Oxide fluorescent material and light emitting device using the same

Abstract

To provide an oxide fluorescent material having a light emission peak wavelength in a wavelength range from red light to near-infrared light and having a wide full width at half maximum of the light emission spectrum, and a light emitting device using the same.SOLUTION: An oxide fluorescent material has a composition represented by the following formula (1). (Ga1-uM1u)2(Ge1-vM2v)wOx:Cry, M3z (1), where M1 represents at least one element selected from the group consisting of Al, Sc, and In; M2 represents at least one element selected from the group consisting of Si, Ti, Zr, Sn, and Hf, M3 represents at least one element selected from the group consisting of Ni, Eu, Fe, Mn, Nd, Tm, Ho, Er, and Yb; and u, v, w, x, y, and z satisfy 0≤u≤1.0, 0≤v≤0.5, 1.0≤w≤3.0, 5≤x≤9, 0.005≤y≤1.0, and 0≤z≤0.5, respectively.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to an oxide phosphor and a light-emitting device using the same. [Background technology]

[0002] Light-emitting devices having a light 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 analysis equipment that non-destructively measures the sugar content of agricultural products such as fruits and vegetables or food, analytical equipment that non-destructively measures the presence of foreign matter in medicines, etc. Light-emitting devices that emit light in the wavelength range of visible light as well as in the wavelength range from red light to near-infrared light are also desired.

[0003] As such a light emitting device, there is a light emitting device in which a light emitting diode (LED) and a phosphor are combined. Furthermore, examples of phosphors that can be combined with light emitting devices include phosphors that have a relatively large emission spectrum and 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+ There is also a demand for near-infrared emitting phosphors having an emission spectrum with a wider full width at half maximum and an emission peak wavelength in a longer wavelength range, which are suitable for the above-mentioned applications. [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] 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 a wide full width at half maximum of the emission spectrum, and a light emitting device using the oxide phosphor. [Means for solving the problem]

[0007] The first aspect is an oxide phosphor having a composition represented by the following formula (1). (Ga 1-u M 1 u )2(Ge 1-v M 2 v ) w O x :Cr y ,M 3 z (1) (In the above formula (1), M 1 is at least one element selected from the group consisting of Al, Sc and In, and M 2 is at least one element selected from the group consisting of Si, Ti, Zr, Sn and Hf, and M 3 is at least one element selected from the group consisting of Ni, Eu, Fe, Mn, Nd, Tm, Ho, Er, and Yb, and u, v, w, x, y, and z satisfy 0≦u≦1.0, 0≦v≦0.5, 1.0≦w≦3.0, 5≦x≦9, 0.005≦y≦1.0, and 0≦z≦0.5, respectively.

[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. Effect of the Invention

[0009] 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 a wide full width at half maximum of an emission spectrum, and a light emitting device using the same. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic cross-sectional view showing an example of a first configuration example of a light emitting device. [Diagram 2] FIG. 4 is a schematic cross-sectional view showing another example of the first configuration example of the light emitting device. [Figure 3A] FIG. 4 is a schematic plan view showing a second configuration example of the light emitting device. [Figure 3B] FIG. 4 is a schematic cross-sectional view showing a second configuration example of the light emitting device. [Figure 4] FIG. 2 is a diagram showing the emission spectra of the oxide phosphors according to Examples 1 to 5. [Diagram 5] FIG. 2 is a diagram showing the emission spectra of oxide phosphors according to Examples 6 to 10. [Figure 6] FIG. 2 is a diagram showing the emission spectra of the oxide phosphors according to Examples 11 to 15. [Figure 7] FIG. 2 is a diagram showing the emission spectra of the oxide phosphors according to Examples 16 to 18 and the oxide phosphor according to Comparative Example 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The oxide phosphor according to the present disclosure, a light-emitting device using the same, and a method for producing the oxide phosphor will be described below. However, the following embodiments are merely examples for embodying the technical concept of the present invention, and the present invention is not limited to the oxide phosphor and light-emitting device described below. Note that, for visible light, the relationship between color names and chromaticity coordinates, the relationship between the wavelength range of light and the color names of monochromatic light, etc., follow JIS Z8110.

[0012] A light-emitting device using a phosphor is required to emit light in an optimal wavelength range depending on the visual target and the usage situation. For example, in the medical field, it may be required to easily obtain information inside a living body. In a living body, light absorbers include water, hemoglobin, melanin, etc. For example, hemoglobin has a high absorption rate of light in the visible wavelength range of less than 650 nm, and a light-emitting device that emits light in the visible wavelength range has difficulty in transmitting light in the visible wavelength range inside a living body, making it difficult to obtain information inside the living body. If it is possible to irradiate light in a wavelength range in which the absorption and scattering of light in living tissue is small, it becomes easier to obtain information deep inside the living body. Therefore, there is a demand for a light-emitting device that can emit light in a wavelength range called the "biological window" through which light can easily penetrate inside the living body. As the "biological window," the wavelength range of about 650 nm to about 950 nm is sometimes called the "first biological window," the wavelength range of about 1000 nm to about 1350 nm is sometimes called the "second biological window," and the wavelength range of about 1500 nm to about 1800 nm is sometimes called the "third biological window." If it is possible to irradiate light in a wavelength range in which the absorption and scattering of light in tissues in a living body is small, it becomes easier to obtain information about the deep inside of the living body. For example, if it is possible to measure the increase or decrease in the oxygen concentration in blood in a living body by the increase or decrease in the absorption of light by hemoglobin that binds with oxygen, it becomes possible to easily obtain information about the inside of the living body by irradiating it with light from a light-emitting device. In addition, if information about the deep inside of the living body can be obtained by irradiating it with light from a phosphor and a light-emitting element rather than by irradiating it with X-rays or the like, it is possible to obtain information about the inside of the living body more safely. Therefore, the phosphor used in the light-emitting device may be required to have an emission peak wavelength in the range of 760 nm to 970 nm. Recently, there is a demand for a light emitting device that can visualize deep inside a living body more clearly and emits safe light in the wavelength range from infrared light to near infrared light. In addition, if a light emitting device including a light emitting element and a phosphor can pass a high current and emit high-power light, the detection ability can be improved and information inside the living body can be easily obtained.

[0013] In the agricultural and food fields, there is a demand for non-destructive sugar content meters and non-destructive rice taste meters that non-destructively measure the sugar content of agricultural products and fruits and vegetables. Near-infrared spectroscopy may be used as a method for non-destructively measuring the internal quality of fruits and vegetables, such as sugar content, acidity, ripeness, and internal damage, and the surface quality that appears on the surface of the fruit skin or the surface layer near the surface of the fruit skin, such as abnormal dryness. In near-infrared spectroscopy, light in the near-infrared wavelength range is irradiated onto fruits and vegetables, and the transmitted light that has passed through the fruits and vegetables and the reflected light that has been reflected by the fruits and vegetables are received, and the quality of the fruits and vegetables is measured based on the reduction in the intensity of the light (light absorption). In such near-infrared spectroscopy analytical devices used in the food field, light sources such as tungsten lamps and xenon lamps are used. In this specification, the wavelength range of red light complies with JIS Z8110.

[0014] In addition, amid environmental changes such as climate change, it is desirable to provide a stable supply of vegetables and other plants and to increase plant production efficiency. Plant factories, which allow artificial management, are capable of steadily supplying safe vegetables to the market and are expected to be the next-generation industry. In such plant factories, light-emitting devices that irradiate light that can promote plant growth are required. Plant responses to light are divided into photosynthesis and photomorphogenesis. Photosynthesis is a reaction that uses light energy to decompose water, generate oxygen, and fix carbon dioxide into organic matter, and is a reaction necessary for plant growth. Photomorphogenesis is a morphological reaction that uses light as a signal to perform seed germination, differentiation (germination formation, leaf formation, etc.), movement (stoma opening and closing, chloroplast movement), light refraction, etc. It has been found that light in the wavelength range of 690 nm to 800 nm affects the photoreceptors of plants in photomorphogenesis reactions. For this reason, light-emitting devices used in plant factories and the like may be required to be capable of emitting light in a wavelength range that affects plant photoreceptors (chlorophyll a, chlorophyll b, carotenoids, phytochromes, cryptochromes, phototropins) and promotes plant growth. With regard to the near-infrared light-emitting phosphors described above, there is room for improving the light-emitting characteristics as a phosphor so that light can be emitted suitable for the application when a light-emitting device is made using a light-emitting element such as a blue light-emitting diode (LED) or a laser diode (LD) that emits violet to blue light as an excitation light source.

[0015] In addition, there are cases where light emitting devices that emit light in the wavelength range of 365 nm to less than 700 nm, as well as light in the wavelength range from red light to near infrared light, are required. For example, there are cases where light 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.

[0016] The oxide phosphor has a composition represented by the following formula (1). (Ga 1-u M 1 u )2(Ge 1-v M 2 v ) w O x :Cr y ,M 3 z (1) (In the above formula (1), M 1 is at least one element selected from the group consisting of Al, Sc and In, and M 2 is at least one element selected from the group consisting of Si, Ti, Zr, Sn and Hf, and M 3 is at least one element selected from the group consisting of Ni, Eu, Fe, Mn, Nd, Tm, Ho, Er, and Yb, and u, v, w, x, y, and z satisfy 0≦u≦1.0, 0≦v≦0.5, 1.0≦w≦3.0, 5≦x≦9, 0.005≦y≦1.0, and 0≦z≦0.5, respectively.

[0017] In the oxide phosphor, if the variable y in the formula (1) expressing the molar ratio of the activator element Cr is within the range of 0.005 or more and 1.0 or less (0.005≦y≦1.0) in 1 mole of the oxide phosphor composition, the oxide phosphor has an emission peak wavelength in a near-infrared wavelength range desired for the intended use, and can obtain a relatively wide emission spectrum with a full width at half maximum. In the oxide phosphor, the variable y in the formula (1) in 1 mole of the oxide phosphor composition may be within the range of 0.01 or more and 0.50 or less (0.01≦y≦0.50), 0.01 or more and 0.30 or less (0.01≦y≦0.30), 0.01 or more and 0.20 or less (0.01≦y≦0.20), or 0.01 or more and 0.10 or less (0.01≦y≦0.10). y may be in the range of 0.01 or more and 0.09 or less (0.01≦y≦0.09), in the range of 0.015 or more and 0.08 or less (0.015≦y≦0.08), in the range of 0.02 or more and less than 0.08 (0.02≦y<0.08), in the range of 0.02 or more and 0.07 or less (0.02≦y≦0.07), or in the range of 0.02 or more and 0.06 or less (0.02≦y≦0.06). In this specification, in the composition formula showing the composition of a phosphor containing an oxide phosphor, the part before the colon (:) shows the elements constituting the host crystal and their molar ratio, and the part after the colon (:) shows the activator element.

[0018] The oxide phosphor has a composition represented by the formula (1) and may optionally contain a first element M 1 is at least one element selected from the group consisting of Al, Sc, and In, and may be two or more elements selected from the group consisting of Al, Sc, and In. 1 The oxide phosphor may contain Ga instead of the first element M. 1 may be replaced by two or more first elements M 1 In the composition represented by the formula (1), the oxide phosphor may contain the first element M 1 In the case where M is Al, all of Ga may be replaced with Al. The oxide phosphor does not contain Ga in the composition represented by the formula (1), and contains Al and at least one first element M selected from the group consisting of Sc and In.1 may be replaced by two or more first elements M 1 may be substituted.

[0019] The oxide phosphor contains a first element M 1 The molar ratio of the first element M is represented by the product of 2 and the variable u in the formula (1), and the variable u is in the range of 0 to 1.0 (0≦u≦1.0). The variable u in the oxide phosphor may be in the range of 0 to less than 1.0 (0≦u<1.0), 0.05 to 0.95 (0.0.5≦u≦0.95), 0.10 to 0.90 (0.10≦u≦0.90), 0.15 to 0.85 (0.15≦u≦0.85), or 0.20 to 0.80 (0.20≦u≦0.80). In the composition represented by the formula (1), the first element M 1 may not be substantially contained, and the variable u may be substantially 0 (substantially u=0). In this specification, when the numerical value of a variable representing a molar ratio of an element in a composition is "substantially 0", it means that the element is not intentionally contained. Specifically, when the numerical value of a variable representing a molar ratio of an element in a composition is substantially 0, it means that the numerical value is 1000 ppm by mass or less, and also includes the case of 500 ppm by mass or less, and the case of 1 ppm by mass or more.

[0020] The oxide phosphor may include a second element M 2 is at least one element selected from the group consisting of Si, Ti, Zr, Sn and Hf. In order to obtain an emission spectrum having a peak wavelength in a desired range depending on the intended use in the near infrared wavelength region and a wider full width at half maximum, the oxide phosphor may contain a second element M 2 may be either Si or Hf, and the second element M 2 may be Si.

[0021] The oxide phosphor contains Ge and a second element M in 1 mole of the oxide phosphor. 2When the variable w in the formula (1) expressing the molar ratio of the sum of Ga and the first element M is within the range of 1.0 to 3.0 (1.0≦w≦3.0), it is possible to obtain an emission spectrum with a wider full width at half maximum and an emission peak wavelength in a desired range depending on the purpose of use in the near infrared wavelength region. The oxide phosphor may have the variable w in the formula (1) in the range of 1.5 to 3.0 (1.5≦w≦3.0). In 1 mole of the oxide phosphor composition, Ga and the first element M 1 The molar ratio of Ge and the second element M 2 The total molar ratio of Ge and the second element M in 1 mole of the oxide phosphor composition may be the same. 2 The variable w representing the molar ratio of the sum of Ga and the first element M is within the range of 1.0 to 3.0. 1 The molar ratio of the total of these may be smaller or larger than 2.

[0022] The oxide phosphor may contain a second element M 2 The molar ratio of the second element M is represented by the product of the variable v and the variable w in the formula (1), and the variable v is in the range of 0 to 0.5 (0≦v≦0.5), may be in the range of 0 to 0.4 (0≦v≦0.4), or may be in the range of 0 to 0.3 (0≦v≦0.3). 2 may not substantially include, and the variable v may be substantially 0 (v=0).

[0023] The oxide phosphor has an emission peak wavelength in a desired range depending on the purpose of use in the near-infrared wavelength region, and in order to obtain an emission spectrum with a broader full width at half maximum, the variable x in the formula (1) representing the molar ratio of oxygen in 1 mole of the oxide phosphor composition is within a range of 5 or more and 9 or less (5≦x≦9), or may be within a range of 5.5 or more and 8.5 or less (5.5≦x≦8.5), or may be within a range of 6 or more and 8 or less (6≦x≦8).

[0024] The oxide phosphor may include a third element M 3is at least one element selected from the group consisting of Ni, Eu, Fe, Mn, Nd, Tm, Ho, Er and Yb, and may be at least one element selected from the group consisting of Ni, Eu, Fe, Mn and Nd.

[0025] The oxide phosphor has a composition represented by the formula (1) in which, in 1 mole of the oxide phosphor, a third element M, which is an activation element together with Cr and is included as necessary, is 3 The variable z representing the molar ratio is in the range of 0 to 0.5 (0≦z≦0.5), may be in the range of 0 to 0.4 (0≦z≦0.4), may be in the range of 0 to 0.3 (0≦z≦0.3), may be in the range of 0 to 0.2 (0≦z≦0.2), may be in the range of 0 to 0.1 (0≦z≦0.1), or may be 0.001 or more (0.001≦z). 3 may not substantially include, and the variable z may be substantially 0 (z=0).

[0026] The oxide phosphor preferably has an emission intensity of 25% or more at 1000 nm relative to 100% emission intensity at the emission peak wavelength in the emission spectrum. If the oxide phosphor has an emission intensity of 25% or more at 1000 nm relative to 100% emission intensity at the emission peak wavelength in the emission spectrum, it can emit light having an emission intensity required for analysis in the wavelength range of 900 nm to 1100 nm, which is easy to obtain information inside a living body and information on agricultural products, foods, medicines, etc. non-destructively, and can be used in a light-emitting device for an analytical device instead of a tungsten lamp or a xenon lamp.

[0027] The oxide phosphor preferably has an emission spectrum having an emission peak wavelength with a full width at half maximum in the range of 150 nm to 290 nm. The oxide phosphor preferably converts the wavelength of excitation light from the light-emitting element to emit light having an emission peak wavelength in a desired range, a wide full width at half maximum, and an emission intensity required for analysis at a desired wavelength. If light having an emission spectrum with a wide full width at half maximum can be irradiated in a wavelength range that can obtain information inside a living organism or information on agricultural products non-destructively, it becomes easier to obtain information inside a living organism or on agricultural products. In addition, it is desirable for an object to have an emission spectrum in a wide wavelength range in terms of how the color of the object appears when irradiated with light (hereinafter also referred to as "color rendering"), and light with a wide full width at half maximum can be emitted with excellent color rendering. For example, in a plant factory, even when emitting light in a wavelength range that affects plant growth, it may be required to emit light that does not disrupt the spectral balance of the light so that workers can work easily. The oxide phosphor may have an emission spectrum having an emission peak wavelength with a full width at half maximum of 155 nm or more, 160 nm or more, 165 nm or more, 170 nm or more, 175 nm or more, 180 nm or more, 285 nm or less, 280 nm or less, 275 nm or less, 270 nm or less, 265 nm or less, 260 nm or less, 250 nm or less, 240 nm or less, 230 nm or less, 220 nm or less, or within the range of 180 nm or more and 220 nm or less. In this specification, the full width at half maximum refers to the wavelength width that is 50% of the emission intensity at the emission peak wavelength showing the maximum emission intensity in the emission spectrum.

[0028] The oxide phosphor preferably has an emission peak wavelength in the range of 760 nm to 970 nm in the emission spectrum. The oxide phosphor can convert the wavelength of the excitation light from the light-emitting element and replace it with a tungsten lamp or a xenon lamp, and preferably has an emission spectrum that can obtain the emission intensity required for analysis in a wavelength range where it is easy to obtain information on the inside of a living body or agricultural products. If the oxide phosphor has an emission peak wavelength in the range of 760 nm to 970 nm in the emission spectrum, an emission spectrum having the emission intensity required for analysis in a wavelength range where it is easy to obtain information on the inside of a living body or information on agricultural products, foods, medicines, etc. in a non-destructive manner can be obtained. The oxide phosphor more preferably has an emission peak wavelength in the range of 780 nm to 970 nm in the emission spectrum, more preferably has an emission peak wavelength in the range of 790 nm to 970 nm, even more preferably has an emission peak wavelength in the range of 800 nm to 970 nm, even more preferably has an emission peak wavelength in the range of 820 nm to 970 nm, and particularly preferably has an emission peak wavelength in the range of 870 nm to 970 nm.

[0029] The light emitting device includes an oxide phosphor having a composition represented by the formula (1) and a light emitting element having an emission peak wavelength in the range of 365 nm to 650 nm and irradiating the oxide phosphor. The oxide phosphor can be used as a member constituting a wavelength conversion member together with a translucent material.

[0030] A semiconductor element can be used as a light-emitting element that irradiates an oxide phosphor. For example, a nitride semiconductor can be selected as a material for a light-emitting element that emits green and blue light. 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-arsenide-based semiconductor or an aluminum-indium-gallium-phosphorus-based semiconductor can be selected. As the light-emitting element, for example, it is preferable to use an LED chip or an LD chip.

[0031] The light-emitting element may have an emission peak wavelength in the range of 365 nm to 650 nm, may have an emission peak wavelength in the range of 365 nm to 500 nm, 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 have an emission peak wavelength in the range of more than 500 nm to 650 nm, 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 configure a light-emitting device that emits a mixed color light of a desired wavelength range of light from the light-emitting element and fluorescence from a phosphor containing the oxide phosphor. 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 as the light-emitting element. By using a light-emitting element using a nitride-based semiconductor as an excitation light source, it is possible to obtain a light-emitting device that is highly efficient, has a high linearity of output relative to input, and is stable and resistant to mechanical shock. Also, a light-emitting device that includes a light-emitting element that emits red light and an oxide phosphor that converts the wavelength of the light from the light-emitting element and emits light in the near-infrared wavelength range can be used as a heat source, and is useful as a countermeasure against snow accumulation on traffic lights and vehicle-mounted lighting devices in cold regions, etc.

[0032] The light emitting device essentially includes a first phosphor containing the oxide phosphor described above, and may further include a phosphor having a different composition. In addition to the first phosphor, the light emitting device preferably includes at least one phosphor selected from the group consisting of a second phosphor having an emission peak wavelength in the range of 455 nm or more and less than 495 nm, a third phosphor having an emission peak wavelength in the range of 495 nm or more and less than 610 nm, a fourth phosphor having an emission peak wavelength in the range of 610 nm or more and less than 700 nm, and a fifth phosphor having an emission peak wavelength in the range of 700 nm or more and 1050 nm or less in the emission spectrum of each phosphor. The light emitting device includes a light emitting element and a first phosphor containing the oxide phosphor described above, and includes at least one phosphor selected from the group consisting of the second phosphor, the third phosphor, the fourth phosphor, and the fifth phosphor, and can be used as a light source that emits light having an emission spectrum in a wavelength range including visible light to a part of near infrared light. The light emitting device has an emission spectrum similar to that of conventional tungsten lamps and xenon lamps, and can be used as a light source that can be made smaller than tungsten lamps and xenon lamps. The small light emitting device can be mounted on small mobile devices such as smartphones and smart watches, and can be used for health management by obtaining information from within the body. The light emitting device can be used, for example, in a reflectance spectroscopic measuring device or a lighting device that is capable of non-destructively measuring inside a living body, fruits and vegetables, etc. and that is required to produce light with excellent color rendering properties.

[0033] The second phosphor, which has a composition different from that of the first phosphor containing the above-mentioned oxide phosphor, preferably contains at least one phosphor selected from the group consisting of a phosphate phosphor having a composition represented by the following formula (2a), an aluminate phosphor having a composition represented by the following formula (2b), and an aluminate phosphor having a composition represented by the following formula (2c), and may contain two or more phosphors. (Ca, Sr, Ba, Mg) 10 (PO4)6(F,Cl,Br,I)2:Eu (2a) (Ba,Sr,Ca)MgAl 10 O 17:Eu (2b) Sr4Al 14 O 25 :Eu (2c) In this specification, when a plurality of elements are described in a composition formula separated by a comma (,), it means that at least one of these plurality of elements is contained in the composition.

[0034] 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 (3a), an aluminate phosphor or gallate phosphor having a composition represented by the following formula (3b), a β-sialon phosphor having a composition represented by the following formula (3c), a cesium lead halide phosphor having a composition represented by the following formula (3d), and a nitride phosphor having a composition represented by the following formula (3e), 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 has a different emission peak wavelength in the range of 495 nm or more and less than 610 nm. (Ca,Sr,Ba)8MgSi4O 16 (F,Cl,Br)2:Eu (3a) (Lu,Y,Gd,Tb)3(Al,Ga)5O 12 :Ce (3b) S 6-z Al z O z N 8-z :Eu (0 <z≦4.2) (3c) CsPb(F,Cl,Br)3(3d) (La,Y,Gd)3Si6N 11 :Ce (3e)

[0035] 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 (4a), a fluorogermanate phosphor having a composition represented by the following formula (4b), an oxynitride phosphor having a composition represented by the following formula (4c), a fluoride phosphor having a composition represented by the following formula (4d), a fluoride phosphor having a composition represented by the following formula (4e), a nitride phosphor having a composition represented by the following formula (4f), and a nitride phosphor having a composition represented by the following formula (4g), 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 (4a) 3.5MgO·0.5MgF2·GeO2:Mn (4b) (Ca,Sr,Mg) k Si 12-(m+n) Al m+n O n N 16-n :Eu (4c) (In the formula (4c), k, m, and n satisfy 0 < k ≤ 2.0, 2.0 ≤ m ≤ 6.0, and 0 ≤ n ≤ 2.0.) A 1 c1 [M 5 1-b1 Mn 4+ b1 F d1 (4d) (In the formula (4d), A 1 is selected from the group consisting of K + , Li + , Na + , Rb + , Cs + and NH4 + and contains at least one selected from the group, and among them, K + is preferable. M 5 contains at least one element selected from the group consisting of Group 4 elements and Group 14 elements, and among them, Si and Ge are preferable. b1 satisfies 0 < b1 < 0.2, and c1 is [M 5 1-b1 Mn4+ b1 F d1 is the absolute value of the charge of the ion, and d1 satisfies 5 < d1 < 7.) A 2 c2 [M 6 1-b2 Mn 4+ b2 F d2 (4e) (In the formula (4e), A 2 is K + , Li + , Na + , Rb + , Cs + and NH4 + and includes at least one selected from the group consisting of, and among them K + is preferred. M 6 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 6 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 (4f) (Sr,Ca)LiAl3N4:Eu (4g)

[0036] The fifth phosphor preferably includes at least one phosphor selected from the group consisting of a gallate phosphor having a composition represented by the following formula (5a), an aluminate phosphor having a composition represented by the following formula (5b), a gallate phosphor having a composition represented by the following formula (5c), an aluminate phosphor having a composition represented by the following formula (5d), and a phosphor having a composition represented by the following formula (5e) different in composition from the above oxide phosphor, a phosphor having a composition represented by the following formula (5f) different in composition from the above oxide phosphor, and a phosphor having a composition represented by the following formula (5g) different in composition from the above oxide phosphor, and may include two or more phosphors.) Ga2O3:Cr (5a) Al2O3:Cr (5b) ZnGa2O4:Cr (5c) (Lu,Y,Gd,Tb)3(Al,Ga)5O 12 :Ce,Cr (5d) M 7 g M 8 h M 9 i M 10 5O j :Cr e 、M 11 f (5e) (In the formula (5e), M 7 is at least one element selected from the group consisting of Li, Na, Ka, Rb, and Cs, M 8 is at least one element selected from the group consisting of Mg, Ca, Sr, Ba, and Zn, M 9 is at least one element selected from the group consisting of Ba, Al, Ga, In, and rare earth elements, M 10 is at least one element selected from the group consisting of Si, Ti, Ge, Zr, Sn, Hf, and Pb, M 11 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.) (Mg 1-t1 M 12 t1 ) u1 (Ga 1-v1-x1-y1 M 13 v1 )2O w1 :Cr x1 ,M 14 y1 (5f) (In the formula (5f), M 12 is at least one element selected from the group consisting of Ca, Sr, Ba, Ni, and Zn, M 13is at least one element selected from the group consisting of B, Al, Sc, and In, and M 14 is at least one element selected from the group consisting of Eu, Ce, Tb, Pr, Nd, Sm, Yb, Ho, Er, Tm, and Mn, and t1, u1, v1, w1, x1, and y1 satisfy 0 ≦ t1 ≦ 0.8, 0.7 ≦ u1 ≦ 1.3, 0 ≦ v1 ≦ 0.8, 3.7 ≦ w1 ≦ 4.3, 0.02 < x1 ≦ 0.3, 0 ≦ y1 ≦ 0.2, and y1 < x1.) (Li 1-t2 M 15 t2 ) u2 (Ga 1-v2 M 16 v2 )5O w2 :Cr x2 ,Ni y2 ,M 17 z2 (5g) (In the formula (5g), M 15 is at least one element selected from the group consisting of Na, K, Rb, and Cs, M 16 is at least one element selected from the group consisting of B, Al, Sc, In, and rare earth elements, M 17 is at least one element selected from the group consisting of Si, Ge, Sn, Ti, Zr, Hf, Bi, V, Nb, and Ta, and t2, u2, v2, w2, x2, y2, and z2 satisfy 0 ≦ t2 ≦ 1.0, 0.7 ≦ u2 ≦ 1.6, 0 ≦ v2 < 1.0, 7.85 ≦ w2 ≦ 11.5, 0.05 ≦ x2 ≦ 1.2, 0 ≦ y2 ≦ 0.5, 0.25 < x2 + y2 ≦ 1.2, y2 < x2, and 0 ≦ z2 ≦ 0.5.)

[0037] 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 the light-emitting device. FIG. 2 is a schematic cross-sectional view showing another example of the first configuration example of the light-emitting device.)

[0038] 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 part 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 part 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 a wavelength conversion member 50. The wavelength conversion member 50 includes a phosphor 70 that converts the wavelength of light emitted from the light emitting element 10, and a translucent material. The phosphor 70 essentially includes a first phosphor 71 including an oxide phosphor. The phosphor 70 may include a phosphor having an emission peak wavelength in a wavelength range different from the emission peak wavelength of the first phosphor 71 and having a composition different from that of the first phosphor 71. As shown in FIG. 2, the phosphor 70 preferably includes at least one phosphor selected from the group consisting of the second phosphor 72, the third phosphor 73, the fourth phosphor 74, and the fifth phosphor 75 described above, and may include two or more phosphors. The phosphor 70 essentially includes the first phosphor 71, and may include the second phosphor 72, the third phosphor 73, the fourth phosphor 74, and the 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, and the like from the external environment. The light emitting device 100 receives power from the outside via the first lead 20 and the second lead 30 and emits light.

[0039] 3A and 3B show a second configuration example of the light emitting device. FIG. 3A is a schematic plan view of the light emitting device 200. FIG. 3B is a schematic cross-sectional view of the light emitting device 200 shown in FIG. 3A 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 including a wavelength converter 52 containing a first phosphor 71 that is excited by light from the light emitting element 10 and emits light, and a light-transmitting body 53 disposed on the wavelength converter 52. The light emitting element 10 is flip-chip mounted on the substrate 1 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 sides covered by a covering member 90 that reflects light. The wavelength converter 52 is excited by light from the light emitting element 10 and essentially contains a first phosphor 71 that contains an oxide phosphor. The wavelength converter 52 may include at least one 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 the outside of the light emitting device 200 via wiring and a conductive member 61 formed on the substrate 1 to cause 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 destruction due to application of an excessive voltage. The covering member 90 is disposed so as to cover, for example, the semiconductor element 11. Each member used in the light emitting device will be described below. For details, the disclosure of JP 2014-112635 A may be referred to.

[0040] The light-transmitting material constituting the wavelength conversion body together with the phosphor may be at least one selected from the group consisting of resin, glass, and inorganic material. The resin may be at least one selected from the group consisting of silicone resin, epoxy resin, phenol resin, polycarbonate resin, acrylic resin, and modified resins thereof. Silicone resin and modified silicone resin are preferable in terms of excellent heat resistance and light resistance. In addition to the phosphor and the light-transmitting material, the wavelength conversion member may contain a filler, a colorant, and a light diffusing material as necessary. Examples of the filler include silicon oxide, barium titanate, titanium oxide, and aluminum oxide.

[0041] 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 phenol 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, phenol resin, and polyimide resin. The light-transmitting body does not have to be disposed in the wavelength conversion member.

[0042] Examples of the semiconductor element provided in the light emitting device as required include a transistor for controlling the light emitting element and a protective element for suppressing the destruction or performance deterioration of the light emitting element due to the application of an excessive voltage. An example of the protective element is a Zener diode. When the light emitting device includes a covering member, it is preferable to use an insulating material as the material of the covering member. More specifically, examples of the insulating material include phenol resin, epoxy resin, bismaleimide triazine resin (BT resin), polyphthalamide (PPA) resin, and silicone resin. A colorant, a phosphor, and a filler may be added to the covering member as required. The light emitting device may use bumps as the conductive member. The bump material may be Au or its alloy, and other conductive members may be eutectic solder (Au-Sn), Pb-Sn, lead-free solder, and the like.

[0043] An example of a method for manufacturing the light emitting device of the first configuration example will be described. For details, the disclosure of JP 2010-062272 A can be referred to. 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, a singulation step of separating the resin packages of each unit area may be included after the resin package formation step.

[0044] 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 having a side surface and a bottom surface. The molded body may be a molded body made of an aggregate base including a plurality of recesses. In the step of arranging the light-emitting element, the light-emitting element is arranged on the bottom surface of the recess of 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. 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. In the resin package molding step, the composition for forming the wavelength conversion member arranged in the recess of the molded body is cured to form a resin package, and a light emitting device is manufactured. When a molded body made of an aggregate base having a plurality of recesses is used, after the resin package forming step, the aggregate base having a plurality of recesses is separated into each resin package of each unit area in the singulation step, and individual light emitting devices are manufactured. In this manner, the light emitting device shown in FIG. 1 or FIG. 2 can be manufactured.

[0045] An example of a method for manufacturing the light emitting device of the second configuration example will be described. For details, refer to the disclosure of, for example, JP 2014-112635 A or JP 2017-117912 A. The method for manufacturing the light emitting device preferably includes a step of arranging the light emitting element, a step of arranging the semiconductor element as necessary, 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.

[0046] For example, in the step of arranging the light-emitting element, the light-emitting element is arranged on the substrate. The light-emitting element and the semiconductor element are, for example, flip-chip mounted on the substrate. Next, in the step of forming the wavelength conversion member including the wavelength converter, the wavelength conversion member may be obtained by forming a plate-shaped, sheet-shaped or layer-shaped wavelength conversion member on one side of the light-transmitting body by a printing method, an adhesion method, a compression molding method or an electrodeposition method. For example, the printing method can print a composition for wavelength conversion body containing a phosphor and a resin serving as a binder or a solvent on one side of the light-transmitting body to form a wavelength conversion member including a wavelength conversion body. Next, in the adhesion step of the light-emitting element and the wavelength conversion member, the wavelength conversion member is opposed to the light-emitting surface of the light-emitting element, and the wavelength conversion member is bonded to the light-emitting element by an adhesive layer. Next, in the step of forming the covering member, the side surfaces of the light-emitting element and the wavelength conversion member are covered with the composition for covering member. This covering member is for reflecting the light emitted from the light-emitting element, and when the light-emitting device also includes a semiconductor element, it is preferable to form the semiconductor element so that it is embedded in the covering member. In the above manner, the light-emitting device shown in FIG. 3A and FIG. 3B can be manufactured.

[0047] The method for producing an oxide phosphor includes: 1 a second compound containing Ge; a third compound containing Cr; and, as required, at least one second element M selected from the group consisting of Si, Ti, Zr, Sn, and Hf. 2 and optionally at least one third element M selected from the group consisting of Ni, Eu, Fe, Mn, Nd, Tm, Ho, Er and Yb. 3 and a sixth compound containing Ga and / or the first element M in 1 mole of the oxide phosphor composition. 1 When the total molar ratio of the first element M 1 The molar ratio of Ga is the product of the variable u and 2, where the variable u is a value between 0 and 1.0, the molar ratio of Ga is the product of 2 and the value obtained by subtracting the variable u from 1, and the molar ratio of the second element M 2 the molar ratio of Ge is the product of the variable v and the variable w, the variable v being a number between 0 and 0.5, the variable w being a number between 1.0 and 3.0, the molar ratio of Ge is the product of the variable w and the number obtained by subtracting the variable v from 1, the molar ratio of Cr is the variable y, the variable y being a number between 0.005 and 1.0, 3 The method includes preparing a raw material mixture in which the first compound and / or the second compound, the third compound, the fourth compound, and optionally the fifth compound and optionally the sixth compound are adjusted and mixed so that the molar ratio of the first compound and / or the second compound is a variable z, and the variable z is a numerical value of 0 to 0.5, and heat-treating the raw material mixture at a temperature in the range of 800°C to 1400°C in an oxygen-containing atmosphere to obtain an oxide phosphor, and it is preferable that at least one selected from the group consisting of the first compound, the second compound, the third compound, and the fourth compound is an oxide. It is preferable that the obtained oxide phosphor has a molar ratio of each element of the oxide phosphor in 1 mole of the oxide phosphor composition in the same range as the charged composition for obtaining the raw material mixture.

[0048] The raw materials for producing the oxide phosphor include a first compound containing Ga, a third compound containing Ge, and a fourth compound containing Cr, and the first element M1 and optionally a second compound comprising a second element M 2 and optionally a third element M 3 The raw material for producing the oxide phosphor may include a sixth compound containing the first element M 1 a second compound containing Ge, a third compound containing Cr, and a fourth compound containing Cr, optionally including a second element M 2 and optionally a third element M 3 and a sixth compound containing the same. The first compound, the second compound, the third compound, the fourth compound, the fifth compound and the sixth compound may each be an oxide, a carbonate, a chloride or a hydrate thereof. At least one compound selected from the group consisting of the first compound, the second compound, the third compound and the fourth compound is an oxide, and two or more of them may be oxides. The second element M 2 A fifth compound containing a third element M 3 The sixth compound including may be an oxide. The first compound, the second compound, the third compound, the fourth compound, the fifth compound and the sixth compound are preferably in the form of powder.

[0049] Examples of the first compound include Ga2O3 and GaCl3. Examples of the second compound include Al2O3, AlCl3, Sc2O3, ScCl3, In2O3, and InCl3. Examples of the third compound include GeO2 and GeCl4. Examples of the fourth compound include Cr2O3, Cr2(CO3)3, and CrCl3. The first compound, the second compound, the third compound, and the fourth compound may be hydrates.

[0050] Specific examples of the fifth compound include SiO2, TiO2, TiCl4, ZrO2, ZrCl4, SnO2, SnCl2, HfO2, HfCl4, etc. The fifth compound may be a hydrate.

[0051] Specific examples of the sixth compound include NiO, NiCl2, Eu2O3, EuCl3, Fe2O3, Fe3O4, FeCl2, FeCl3, FeCO3, Fe2(CO3)3, MnO, MnO2, Mn2O3, Mn3O4, Nd2(CO3)3, Nd2O3, NdCl3, Tm2O3, TmCl3, Ho2O3, HoCl3, Er2O3, ErCl3, Yb2O3, and YbCl3. The sixth compound may be a hydrate.

[0052] The raw material mixture is preferably prepared by adjusting and mixing each raw material so as to have a composition represented by the following formula (1). It is preferable that the resulting oxide phosphor has a composition in which each element of the oxide phosphor in 1 mole of the oxide phosphor composition is the same as the composition represented by the following formula (1) for obtaining the raw material mixture. (Ga 1-u M 1 u )2(Ge 1-v M 2 v ) w O x :Cr y ,M 3 z (1) (In the above formula (1), M 1 is at least one element selected from the group consisting of Al, Sc and In, and M 2 is at least one element selected from the group consisting of Si, Ti, Zr, Sn and Hf, and M 3 is at least one element selected from the group consisting of Ni, Eu, Fe, Mn, Nd, Tm, Ho, Er, and Yb, and u, v, w, x, y, and z satisfy 0≦u≦1.0, 0≦v≦0.5, 1.0≦w≦3.0, 5≦x≦9, 0.005≦y≦1.0, and 0≦z≦0.5, respectively.

[0053] The raw material mixture has a composition represented by the formula (1), in which Ga is the first element M 1 Among them, Al may be substituted, and at least one first element M selected from the group consisting of Al, Sc, and In may be substituted. 1The raw material mixture may contain, in the composition represented by the formula (1), a second element M 2 may be either Si or Hf, and the third element M 3 may be at least one element selected from the group consisting of Ni, Eu, Fe, Mn and Nd.

[0054] In the raw material mixture, in the composition represented by formula (1), u, w and y preferably satisfy 0≦u<1.0, 1.5≦w≦3.0 and 0.02≦y<0.08, respectively.

[0055] The first and / or second compounds, the third compound, the fourth compound, the fifth compound which is included as required, and the sixth compound which is included as required are mixed in a wet or dry manner so that the elements contained in each compound of the raw materials satisfy the above-mentioned composition, thereby obtaining a raw material mixture. The measured compounds may be mixed using a mixer. As the mixer, in addition to a ball mill which is usually used industrially, a vibration mill, a roll mill, a jet mill, etc. can be used.

[0056] The raw material mixture may contain a flux. When the raw material mixture contains a flux, the reaction between the raw materials is promoted, and furthermore, the solid-phase reaction proceeds more uniformly, so that a phosphor having a large particle size and excellent luminescence characteristics can be obtained. When the temperature of the heat treatment for obtaining the phosphor is approximately the same as the temperature at which the liquid phase of the compound used as the flux is generated, the flux promotes the reaction between the raw materials. As the flux, boric acid, a borate containing at least one element selected from the group consisting of an alkaline earth metal element and an alkali metal element, or a halide containing at least one element selected from the group consisting of an alkaline earth metal element and an alkali metal element can be used. As the flux, among the halides, a fluoride can be used. As the flux, for example, boric acid (H3BO3), lithium fluoride (LiF), etc. can be used.

[0057] The raw material mixture can be placed in a crucible or boat made of a material such as graphite or other carbon, boron nitride (BN), alumina (Al2O3), tungsten (W), or molybdenum (Mo), and then heat-treated in a furnace.

[0058] The heat treatment of the raw material mixture is carried out in an atmosphere containing oxygen. The oxygen content in the atmosphere is not particularly limited. 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 a desired composition may not be obtained.

[0059] The temperature at which the raw material mixture is heat-treated is within the range of 800° C. to 1400° C., preferably within the range of 850° C. to 1300° C., more preferably within the range of 870° C. to 1290° C., and more preferably within the range of 900° C. to 1280° C. If the heat treatment temperature is 800° C. to 1400° C., decomposition due to heat is suppressed, and a phosphor having a desired composition and a stable crystal structure can be obtained.

[0060] 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.

[0061] The pressure of the heat treatment atmosphere may be standard atmospheric pressure (0.101 MPa), may be 0.101 MPa or more, or may be a pressurized atmosphere of 0.11 MPa to 200 MPa. When the heat treatment temperature is high, the heat-treated product obtained by the heat treatment is likely to have a decomposition of its crystal structure, but when the heat treatment is performed in a pressurized atmosphere, the decomposition of the crystal structure can be suppressed.

[0062] 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 hours or more and 20 hours or less. Even when two or more stages of heat treatment are performed, it is preferable that the heat treatment time for each stage is 0.5 hours or more and 20 hours or less. If the heat treatment time is 0.5 hours or more and 20 hours or less, decomposition of the heat-treated product obtained is suppressed, and a phosphor having a stable crystal structure and a desired emission intensity can be obtained. In addition, the production cost can be reduced and the manufacturing time can be relatively short. The heat treatment time is more preferably 1 hour or more and 10 hours or less, and even more preferably 1.5 hours or more and 9 hours or less.

[0063] The heat-treated product obtained by the heat treatment may be subjected to post-treatment 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.

[0064] The embodiments according to the present disclosure include the following oxide phosphor and a light emitting device using the same. The embodiments according to the present disclosure preferably include a method for producing the oxide phosphor.

[0065] [Section 1] An oxide phosphor having a composition represented by the following formula (1): (Ga 1-u M 1 u )2(Ge 1-v M 2 v ) w O x :Cr y ,M 3 z (1) (In the above formula (1), M 1 is at least one element selected from the group consisting of Al, Sc and In, and M 2 is at least one element selected from the group consisting of Si, Ti, Zr, Sn and Hf, and M 3is at least one element selected from the group consisting of Ni, Eu, Fe, Mn, Nd, Tm, Ho, Er, and Yb, and u, v, w, x, y, and z satisfy 0≦u≦1.0, 0≦v≦0.5, 1.0≦w≦3.0, 5≦x≦9, 0.005≦y≦1.0, and 0≦z≦0.5, respectively. [Section 2] Item 2. The oxide phosphor according to item 1, wherein in formula (1), 0.02≦y<0.08 is satisfied. [Section 3] Item 3. The oxide phosphor according to item 1 or 2, wherein in formula (1), u satisfies 0≦u<1.0. [Section 4] 4. The oxide phosphor according to any one of items 1 to 3, wherein in formula (1), w satisfies 1.5≦w≦3.0. [Section 5] Item 4. The oxide phosphor according to item 3, wherein in an emission spectrum, the emission intensity at 1000 nm is 25% or more relative to 100% emission intensity at the emission peak wavelength. [Section 6] Item 6. The oxide phosphor according to any one of items 1 to 5, wherein the full width at half maximum of an emission spectrum having an emission peak wavelength is within a range of 150 nm to 290 nm. [Section 7] Item 6. The oxide phosphor according to item 3 or 5, wherein the full width at half maximum of an emission spectrum having an emission peak wavelength is within a range of 180 nm to 220 nm. [Section 8] 8. The oxide phosphor according to claim 1, wherein the oxide phosphor has an emission peak wavelength in the range of 760 nm or more and 970 nm or less in an emission spectrum. [Section 9] 8. The oxide phosphor according to claim 3, wherein the oxide phosphor has an emission peak wavelength in the range of 870 nm or more and 970 nm or less in an emission spectrum. [Section 10] Item 10. An oxide phosphor according to any one of items 1 to 9, A light emitting device comprising: a light emitting element having an emission peak wavelength in the range of 365 nm to 650 nm, which irradiates the oxide phosphor. [Section 11] A first compound containing Ga and / or at least one first element M selected from the group consisting of Al, Sc and In. 1 a second compound containing Ge; a third compound containing Cr; and, as required, at least one second element M selected from the group consisting of Si, Ti, Zr, Sn, and Hf. 2 and optionally at least one third element M selected from the group consisting of Ni, Eu, Fe, Mn, Nd, Tm, Ho, Er and Yb. 3 and a sixth compound containing Ga and / or the first element M in 1 mole of the oxide phosphor composition. 1 When the total molar ratio of the first element M 1 The molar ratio of Ga is the product of the variable u and 2, where the variable u is a value between 0 and 1.0, the molar ratio of Ga is the product of 2 and the value obtained by subtracting the variable u from 1, and the molar ratio of the second element M 2 the molar ratio of Ge is the product of the variable v and the variable w, the variable v being a number between 0 and 0.5, the variable w being a number between 1.0 and 3.0, the molar ratio of Ge is the product of the variable w and the number obtained by subtracting the variable v from 1, the molar ratio of Cr is the variable y, the variable y being a number between 0.005 and 1.0, 3 preparing a raw material mixture by adjusting and mixing a first compound and / or a second compound, a third compound, a fourth compound, and if necessary a fifth compound, and if necessary a sixth compound, so that a molar ratio of the first compound, the second compound, the third compound, the fourth compound, and if necessary a sixth compound is represented by a variable z, and the variable z is a numerical value of 0 or more and 0.5 or less; and heat-treating the raw material mixture at a temperature in the range of 800°C to 1400°C in an oxygen-containing atmosphere to obtain an oxide phosphor, wherein at least one compound selected from the group consisting of the first compound, the second compound, the third compound, and the fourth compound is an oxide. [Section 12] Item 13. The method according to item 12, wherein the raw material mixture is prepared by adjusting and mixing each raw material so as to have a composition represented by the following formula (1): (Ga 1-u M 1 u )2(Ge 1-v M 2 v) w O x :Cr y ,M 3 z (1) (In the formula (1), u, v, w, x, y, and z satisfy 0≦u≦1.0, 0≦v≦0.5, 1.0≦w≦3.0, 5≦x≦9, 0.005≦y≦1.0, and 0≦z≦0.5, respectively.) EXAMPLES

[0066] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0067] Oxide phosphor Example 1 The raw materials used were 9.0 g of Ga2O3 as the first compound, 10.0 g of GeO2 as the third compound, and 0.07 g of Cr2O3 as the fourth compound. The molar ratio of each element in 1 mole of the resulting oxide phosphor was Ga2Ge2O7:Cr 0.02 The raw materials were mixed for 10 minutes using an agate mortar and an agate pestle to obtain a raw material mixture. The obtained raw material mixture was placed in an alumina crucible and heat-treated for 8 hours at 1250°C in an air atmosphere (oxygen 20% by volume) at standard pressure (0.101 MPa). After the heat treatment, the obtained heat-treated product was pulverized to obtain an oxide phosphor of Example 1 having the composition shown in Table 1, which is the molar ratio of the charged composition.

[0068] Example 2 The raw materials used were 9.0 g of Ga2O3 as the first compound, 10.0 g of GeO2 as the third compound, and 0.15 g of Cr2O3 as the fourth compound. The molar ratio of each element in 1 mole of the resulting oxide phosphor was Ga2Ge2O7:Cr 0.04 The rest of the components were weighed out so as to give the following molar ratios in the charged compositions, in the same manner as in Example 1, to obtain an oxide phosphor of Example 2 having the composition shown in Table 1.

[0069] Example 3 The raw materials used were 9.0 g of Ga2O3 as the first compound, 10.0 g of GeO2 as the third compound, and 0.22 g of Cr2O3 as the fourth compound. The molar ratio of each element in 1 mole of the resulting oxide phosphor was Ga2Ge2O7:Cr 0.06 The rest of the components were weighed out so as to give the following molar ratios in the charged compositions, in the same manner as in Example 1, to obtain an oxide phosphor of Example 3 having the composition shown in Table 1.

[0070] Example 4 The raw materials were weighed so that the first compound Ga2O3 was 9.0 g, the third compound GeO2 was 10.0 g, and the fourth compound Cr2O3 was 0.29 g. The molar ratio of each element in 1 mole of the resulting oxide phosphor was Ga2Ge2O7:Cr 0.08 The rest of the components were weighed out so as to give the following molar ratios in the charged compositions, in the same manner as in Example 1, to obtain an oxide phosphor of Example 4 having the composition shown in Table 1.

[0071] Example 5 The raw materials used were 9.0 g of Ga2O3 as the first compound, 12.5 g of GeO2 as the third compound, and 0.22 g of Cr2O3 as the fourth compound. The molar ratio of each element in 1 mole of the resulting oxide phosphor was Ga2Ge 2.5 O8:Cr 0.06 The rest of the components were weighed out so as to give the following molar ratios in the charged compositions, in the same manner as in Example 1, to obtain an oxide phosphor of Example 5 having the composition shown in Table 1.

[0072] Example 6 The raw materials were weighed out so that the first compound Ga2O3 was 4.5g, the second compound Al2O3 was 2.5g, the third compound GeO2 was 10.0g, and the fourth compound Cr2O3 was 0.22g. The molar ratio of each element in 1 mole of the resulting oxide phosphor was Ga1Al1Ge2O7:Cr 0.06Except for changing the heat treatment temperature to 1275° C., the same procedure as in Example 1 was carried out to obtain an oxide phosphor of Example 6 having the composition shown in Table 1, which is the molar ratio of the charged composition.

[0073] Example 7 The raw materials used were 6.8g of Ga2O3 as the first compound, 1.3g of Al2O3 as the second compound, 10.0g of GeO2 as the third compound, and 0.22g of Cr2O3 as the fourth compound. The molar ratio of each element in 1 mole of the resulting oxide phosphor was Ga 1.5 Al 0.5 Ge2O7:Cr 0.06 In the composition formula, the molar ratio of an element without a numerical value is 1. Except for the heat treatment temperature being 1275°C, an oxide phosphor of Example 7 having the composition shown in Table 1, which is the molar ratio of the charged composition, was obtained in the same manner as in Example 1.

[0074] Example 8 The raw materials used were 6.8 g of Ga2O3 as the first compound, 3.3 g of In2O3 as the second compound, 10.0 g of GeO2 as the third compound, and 0.22 g of Cr2O3 as the fourth compound. The molar ratio of each element in 1 mole of the resulting oxide phosphor was Ga 1.5 In 0.5 Ge2O7:Cr 0.06 In the composition formula, the molar ratio of an element without a numerical value is 1. Otherwise, in the same manner as in Example 1, an oxide phosphor of Example 8 having the composition shown in Table 1, which is the molar ratio of the charged composition, was obtained.

[0075] Example 9 The raw materials used were 6.8 g of Ga2O3 as the first compound, 1.7 g of Sc2O3 as the second compound, 10.0 g of GeO2 as the third compound, and 0.22 g of Cr2O3 as the fourth compound. The molar ratio of each element in 1 mole of the resulting oxide phosphor was Ga 1.5 Sc 0.5Ge2O7:Cr 0.06 In the composition formula, the molar ratio of an element without a numerical value is 1. Otherwise, in the same manner as in Example 1, an oxide phosphor of Example 9 having the composition shown in Table 1, which is the molar ratio of the charged composition, was obtained.

[0076] Example 10 The raw materials used were 9.0 g of Ga2O3 (first compound), 7.5 g of GeO2 (third compound), 1.4 g of SiO2 (fifth compound), and 0.22 g of Cr2O3 (fourth compound). The molar ratio of each element in 1 mole of the resulting oxide phosphor was Ga2Ge 1.5 S 0.5 O7:Cr 0.06 Except for changing the heat treatment temperature to 1300° C., the same procedure as in Example 1 was carried out to obtain an oxide phosphor of Example 10 having the composition shown in Table 1, which is the molar ratio of the charged composition.

[0077] Example 11 The raw materials used were 4.9 g of Al2O3 as the second compound, 10.0 g of GeO2 as the third compound, and 0.07 g of Cr2O3 as the fourth compound. The molar ratio of each element in 1 mole of the resulting oxide phosphor was Al2Ge2O7:Cr 0.02 Except for changing the heat treatment temperature to 1275° C., the same procedure as in Example 1 was carried out to obtain an oxide phosphor of Example 11 having the composition shown in Table 1, which is the molar ratio of the charged composition.

[0078] Example 12 The raw materials used were 4.9 g of Al2O3 as the second compound, 10.0 g of GeO2 as the third compound, and 0.15 g of Cr2O3 as the fourth compound. The molar ratio of each element in 1 mole of the resulting oxide phosphor was Al2Ge2O7:Cr 0.04Except for changing the heat treatment temperature to 1275° C., the same procedure as in Example 1 was carried out to obtain an oxide phosphor of Example 12 having the composition shown in Table 1, which is the molar ratio of the charged composition.

[0079] Example 13 The raw materials used were 4.9 g of Al2O3 as the second compound, 10.0 g of GeO2 as the third compound, and 0.26 g of Cr2O3 as the fourth compound. The molar ratio of each element in 1 mole of the resulting oxide phosphor was Al2Ge2O7:Cr 0.07 Except for changing the heat treatment temperature to 1275° C., the same procedure as in Example 1 was carried out to obtain an oxide phosphor of Example 13 having the composition shown in Table 1, which is the molar ratio of the charged composition.

[0080] Example 14 The raw materials used were 4.9 g of Al2O3 as the second compound, 10.0 g of GeO2 as the third compound, and 0.37 g of Cr2O3 as the fourth compound. The molar ratio of each element in 1 mole of the resulting oxide phosphor was Al2Ge2O7:Cr 0.10 Except for changing the heat treatment temperature to 1275° C., the same procedure as in Example 1 was carried out to obtain an oxide phosphor of Example 14 having the composition shown in Table 1, which is the molar ratio of the charged composition.

[0081] Example 15 The raw materials used were 4.9 g of Al2O3 as the second compound, 12.5 g of GeO2 as the third compound, and 0.15 g of Cr2O3 as the fourth compound. The molar ratio of each element in 1 mole of the resulting oxide phosphor was Al2Ge 2.5 O8:Cr 0.04 Except for changing the heat treatment temperature to 1275° C., the same procedure as in Example 1 was carried out to obtain an oxide phosphor of Example 15 having the composition shown in Table 1, which is the molar ratio of the charged composition.

[0082] Example 16 The raw materials used were 4.9 g of Al2O3 as the second compound, 15.0 g of GeO2 as the third compound, and 0.15 g of Cr2O3 as the fourth compound. The molar ratio of each element in 1 mole of the resulting oxide phosphor was Al2Ge3O9:Cr 0.04 Except for changing the heat treatment temperature to 1275° C., the same procedure as in Example 1 was carried out to obtain an oxide phosphor of Example 16 having the composition shown in Table 1, which is the molar ratio of the charged composition.

[0083] Example 17 The raw materials used were 3.7 g of Al2O3, 3.3 g of In2O3, 10.0 g of GeO2, and 0.22 g of Cr2O3, the fourth compound. The molar ratio of each element in 1 mole of the resulting oxide phosphor was Al. 1.5 In 0.5 Ge2O7:Cr 0.06 The rest of the components were weighed out so as to give the following molar ratios in the charged compositions, in the same manner as in Example 1, to obtain an oxide phosphor of Example 17 having the composition shown in Table 1.

[0084] Example 18 The raw materials were weighed so that the second compound Al2O3 was 3.7 g, the second compound Sc2O3 was 1.7 g, the second compound GeO2 was 10.0 g, and the fourth compound Cr2O3 was 0.22 g. The molar ratio of each element in 1 mole of the resulting oxide phosphor was Al. 1.5 Sc 0.5 Ge2O7:Cr 0.06 The rest of the components were weighed out so as to give the following molar ratios in the charged compositions, in the same manner as in Example 1, to obtain an oxide phosphor of Example 17 having the composition shown in Table 1.

[0085] Comparative Example 1 The raw materials used were 18.0 g of Ga2O3 as the first compound, 5.5 g of GeO2 as the third compound, and 0.15 g of Cr2O3 as the fourth compound. The molar ratio of each element in 1 mole of the resulting oxide phosphor was Ga4Ge1O8:Cr 0.04 The rest of the components were weighed out so as to give the following molar ratios in the charged compositions, in the same manner as in Example 1, to obtain an oxide phosphor of Comparative Example 1 having the composition shown in Table 1.

[0086] Measurement of emission spectrum and emission characteristics 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 used in the quantum efficiency measurement system was 450 nm. From the emission spectrum of each phosphor obtained, the relative emission intensity, emission peak wavelength, and full width at half maximum were obtained as emission characteristics. That is, the emission peak wavelength (λp) (nm) in the emission spectrum of each phosphor and the full width at half maximum (FWHM) (nm) of the emission spectrum at the emission peak wavelength were obtained. In addition, in the emission spectrum of each oxide phosphor, the emission intensity (%) at 1000 nm was obtained relative to the emission intensity at the emission peak wavelength of 100%. The emission intensity of the oxide phosphor of Example 1 was set to 100%, and the relative emission intensity (%) of the emission intensity of each oxide phosphor of Examples other than Example 1 and Comparative Example was obtained. The results are shown in Table 1. FIG. 4 to FIG. 7 show the emission spectra of the oxide phosphors of Examples 1 to 18 and the oxide phosphor of Comparative Example 1.

[0087] [Table 1]

[0088] As shown in Table 1 or Figs. 4 to 7, the oxide phosphors according to Examples 1 to 18 have an emission peak wavelength in the range of 760 nm to 970 nm in the emission spectrum. The oxide phosphors according to Examples 1 to 10 contain Ga in their composition and have an emission peak wavelength in the range of 870 nm to 970 nm in the emission spectrum. Furthermore, the oxide phosphors according to Examples 1 to 18 have an emission spectrum with an emission peak wavelength that has a full width at half maximum in the range of 150 nm to 290 nm, and emit light having an emission peak wavelength in a desired range, a wide full width at half maximum, and an emission intensity required for analysis at a desired wavelength by wavelength conversion of excitation light from a light-emitting element.

[0089] The oxide phosphors of Examples 1 to 10 containing Ga in their composition and the oxide phosphor of Example 17 have an emission spectrum in which the emission intensity at 1000 nm is 25% or more relative to the emission intensity at the emission peak wavelength of 100%, and can emit light having an emission intensity required for analysis in the wavelength range of 900 nm to 1100 nm.

[0090] In the oxide phosphor according to Comparative Example 1, the molar ratio of Ga in 1 mole of the oxide phosphor composition exceeded 2, and the emission peak wavelength was less than 760 nm. [Industrial Applicability]

[0091] The oxide phosphor according to the present disclosure can also be used in medical light-emitting devices for obtaining information within a living body, light-emitting devices mounted on small mobile devices such as smartphones and smartwatches for managing physical condition, light-emitting devices used in medical devices, light-emitting devices for analytical devices that non-destructively measure internal information of agricultural products such as fruits and vegetables, rice, and foods, and pharmaceuticals, light-emitting devices for plant cultivation that affect the photoreceptors of plants, and light-emitting devices for reflectance spectroscopy measuring devices used to measure film thickness, etc. [Explanation of symbols]

[0092] 10: light-emitting element, 11: semiconductor element, 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. An oxide phosphor having a composition represented by the following formula (1): (Ga １－ｕ M １ ｕ ) ２ (Ge １－ｖ M ２ ｖ ) ｗ O ｘ :Cr ｙ ,M ３ ｚ (1) (In the above formula (1), M １ is at least one element selected from the group consisting of Al, Sc and In, M ２ is at least one element selected from the group consisting of Si, Ti, Zr, Sn and Hf, M ３ is at least one element selected from the group consisting of Ni, Eu, Fe, Mn, Nd, Tm, Ho, Er, and Yb, and u, v, w, x, y, and z each satisfy 0≦u≦1.0, 0≦v≦0.5, 1.0≦w≦3.0, 5≦x≦9, 0.005≦y≦1.0, and 0≦z≦0.

5.

2. The oxide phosphor according to claim 1 , wherein in formula (1), 0.02≦y<0.08 is satisfied.

3. The oxide phosphor according to claim 1 , wherein in the formula (1), u satisfies 0≦u<1.

0.

4. The oxide phosphor according to claim 1 , wherein in the formula (1), w satisfies 1.5≦w≦3.

0.

5. 3. The oxide phosphor according to claim 2, wherein in an emission spectrum, an emission intensity at 1000 nm is 25% or more relative to an emission intensity of 100% at an emission peak wavelength.

6. 2. The oxide phosphor according to claim 1, wherein the full width at half maximum of an emission spectrum having an emission peak wavelength is within a range of 150 nm to 290 nm.

7. 4. The oxide phosphor according to claim 3, wherein the full width at half maximum of an emission spectrum having an emission peak wavelength is within a range of 180 nm to 220 nm.

8. The oxide phosphor according to claim 1 , wherein the oxide phosphor has an emission peak wavelength in the range of 760 nm to 970 nm in an emission spectrum.

9. The oxide phosphor according to claim 3 , wherein the oxide phosphor has an emission peak wavelength in the range of 870 nm to 970 nm in an emission spectrum.

10. The oxide phosphor according to any one of claims 1 to 9, A light emitting device comprising: a light emitting element having an emission peak wavelength in the range of 365 nm to 650 nm, which irradiates the oxide phosphor.

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