by the reaction of the compound used as the flux with a portion of the raw material mixture is similar to or lower than the temperature of the heat treatment for obtaining the phosphor particles. The melting temperature of the oxide containing the first element used as the first flux may be higher than the heat treatment temperature. It is preferable that the flux contains a first flux and a second flux, and the temperature at which the liquid phase of the product formed by the reaction of the compound used as the flux with a portion of the raw material mixture is similar to or lower than the temperature of the heat treatment for obtaining the phosphor particles. In this case, it is believed that the flux promotes the reaction of the compounds contained in the raw material mixture. The elements contained in the first flux may be the same as at least some of the elements constituting the oxide phosphor.

[0084] The method for producing an oxide phosphor includes mixing a raw material mixture with a first flux to obtain a mixture. In obtaining the mixture, the first flux is preferably added in an amount of 0.05% by mass or more relative to 100% by mass of the raw material mixture. In obtaining the mixture, adding the first flux in an amount of 0.05% by mass or more relative to 100% by mass of the raw material mixture promotes the reaction of the compounds contained in the raw material mixture, resulting in phosphor particles with large particle sizes. When the first flux is composed of an oxide containing a first element, the oxide containing the first element that is the first flux is preferably added in an amount of 0.05% by mass or more relative to 100% by mass of the raw material mixture. The first flux may be added in an amount of 0.1% by mass or more, or 0.5% by mass or more relative to 100% by mass of the raw material mixture. The first flux may be added in an amount of 100% by mass or more relative to 100% by mass of the raw material mixture. The first flux may be added in an amount of 90 mass% or less, 80 mass% or less, or 70 mass% or less relative to 100 mass% of the raw material mixture, as long as the amount of the first flux is sufficient to promote the reaction of the raw material mixture.

[0085] In preparing the second flux, the second flux includes a compound containing at least one second element selected from the group consisting of alkali metal elements and alkaline earth metal elements. In preparing the second flux, the second element is preferably at least one selected from the group consisting of Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, and Ba. Specific examples of the compound containing the second element include carbonates and halides containing the second element. The compound containing the second element included in the second flux is preferably at least one selected from the group consisting of Li2CO3, Na2CO3, K2CO3, Rb2CO3, Cs2CO3, MgO, MgCO3, CaCO3, SrCO3, BaCO3, LiF, NaF, KF, RbF, BeF2, MgF2, CaF2, SrF2, BaF2, LiCl, NaCl, KCl, MgCl2, CaCl2, SrCl2, and BaCl2.

[0086] The second flux, together with the first flux, promotes the reaction of the compounds contained in the raw material mixture and allows the solid-phase reaction to proceed more uniformly. The melting point of the second flux is different from that of the first flux. By performing heat treatment with two fluxes, the first and second fluxes, with different melting points, the reaction of the compounds contained in the raw material mixture is further promoted, resulting in phosphor particles with higher luminescence intensity. The oxide contained in the first flux may adhere to the surface of the resulting phosphor particles in the form of particles or a film, and a compound containing a second element contained in the second flux may also adhere. The element contained in the second flux may be the same as at least some of the elements constituting the oxide phosphor. When the compound containing the elements constituting the oxide phosphor and the compound used as the second flux are the same, a compound containing the element is added to the raw material mixture so that the resulting oxide phosphor has the desired composition. Furthermore, since the compound added as a raw material may react with the first flux, it is preferable to add the same compound as the compound added as a raw material to the raw material mixture as the second flux.

[0087] The method for producing an oxide phosphor includes mixing a raw material mixture, a first flux, and a second flux to obtain a mixture. In obtaining the mixture, the second flux is preferably added in an amount of 0.01% by mass or more relative to 100% by mass of the raw material mixture. In obtaining the mixture, adding the second flux in an amount of 0.01% by mass or more relative to 100% by mass of the raw material mixture promotes the reaction of the compounds contained in the raw material mixture, resulting in phosphor particles with large particle sizes. When the second flux is composed of a compound containing a second element, the compound containing the second element that is the second flux is preferably added in an amount of 0.01% by mass or more relative to 100% by mass of the raw material mixture. The second flux may be added in an amount of 0.05% by mass or more, or may be added in an amount of 0.1% by mass or more relative to 100% by mass of the raw material mixture. The second flux may be added in an amount of less than 50% by mass relative to 100% by mass of the raw material mixture. The second flux may be added in an amount necessary to promote the reaction of the raw material mixture, and may be added in an amount of 30 mass% or less, 20 mass% or less, or 10 mass% or less relative to 100 mass% of the raw material mixture.

[0088] In obtaining the mixture, the amount (mass %) of the first flux added relative to 100% by mass of the raw material mixture is preferably 1.5 times or more the amount (mass %) of the second flux added. When the amount of the first flux added is 1.5 times or more the amount of the second flux added, the reaction of the compounds contained in the raw material mixture is further promoted, and phosphor particles with higher luminescence intensity can be obtained. In obtaining the mixture, the amount (mass %) of the first flux added relative to 100% by mass of the raw material mixture is more preferably 1.75 times or more the amount (mass %) of the second flux added, and may be 10 times or less, 7.5 times or less, or 5 times or less.

[0089] In obtaining the mixture, when mixing the raw material mixture with the first flux, or when mixing the raw material mixture with the first flux and the second flux, a mixer may be used. The mixer may be a ball mill, which is commonly used industrially, or a vibration mill, a roll mill, a jet mill, or the like.

[0090] The method for producing an oxide phosphor includes heat-treating the mixture to obtain an oxide phosphor including phosphor particles and first compound particles containing a first element arranged on the surfaces of the phosphor particles.

[0091] A method for producing an oxide phosphor includes heat-treating a mixture to obtain an oxide phosphor including phosphor particles, first compound particles containing a first element arranged on the surface of the phosphor particles, and second compound particles containing a second element arranged on the surface of the phosphor particles.

[0092] The resulting mixture can be placed in a crucible or boat made of carbon such as graphite, boron nitride (BN), alumina (Al2O3), tungsten (W), molybdenum (Mo), or other materials, and heat-treated in a furnace.

[0093] In obtaining an oxide phosphor, the heat treatment temperature is preferably in the range of 1000° C. to 1700° C., more preferably in the range of 1100° C. to 1600° C., and even more preferably in the range of 1300° C. to 1550° C. If the heat treatment temperature is 1000° C. to 1700° C., thermal decomposition is suppressed, and an oxide phosphor having the desired composition and a stable crystal structure is obtained.

[0094] The heat treatment is preferably carried out in an oxygen-containing atmosphere. There are no particular restrictions on the oxygen content in the atmosphere. The oxygen content in the oxygen-containing atmosphere is preferably 5% by volume or more, more preferably 10% by volume or more, and even more preferably 15% by volume or more. The heat treatment is preferably carried out in an air atmosphere (oxygen content of 20% by volume or more). If the oxygen-free atmosphere has an oxygen content of less than 1% by volume, an oxide phosphor having the desired composition may not be obtained.

[0095] In the heat treatment, a holding time may be set at a predetermined temperature. The holding time may be, for example, 0.5 hours to 48 hours, 1 hour to 40 hours, or 2 hours to 30 hours. By setting the holding time to 0.5 hours to 48 hours, crystal growth can be promoted.

[0096] The pressure of the heat treatment atmosphere may be standard atmospheric pressure (0.101 MPa), or may be 0.101 MPa or higher, or may be a pressurized atmosphere in the range of 0.11 MPa to 200 MPa. The heat-treated product obtained by heat treatment is prone to decomposition of its crystalline structure when the heat treatment temperature is high, but decomposition of the crystalline structure can be suppressed when the heat treatment is performed in a pressurized atmosphere.

[0097] The heat treatment time can be appropriately selected depending on the heat treatment temperature and the pressure of the atmosphere during the heat treatment, and is preferably 0.5 to 20 hours. Even when two or more stages of heat treatment are performed, the heat treatment time for each stage is preferably 0.5 to 20 hours. If the heat treatment time is 0.5 to 20 hours, decomposition of the resulting heat-treated product is suppressed, and a phosphor with a stable crystal structure and desired emission intensity can be obtained. Furthermore, production costs can be reduced and the manufacturing time can be relatively shortened. The heat treatment time is more preferably 1 to 10 hours, and even more preferably 1.5 to 9 hours.

[0098] In obtaining an oxide phosphor, it is preferable that the obtained phosphor particles have a composition represented by formula (1), a composition represented by formula (2), or a composition represented by formula (3).

[0099] The heat-treated product obtained by the heat treatment may be subjected to post-treatments such as pulverization, dispersion, solid-liquid separation, drying, etc. Solid-liquid separation can be carried out by an industrially commonly used method such as filtration, suction filtration, pressure filtration, centrifugation, decantation, etc. Drying can be carried out by an industrially commonly used device such as a vacuum dryer, a hot air heating dryer, a conical dryer, a rotary evaporator, etc. [Example]

[0100] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0101] The oxide phosphors of the Examples and Comparative Examples were evaluated as follows, and the results are shown in the tables.

[0102] Measurement of emission spectrum, emission peak wavelength, full width at half maximum (FWHM), and relative emission intensity The emission spectrum of each oxide phosphor of the Examples and Comparative Examples was measured using a quantum efficiency measurement system (QE-2000, manufactured by Otsuka Electronics Co., Ltd.). The emission peak wavelength of the excitation light of the light-emitting element, which is a semiconductor element, used in the quantum efficiency measurement system was 450 nm. From the obtained emission spectrum of each phosphor, the relative emission intensity, emission peak wavelength, and full width at half maximum were determined as emission characteristics. That is, the emission peak wavelength (nm) and the full width at half maximum (FWHM) (nm) of the emission spectrum at the emission peak wavelength of each phosphor were determined. For the oxide phosphors of Examples 1 to 28, the relative emission intensity (%) was determined by setting the emission intensity at the emission peak wavelength of the oxide phosphor of Comparative Example 1 as 100%. For the oxide phosphors of Examples 29 to 31, the relative emission intensity (%) was determined by setting the emission intensity at the emission peak wavelength of the oxide phosphor of Comparative Example 2 as 100%. For the oxide phosphor of Example 32, the relative emission intensity (%) was determined by setting the emission intensity at the emission peak wavelength of the oxide phosphor of Comparative Example 3 as 100%. For the oxide phosphor of Example 33, the relative luminous intensity (%) was calculated by setting the luminous intensity at the emission peak wavelength of the oxide phosphor of Comparative Example 4 as 100%. For the oxide phosphor of Example 34, the relative luminous intensity (%) was calculated by setting the luminous intensity at the emission peak wavelength of the oxide phosphor of Comparative Example 5 as 100%. For the oxide phosphor of Example 35, the relative luminous intensity (%) was calculated by setting the luminous intensity at the emission peak wavelength of the oxide phosphor of Comparative Example 6 as 100%. For the oxide phosphor of Example 36, the relative luminous intensity (%) was calculated by setting the luminous intensity at the emission peak wavelength of the oxide phosphor of Comparative Example 7 as 100%. The results are shown in the tables. Furthermore, the emission spectra of the oxide phosphors of the Examples and Comparative Examples are shown in the figures.

[0103] Amount of the first element or the second element (mass%) The oxide phosphor containing the first compound particles and / or the second compound particles was completely dissolved in a mixed solution of sulfuric acid and nitric acid, and then an inductively coupled plasma atomic emission spectrometry (ICP-AES) apparatus (Perkin Elmer) was used to calculate the mass % of each element derived from the phosphor particles, the first element derived from the first compound particles, and / or the second element derived from the second compound particles. Specifically, the ICP-AES analysis was used to measure each element derived from the phosphor particles, the first element derived from the first compound particles, and the second element derived from the second compound particles. The total amount of each element derived from the phosphor particles, the first element derived from the first compound particles, and the second element derived from the second compound particles was taken as 100% by mass of the total amount of each element derived from the oxide phosphor. When the total amount of each element derived from the oxide phosphor was taken as 100% by mass, the amount (mass %) of the first element derived from the first compound particles and the amount (mass %) of the second element derived from the second compound particles were calculated. In the oxide phosphors of the examples, there were no identical elements among the elements derived from the phosphor particles, the first element derived from the first compound particles, and the second element derived from the second compound particles. When the total amount of elements derived from the oxide phosphor was taken as 100 mass%, the amount (mass%) of the first element derived from the first compound particles and the amount (mass%) of the second element derived from the second compound particles were calculated.

[0104] Observation of oxide phosphors The oxide phosphors are observed using an SEM-EDX device (model number SU8230, manufactured by Shimadzu Corporation, and a silicon drift detector, manufactured by Horiba, Ltd.). Fig. 10 is an SEM photograph of the oxide phosphor according to Example 1. Fig. 11 is an SEM photograph of the surface of the oxide phosphor according to Example 4. Fig. 12 is an SEM photograph showing the distribution of the first element (Nb) contained in the oxide particles, obtained by EDX analysis of the surface of the oxide phosphor according to Example 4. Fig. 13 is an SEM photograph showing the distribution of the second element (Na) contained in the second compound particles, obtained by EDX analysis of the surface of the oxide phosphor according to Example 4. Fig. 14 is an SEM photograph of the oxide phosphor according to Comparative Example 1.

[0105] Volume average particle size For the oxide phosphors of the examples and comparative examples, the volume median diameter at which the product of cumulative frequencies from the small diameter side in the volume-based particle size distribution reached 50% was measured using a laser diffraction particle size distribution analyzer (MASTER SIZER2000, manufactured by MALVERN).

[0106] X-ray diffraction pattern and peak intensities The X-ray diffraction pattern of the oxide phosphor according to Example 12 was measured using a horizontal sample multipurpose X-ray diffractometer (Ultima IV, manufactured by Rigaku Corporation) and an X-ray source: CuKα radiation (λ=1.5418 Å, tube voltage 40 kV, tube current 40 mA). In the X-ray diffraction pattern of the oxide phosphor according to Example 12, a first peak P1 having the highest intensity in the Bragg angle 2θ range of 34° to 36° and a second peak P2 having the lowest intensity in the Bragg angle 2θ range of 31° to 33° were determined, and the intensity ratio P1 / P2 of the first peak P1 to the second peak P2 was calculated. FIG. 15 shows the X-ray diffraction pattern of the oxide phosphor according to Example 12 and the X-ray diffraction pattern of the oxide phosphor according to Example 12, as well as the X-ray diffraction patterns of β-Ga2O3, Na 13 Nb 35 O 94 , Na(NbO3) crystalline structure. 13 Nb 35 O 94 For the powder X-ray diffraction pattern showing the crystal structure of Na(NbO3), reference can be made to the values ​​of the International Centre for Diffraction Data (ICDD).

[0107] Example 1 The raw materials were 18.8 g of Ga2O3 and 0.23 g of Cr2O3 (the composition was Ga2O3:Cr 0.03 ) to prepare a raw material mixture. The first flux is prepared to contain 2.01 g of Nb2O5 (10.5 mass% of the raw material mixture as a whole), and the second flux is prepared to contain 0.54 g of Na2CO3 (2.8 mass% of the raw material mixture as a whole). The raw material mixture, first flux, and second flux are mixed together using an agate mortar and pestle for approximately 10 minutes to obtain a mixture. The resulting mixture is placed in an alumina crucible and heat-treated at 1400° C. in an air atmosphere (20% by volume of oxygen) at standard atmospheric pressure (0.101 MPa) for 8 hours. After the heat treatment, the heat-treated product is pulverized to obtain the oxide phosphor of Example 1 having the composition shown in Table 1, which corresponds to the molar ratio of the charged composition. The oxide phosphor of Example 1 and the oxide phosphors of Examples 2 to 28 described below have the composition represented by the formula (1), in which the variables v1 are 0 (v1=0) and x1 are 0.03 (x1=0.03). The oxide phosphor of Example 1 has a volume-average particle size at 50% cumulative in the volume-based particle size distribution measured by a laser diffraction particle size distribution measurement method of 20.3 μm.

[0108] Example 2 An oxide phosphor of Example 2 is obtained in the same manner as in Example 1, except that 0.4 g of Na2CO3 (2.1 mass % relative to 100 mass % of the raw material mixture) is prepared as the second flux.

[0109] Example 3 An oxide phosphor of Example 3 is obtained in the same manner as in Example 1, except that 0.27 g of Na2CO3 (1.4 mass % relative to 100 mass % of the raw material mixture) is prepared as the second flux.

[0110] Example 4 The oxide phosphor of Example 4 is obtained in the same manner as in Example 1, except that 1.34 g of Nb2O5 (7.0 mass % relative to 100 mass % of the raw material mixture) is prepared as the first flux, and 0.27 g of Na2CO3 (1.4 mass % relative to 100 mass % of the raw material mixture) is prepared as the second flux. The oxide phosphor of Example 1 has a cumulative 50% volume average particle size of 19.4 μm in the volume-based particle size distribution measured by laser diffraction particle size distribution measurement. The oxide phosphor of Example 4 has a first element, Nb, contained in the first compound particles of 1.5 mass % and a second element, Na, contained in the second compound particles of 0.16 mass % when the oxide phosphor is taken as 100 mass % as measured using an ICP-AES analyzer.

[0111] Example 5 The oxide phosphor of Example 5 is obtained in the same manner as Example 1, except that the first flux contains 1.34 g of Nb2O5 (7.0 mass% relative to 100 mass% of the raw material mixture) and the second flux contains 0.19 g of Na2CO3 (1.0 mass% relative to 100 mass% of the raw material mixture).

[0112] Example 6 The oxide phosphor of Example 6 is obtained in the same manner as in Example 1, except that the first flux contains 1.34 g of Nb2O5 (7.0 mass% relative to 100 mass% of the raw material mixture) and the second flux contains 0.27 g of Li2CO3 (1.4 mass% relative to 100 mass% of the raw material mixture).

[0113] Example 7 The oxide phosphor of Example 7 is obtained in the same manner as in Example 1, except that the first flux contains 1.34 g of Nb2O5 (7.0 mass% relative to 100 mass% of the raw material mixture) and the second flux contains 0.27 g of K2CO3 (1.4 mass% relative to 100 mass% of the raw material mixture).

[0114] Example 8 The oxide phosphor of Example 8 is obtained in the same manner as in Example 1, except that the first flux contains 1.34 g of Nb2O5 (7.0 mass% relative to 100 mass% of the raw material mixture) and the second flux contains 0.27 g of Rb2CO3 (1.4 mass% relative to 100 mass% of the raw material mixture).

[0115] Example 9 The oxide phosphor of Example 9 is obtained in the same manner as in Example 1, except that 1.34 g of Nb2O5 (7.0 mass% relative to 100 mass% of the raw material mixture) is prepared as the first flux, and 0.27 g of SrCO3 (1.4 mass% relative to 100 mass% of the raw material mixture) is prepared as the second flux. The oxide phosphor of Example 9 is measured using an ICP-AES analyzer, and when the oxide phosphor is taken as 100 mass%, the first element Nb contained in the first compound particles is 1.1 mass%, and the second element Sr contained in the second compound particles is 0.05 mass%.

[0116] Example 10 The oxide phosphor of Example 10 is obtained in the same manner as in Example 1, except that the first flux contains 1.34 g of Nb2O5 (7.0 mass% relative to 100 mass% of the raw material mixture) and the second flux contains 0.27 g of BaCO3 (1.4 mass% relative to 100 mass% of the raw material mixture).

[0117] Example 11 The oxide phosphor of Example 11 is obtained in the same manner as in Example 1, except that 1.34 g of Nb2O5 (7.0 mass% relative to 100 mass% of the raw material mixture) is prepared as the first flux and no second flux is prepared. The oxide phosphor of Example 11 contains 4.5 mass% of Nb, the first element contained in the first compound particles, when the oxide phosphor is taken as 100 mass%, as measured using an ICP-AES analyzer.

[0118] Example 12 The oxide phosphor of Example 12 is obtained in the same manner as in Example 1, except that the first flux was prepared to contain 13.4 g of Nb2O5 (70.0 mass% relative to 100 mass% of the raw material mixture), the second flux was prepared to contain 2.7 g of Na2CO3 (14.0 mass% relative to 100 mass% of the raw material mixture), and the heat treatment temperature was set to 1250°C.

[0119] Example 13 The oxide phosphor of Example 13 is obtained in the same manner as in Example 1, except that the first flux is prepared to contain 1.34 g of Ta2O5 (7.0 mass% relative to 100 mass% of the raw material mixture) and the second flux is prepared to contain 0.27 g of Na2CO3 (1.4 mass% relative to 100 mass% of the raw material mixture).

[0120] Example 14 The oxide phosphor of Example 14 is obtained in the same manner as in Example 13, except that 1.34 g (7.0 mass % relative to 100 mass % of the raw material mixture) of diammonium hydrogen phosphate (NH4)2HPO4 is prepared as the first flux.

[0121] Example 15 An oxide phosphor of Example 15 is obtained in the same manner as in Example 13, except that 1.34 g of GeO2 (7.0 mass % relative to 100 mass % of the raw material mixture) is prepared as the first flux.

[0122] Example 16 An oxide phosphor of Example 16 is obtained in the same manner as in Example 13, except that 1.34 g of ZrO2 (7.0 mass % relative to 100 mass % of the raw material mixture) is prepared as the first flux.

[0123] Example 17 An oxide phosphor of Example 17 is obtained in the same manner as in Example 13, except that 1.34 g of HfO2 (7.0 mass % relative to 100 mass % of the raw material mixture) is prepared as the first flux.

[0124] Example 18 An oxide phosphor of Example 18 is obtained in the same manner as in Example 13, except that 1.34 g of SiO2 (7.0 mass % relative to 100 mass % of the raw material mixture) is prepared as the first flux.

[0125] Example 19 The oxide phosphor of Example 19 is obtained in the same manner as in Example 1, except that the first flux contains 1.34 g of Nb2O5 (7.0 mass% relative to 100 mass% of the raw material mixture) and the second flux contains 0.21 g of NaF (1.1 mass% relative to 100 mass% of the raw material mixture).

[0126] Example 20 An oxide phosphor of Example 20 is obtained in the same manner as in Example 19, except that 0.12 g of LiF (0.6 mass % relative to 100 mass % of the raw material mixture) is prepared as the second flux.

[0127] Example 21 The oxide phosphor of Example 21 is obtained in the same manner as in Example 1, except that the first flux contains 0.67 g of Nb2O5 (3.5 mass% relative to 100 mass% of the raw material mixture) and the second flux contains 0.23 g of SrCO3 (1.2 mass% relative to 100 mass% of the raw material mixture).

[0128] Example 22 The oxide phosphor of Example 22 is obtained in the same manner as in Example 1, except that the first flux contains 0.67 g of Nb2O5 (3.5 mass% relative to 100 mass% of the raw material mixture) and the second flux contains 0.32 g of SrCO3 (1.7 mass% relative to 100 mass% of the raw material mixture).

[0129] Example 23 The oxide phosphor of Example 23 is obtained in the same manner as in Example 1, except that the first flux contains 0.67 g of Nb2O5 (3.5 mass% relative to 100 mass% of the raw material mixture) and the second flux contains 0.38 g of SrCO3 (2.0 mass% relative to 100 mass% of the raw material mixture).

[0130] Example 24 The oxide phosphor of Example 24 is obtained in the same manner as in Example 1, except that the first flux contains 0.67 g of Nb2O5 (3.5 mass% relative to 100 mass% of the raw material mixture) and the second flux contains 0.67 g of SrCO3 (3.5 mass% relative to 100 mass% of the raw material mixture).

[0131] Example 25 The oxide phosphor of Example 25 is obtained in the same manner as in Example 1, except that the first flux contains 0.33 g of Nb2O5 (1.7 mass% relative to 100 mass% of the raw material mixture) and the second flux contains 0.19 g of SrCO3 (1.0 mass% relative to 100 mass% of the raw material mixture).

[0132] Example 26 The oxide phosphor of Example 26 is obtained in the same manner as in Example 1, except that the first flux contains 1.0 g of Nb2O5 (5.3 mass% relative to 100 mass% of the raw material mixture) and the second flux contains 0.57 g of SrCO3 (3.0 mass% relative to 100 mass% of the raw material mixture).

[0133] Example 27 The oxide phosphor of Example 27 is obtained in the same manner as in Example 1, except that 1.34 g of Nb2O5 (7.0 mass % relative to 100 mass % of the raw material mixture) is prepared as the first flux and 0.76 g of SrCO3 (4.0 mass % relative to 100 mass % of the raw material mixture) is prepared as the second flux. The oxide phosphor of Example 27 has a volume average particle size of 22.7 μm at 50% cumulative volume in the volume-based particle size distribution measured by a laser diffraction particle size distribution measurement method.

[0134] Example 28 The oxide phosphor of Example 28 was obtained in the same manner as in Example 1, except that the first flux was prepared to contain 1.67 g of Nb2O5 (8.8 mass% relative to 100 mass% of the raw material mixture) and the second flux was prepared to contain 0.95 g of SrCO3 (5.0 mass% relative to 100 mass% of the raw material mixture).

[0135] Comparative Example 1 The oxide phosphor of Comparative Example 1 is obtained in the same manner as in Example 1, except that the first flux and the second flux are not used and 0.10 g of H3BO3 (0.5 mass % relative to 100 mass % of the raw material mixture) is used as the flux. The oxide phosphor of Comparative Example 1 has a composition represented by the formula (1) above, in which the variables v1 are 0 (v1=0) and x1 are 0.03 (x1=0.03). The oxide phosphor of Comparative Example 1 has a volume average particle size at 50% cumulative in the volume-based particle size distribution measured by a laser diffraction particle size distribution measurement method of 4.1 μm.

[0136] [Table 1]

[0137] The oxide phosphors of Examples 1 to 28, when heat-treated with the first flux and / or the second flux, have a higher luminescence intensity than the oxide phosphor of Comparative Example 1, which was heat-treated with a flux different from the first flux and / or the second flux.

[0138] The oxide phosphor of Example 12 has a higher luminous intensity than Comparative Example 1, although the masses of the first flux and the second flux are increased and the heat treatment temperature is lowered to 1250°C.

[0139] The volume average particle size of the oxide phosphor according to Example 1 is 20.3 μm, the volume average particle size of the oxide phosphor according to Example 4 is 19.4 μm, and the volume average particle size of the oxide phosphor according to Comparative Example 1 is 4.1 μm. The volume average particle sizes of the oxide phosphors according to Examples 1 and 4 are larger than that of the oxide phosphor according to Comparative Example 1, which was heat-treated with a flux different from the first flux and / or the second flux.

[0140] The oxide phosphor according to Example 4 was measured using an ICP-AES analyzer, and the first compound particles contained 1.5 mass% of Nb as the first element and 0.16 mass% of Na as the second element, when the oxide phosphor was taken as 100 mass%. The oxide phosphor according to Example 9 was measured using an ICP-AES analyzer, and the first compound particles contained 1.1 mass% of Nb as the first element and 0.05 mass% of Sr as the second element, when the oxide phosphor was taken as 100 mass%. The oxide phosphor according to Example 11 was measured using an ICP-AES analyzer, and the first compound particles contained 4.5 mass% of Nb as the first element, when the oxide phosphor was taken as 100 mass%. The amount of the first element contained in the first compound particles of the oxide phosphors according to Examples 4, 9, and 11 was within the range of 0.05 mass% to 100 mass% when the oxide phosphor was taken as 100 mass%. The amount of the second element contained in the second compound particles of the oxide phosphors according to Examples 4 and 9 is in the range of 0.01% by mass to 100% by mass, when the oxide phosphor is taken as 100% by mass.

[0141] The oxide phosphors according to Examples 21 to 24 have a higher relative luminous intensity when heat-treated with the first flux and the second flux. It is presumed that the oxide phosphors according to Examples 21 to 23 have a greater amount of the first flux than the second flux relative to 100% by mass of the raw material mixture, and that the amount of the first element is greater than the amount of the second element. It is presumed that the oxide phosphor according to Example 24 has a smaller amount of the first flux than the amount of the second flux relative to 100% by mass of the raw material mixture, and that the amount of the first element is less than the amount of the second element. Since the oxide phosphors according to Examples 21 to 23 have a higher relative luminous intensity than the oxide phosphor according to Example 24, a greater amount of the first element than the amount of the second element results in a higher relative luminous intensity.

[0142] The oxide phosphors according to Examples 25 to 28 have higher relative luminescence intensities when heat-treated together with the first flux and the second flux. The oxide phosphors according to Examples 25 to 28 have almost the same ratio of the amount of the first flux to the amount of the second flux relative to 100% by mass of the raw material mixture (first flux:second flux = 1.7 to 1.76:1), but the relative luminescence intensities of the oxide phosphors according to Examples 26 and 27 are higher than those of Examples 25 and 28. When the total amount of the first flux and the second flux relative to 100% by mass of the raw material mixture is in the range of 5% by mass to 12% by mass, the resulting oxide phosphor has higher luminescence intensity.

[0143] The volume average particle size of the oxide phosphor of Example 26 is 22.7 μm, which is larger than that of the oxide phosphor of Comparative Example 1 which was heat-treated with a flux different from the first flux and / or the second flux.

[0144] 5 to 9, the emission peak wavelengths of the emission spectra of the oxide phosphors according to Examples 1 to 12 were identical to those of the oxide phosphor according to Comparative Example 1. The relative emission intensities at the emission peak wavelengths of the emission spectra of the oxide phosphors according to Examples 1 to 12 were 100% or more, which were higher than the emission intensity at the emission peak wavelength of the emission spectrum of the oxide phosphor according to Comparative Example 1.

[0145] 10 is an SEM photograph of the oxide phosphor according to Example 1. As can be seen in the SEM photograph of the oxide phosphor according to Example 1, it can be seen that first compound particles 1 and / or second compound particles 2 are attached to the surfaces of the phosphor particles of phosphor 70, which is an oxide phosphor.

[0146] Fig. 11 is an SEM photograph of the surface of the oxide phosphor according to Example 4. Fig. 12 is an SEM photograph showing the distribution of the first element (Nb) contained in the oxide particles, as determined by EDX analysis of the surface of the oxide phosphor according to Example 4. Fig. 13 is an SEM photograph showing the distribution of the second element (Na) contained in the second compound particles, as determined by EDX analysis of the surface of the oxide phosphor according to Example 4. As shown in Figs. 11 to 13, first compound particles 1 containing oxide particles containing Nb, the first element contained in the first flux, and second compound particles 2 containing Na, the second element contained in the second flux, can be seen on the surface of phosphor 70, which is an oxide phosphor.

[0147] 14 is an SEM photograph of the oxide phosphor according to Comparative Example 1. The oxide phosphor according to Comparative Example 1 did not use the first flux and / or the second flux, but used boric acid (H3BO3) as a flux different from the first flux and the second flux. In the oxide phosphor according to Comparative Example 1, the phosphor particles of phosphor 70 are not large and do not form crystals like the oxide phosphor according to Example 1, and the first compound particles and the second compound particles cannot be confirmed on the surfaces of the phosphor particles of phosphor 70.

[0148] Fig. 15 shows the X-ray diffraction pattern of the oxide phosphor according to Example 12. The oxide phosphor according to Example 12 has a composition represented by the formula (1-1), and in the formula (1-1), x1 satisfies 0.03 (x1 = 0.03). The X-ray diffraction pattern of the oxide phosphor according to Example 12 shown in Fig. 15 is composed of gallium oxide (Ga2O3), sodium and niobium oxide (Na 13 Nb 35 O 9415 shows peaks at the same positions as in the powder X-ray diffraction pattern of niobium oxide (Na(NbO3)), confirming that the oxide phosphor of Example 12 has a gallium oxide crystal structure and contains first compound particles made of niobium oxide and second compound particles containing Na as a second element. In the X-ray diffraction pattern of the oxide phosphor of Example 12 shown in Fig. 15, the peak intensity ratio (P1 / P2) between the first peak P1, which has the highest intensity within the Bragg angle 2θ range of 34° to 36°, and the second peak P2, which has the lowest peak top intensity within the Bragg angle 2θ range of 31° to 33°, is 14.

[0149] As shown in FIGS. 16 and 17, the emission spectra of the oxide phosphors according to Examples 13 to 18 have emission peak wavelengths at approximately the same positions.

[0150] As shown in FIG. 18, the emission spectra of the oxide phosphors according to Examples 19 and 20 have emission peak wavelengths at approximately the same positions.

[0151] As shown in FIG. 19, the emission spectra of the oxide phosphors according to Examples 21 to 24 have emission peak wavelengths at approximately the same positions.

[0152] As shown in FIG. 20, the emission spectra of the oxide phosphors according to Examples 25 to 28 have emission peak wavelengths at approximately the same positions.

[0153] Example 29 The raw materials were Ga2O3 16.9g, In2O3 2.78g, and Cr2O3 0.31g (the composition was (Ga 0.9 In 0.1 )2O3:Cr 0.04 ) to prepare a raw material mixture. The first flux is prepared to contain 0.11 g of Nb2O5 (0.55 mass% relative to 100 mass% of the raw material mixture), and the second flux is prepared to contain 0.02 g of Na2CO3 (0.1 mass% relative to 100 mass% of the raw material mixture). The raw material mixture, first flux, and second flux are mixed using an agate mortar and pestle for approximately 10 minutes to obtain a mixture. The resulting mixture is placed in an alumina crucible and heat-treated at 1400° C. in an air atmosphere (20% by volume of oxygen) at standard atmospheric pressure (0.101 MPa) for 8 hours. After the heat treatment, the heat-treated product is pulverized to obtain the oxide phosphor of Example 29 having the composition shown in Table 1, which is the molar ratio of the charged composition. The oxide phosphors of Examples 29 to 31 have the composition represented by the formula (1), and M 1 is In, v1 is 0.1 (v1=0.1), and x1 is 0.04 (x1=0.04). In the oxide phosphor according to Example 29, when the oxide phosphor is taken as 100 mass%, the first element Nb contained in the first compound particles is 0.20 mass%, and the second element Na contained in the second compound particles is 0.02 mass%, as measured using an ICP-AES analyzer.

[0154] Example 30 An oxide phosphor of Example 30 is obtained in the same manner as in Example 29, except that 0.02 g of Li2CO3 is prepared as the second flux (0.1 mass % relative to 100 mass % of the raw material mixture).

[0155] Example 31 An oxide phosphor of Example 31 is obtained in the same manner as in Example 29, except that 0.02 g of SrCO3 (0.1 mass % relative to 100 mass % of the raw material mixture) is prepared as the second flux.

[0156] Comparative Example 2 The oxide phosphor of Comparative Example 2 is obtained in the same manner as in Example 29, except that no flux is used. The oxide phosphor of Comparative Example 2 has a composition represented by the formula (1) and contains M 1 is In, v1 is 0.1 (v1=0.1), and x1 is 0.04 (x1=0.04).

[0157] [Table 2]

[0158] The oxide phosphors according to Examples 29 to 31 have higher emission intensities than the oxide phosphor according to Comparative Example 2, which has the same composition but is heat-treated without using the first flux and the second flux. As shown in Fig. 21, the emission spectra of the oxide phosphors according to Examples 29 to 31 and the oxide phosphor according to Comparative Example 2 have emission peak wavelengths at approximately the same positions, but the emission intensities at the emission peak wavelengths of the oxide phosphors according to Examples 29 to 31 are higher than the emission intensity at the emission peak wavelength of the oxide phosphor according to Comparative Example 2.

[0159] The oxide phosphor of Example 29, when measured using an ICP-AES analyzer, contains 0.20 mass% of Nb as a first element in the first compound particles and 0.02 mass% of Na as a second element in the second compound particles, when the oxide phosphor is taken as 100 mass%. The mass of the first element contained in the first compound particles of the oxide phosphor of Example 29 is within the range of 0.05 mass% to 100 mass% when the oxide phosphor is taken as 100 mass%, and the amount of the second element contained in the second compound particles is within the range of 0.01 mass% to 100 mass% when the oxide phosphor is taken as 100 mass%.

[0160] Example 32 The raw materials were 11.7 g of Ga2O3, 3.82 g of Al2O3, and 0.23 g of Cr2O3 (the composition was Ga 0.625 Al 0.375 )2O3:Cr 0.03 ) to prepare a raw material mixture. The first flux is prepared to contain 1.09 g of Nb2O5 (7.0 mass % relative to 100 mass % of the raw material mixture), and the second flux is prepared to contain 0.22 g of Na2CO3 (1.4 mass % relative to 100 mass % of the raw material mixture). Except for using the prepared raw material mixture, first flux, and second flux, the oxide phosphor of Example 32 is obtained in the same manner as in Example 1. The oxide phosphor of Example 32 has a composition represented by the above formula (1), and contains M 1 is Al, v1 is 0.375 (v1 = 0.375), and x1 is 0.03 (x1 = 0.03).

[0161] Comparative Example 3 The oxide phosphor of Comparative Example 3 is obtained in the same manner as in Example 29, except that the first flux and the second flux are not used and 0.08 g of H3BO3 (0.5 mass % relative to 100 mass % of the raw material mixture) is used as the flux. The oxide phosphor of Comparative Example 3 and the oxide phosphor of Comparative Example 3 described later have a composition represented by the formula (1) above, and 1 is Al, v1 is 0.375 (v1 = 0.375), and x1 is 0.03 (x1 = 0.03).

[0162] [Table 3]

[0163] The oxide phosphor of Example 32, by being heat-treated together with the first flux and / or the second flux, has a larger particle size and a higher emission intensity than the oxide phosphor of Comparative Example 3, which was heat-treated together with a flux different from the first flux and / or the second flux. As shown in Fig. 22, the emission spectra of the oxide phosphor of Example 32 and the oxide phosphor of Comparative Example 3 have emission peak wavelengths at almost the same positions, but the emission intensity at the emission peak wavelength of the oxide phosphor of Example 32 is higher than the emission intensity at the emission peak wavelength of the oxide phosphor of Comparative Example 3.

[0164] Example 33 The raw materials were 3.22g of MgO, 14.3g of Ga2O3, and 0.55g of Cr2O3 (the composition was (MgGa 1.91 O4:Cr 0.09 ) to prepare a raw material mixture. The first flux is prepared to contain 1.27 g of Nb2O5 (7.0 mass% relative to 100 mass% of the raw material mixture), and the second flux is prepared to contain 0.25 g of Na2CO3 (1.4 mass% relative to 100 mass% of the raw material mixture). The raw material mixture, first flux, and second flux are mixed using an agate mortar and pestle for approximately 10 minutes to obtain a mixture. The resulting mixture is placed in an alumina crucible and heat-treated at 1400° C. in an air atmosphere (20% by volume of oxygen) at standard atmospheric pressure (0.101 MPa) for 8 hours. After the heat treatment, the heat-treated product is pulverized to obtain the oxide phosphor of Example 33, which has the composition shown in Table 5, which corresponds to the molar ratio of the starting composition. The oxide phosphor of Example 33 has a composition represented by formula (2), where t2 is 0 (t2 = 0), u2 is 1.0 (u2 = 1.0), v2 is 0 (v2 = 0), w2 is 4 (w2 = 4), x2 is 0.045 (x2 = 0.045), and y2 is 0 (y2 = 0). In Table 4, the molar ratio of Cr per mole of the oxide phosphor of Example 33 is 0.09, which is the product of 2 and x2.

[0165] Comparative Example 6 The oxide phosphor of Comparative Example 6 is obtained in the same manner as in Example 33, except that no flux is used and the heat treatment temperature is 1500°C. The oxide phosphor of Comparative Example 6 has a composition represented by formula (2) above, where t2 is 0 (t2 = 0), u2 is 1.0 (u2 = 1.0), v2 is 0 (v2 = 0), w2 is 4 (w2 = 4), x2 is 0.045 (x2 = 0.045), and y2 is 0 (y2 = 0). In Table 4, the molar ratio of Cr in 1 mole of the oxide phosphor composition of Comparative Example 6 is 0.09, which is the product of 2 and x2.

[0166] [Table 4]

[0167] The oxide phosphor of Example 33 has a higher emission intensity than the oxide phosphor of Comparative Example 4, which has the same composition but is heat-treated without using the first flux or the second flux. As shown in Fig. 23, the emission spectra of the oxide phosphor of Example 33 and the oxide phosphor of Comparative Example 4 have emission peak wavelengths at almost the same positions, but the emission intensity at the emission peak wavelength of the oxide phosphor of Example 33 is higher than the emission intensity at the emission peak wavelength of the oxide phosphor of Comparative Example 4.

[0168] Example 34 The raw materials were 3.22g of MgO, 14.3g of Ga2O3, 0.55g of Cr2O3, and 0.18g of NiO (the composition was (MgGa 1.91 O4:Cr 0.09 ,Ni 0.03 ) to prepare a raw material mixture. The first flux is prepared to contain 1.27 g of Nb2O5 (7.0 mass% relative to 100 mass% of the raw material mixture), and the second flux is prepared to contain 0.25 g of Na2CO3 (1.4 mass% relative to 100 mass% of the raw material mixture). The raw material mixture, first flux, and second flux are mixed using an agate mortar and pestle for approximately 10 minutes to obtain a mixture. The resulting mixture is placed in an alumina crucible and heat-treated at 1400° C. in an air atmosphere (20% by volume of oxygen) at standard atmospheric pressure (0.101 MPa) for 8 hours. After the heat treatment, the resulting heat-treated product is pulverized to obtain the oxide phosphor of Example 34, which has the composition shown in Table 6, which corresponds to the molar ratio of the starting composition. The oxide phosphor of Example 34 has a composition represented by formula (2), where t2 is 0 (t2 = 0), u2 is 1.0 (u2 = 1.0), v2 is 0 (v2 = 0), w2 is 4 (w2 = 4), x2 is 0.045 (x2 = 0.045), and y2 is 0.03 (y2 = 0.03). In Table 5, the molar ratio of Cr per mole of the oxide phosphor of Example 34 is 0.09, which is the product of 2 and x2.

[0169] Comparative Example 5 The oxide phosphor of Comparative Example 5 is obtained in the same manner as in Example 34, except that no flux is used and the heat treatment temperature is 1500°C. The oxide phosphor of Comparative Example 5 has a composition represented by the above formula (2), where t2 is 0 (t2 = 0), u2 is 1.0 (u2 = 1.0), v2 is 0 (v2 = 0), w2 is 4 (w2 = 4), x2 is 0.045 (x2 = 0.045), and y2 is 0.03 (y2 = 0.03). In Table 5, the molar ratio of Cr in 1 mole of the oxide phosphor composition of Example 34 is 0.09, which is the product of 2 and x2.

[0170] [Table 5]

[0171] The oxide phosphor of Example 34, by being heat-treated together with the first flux and / or the second flux, has a larger particle size and a higher emission intensity than the oxide phosphor of Comparative Example 5, which was heat-treated without using a flux. As shown in Fig. 24, the emission spectra of the oxide phosphor of Example 34 and the oxide phosphor of Comparative Example 5 have emission peak wavelengths at almost the same positions, but the emission intensity at the emission peak wavelength of the oxide phosphor of Example 34 is higher than the emission intensity at the emission peak wavelength of the oxide phosphor of Comparative Example 5.

[0172] Example 35 The raw materials were 1.48g of Li2CO3, 18.1g of Ga2O3, and 0.52g of Cr2O3 (the composition was (LiGa 4.83 O8:Cr 0.17 ) to prepare a raw material mixture. The first flux is prepared to contain 1.41 g of Nb2O5 (7.0 mass% relative to 100 mass% of the raw material mixture), and the second flux is prepared to contain 0.28 g of Na2CO3 (1.4 mass% relative to 100 mass% of the raw material mixture). The raw material mixture, first flux, and second flux are mixed for approximately 10 minutes using an agate mortar and pestle to obtain a mixture. In 1 mole of the oxide phosphor composition, the molar ratio of elements without a specified numerical value is 1.0. The resulting mixture is placed in an alumina crucible and heat-treated at 1250°C in an air atmosphere (20% by volume of oxygen) at standard atmospheric pressure (0.101 MPa) for 8 hours. After the heat treatment, the heat-treated product is pulverized to obtain the oxide phosphor of Example 35, which has the composition shown in Table 1, which corresponds to the molar ratio of the starting composition. The oxide phosphor of Example 35 has a composition represented by formula (3), where t3 is 0 (t3 = 0), u3 is 1.0 (u3 = 1.0), v3 is 0 (v3 = 0), w3 is 8 (w3 = 8), x3 is 0.034 (x3 = 0.034), y3 is 0 (y3 = 0), and z3 is 0 (z3 = 0). In Table 6, the molar ratio of Cr per mole of the oxide phosphor of Example 35 is 0.17, which is the product of 5 and x3.

[0173] Comparative Example 6 The oxide phosphor of Comparative Example 6 is obtained in the same manner as in Example 35, except that no flux is used and the heat treatment temperature is 1400°C. The oxide phosphor of Comparative Example 6 has a composition represented by formula (3) above, where t3 is 0 (t3 = 0), u3 is 1.0 (u3 = 1.0), v3 is 0 (v3 = 0), w3 is 8 (w3 = 8), x3 is 0.034 (x3 = 0.034), y3 is 0 (y3 = 0), and z3 is 0 (z3 = 0). In Table 6, the molar ratio of Cr in 1 mole of the oxide phosphor composition of Example 35 is 0.17, which is the product of 5 and x3.

[0174] [Table 6]

[0175] The oxide phosphor of Example 35 has a higher emission intensity than the oxide phosphor of Comparative Example 6, which has the same composition but is heat-treated without using the first flux and the second flux. As shown in Fig. 25, the emission spectra of the oxide phosphor of Example 35 and the oxide phosphor of Comparative Example 6 have emission peak wavelengths at almost the same positions, but the emission intensity at the emission peak wavelength of the oxide phosphor of Example 35 is higher than the emission intensity at the emission peak wavelength of the oxide phosphor of Comparative Example 6.

[0176] Example 36 The raw materials were 1.48g of Li2CO3, 17.8g of Ga2O3, 0.79g of Cr2O3, and 0.07g of NiO (the composition was (LiGa 4.74 O8:Cr 0.26 ,Ni 0.022) to prepare a raw material mixture. The first flux is prepared to contain 2.80 g of Nb2O5 (14.0 mass% of the raw material mixture as a whole), and the second flux is prepared to contain 0.56 g of Li2CO3 (2.8 mass% of the raw material mixture as a whole). The raw material mixture, first flux, and second flux are mixed for approximately 10 minutes using an agate mortar and pestle to obtain a mixture. In 1 mole of the oxide phosphor composition, the molar ratio of elements without a specified numerical value is 1.0. The resulting mixture is placed in an alumina crucible and heat-treated at 1250°C in an air atmosphere (20% by volume of oxygen) at standard atmospheric pressure (0.101 MPa) for 8 hours. After the heat treatment, the resulting heat-treated product was pulverized to obtain the oxide phosphor of Example 36, which had the composition shown in Table 8, which corresponds to the molar ratio of the starting composition. The oxide phosphor of Example 36 had a composition represented by formula (3), where t3 was 0 (t3 = 0), u3 was 1.0 (u3 = 1.0), v3 was 0 (v3 = 0), w3 was 8 (w3 = 8), x3 was 0.052 (x3 = 0.052), y3 was 0.022 (y3 = 0.022), and z3 was 0 (z3 = 0). In Table 7, the oxide phosphor of Example 36 had a molar ratio of Cr per mole of the oxide phosphor composition of 0.26, which is the product of 5 and x3. The oxide phosphor of Example 36 had a volume-average particle size at 50% of the cumulative volume in the volume-based particle size distribution measured by laser diffraction particle size distribution measurement.

[0177] Comparative Example 7 The oxide phosphor of Comparative Example 7 was obtained in the same manner as in Example 36, except that no flux was used and the heat treatment temperature was 1400°C. The oxide phosphor of Comparative Example 7 had a composition represented by the formula (3), where t3 was 0 (t3 = 0), u3 was 1.0 (u3 = 1.0), v3 was 0 (v3 = 0), w3 was 8 (w3 = 8), x3 was 0.052 (x3 = 0.052), y3 was 0.022 (y3 = 0.022), and z3 was 0 (z3 = 0). In Table 7, the oxide phosphor of Comparative Example 7 had a molar ratio of Cr per mole of the oxide phosphor composition of 0.26, which is the product of 5 and x3. The oxide phosphor of Comparative Example 7 had a volume-average particle size at 50% of the cumulative volume in the volume-based particle size distribution measured by a laser diffraction particle size distribution measurement method of 9.8 μm.

[0178] [Table 7]

[0179] The oxide phosphor of Example 36, by being heat-treated together with the first flux and / or the second flux, has a larger particle size and a higher emission intensity than the oxide phosphor of Comparative Example 7, which was heat-treated without using a flux, even when heat-treated at a temperature of 1250°C, which is lower than that of Comparative Example 7. As shown in Fig. 26, the emission spectra of the oxide phosphor of Example 36 and the oxide phosphor of Comparative Example 7 have emission peak wavelengths at almost the same positions, but the emission intensity at the emission peak wavelength of the oxide phosphor of Example 36 is higher than the emission intensity at the emission peak wavelength of the oxide phosphor of Comparative Example 7.

[0180] The volume average particle size of the oxide phosphor of Example 36 is 17.6 μm, which is larger than that of the oxide phosphor of Comparative Example 7 which was heat-treated without using the first flux and / or the second flux.

[0181] Embodiments according to the present disclosure include the following oxide phosphor, light-emitting device, and method for producing the oxide phosphor.

[0182] [Section 1] phosphor particles including a host crystal containing Ga and oxygen and an activator element; a first compound particle disposed on a surface of the phosphor particle; The first compound particles include oxide particles, and the oxide particles include at least one first element selected from the group consisting of Group 4 elements, Group 5 elements, Group 14 elements, and Group 15 elements. [Section 2] Further comprising second compound particles disposed on the surface of the phosphor particles, 2. The oxide phosphor according to claim 1, wherein the second compound particles contain at least one second element selected from the group consisting of alkali metal elements and alkaline earth metal elements. [Section 3] Item 3. The oxide phosphor according to item 1 or 2, wherein the amount of the first element contained in the first compound particles is in the range of 0.05% by mass or more and 80% by mass or less when the total amount of the oxide phosphor is taken as 100% by mass. [Section 4] Item 4. The oxide phosphor according to any one of items 1 to 3, wherein the amount of the second element contained in the second compound particles is in the range of 0.01% by mass or more and 80% by mass or less when the total amount of the oxide phosphor is taken as 100% by mass. [Section 5] Item 3. The oxide phosphor according to item 2, wherein the amount of the first element is greater than the amount of the second element. [Section 6] Item 6. The oxide phosphor according to any one of items 1 to 5, wherein the volume average particle size at 50% cumulative in a volume-based particle size distribution measured by a laser diffraction particle size distribution measurement method is in the range of 10 μm to 50 μm. [Section 7] Item 7. The oxide phosphor according to any one of items 1 to 6, wherein the phosphor particles have a composition represented by the following formula (1), a composition represented by the following formula (2), or a composition represented by the following formula (3): (Ga 1-V1 M 1 V1 )2O3:Cr x1 (1) (In the above formula (1), M 1 is at least one element selected from the group consisting of Al, In, and rare earth elements, and v1 and x1 satisfy 0≦v1≦1.0 and 0.02≦x1≦0.3, respectively. (Mg 1-t2 M 2 t2 ) u2 (Ga 1-v2-x2 M 3 v2 )2O w2 :Cr 2x2 ,M 4 y2 (2) (In the above formula (2), M 2 is at least one element selected from the group consisting of Ca, Sr, Ba, Ni and Zn, and M3 is at least one element selected from the group consisting of B, Al, In, and Sc, and M 4 is at least one element selected from the group consisting of Eu, Ce, Tb, Pr, Nd, Sm, Yb, Ho, Er, Tm, and Mn, and t2, u2, v2, w2, x2, and y2 satisfy 0 ≦ t2 ≦ 0.8, 0.7 ≦ u2 ≦ 1.3, 0 ≦ v2 ≦ 0.8, 3.7 ≦ w2 ≦ 4.3, 0.01 < x2 ≦ 0.15, 0 ≦ y2 ≦ 0.2, and y2 < 2x2, respectively. In the formula (2), "2x2" is the product of 2 and the variable x2.) (Li 1-t3 M 5 t3 ) u3 (Ga 1-v3-x3-z3 M 6 v3 )5O w3 :Cr 5x3 ,Ni y3 ,M 7 5z3 (3) (In the formula (3), M 5 is at least one element selected from the group consisting of Na, K, Rb, and Cs, M 6 is at least one element selected from the group consisting of B, Al, In, and rare earth elements, M 7 is at least one element selected from the group consisting of Si, Ge, Sn, Ti, Zr, Hf, Bi, V, Nb, and Ta, and t3, u3, v3, w3, x3, y3, and z3 satisfy 0 ≦ t3 ≦ 1.0, 0.7 ≦ u3 ≦ 1.6, 0 ≦ v3 < 1.0, 7.85 ≦ w3 ≦ 11.5, 0.01 ≦ x3 ≦ 0.24, 0 ≦ y3 ≦ 0.5, 0.25 < 5x3 + y3 ≦ 1.2, y3 < 5x3, and 0 ≦ z3 ≦ 0.1, respectively. In the formula (3), "5x3" is the product of 5 and the variable x3. In the formula (3), "5z3" is the product of 5 and the variable z3.) [Item 8] The oxide phosphor according to any one of Items 1 to 7, wherein the first element is at least one selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Si, Ge, Sn, P, and Bi. [Item 9] Item 9. The oxide phosphor according to any one of items 1 to 8, wherein the second element is at least one selected from the group consisting of Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, and Ba. [Section 10] The oxide phosphor according to Items 1 to 6 and Items 8 and 9, which cite Item 1, wherein the phosphor particles have a composition represented by the following formula (1-1): the oxide phosphor has, in a powder X-ray diffraction pattern measured using CuKα radiation, a first peak P1 having the highest intensity within a Bragg angle 2θ range of 34° to 36° and a second peak P2 having the lowest peak top intensity within a Bragg angle 2θ range of 31° to 33°, and a peak intensity ratio (P1 / P2) of the first peak P1 to the second peak P2 is within a range of 5 to 100: Ga2O3:Cr x1 (1-1) (In the formula (1-1), x1 satisfies 0.02≦x1≦0.3.) [Section 11] Item 11. The oxide phosphor according to any one of items 1 to 10, a light-emitting element having an emission peak wavelength in the range of 365 nm to 650 nm, which irradiates the oxide phosphor with excitation light; [Section 12] preparing a raw material mixture containing a compound containing Ga and a compound containing Cr as an activator element; preparing a first flux containing an oxide containing at least one first element selected from the group consisting of Group 4 elements, Group 5 elements, Group 14 elements, and Group 15 elements; mixing the raw material mixture and the first flux to obtain a mixture; and heat-treating the mixture to obtain an oxide phosphor comprising phosphor particles and first compound particles containing the first element arranged on the surfaces of the phosphor particles. [Section 13] preparing a raw material mixture containing a compound containing Ga and a compound containing Cr as an activator element; preparing a first flux containing an oxide containing at least one first element selected from the group consisting of Group 4 elements, Group 5 elements, Group 14 elements, and Group 15 elements; preparing a second flux containing a compound containing at least one second element selected from the group consisting of alkali metal elements and alkaline earth metal elements; mixing the raw material mixture, the first flux, and the second flux to obtain a mixture; and heat-treating the mixture to obtain an oxide phosphor comprising phosphor particles, first compound particles containing the first element and disposed on the surfaces of the phosphor particles, and second compound particles containing the second element and disposed on the surfaces of the phosphor particles. [Section 14] Item 14. The method for producing an oxide phosphor according to Item 12 or 13, wherein the first flux is added in an amount of 0.05% by mass or more relative to 100% by mass of the raw material mixture in obtaining the mixture. [Section 15] Item 15. The method for producing an oxide phosphor according to Item 13 or Item 14 citing Item 13, wherein the second flux is added in an amount of 0.01 mass % or more relative to 100 mass % of the raw material mixture in obtaining the mixture. [Section 16] Item 13 or Item 14 or 15 citing Item 13. The method for producing an oxide phosphor according to Item 13, wherein the amount (mass%) of the first flux added relative to 100 mass% of the raw material mixture is 1.5 times or more the amount (mass%) of the second flux added. [Section 17] Item 17. The method for producing an oxide phosphor according to any one of items 12 to 16, wherein the temperature of the heat treatment in obtaining the oxide phosphor is in the range of 1000°C or more and 1700°C or less. [Section 18] Item 18. The method for producing an oxide phosphor according to any one of items 12 to 17, wherein, in obtaining the oxide phosphor, the phosphor particles have any of a composition represented by the following formula (1), a composition represented by the following formula (2), or a composition represented by the following formula (3): (Ga1-V1 M 1 V1 )2O3:Cr x1 (1) (In the formula (1), M 1 is at least one element selected from the group consisting of Al, In, and rare earth elements, and v1 and x1 satisfy 0 ≦ v1 ≦ 1.0 and 0.02 ≦ x1 ≦ 0.3, respectively.) (Mg 1-t2 M 2 t2 ) u2 (Ga 1-v2-y2 M 3 v2 )2O w2 :Cr 2x2 ,M 4 y2 (2) (In the formula (2), M 2 is at least one element selected from the group consisting of Ca, Sr, Ba, Ni, and Zn, M 3 is at least one element selected from the group consisting of B, Al, In, and Sc, M 4 is at least one element selected from the group consisting of Eu, Ce, Tb, Pr, Nd, Sm, Yb, Ho, Er, Tm, and Mn, and t2, u2, v2, w2, x2, and y2 satisfy 0 ≦ t2 ≦ 0.8, 0.7 ≦ u2 ≦ 1.3, 0 ≦ v2 ≦ 0.8, 3.7 ≦ w2 ≦ 4.3, 0.01 < x2 ≦ 0.15, 0 ≦ y2 ≦ 0.2, and y2 < 2x2, respectively. In the formula (2), "2x2" is the product of 2 and the variable x2.) (Li 1-t3 M 5 t3 ) u3 (Ga 1-v3-x3-z3 M 6 v3 )5O w3 :Cr 5x3 ,Ni y3 ,M 7 5z3 (3) (In the formula (3), M 5 is at least one element selected from the group consisting of Na, K, Rb, and Cs, M 6is at least one element selected from the group consisting of B, Al, In and rare earth elements, and M 7 is at least one element selected from the group consisting of Si, Ge, Sn, Ti, Zr, Hf, Bi, V, Nb, and Ta, and t3, u3, v3, w3, x3, y3, and z3 satisfy the following conditions: 0≦t3≦1.0, 0.7≦u3≦1.6, 0≦v3<1.0, 7.85≦w3≦11.5, 0.01≦x3≦0.24, 0≦y3≦0.5, 0.25<5x3+y3≦1.2, y3<5x3, and 0≦z3≦0.1, respectively. In the formula (3), "5x3" is the product of 5 and the variable x3. In the formula (3), "5z3" is the product of 5 and the variable z3. [Section 19] Item 19. The method for producing an oxide phosphor according to any one of items 12 to 18, wherein in preparing the first flux, the first element is at least one selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Si, Ge, Sn, P and Bi. [Section 20] Item 13 or any one of Items 14 to 19 citing Item 13, wherein in preparing the second flux, the second element is at least one selected from the group consisting of Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, and Ba. [Industrial Applicability]

[0183] The oxide phosphor according to the present disclosure can also be used in medical light-emitting devices for obtaining information from within a living body, light-emitting devices that are mounted on small mobile devices such as smartphones and smartwatches to manage health conditions, light-emitting devices used in medical devices, light-emitting devices for analytical devices that non-destructively measure internal information about agricultural products such as fruits and vegetables and rice, food products, and pharmaceuticals, light-emitting devices for plant cultivation that affect the photoreceptors of plants, and light-emitting devices for reflectance spectroscopy measurement devices used to measure film thickness, etc. [Explanation of symbols]

[0184] 1: first compound particle, 2: second compound particle, 10: light-emitting element, 11: semiconductor element, 12: substrate, 20: first lead, 30: second lead, 40: molded body, 42: resin part, 50, 51: wavelength conversion member, 52: wavelength conversion member, 53: light-transmitting body, 60: wire, 61: conductive member, 70: phosphor, 71: first phosphor, 72: second phosphor, 73: third phosphor, 74: fourth phosphor, 75: fifth phosphor, 80: adhesive layer, 90: covering member, 100, 200: light-emitting device.

Claims

1. phosphor particles including a host crystal containing Ga and oxygen and an activator element; a first compound particle disposed on a surface of the phosphor particle; The first compound particles include oxide particles, and the oxide particles include at least one first element selected from the group consisting of Group 4 elements, Group 5 elements, Group 14 elements, and Group 15 elements.

2. Further comprising second compound particles disposed on the surface of the phosphor particles, The oxide phosphor according to claim 1 , wherein the second compound particles contain at least one second element selected from the group consisting of alkali metal elements and alkaline earth metal elements.

3. 3. The oxide phosphor according to claim 1, wherein the amount of the first element contained in the first compound particles is in the range of 0.05% by mass or more and 80% by mass or less when the total amount of the oxide phosphor is 100% by mass.

4. 3. The oxide phosphor according to claim 2, wherein the amount of the second element contained in the second compound particles is in the range of 0.01 mass% or more and 80 mass% or less when the total amount of the oxide phosphor is 100 mass%.

5. The oxide phosphor according to claim 2 , wherein the amount of the first element is greater than the amount of the second element.

6. 3. The oxide phosphor according to claim 1, wherein a volume average particle size at 50% cumulative volume in a volume-based particle size distribution measured by a laser diffraction particle size distribution measurement method is in the range of 10 μm to 50 μm.

7. 3. The oxide phosphor according to claim 1, wherein the phosphor particles have any one of a composition represented by the following formula (1), a composition represented by the following formula (2), and a composition represented by the following formula (3): (Ga １－Ｖ１ M １ Ｖ１ ) ２ O ３ :Cr ｘ１ (1) (In the above formula (1), M １ is at least one element selected from the group consisting of Al, In and rare earth elements, and v1 and x1 satisfy 0≦v1≦1.0 and 0.02≦x1≦0.3, respectively. (Mg １－ｔ２ M ２ ｔ２ ) ｕ２ (Ga １－ｖ２－ｘ２ M ３ ｖ２ ) ２ O ｗ２ :Cr ２ｘ２ ,M ４ ｙ２ (2) (In the above formula (2), M ２ is at least one element selected from the group consisting of Ca, Sr, Ba, Ni and Zn, and M ３ is at least one element selected from the group consisting of B, Al, In and Sc, and M ４ is at least one element selected from the group consisting of Eu, Ce, Tb, Pr, Nd, Sm, Yb, Ho, Er, Tm, and Mn, and t2, u2, v2, w2, x2, and y2 satisfy the following conditions: 0≦t2≦0.8, 0.7≦u2≦1.3, 0≦v2≦0.8, 3.7≦w2≦4.3, 0.01<x2≦0.15, 0≦y2≦0.2, and y2<2x2. In the formula (2), "2x2" is the product of 2 and the variable x2. (Li １－ｔ３ M ５ ｔ３ ) ｕ３ (G １－ｖ３－ｘ３－ｚ３ M ６ ｖ３ ) ５ O ｗ３ :Cr ５ｘ３ , Ni ｙ３ , M ７ ５ｚ３ (3) (In the above formula (3), M ５ is at least one element selected from the group consisting of Na, K, Rb, and Cs, and M ６ is at least one element selected from the group consisting of B, Al, In and rare earth elements, and M ７ is at least one element selected from the group consisting of Si, Ge, Sn, Ti, Zr, Hf, Bi, V, Nb, and Ta, and t3, u3, v3, w3, x3, y3, and z3 satisfy the following conditions: 0≦t3≦1.0, 0.7≦u3≦1.6, 0≦v3<1.0, 7.85≦w3≦11.5, 0.01≦x3≦0.24, 0≦y3≦0.5, 0.25<5x3+y3≦1.2, y3<5x3, and 0≦z3≦0.

1. In the formula (3), "5x3" is the product of 5 and the variable x3. In the formula (3), "5z3" is the product of 5 and the variable z3.

8. 3. The oxide phosphor according to claim 1, wherein the first element is at least one selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Si, Ge, Sn, P, and Bi.

9. 3. The oxide phosphor according to claim 2, wherein the second element is at least one selected from the group consisting of Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, and Ba.

10. 3. The oxide phosphor according to claim 1, wherein the phosphor particles have a composition represented by the following formula (1-1): In a powder X-ray diffraction pattern measured using CuKα radiation, the oxide phosphor has a first peak P1 having the highest intensity within a Bragg angle 2θ range of 34° or more and 36° or less, and a second peak P2 having the lowest peak top intensity within a Bragg angle 2θ range of 31° or more and 33° or less, and a peak intensity ratio (P1 / P2) of the first peak P1 to the second peak P2 is within a range of 5 or more and 100 or less. Ga ２ O ３ :Cr ｘ１ (1-1) (In the formula (1-1), x1 satisfies 0.02≦x1≦0.3.)

11. The oxide phosphor according to claim 1 or 2; a light-emitting element having an emission peak wavelength in the range of 365 nm to 650 nm, which irradiates the oxide phosphor with excitation light;

12. preparing a raw material mixture containing a compound containing Ga and a compound containing Cr as an activator element; preparing a first flux containing an oxide containing at least one first element selected from the group consisting of Group 4 elements, Group 5 elements, Group 14 elements, and Group 15 elements; mixing the raw material mixture and the first flux to obtain a mixture; and heat-treating the mixture to obtain an oxide phosphor comprising phosphor particles and first compound particles containing the first element arranged on the surfaces of the phosphor particles.

13. preparing a raw material mixture containing a compound containing Ga and a compound containing Cr as an activator element; preparing a first flux containing an oxide containing at least one first element selected from the group consisting of Group 4 elements, Group 5 elements, Group 14 elements, and Group 15 elements; preparing a second flux containing a compound containing at least one second element selected from the group consisting of alkali metal elements and alkaline earth metal elements; mixing the raw material mixture, the first flux, and the second flux to obtain a mixture; and heat-treating the mixture to obtain an oxide phosphor comprising phosphor particles, first compound particles containing the first element and disposed on the surfaces of the phosphor particles, and second compound particles containing the second element and disposed on the surfaces of the phosphor particles.

14. 14. The method for producing an oxide phosphor according to claim 12, wherein in obtaining the mixture, the first flux is added in an amount of 0.05 mass % or more relative to 100 mass % of the raw material mixture.

15. 14. The method for producing an oxide phosphor according to claim 13, wherein in obtaining the mixture, the second flux is added in an amount of 0.01 mass % or more with respect to 100 mass % of the raw material mixture.

16. 14. The method for producing an oxide phosphor according to claim 13, wherein, in obtaining the mixture, an amount (mass%) of the first flux added relative to 100 mass% of the raw material mixture is 1.5 times or more an amount (mass%) of the second flux added.

17. 14. The method for producing an oxide phosphor according to claim 12, wherein the temperature of the heat treatment in obtaining the oxide phosphor is in the range of 1000°C or more and 1700°C or less.

18. 14. The method for producing an oxide phosphor according to claim 12 or 13, wherein, in obtaining the oxide phosphor, the phosphor particles have any of a composition represented by the following formula (1), a composition represented by the following formula (2), or a composition represented by the following formula (3): (Ga １－Ｖ１ M １ Ｖ１ ) ２ O ３ :Cr ｘ１ (1) (In the above formula (1), M １ is at least one element selected from the group consisting of Al, In and rare earth elements, and v1 and x1 satisfy 0≦v1≦1.0 and 0.02≦x1≦0.3, respectively. (Mg １－ｔ２ M ２ ｔ２ ) ｕ２ (Ga １－ｖ２－ｘ２ M ３ ｖ２ ) ２ O ｗ２ :Cr ２ｘ２ ,M ４ ｙ２ (2) (In the above formula (2), M ２ is at least one element selected from the group consisting of Ca, Sr, Ba, Ni and Zn, and M ３ is at least one element selected from the group consisting of B, Al, In and Sc, and M ４ is at least one element selected from the group consisting of Eu, Ce, Tb, Pr, Nd, Sm, Yb, Ho, Er, Tm, and Mn, and t2, u2, v2, w2, x2, and y2 satisfy the following conditions: 0≦t2≦0.8, 0.7≦u2≦1.3, 0≦v2≦0.8, 3.7≦w2≦4.3, 0.01<x2≦0.15, 0≦y2≦0.2, and y2<2x2. In the formula (2), "2x2" is the product of 2 and the variable x2. (Li １－ｔ３ M ５ ｔ３ ) ｕ３ (G １－ｖ３－ｘ３－ｚ３ M ６ ｖ３ ) ５ O ｗ３ :Cr ５ｘ３ , Ni ｙ３ , M ７ ５ｚ３ (3) (In the above formula (3), M ５ is at least one element selected from the group consisting of Na, K, Rb, and Cs, and M ６ is at least one element selected from the group consisting of B, Al, In and rare earth elements, and M ７ is at least one element selected from the group consisting of Si, Ge, Sn, Ti, Zr, Hf, Bi, V, Nb, and Ta, and t3, u3, v3, w3, x3, y3, and z3 satisfy the following conditions: 0≦t3≦1.0, 0.7≦u3≦1.6, 0≦v3<1.0, 7.85≦w3≦11.5, 0.01≦x3≦0.24, 0≦y3≦0.5, 0.25<5x3+y3≦1.2, y3<5x3, and 0≦z3≦0.

1. In the formula (3), "5x3" is the product of 5 and the variable x3. In the formula (3), "5z3" is the product of 5 and the variable z3.

19. 14. The method for producing an oxide phosphor according to claim 12 or 13, wherein in preparing the first flux, the first element is at least one selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Si, Ge, Sn, P and Bi.

20. 14. The method for producing an oxide phosphor according to claim 13, wherein in preparing the second flux, the second element is at least one selected from the group consisting of Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, and Ba.

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