Oxide phosphors and light-emitting devices

Abstract

Provided is an oxide phosphor having an emission peak wavelength in the wavelength range from red light to near-infrared light. 【Solution means】The oxide phosphor has a composition contained in the compositional formula represented by the following formula (1). (Li 1-t M 1 t ) u (Ga 1-v M 2 v )5O w :Cr x ,Ni y ,M 3 z (1) (In formula (1), M 1 is at least one element selected from the group consisting of Na, K, Rb, and Cs, M 2 is at least one element selected from the group consisting of B, Al, Sc, In, and rare earth elements, M 3 is at least one element selected from the group consisting of Si, Ge, Sn, Ti, Zr, Hf, Bi, V, Nb, and Ta, and t, u, v, w, x, y, and z are respectively 0 ≦ t ≦ 1.0, 0.7 ≦ u ≦ 1.6, 0 ≦ v < 1.0, 7.85 ≦ w ≦ 11.5, 0.05 ≦ x ≦ 1.2, 0 ≦ y ≦ 0.5, 0.25

Description

[Technical Field]

[0001] This disclosure relates to oxide phosphors and light-emitting devices. [Background technology]

[0002] Light-emitting devices that have emission intensity in the wavelength range from red light to near-infrared light are desired for use in applications such as infrared cameras, infrared communications, vein authentication (a type of biometric authentication), and food component analysis equipment that non-destructively measures the sugar content of fruits and vegetables.

[0003] One example of such a light-emitting device is one that combines a light-emitting diode (LED) and a phosphor. Furthermore, examples of phosphors to be incorporated into 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 emission phosphors").

[0004] Patent Document 1 describes a phosphor having an emission peak wavelength in the wavelength range of 680 nm to 760 nm, and a composition of CaYAlO4:Mn 4+ A phosphor represented by [formula] is disclosed. As a phosphor suitable for each of the above-mentioned applications, for example, a near-infrared phosphor having an emission spectrum with a larger full width at half maximum and an emission peak wavelength in a longer wavelength range may be required. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Special Publication No. 2020-528486 [Overview of the project] [Problems that the invention aims to solve]

[0006] The present disclosure aims to provide an oxide phosphor having an emission peak wavelength in the wavelength range from red light to near-infrared light, a broader full width at half maximum of the emission spectrum, and high emission energy, and a light-emitting device using the same.

Means for Solving the Problems

[0007] The first aspect is an oxide phosphor having a composition included in the compositional formula represented by the following formula (1). (Li 1-t M 1 t ) u (Ga 1-v M 2 v )5O w :Cr x ,Ni y ,M 3 z (1) (In the formula (1), M 1 is at least one element selected from the group consisting of Na, K, Rb, and Cs, M 2 is at least one element selected from the group consisting of B, Al, Sc, In, and rare earth elements, M 3 is at least one element selected from the group consisting of Si, Ge, Sn, Ti, Zr, Hf, Bi, V, Nb, and Ta, and t, u, v, w, x, y, and z satisfy 0≦t≦1.0, 0.7≦u≦1.6, 0≦v<1.0, 7.85≦w≦11.5, 0.05≦x≦1.2, 0≦y≦0.5, 0.25<x + y≦1.2, y<x, 0≦z≦0.5, respectively.)

[0008] The second aspect is a light-emitting device including the oxide phosphor and a light-emitting element having an emission peak wavelength in the range of 365 nm or more and 500 nm or less and irradiating the oxide phosphor.

Advantages of the Invention

[0009] According to the present disclosure, an oxide phosphor and a light-emitting device having an emission peak wavelength in the wavelength range from red light to near-infrared light, a broader full width at half maximum of the emission spectrum, and high emission energy can be provided. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a schematic cross-sectional view showing an example of a first configuration of a light-emitting device. [Figure 2] Figure 2 is a schematic cross-sectional view showing another example of the first configuration of the light-emitting device. [Figure 3A] Figure 3A is a schematic plan view showing a second configuration example of the light-emitting device. [Figure 3B] Figure 3B is a schematic cross-sectional view showing a second example configuration of the light-emitting device. [Figure 4] Figure 4 shows the emission spectra of oxide phosphors according to Examples 1 and 2, and the emission spectra of oxide phosphors according to Comparative Examples 1 and 5. [Figure 5] Figure 5 shows the emission spectra of oxide phosphors according to Examples 3 and 4, and the emission spectra of oxide phosphors according to Comparative Examples 1 and 5. [Figure 6] Figure 6 shows the emission spectra of oxide phosphors according to Examples 5 and 6, and the emission spectra of oxide phosphors according to Comparative Examples 1 and 5. [Figure 7] Figure 7 shows the emission spectra of oxide phosphors according to Examples 7 and 8, and the emission spectra of oxide phosphors according to Comparative Examples 1 and 5. [Figure 8] Figure 8 shows the emission spectra of oxide phosphors according to Examples 9 and 10, and the emission spectra of oxide phosphors according to Comparative Examples 1 and 5. [Figure 9] Figure 9 shows the emission spectra of oxide phosphors according to Examples 11 and 12, and the emission spectra of oxide phosphors according to Comparative Examples 1 and 5. [Figure 10] Figure 10 shows the emission spectra of the oxide phosphor according to Example 13 and the oxide phosphors according to Comparative Examples 1 and 5. [Figure 11] Figure 11 shows the emission spectra of oxide phosphors according to Examples 14 and 15, and the emission spectra of oxide phosphors according to Comparative Examples 1 and 5. [Figure 12]Figure 12 shows the emission spectra of oxide phosphors according to Examples 16 and 17, and the emission spectra of oxide phosphors according to Comparative Examples 1 and 5. [Figure 13] Figure 13 shows the emission spectra of oxide phosphors related to Comparative Examples 1 to 5. [Figure 14] Figure 14 shows the emission spectrum of the light-emitting device according to the embodiment. [Modes for carrying out the invention]

[0011] The oxide phosphors and light-emitting devices relating to this disclosure will be described below. However, the embodiments shown below are illustrative examples for realizing the technical concept of the present invention, and the present invention is not limited to the oxide phosphors and light-emitting devices described below. Regarding 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., for example, the wavelength range of red light will conform to JIS Z8110.

[0012] Light-emitting devices using phosphors are required to emit light within an optimal wavelength range depending on the object being viewed and the usage situation. For example, in medical settings, it is sometimes necessary to easily obtain information about the inside of a living organism. The inside of a living organism contains light absorbers such as water, hemoglobin, and melanin. For example, hemoglobin has a high absorption rate of light in the visible light wavelength range with a wavelength of less than 650 nm. Therefore, with light-emitting devices that emit light in the visible light wavelength range, it is difficult for light in the visible light wavelength range to penetrate the inside of a living organism, making it difficult to obtain information about the inside of a living organism. For this reason, there is a wavelength range called the "biological window" in which light easily penetrates the inside of a living organism. In some cases, there is a need for light-emitting devices that emit light in the near-infrared wavelength range, for example, 650 nm to 1050 nm, which includes at least a part of the wavelength range called the "biological window". For example, if it is possible to measure the increase or decrease in oxygen concentration in the blood inside a living organism by the increase or decrease in light absorption of hemoglobin that binds to oxygen, it becomes possible to easily obtain information about the inside of a living organism by irradiating it with light from a light-emitting device. Therefore, phosphors used in light-emitting devices are sometimes required to absorb light from an excitation light source and emit light that includes, for example, a portion of the near-infrared wavelength range between 650 nm and 1050 nm.

[0013] For example, in the food industry, there is a demand for non-destructive refractometers to measure the sugar content of fruits and vegetables, and non-destructive taste meters for rice. Near-infrared spectroscopy, using near-infrared light with wavelengths between 700 nm and 2500 nm, is sometimes used as a non-destructive method to measure internal quality such as sugar content, acidity, ripeness, and internal damage of fruits and vegetables, as well as surface quality that appears on the surface of the peel or the surface layer near the peel, such as abnormal drying. Near-infrared spectroscopy involves irradiating fruits and vegetables with light in the near-infrared wavelength range, and measuring the quality of the fruits and vegetables by receiving the transmitted light that passes through the fruits and vegetables and the reflected light that is reflected by the fruits and vegetables, and observing the decrease in light intensity (light absorption). Light sources such as tungsten lamps and xenon lamps are used in the analytical instruments for near-infrared spectroscopy used in the food industry.

[0014] Oxide phosphors The oxide phosphor has a composition included in the composition formula shown in the following formula (1). (Li 1-t M 1 t ) u (Ga 1-v M 2 v )5O w :Cr x ,Ni y M 3 z (1) In the above formula (1), M 1 is at least one element selected from the group consisting of Na, K, Rb, and Cs, and M 2 is at least one element selected from the group consisting of B, Al, Sc, In and rare earth elements, and M 3is at least one element selected from the group consisting of Si, Ge, Sn, Ti, Zr, Hf, Bi, V, Nb, and Ta, and t, u, v, w, x, y, and z satisfy 0≦t≦1.0, 0.7≦u≦1.6, 0≦v<1.0, 7.85≦w≦11.5, 0.05≦x≦1.2, 0≦y≦0.5, 0.25<x + y≦1.2, y<x, and 0≦z≦0.5, respectively. The oxide phosphor can absorb excitation light and emit light with a wide full width at half maximum of the emission spectrum and high emission energy in a wide wavelength range including a part of the wavelength range of near infrared light that enables measurement of information inside living bodies or foods such as fruits and vegetables. In this specification, the "molar ratio" represents the ratio of each element in 1 mole of the chemical composition of the phosphor, unless otherwise specified. In this specification, in the composition formula, a plurality of elements described separated by a comma (,) means that the composition contains at least one of these plurality of elements. Also, in this specification, in the composition formula representing the composition of the phosphor, before the colon (:) represents the elements constituting the host crystal and their molar ratios, and after the colon (:) represents the activating element.

[0015] In the composition included in the compositional formula represented by the above formula (1), as the activating element, it preferably contains at least Cr, and as the co-activating elements, it preferably contains both Cr and Ni. When it contains both Cr and Ni as the co-activating elements, first Cr absorbs the energy of the excitation light, and the energy absorbed by Cr is transmitted to Ni and Ni is efficiently excited, so that light having an emission spectrum with a wide full width at half maximum in the wavelength range of near-infrared light can be emitted. In 1 mole of the composition included in the compositional formula represented by the above formula (1), x represents the molar ratio of Cr, and y represents the molar ratio of Ni. In the above formula (1), x and y preferably satisfy 0 < y ≤ 0.5 and 1.5 ≤ x / y ≤ 50. The oxide phosphor having the composition included in the compositional formula represented by the above formula (1) has a larger molar ratio of Cr than the molar ratio of Ni, a large absorption of excitation light by Cr, and Ni is efficiently excited, so that light having an emission spectrum with a wide full width at half maximum in the wavelength range of near-infrared light can be emitted. In the above formula (1), x and y may satisfy 2.0 ≤ x / y ≤ 40, may satisfy 2.5 ≤ x / y ≤ 30, or may satisfy 2.8 ≤ x / y ≤ 25. In the above formula (1), x and y may satisfy 0.26 ≤ x + y ≤ 1.2.

[0016] In the composition included in the compositional formula represented by the above formula (1), the variable x representing the molar ratio of Cr as the activating element satisfies 0.05 ≤ x ≤ 1.2, preferably satisfies 0.08 ≤ x ≤ 0.8, and more preferably satisfies 0.1 ≤ x ≤ 0.5. The oxide phosphor having Cr as the activating element may emit light such as Al2O3 (ruby) having an emission peak wavelength near 696 nm depending on the intensity of the crystal field of the host crystal when Cr absorbs the excitation light, or may emit light such as BeAl2O4 (alexandrite) having an emission peak wavelength in the range of 700 nm to 815 nm included in the wavelength range of near-infrared light.

[0017] In the composition included in the compositional formula represented by the above formula (1), when Ni is not included, that is, when y = 0, light having an emission peak wavelength within the range of 700 nm or more and 900 nm or less and a relatively wide full width at half maximum of the emission spectrum is emitted.

[0018] In the composition included in the compositional formula represented by the formula (1), in addition to Cr, the variable y representing the molar ratio of Ni which is an activating element satisfies 0 ≦ y ≦ 0.5, and may satisfy 0 < y ≦ 0.5, may satisfy 0.001 ≦ y ≦ 0.3, or may satisfy 0.005 ≦ y ≦ 0.2. Since the oxide phosphor having Ni as a co-activating element has a plurality of energy levels for Ni, it has a complex emission spectrum and emits light having an emission peak wavelength with a wide full width at half maximum in the wavelength range of near infrared light.

[0019] The oxide phosphor, in the composition included in the compositional formula represented by the formula (1), when the total number of moles of Ga and element M 2 is 100 mol%, it is preferable that the total of Cr and Ni exceeds 5 mol%, and it is more preferable that it is within the range of 5.01 mol% or more and 24 mol% or less. When the total number of moles of Ga and element M 2 is 100 mol% in the composition included in the compositional formula represented by the formula (1), when the total of Cr and Ni exceeds 5 mol%, the oxide phosphor emits light having an emission spectrum with a wider full width at half maximum in the wavelength range of near infrared light.

[0020] In the composition included in the compositional formula represented by the formula (1), the first element M 1 may be at least one element selected from the group consisting of Na, K, and Rb. In the composition included in the compositional formula represented by the formula (1), the molar ratio of the first element M 1 contained as necessary, in 1 mol of the composition of the oxide phosphor, when the molar ratio of Ga or the second element M 2 is included, when the total molar ratio of the second element M 2 and Ga is 5, the molar ratio of the first element M 1 is represented by the product of the variable t and the variable u. The variable t may satisfy 0 ≦ t ≦ 0.8, or may satisfy 0 ≦ t ≦ 0.5. The variable u may satisfy 0.8 ≦ u ≦ 1.5, may satisfy 0.9 ≦ u ≦ 1.2, or may satisfy u = 1.

[0021] In the composition included in the composition formula represented by the above formula (1), the second element M 2 The second element M may be at least one element selected from the group consisting of B, Al, Sc, In, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. 2 This may be at least one element selected from the group consisting of Al, Sc, In, and rare earth elements. Second element M 2 The molar ratio is the molar ratio of Ga or the second element M per mole of the oxide phosphor composition. 2 When it contains the second element M 2 When the total molar ratio of and Ga is set to 5, the second element M is included as needed. 2 The molar ratio is expressed as the product of the variable v and 5, where the variable v may satisfy 0 ≤ v ≤ 0.8, 0 ≤ v ≤ 0.5, or 0 ≤ v ≤ 0.3.

[0022] In the composition represented by formula (1) above, the molar ratio of O (oxygen) contained in the oxide phosphor is equal to the molar ratio of Ga or the second element M per mole of the oxide phosphor composition. 2 When it contains the second element M 2 When the total molar ratio of ions and Ga is set to 5, the variable w representing the molar ratio of O (oxygen) satisfies 7.85 ≤ w ≤ 11.5, may also satisfy 7.9 ≤ w ≤ 11.0, may satisfy 7.95 ≤ w ≤ 10.5, and may even be w = 8.

[0023] In the composition included in the composition formula represented by the above formula (1), the third element M is present in 1 mole of the oxide phosphor. 3 The variable z, which represents the molar ratio, satisfies 0 ≤ z ≤ 0.5, may also satisfy 0 ≤ z ≤ 0.3, or may satisfy 0 ≤ z ≤ 0.2.

[0024] The oxide phosphor having the composition included in the composition formula represented by formula (1) preferably has a full width at half maximum (FMAX) of 150 nm or more of the emission spectrum having the emission peak wavelength. The full width at half maximum of the emission spectrum having the emission peak wavelength of the oxide phosphor having the composition included in the composition formula represented by formula (1) is preferably 160 nm or more, more preferably 170 nm or more, and even more preferably 180 nm or more. The oxide phosphor preferably has a larger full width at half maximum of the emission spectrum having the emission peak wavelength. The full width at half maximum of the emission spectrum having the emission peak wavelength may be 250 nm or less, 240 nm or less, 230 nm or less, or 220 nm or less. In this specification, full width at half maximum refers to the wavelength width in the emission spectrum that is 50% of the emission intensity at the emission peak wavelength showing the maximum emission intensity. For example, in living organisms, light absorption and scattering occur, and in order to measure subtle changes in the propagation behavior of light in the blood in living organisms, it is preferable to irradiate with light having an emission spectrum with a wide full width at half maximum. Furthermore, when non-destructively measuring foods such as fruits, vegetables, and rice, it is preferable to irradiate them with light having a broad emission spectrum at half maximum in order to obtain information about the inside of the food. For light having a broad emission spectrum at half maximum, it is preferable that the area obtained by integrating the region enclosed by the baseline (where the emission intensity is 0) and the emission spectrum curve with emission intensity over a specific wavelength range is wider, as this indicates a higher emission energy for the oxide phosphor. Note that emission intensity may be expressed as a relative emission intensity ratio in the emission spectrum, with the emission intensity of the excitation light as the reference.

[0025] The oxide phosphor having the composition included in the composition formula represented by formula (1) preferably has an emission peak wavelength in the range of 1150 nm to 1300 nm, and more preferably in the range of 1200 nm to 1300 nm. When the oxide phosphor having the composition included in the composition formula represented by formula (1) does not contain Ni, i.e., when y=0, it preferably has an emission peak wavelength in the range of 700 nm to 900 nm, and more preferably in the range of 710 nm to 850 nm. By having an emission peak wavelength in a range that overlaps with the wavelength range of 700 nm to 2500 nm, it is possible to create a light-emitting device that can easily obtain information from living organisms or information from fruits and vegetables in a non-destructive manner.

[0026] Light-emitting device The light-emitting device comprises an oxide phosphor included in the compositional formula represented by formula (1) above, and a light-emitting element having an emission peak wavelength in the range of 365 nm to 500 nm, which irradiates the oxide phosphor. The oxide phosphor can be used together with a light-transmitting material as a component constituting a wavelength conversion member.

[0027] The light-emitting device preferably includes, for example, an LED chip or LD chip made of a nitride-based semiconductor as a light-emitting element that irradiates an oxide phosphor.

[0028] The light-emitting element preferably has an emission peak wavelength in the range of 365 nm to 500 nm, more preferably in the range of 370 nm to 490 nm, and even more preferably in the range of 375 nm to 480 nm. By using the light-emitting element as an excitation light source for an oxide phosphor, it is possible to configure a light-emitting device that emits mixed light in a desired wavelength range of light from the light-emitting element and fluorescence from a phosphor containing an 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 made of a nitride semiconductor as the light-emitting element. By using a light-emitting element made of a nitride semiconductor as an excitation light source, it is possible to obtain a stable light-emitting device that is highly efficient, has high linearity of output to input, and is resistant to mechanical shock.

[0029] The light-emitting device requires a first phosphor containing the oxide phosphor described above, and may also contain other phosphors. Preferably, in addition to the first phosphor, the light-emitting device comprises at least one phosphor selected from the group consisting of a second phosphor having an emission peak wavelength in the range of 420 nm to less than 495 nm in the emission spectrum of the phosphor, a third phosphor having an emission peak wavelength in the range of 495 nm to less than 590 nm, a fourth phosphor having an emission peak wavelength in the range of 590 nm to less than 700 nm, and a fifth phosphor having an emission peak wavelength in the range of 700 nm to 1050 nm. By requiring a first phosphor containing the oxide phosphor described above, and further including other phosphors, a continuous emission spectrum can be obtained in the range of the emission peak wavelength of the light-emitting element and up to 1600 nm. For a light-emitting device's emission spectrum to be continuous within the range of the light-emitting element's emission peak wavelength to 1600 nm means that the emission spectrum is continuous without interruption, without the emission intensity of the emission spectrum dropping to 0% within the entire wavelength range from the light-emitting element's emission peak wavelength to 1600 nm. Depending on the object being measured or detected, such as living organisms or fruits and vegetables, a light source that emits light with a continuous emission spectrum in a wavelength range including visible light to a portion of the near-infrared light may be required. When using tungsten lamps or xenon lamps as light sources, light with a continuous emission spectrum is emitted without interruption from visible light to a portion of the near-infrared light. However, miniaturization of the device is difficult when using tungsten lamps or xenon lamps as light sources. A light-emitting device that emits light with a continuous emission spectrum within the range of the light-emitting element's emission peak wavelength to 1600 nm can be miniaturized compared to a light-emitting device using tungsten lamps or xenon lamps as light sources. The small light-emitting device can be mounted on small mobile devices such as smartphones, and if it can obtain information from within the body, it can be used for health management, etc. Here, "within the range of the light-emitting element's emission peak wavelength and up to 1600 nm" means, for example, if the light-emitting element's emission peak wavelength is 450 nm, then it means the range of 450 nm to 1600 nm.

[0030] The light-emitting device has a continuous emission spectrum within the range of the emission peak wavelength of the light-emitting element and up to 1600 nm, and emits light in a wide wavelength range from visible light to near-infrared. Such a light-emitting device can be used, for example, in reflection spectroscopic measuring devices or in lighting devices that require light with excellent color rendering that can non-destructively measure living organisms or fruits and vegetables.

[0031] 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 compositional formula represented by the following formula (2a), an aluminate phosphor having a compositional formula represented by the following formula (2b), and an aluminate phosphor having a compositional formula 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)

[0032] The third phosphor preferably contains at least one phosphor selected from the group consisting of a silicate phosphor having a compositional formula represented by the following formula (3a), an aluminate phosphor or galliumate phosphor having a compositional formula represented by the following formula (3b), a β-sialon phosphor having a compositional formula represented by the following formula (3c), a cesium lead halide phosphor having a compositional formula represented by the following formula (3d), and a nitride phosphor having a compositional formula represented by the following formula (3e), and may contain two or more phosphors. If the third phosphor contains two or more phosphors, it is preferable that each of the two or more third phosphors has an emission peak wavelength in a different range within the range of 495 nm to 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) Si 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)

[0033] The fourth phosphor preferably contains at least one phosphor selected from the group consisting of a nitride phosphor having a composition included in the compositional formula represented by the following formula (4a), a fluorogermanate phosphor having a composition represented by the following formula (4b), an oxynitride phosphor having a composition included in the compositional formula represented by the following formula (4c), a fluoride phosphor having a composition included in the compositional formula represented by the following formula (4d), a fluoride phosphor having a composition included in the compositional formula represented by the following formula (4e), a nitride phosphor having a composition included in the compositional formula represented by the following formula (4f), and a nitride phosphor having a composition included in the compositional formula 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 above formula (4c), k, m, and n satisfy 0 < k ≦ 2.0, 2.0 ≦ m ≦ 6.0, and 0 ≦ n ≦ 2.0.) A c [M 6 1-b Mn 4+ b F d(4d) (In the formula (4d), A includes at least one selected from the group consisting of K + , Li + , Na + , Rb + , Cs + and NH4 + , and among them, K + is preferred. M 6 includes at least one element selected from the group consisting of Group 4 elements and Group 14 elements, and among them, Si and Ge are preferred. b satisfies 0 < b < 0.2, and c is the absolute value of the charge of the [M 6 1-b Mn 4+ b F d ion, and d satisfies 5 < d < 7.) A’ c’ [M 6 ’ 1-b’ Mn 4+ b’ F d’ (4e) (In the formula (4e), A’ includes at least one selected from the group consisting of K + , Li + , Na + , Rb + , Cs + and NH4 + , and among them, K + is preferred. M 6 ’ includes at least one element selected from the group consisting of Group 4 elements, Group 13 elements and Group 14 elements, and among them, Si and Al are preferred. b’ satisfies 0 < b’ < 0.2, and c’ is the absolute value of the charge of the [M 6 ’ 1-b’ Mn 4+ b’ F d’ ion, and d’ satisfies 5 < d’ < 7.) (Ba,Sr,Ca)2Si5N8:Eu (4f) (Sr,Ca)LiAl3N4:Eu (4g)

[0034] 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 (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 oxide phosphor having a composition contained in the following compositional formula represented by the following formula (5d), an aluminate phosphor having a composition contained in the following compositional formula represented by the following formula (5e), an oxide phosphor having a composition contained in the following compositional formula represented by the following formula (5f) different in composition from the above oxide phosphor, and an oxide phosphor having a composition contained in the following compositional formula represented by the following formula (5g) different in composition from the above oxide phosphor, and may contain two or more phosphors. Ga2O3:Cr (5a) Al2O3:Cr (5b) ZnGa2O4:Cr (5c) (Mg 1-t1 M 7 t1 ) u1 (Ga 1-v1-x1-y1 M 8 v1 )2O w1 :Cr x1 ,M 9 y1 (5d) (In the formula (5d), M 7 is at least one element selected from the group consisting of Ca, Sr, Ba, Ni, and Zn, M 8 is at least one element selected from the group consisting of B, Al, In, and Sc, M 9 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.) (Lu,Y,Gd,Tb)3(Al,Ga)5O 12 :Ce,Cr (5e) M 10 g M 11 h M12 i M 13 5O j :Cr e 、M 14 f (5f) (In the formula (5f), M 10 is at least one element selected from the group consisting of Li, Na, K, Rb, and Cs, M 11 is at least one element selected from the group consisting of Mg, Ca, Sr, Ba, and Zn, M 12 is at least one element selected from the group consisting of Ba, Al, Ga, In, and rare earth elements, M 13 is at least one element selected from the group consisting of Si, Ti, Ge, Zr, Sn, Hf, and Pb, M 14 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.) M 15 t2 M 16 u2 (Ge 1-v2 M 17 v2 )6O w2 :Cr x2 ,M 18 y2 (5g) (In the formula (5g), M 15 is at least one element selected from the group consisting of Li, Na, K, Rb, and Cs, M 16 is at least one element selected from the group consisting of Ca, Sr, Mg, Ba, and Zn, M 17 is at least one element selected from the group consisting of Si, Ti, Zr, Sn, Hf, and Pb, M 18is at least one element selected from the group consisting of Eu, Ce, Tb, Pr, Nd, Sm, Yb, Ho, Er, Tm, Ni, and Mn, and t2, u2, v2, w2, x2, and y2 satisfy 1.5 ≦ t2 ≦ 2.5, 0.7 ≦ u2 ≦ 1.3, 0 ≦ v2 ≦ 0.4, 12.9 ≦ w2 ≦ 15.1, 0 < x2 ≦ 0.2, 0 ≦ y2 ≦ 0.10, and y2 < x2.)

[0035] An example of a light-emitting device will be described based on 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.)

[0036] As shown in Figure 1, the light-emitting device 100 comprises a molded body 40 having a recess, a light-emitting element 10 which serves as an excitation light source, and a wavelength conversion member 50 which covers the light-emitting element 10. The molded body 40 is integrally molded with a first lead 20 and a second lead 30 and a resin part 42 containing a thermoplastic resin or a thermosetting resin. The molded body 40 has the first lead 20 and the second lead 30 which constitute the bottom surface of the recess, and the resin part 42 which constitutes 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, and these pairs of positive and negative electrodes are electrically connected to the first lead 20 and the second lead 30 via wires 60, respectively. The light-emitting element 10 is covered by the wavelength conversion member 50. The wavelength conversion member 50 includes a phosphor 70 which converts the wavelength of the light-emitting element 10 and a light-transmitting material. The phosphor 70 essentially includes a first phosphor 71 containing an oxide phosphor. The phosphor 70 may also include phosphors having emission peak wavelengths in a different wavelength range than the emission peak wavelength of the first phosphor 71. As shown in Figure 2, the phosphor 70 preferably includes at least one phosphor selected from the group consisting of the second phosphor 72, third phosphor 73, fourth phosphor 74, and fifth phosphor 75 described above, and may include two or more. The phosphor 70 essentially includes the first phosphor 71 and may also include the second phosphor 72, third phosphor 73, fourth phosphor 74, and fifth phosphor 75. The wavelength conversion member 50 also functions as a member for protecting the light-emitting element 10 and the phosphor 70 from the external environment. The light-emitting device 100 emits light by receiving power from an external source via the first lead 20 and the second lead 30.

[0037] Figures 3A and 3B show a second configuration example of the light-emitting device. Figure 3A is a schematic plan view of the light-emitting device 200. Figure 3B is a schematic cross-sectional view of the light-emitting device 200 shown in Figure 3A, taken along the line IIIB-IIIB'. The light-emitting device 200 comprises a light-emitting element 10 having an emission peak wavelength in the range of 365 nm to 500 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 on which the wavelength converter 52 is arranged. The light-emitting element 10 is flip-chip mounted on a substrate 1 via a bump which is a conductive member 61. The wavelength converter 52 of the wavelength conversion member 51 is provided 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 are covered on their sides by a coating member 90 that reflects light. The wavelength converter 52 is excited by light from the light-emitting element 10 and contains a first phosphor 71 which includes 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 emit light by receiving power from outside the light-emitting device 200 via wiring and conductive members 61 formed on the substrate 1. The light-emitting device 200 may include semiconductor elements 11 such as protective elements to prevent the light-emitting element 10 from being destroyed by the application of excessive voltage. The covering member 90 is provided, for example, to cover the semiconductor elements 11. The individual components used in the light-emitting device will be described below. Further details can be found in, for example, the disclosure in Japanese Patent Application Publication No. 2014-112635.

[0038] The light-transmitting material that constitutes the wavelength conversion member together with the phosphor may be at least one selected from the group consisting of resins, glass, and inorganic materials. The resin may be at least one selected from the group consisting of silicone resins, epoxy resins, phenolic resins, polycarbonate resins, acrylic resins, and modified resins thereof. Silicone resins and modified silicone resins are preferred because they have excellent heat resistance and light resistance. In addition to the phosphor and light-transmitting material, the wavelength conversion member may optionally contain fillers, colorants, and light-diffusing materials. Examples of fillers include silicon dioxide, barium titanate, titanium dioxide, and aluminum oxide.

[0039] When the wavelength conversion member includes a resin and a phosphor, it is preferable to form a wavelength conversion member forming composition containing a phosphor in the resin and to form the wavelength conversion member using the wavelength conversion member forming composition. The wavelength conversion member forming composition preferably contains a first phosphor including an oxide phosphor in the range of 20 parts by mass or more and 100 parts by mass or less per 100 parts by mass of resin, but may also be in the range of 25 parts by mass or more and 90 parts by mass or in the range of 30 parts by mass or more and 85 parts by mass or less. The first phosphor may contain only an oxide phosphor. The oxide phosphor contained in the first phosphor may contain two or more oxide phosphors with different compositions.

[0040] The composition for forming the wavelength conversion component shall contain each phosphor within the range described below. The content of the second phosphor in the wavelength conversion member forming composition may be in the range of 10 parts by mass or more and 100 parts by mass or in the range of 20 parts by mass or more and 90 parts by mass or in the range of 30 parts by mass or more and 80 parts by mass or less, per 100 parts by mass of resin. The amount of the third phosphor contained in the wavelength conversion member forming composition may be in the range of 5 parts by mass or more and 100 parts by mass or less, 10 parts by mass or more and 90 parts by mass or less, 15 parts by mass or more and 80 parts by mass or less, 20 parts by mass or more and 70 parts by mass or less, or 25 parts by mass or more and 60 parts by mass or less, per 100 parts by mass of resin. The amount of the fourth phosphor contained in the wavelength conversion member forming composition may be in the range of 1 to 50 parts by mass, 2 to 40 parts by mass, 3 to 30 parts by mass, 4 to 40 parts by mass, or 5 to 20 parts by mass per 100 parts by mass of resin. The content of the fifth phosphor in the wavelength conversion member forming composition may be within the range of 5 parts by mass or more and 100 parts by mass or within the range of 10 parts by mass or more and 90 parts by mass or within the range of 20 parts by mass or more and 80 parts by mass or within the range of 30 parts by mass or more and within the range of 30 parts by mass or more and per 100 parts by mass of resin. If the wavelength conversion member forming composition contains the fifth phosphor and the fifth phosphor contains two or more types of phosphors, the content of the fifth phosphor refers to the total content of the two or more types of fifth phosphors. Similarly, if the wavelength conversion member forming composition contains two or more types of phosphors from the second to the fifth phosphor, the content refers to the total content of the two or more types of phosphors. The total amount of phosphors contained in the composition for forming wavelength conversion members may be in the range of 50 parts by mass or more and 300 parts by mass or 100 parts by mass or 280 parts by mass or 120 parts by mass or 260 parts by mass or 150 parts by mass or 250 parts by mass per 100 parts by mass of resin.

[0041] The wavelength conversion member may include a light-transmitting body. 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. If the wavelength conversion member includes a substrate, the substrate is preferably made of an insulating material that does not easily transmit light from the light-emitting element or ambient light. Examples of substrate materials include ceramics such as aluminum oxide and aluminum nitride, and resins such as phenolic resin, epoxy resin, polyimide resin, bismaleimidotriazine resin (BT resin), and polyphthalamide (PPA) resin. If 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.

[0042] Semiconductor elements that may be provided in the light-emitting device as needed include, for example, transistors for controlling light-emitting elements and protective elements for suppressing damage or performance degradation of light-emitting elements due to excessive voltage application. Zener diodes are an example of protective elements. If the light-emitting device is equipped with a covering member, it is preferable to use an insulating material for the covering member. More specifically, examples include phenolic resin, epoxy resin, bismaleimidotriazine 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 also use bumps as conductive members. As materials for the bumps, Au or its alloys can be used, and as other conductive members, eutectic solder (Au-Sn), Pb-Sn, lead-free solder, etc. can be used.

[0043] Method for manufacturing a light-emitting device An example of a method for manufacturing the light-emitting device of the first configuration example is described below. For further details, see, for example, the disclosure in Japanese Patent Application Publication 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. If an aggregate molded body having a plurality of recesses is used as the molded body, a fragmentation step of separating each unit region into resin packages may be included after the resin package formation step.

[0044] In the preparation process for the molded body, multiple leads are integrally molded using a thermosetting resin or thermoplastic resin to prepare a molded body having recesses with sides and bottoms. The molded body may be a molded body consisting of an aggregate substrate containing multiple recesses. In the process of arranging the light-emitting element, 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. In the step of arranging the composition for forming the wavelength conversion member, the composition for forming the wavelength conversion member is placed in the recess of the molded body. In the resin package molding process, a wavelength conversion member forming composition placed in the recesses of the molded body is cured to form a resin package and manufacture a light-emitting device. When a molded body consisting of an aggregate substrate containing multiple recesses is used, after the resin package formation process, in the individualization process, each unit region of the aggregate substrate having multiple recesses is separated into resin packages, and individual light-emitting devices are manufactured. In this way, the light-emitting device shown in Figure 1 or Figure 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 further details, please refer to, for example, the disclosures in Japanese Patent Publication No. 2014-112635 or Japanese Patent Publication No. 2017-117912. 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 if 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 coating member.

[0046] For example, in the process of arranging the light-emitting element, the light-emitting element is arranged on a substrate. The light-emitting element and the semiconductor element are mounted on the substrate, for example, using a flip-chip mounting method. Next, in the process of forming a wavelength conversion member including a wavelength converter, the wavelength converter may be obtained by forming a plate-shaped, sheet-shaped, or layered wavelength converter on one surface of a transparent material by printing, bonding, compression molding, or electrodeposition. For example, in the printing method, a wavelength conversion member including a wavelength converter can be formed by printing a wavelength conversion member composition containing a phosphor and a resin that acts as a binder or solvent onto one surface of a transparent material. Next, in the bonding process of the light-emitting element and the wavelength conversion member, the wavelength conversion member is placed facing the light-emitting surface of the light-emitting element and bonded to the light-emitting element by an adhesive layer. Next, in the process of forming a coating member, the sides of the light-emitting element and the wavelength conversion member are covered with a coating member composition. This coating member is for reflecting the light emitted from the light-emitting element, and if the light-emitting device also includes a semiconductor element, it is preferable to form the coating member so that the semiconductor element is embedded in the coating member. In this way, the light-emitting device shown in Figures 3A and 3B can be manufactured.

[0047] Method for producing oxide phosphors A method for producing an oxide phosphor involves a first compound containing Li, a second compound containing Ga, a third compound containing Cr, a fourth compound optionally containing Ni, and optionally at least one first element M selected from the group consisting of Na, K, Rb, and Cs. 1 A fifth compound containing and, if necessary, at least one second element M selected from the group consisting of B, Al, Sc, In and rare earth elements. 2 A sixth compound containing and, optionally, at least one third element M selected from the group consisting of Si, Ge, Sn, Ti, Zr, Hf, Bi, V, Nb, and Ta. 3 The seventh compound containing and the molar ratio of Ga in 1 mole of oxide phosphor or the second element M 2 When it contains the second element M 2 When the total molar ratio of Li and Ga is set to 5, the ratio of Li and the first element M 1The process involves preparing a raw material mixture by adjusting and mixing a first compound, a second compound, a third compound, a fourth compound if necessary, and a fifth, sixth, and seventh compound if necessary, such that the molar ratio of the first compound is in the range of 0.7 to 1.6, the molar ratio of Cr is in the range of 0.05 to 1.2, the molar ratio of Ni is in the range of 0 to 0.5, and the total molar ratio of Cr and Ni is greater than 0.25 and less than or equal to 1.2, and if Ni is included, the molar ratio of Cr is greater than that of Ni; and obtaining an oxide phosphor by heat-treating the raw material mixture in an oxygen-containing atmosphere at a temperature in the range of 1000°C to 1700°C, wherein it is preferable to use an oxide selected from the group consisting of the first compound, the second compound, and the third compound. The raw material mixture may also be prepared so that the total molar ratio of Cr and Ni is in the range of 0.26 to 1.2.

[0048] Preparation process of raw material mixture raw material To produce oxide phosphors, the raw materials described above are prepared. The first compound, etc., can be an oxide, carbonate, chloride, or hydrate thereof, with oxides being preferred. The first compound, etc., is preferably in powder form.

[0049] The first compound specifically includes Li2O, Li2CO3, and LiCl. The second compound specifically includes Ga2O3, GaCl2, GaCl3, and GaBr3. The third compound specifically includes Cr2O3, Cr2(CO3)3, and CrCl3. The fourth compound includes NiO, Ni4CO3(OH)6(H2O)4, and NiCl2. 1st element M 1 The fifth compound, containing the second element M 2 The sixth compound, containing the third element M 3 The seventh compound containing this compound includes oxides, carbonates, chlorides, and hydrates thereof.

[0050] raw material mixture Each compound used as a raw material has a molar ratio of Ga per mole of the oxide phosphor to be obtained, or the first element M 1When it contains the first element M 1 When the total molar ratio of Li and Ga is set to 5, the ratio of Li and the first element M 1 The first compound, the second compound, the third compound, and optionally the fourth compound, and optionally the fifth, sixth, and seventh compounds, may be weighed and mixed to obtain a raw material mixture, such that the molar ratio of the first compound is in the range of 0.7 to 1.6, the molar ratio of Cr is in the range of 0.05 to 1.2, the molar ratio of Ni is in the range of 0 to 0.5, and the total molar ratio of Cr and Ni is greater than 0.25 and within the range of 1.2, and if Ni is included, the molar ratio of Cr is greater than that of Ni.

[0051] Each compound used as a raw material contains Li, Ga, Cr, Ni (if applicable), and, if applicable, the first element M. 1 , second element M 2 , and the third element M 3 However, it is preferable to weigh each compound and mix them to prepare a raw material mixture so that the composition is included in the composition formula represented by formula (1) above.

[0052] Flux The raw material mixture may contain a flux. The inclusion of a flux in the raw material mixture promotes the reaction between the raw materials and allows for more uniform solid-phase reactions, resulting in a phosphor with larger particle size and superior luminescence properties. If the heat treatment temperature for obtaining the phosphor is approximately the same as the temperature at which the liquid phase of the compound used as the flux is formed, the flux promotes the reaction between the raw materials. As the flux, a halide containing at least one element selected from the group consisting of rare earth elements, alkaline earth metal elements, and alkali metal elements can be used. Among halides, fluorides can be used as the flux. If the elements contained in the flux are the same as at least some of the elements constituting the oxide phosphor, the flux can be added as part of the raw materials for the oxide phosphor having the desired composition, or the flux can be added after the raw materials have been mixed to achieve the desired composition.

[0053] A process to obtain an oxide phosphor by heat treatment. The raw material mixture can be placed in a crucible or boat made of materials such as graphite (carbon), boron nitride (BN), alumina (Al2O3), tungsten (W), or molybdenum (Mo), and then heat-treated in a furnace.

[0054] Heat treatment atmosphere The heat treatment is preferably carried out in an oxygen-containing atmosphere. 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 atmosphere does not contain oxygen, with an oxygen content of less than 1% by volume, an oxide phosphor with a desirable composition may not be obtained.

[0055] Heat treatment temperature The heat treatment temperature is in the range of 1000°C to 1700°C, preferably in the range of 1100°C to 1600°C, and more preferably in the range of 1300°C to 1550°C. If the heat treatment temperature is between 1000°C and 1700°C, thermal decomposition is suppressed, and a phosphor with the desired composition and a stable crystalline structure can be obtained.

[0056] In heat treatment, a holding time at a predetermined temperature may be provided. 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 providing a holding time of 0.5 hours to 48 hours, crystal growth can be promoted.

[0057] The pressure of the heat treatment atmosphere may be standard atmospheric pressure (0.101 MPa), or higher than 0.101 MPa, or it may be a pressurized atmosphere between 0.11 MPa and 200 MPa. When the heat treatment temperature is high, the crystal structure of the heat-treated material is prone to decomposition, but when a pressurized atmosphere is used, the decomposition of the crystal structure can be suppressed.

[0058] The heat treatment time can be appropriately selected depending on the heat treatment temperature and the atmospheric pressure during heat treatment, and is preferably 0.5 hours to 20 hours. Even when two or more heat treatments are performed, it is preferable that the time for each heat treatment is 0.5 hours to 20 hours. When the heat treatment time is 0.5 hours to 20 hours, the decomposition of the resulting heat-treated product is suppressed, and an oxide phosphor with a stable crystalline structure can be obtained that emits light with a broad emission spectrum having a full width at half maximum in the near-infrared wavelength range when irradiated with excitation light. Furthermore, production costs can be reduced and the manufacturing time can be made relatively short. The heat treatment time is more preferably 1 hour to 10 hours, and even more preferably 1.5 hours to 9 hours.

[0059] The heat-treated product obtained by heat treatment may undergo post-treatment such as grinding, dispersion, solid-liquid separation, and drying. Solid-liquid separation can be carried out by industrially commonly used methods such as filtration, suction filtration, pressure filtration, centrifugal separation, and decantation. Drying can be carried out by industrially commonly used equipment such as vacuum dryers, hot air heating dryers, conical dryers, and rotary evaporators. [Examples]

[0060] The present invention will be described in detail below with reference to examples. The present invention is not limited to these examples.

[0061] Oxide phosphors Example 1 The raw materials used were weighed to the extent that 2.67g of Li2CO3, 33.9g of Ga2O3, 1.37g of Cr2O3, and 0.27g of NiO were used. The molar ratio of each element in the initial composition of each raw material was LiGa5O8:Cr 0.25 ,Ni 0.05 The materials were weighed accordingly. In the preparation composition, the molar ratio of elements not specified in molar ratio is 1. The raw materials were mixed for 10 minutes using an agate mortar and 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 1450°C in an atmospheric atmosphere (oxygen content of 20 vol%) at standard pressure (0.101 MPa). After heat treatment, the obtained heat-treated material was pulverized to obtain the oxide phosphor of Example 1.

[0062] Example 2 The raw materials used were weighed to the extent that 2.67g of Li2CO3, 33.9g of Ga2O3, 1.37g of Cr2O3, and 0.22g of NiO were used. The molar ratio of each element in the initial composition of each raw material was LiGa5O8:Cr 0.25 ,Ni 0.04 The oxide phosphor of Example 2 was obtained in the same manner as in Example 1, except that the amount was measured to achieve the desired result.

[0063] Example 3 The raw materials used were weighed to the extent that 2.67g of Li2CO3, 33.9g of Ga2O3, 1.37g of Cr2O3, and 0.16g of NiO were used. The molar ratio of each element in the initial composition of each raw material was LiGa5O8:Cr 0.25 ,Ni 0.03 The oxide phosphor of Example 3 was obtained in the same manner as in Example 1, except that the amount was measured to achieve the desired result.

[0064] Example 4 The raw materials used were weighed to the extent that 2.67g of Li2CO3, 33.9g of Ga2O3, 1.37g of Cr2O3, and 0.05g of NiO were used. The molar ratio of each element in the initial composition of each raw material was LiGa5O8:Cr 0.25 ,Ni 0.01 The oxide phosphor of Example 4 was obtained in the same manner as in Example 1, except that the amount was measured to achieve the desired result.

[0065] Example 5 The raw materials used were weighed to the extent that 2.67g of Li2CO3, 33.9g of Ga2O3, 1.48g of Cr2O3, and 0.16g of NiO were used. The molar ratio of each element in the initial composition of each raw material was LiGa5O8:Cr 0.27 ,Ni 0.03 The oxide phosphor of Example 5 was obtained in the same manner as in Example 1, except that the amount was measured to achieve the desired result.

[0066] Example 6 The raw materials used were weighed to the extent that 2.67g of Li2CO3, 33.9g of Ga2O3, 1.48g of Cr2O3, and 0.22g of NiO were used. The molar ratio of each element in the initial composition of each raw material was LiGa5O8:Cr 0.27 ,Ni 0.04 The oxide phosphor of Example 6 was obtained in the same manner as in Example 1, except that the amount was measured to achieve the desired result.

[0067] Example 7 The raw materials used were weighed to the extent that 2.67g of Li2CO3, 33.9g of Ga2O3, 1.65g of Cr2O3, and 0.16g of NiO were used. The molar ratio of each element in the initial composition of each raw material was LiGa5O8:Cr 0.30 ,Ni 0.03 The oxide phosphor of Example 7 was obtained in the same manner as in Example 1, except that the amount was measured to achieve the desired result.

[0068] Example 8 The raw materials used were weighed to the extent that 2.67g of Li2CO3, 33.9g of Ga2O3, 1.65g of Cr2O3, and 0.22g of NiO were used. The molar ratio of each element in the initial composition of each raw material was LiGa5O8:Cr 0.30 ,Ni 0.04 The oxide phosphor of Example 8 was obtained in the same manner as in Example 1, except that the amount was measured to achieve the desired result.

[0069] Example 9 The raw materials used were weighed to the extent that 2.67g of Li2CO3, 33.9g of Ga2O3, 1.92g of Cr2O3, and 0.22g of NiO were used. The molar ratio of each element in the initial composition of each raw material was LiGa5O8:Cr 0.35 ,Ni 0.04 The oxide phosphor of Example 9 was obtained in the same manner as in Example 1, except that the amount was measured to achieve the desired result.

[0070] Example 10 The raw materials used were weighed to the extent that 2.67g of Li2CO3, 33.9g of Ga2O3, 1.92g of Cr2O3, and 0.27g of NiO were used. The molar ratio of each element in the initial composition of each raw material was LiGa5O8:Cr 0.35 ,Ni 0.05 Except for the measurement being performed to achieve the desired result, the oxide phosphor of Example 10 was obtained in the same manner as in Example 1.

[0071] Example 11 The raw materials used were weighed to the extent that 2.67g of Li2CO3, 33.9g of Ga2O3, 1.92g of Cr2O3, and 0.16g of NiO were used. The molar ratio of each element in the initial composition of each raw material was LiGa5O8:Cr 0.35 ,Ni 0.03 The oxide phosphor of Example 11 was obtained in the same manner as in Example 1, except that the amount was measured to achieve the desired result.

[0072] Example 12 The raw materials used were weighed to the extent that 2.67g of Li2CO3, 33.9g of Ga2O3, 1.10g of Cr2O3, and 0.38g of NiO were used. The molar ratio of each element in the initial composition of each raw material was LiGa5O8:Cr 0.20 ,Ni 0.07 The oxide phosphor of Example 12 was obtained in the same manner as in Example 1, except that the amount was measured to achieve the desired result.

[0073] Example 13 The raw materials used were weighed to the point where 2.67g of Li2CO3, 33.9g of Ga2O3, and 1.54g of Cr2O3 were used. The molar ratio of each element in the initial composition of each raw material was LiGa5O8:Cr 0.28 The oxide phosphor of Example 13 was obtained in the same manner as in Example 1, except that the amount was measured to achieve the desired result.

[0074] Example 14 The raw materials used were weighed to the following amounts: Li2CO3 2.67g, Ga2O3 28.8g, Al2O3 2.77g, Cr2O3 1.37g, and NiO 0.27g. The molar ratio of each element in the initial composition of each raw material was determined to be LiGa 4.25 Al 0.75 O8:Cr 0.25 ,Ni 0.05 Except for weighing to achieve the desired result, the oxide phosphor of Example 14 was obtained in the same manner as in Example 1.

[0075] Example 15 The raw materials used were weighed to the extent that 2.67g of Li2CO3, 23.7g of Ga2O3, 5.55g of Al2O3, 1.37g of Cr2O3, and 0.27g of NiO were used. The molar ratio of each element in the initial composition of each raw material was LiGa 3.5 Al 1.5 O8:Cr 0.25 ,Ni 0.05 Except for weighing to achieve the desired result, the oxide phosphor of Example 15 was obtained in the same manner as in Example 1.

[0076] Example 16 The raw materials used were weighed to the following amounts: Li2CO3 2.67g, Ga2O3 28.8g, Sc2O3 3.75g, Cr2O3 1.37g, and NiO 0.27g. The molar ratio of each element in the initial composition of each raw material was determined to be LiGa 4.25 Sc 0.75 O8:Cr 0.25 ,Ni 0.05 Except for weighing to achieve the desired result, the oxide phosphor of Example 16 was obtained in the same manner as in Example 1.

[0077] Example 17 The raw materials used were weighed to the extent that 2.67g of Li2CO3, 28.8g of Ga2O3, 7.55g of In2O3, 1.37g of Cr2O3, and 0.27g of NiO were used. The molar ratio of each element in the initial composition of each raw material was LiGa 4.25 In 0.75 O8:Cr 0.25 ,Ni 0.05 Except for weighing to achieve the desired result, the oxide phosphor of Example 17 was obtained in the same manner as in Example 1.

[0078] Comparative Example 1 The raw materials used were weighed to the extent that 2.67g of Li2CO3, 33.9g of Ga2O3, 0.33g of Cr2O3, and 0.32g of NiO were used. The molar ratio of each element in the initial composition of each raw material was LiGa5O8:Cr 0.06 ,Ni 0.06 The oxide phosphor of Comparative Example 1 was obtained in the same manner as in Example 1, except that the amount was measured to achieve the desired result.

[0079] Comparative Example 2 The raw materials used were weighed to the extent that 2.67g of Li2CO3, 33.9g of Ga2O3, 0.33g of Cr2O3, and 0.05g of NiO were used. The molar ratio of each element in the initial composition of each raw material was LiGa5O8:Cr 0.06 ,Ni 0.01 The oxide phosphor of Comparative Example 2 was obtained in the same manner as in Example 1, except that the amount was measured to achieve the desired result.

[0080] Comparative Example 3 The raw materials used were weighed to the extent that 2.67g of Li2CO3, 33.9g of Ga2O3, 0.33g of Cr2O3, and 1.25g of NiO were used. The molar ratio of each element in the initial composition of each raw material was LiGa5O8:Cr 0.06 ,Ni 0.25 The oxide phosphor of Comparative Example 3 was obtained in the same manner as in Example 1, except that the amount was measured to achieve the desired result.

[0081] Comparative Example 4 The raw materials used were weighed to the point where 2.67g of Li2CO3, 33.9g of Ga2O3, and 0.006g of Cr2O3 were used. The molar ratio of each element in the initial composition was LiGa5O8:Cr 0.001 The oxide phosphor of Comparative Example 4 was obtained in the same manner as in Example 1, except that the amount was measured to achieve the desired result.

[0082] Comparative Example 5 The raw materials used were weighed to the extent that 2.67g of Li2CO3, 33.9g of Ga2O3, 0.006g of Cr2O3, and 0.005g of NiO were used. The composition of each element in 1 mole of the resulting oxide phosphor was such that the molar ratio of each element in the initial composition was LiGa5O8:Cr 0.001 ,Ni 0.001 The oxide phosphor of Comparative Example 5 was obtained in the same manner as in Example 1, except that the amount was measured to achieve the desired result.

[0083] Measurement of emission spectrum and emission characteristics The emission spectra of each oxide phosphor in the Examples and the oxide in Comparative Example 1 were 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. Figures 4 to 12 show the emission spectra of each oxide phosphor in each Example, and for comparison, the emission spectra of the oxide phosphor in Comparative Example 1 and the oxide phosphor in Comparative Example 5. Figure 13 also shows the emission spectra of each oxide phosphor in each Comparative Example. From the emission spectra of each obtained phosphor, the emission characteristics were determined, including the emission peak wavelength in the wavelength range exceeding the emission peak wavelength of the excitation light, the full width at half maximum (FWHM), and the emission spectral area. In the emission spectra of each obtained oxide phosphor, the emission intensity is expressed as a relative value to the emission intensity of the excitation light, as a relative emission intensity ratio (arbitrary value). A baseline value was set where the relative emission intensity ratio (arbitrary value) was 0. The integral value of the region enclosed by this baseline, the emission spectrum between 1100 nm and 1400 nm with an emission peak wavelength, the vertical axis line at 1100 nm, and the vertical axis line at 1400 nm was defined as the emission spectral area of ​​each oxide phosphor. The relative value of the emission spectral area of ​​each oxide phosphor to 100% of the emission spectral area of ​​the oxide phosphor in Comparative Example 1 was defined as the emission spectral area ratio (%). A larger emission spectral area ratio indicates higher emission energy of the oxide phosphor. The results are shown in Table 1.

[0084] [Table 1]

[0085] As shown in Table 1 or Figures 4 to 9, the oxide phosphors of Examples 1 to 12 had a composition included in the composition formula represented by formula (1), had an emission peak wavelength in the near-infrared wavelength range of 1150 nm to 1300 nm, and obtained emission spectra with a full width at half maximum of 150 nm or more. The oxide phosphors of Examples 1 to 12 had an emission spectral area, represented by the integral value of the region enclosed by the baseline (where the emission intensity is 0), a straight line indicating the vertical axis at 1150 nm, a straight line indicating the vertical axis at 1400 nm, and the emission spectrum, with the baseline being the baseline, and the emission spectral area was wider than that of the oxide phosphor of Comparative Example 1, indicating that they emitted light with higher emission energy.

[0086] As shown in Table 1 or Figure 10, the oxide phosphor of Example 13 had a composition included in the composition formula represented by formula (1), and its emission spectrum had an emission peak wavelength in the wavelength range of 700 nm to 900 nm and a full width at half maximum of 150 nm or more, which was wider than that of Comparative Example 4.

[0087] As shown in Table 1 or Figures 11 and 12, the oxide phosphors of Examples 14 to 17 had a composition included in the composition formula represented by formula (1), and their emission spectra had an emission peak wavelength in the wavelength range of 1150 nm to 1300 nm and a full width at half maximum of 150 nm or more.

[0088] As shown in Table 1 or Figure 13, the oxide phosphors of Comparative Examples 1 to 3 and 5 had emission peak wavelengths in the near-infrared wavelength range of 1150 nm to 1300 nm. The oxide phosphors in Comparative Examples 1 to 3 and 5 did not satisfy the compositional formula represented by formula (1), and the molar ratio of the sum of Cr and Ni to the total molar ratio of Ga was less than 5 mol%, so the emission spectral area in the range of 1150 nm to 1400 nm was smaller than that of the oxide phosphors in Examples 1 to 12. Furthermore, the emission spectral area ratio of the oxide phosphor in Comparative Example 5 was 50% or less smaller than that of Comparative Example 1. In the oxide phosphor of Comparative Example 3, the molar ratio of Cr is smaller than the molar ratio of Ni in the oxide phosphor composition, resulting in less absorption of excitation light by Cr and thus less energy transfer of excitation light from Cr to Ni. Therefore, the emission spectral area in the range of 1150 nm to 1400 nm was smaller than that of the oxide phosphors of Comparative Examples 1 and 2. Furthermore, in the oxide phosphor of Comparative Example 4, which has a small molar ratio of Cr (less than 0.05) and does not contain Ni as an activating element, an emission peak wavelength was confirmed in the range of 700 nm to 815 nm, which is derived from the activating element Cr, but no emission peak wavelength was confirmed in the range of 1150 nm to 1300 nm, which is derived from the activating element Ni.

[0089] Light-emitting device according to an example The wavelength conversion components used in the light-emitting device are represented by the following composition, and the emission peak wavelengths of each phosphor when excited by a light-emitting element with an emission peak wavelength of 420 nm are shown in Table 2. First phosphor Example 1: Formula (1-1): LiGa5O8:Cr 0.25 ,Ni 0.05 Second phosphor Formula (2a-1):Ca 10 (PO4)6Cl2:Eu Third phosphor Formula (3a-1): Ca8MgSi4O 16 Cl2:Eu Equation (3b-1): Lu3Al5O 12 :Ce Fourth phosphor Equation (4a-1): (Sr,Ca)AlSiN3:Eu Equation (4f-1): (Ba,Sr)2Si5N8:Eu Fifth phosphor Formula (5a-1): Ga2O3:Cr Formula (5g-1):Na2CaGe6O 14 :Cr

[0090] Light-emitting device of an example The oxide phosphor according to Example 1 was used as the first phosphor. The second, third, fourth, and fifth phosphors shown in Table 2 were mixed and dispersed with a silicone resin in the formulations shown in Table 2, and then degassed to obtain a composition for forming a wavelength conversion member. Table 2 shows the formulations of the first, second, third, fourth, and fifth phosphors in parts by mass per 100 parts by mass of resin for each example and comparative example. The total amount of phosphors in the composition for forming a wavelength conversion member was 205.4 parts by mass per 100 parts by mass of resin. Next, a molded body having a recess as shown in Figure 2 was prepared, and a light-emitting element having a gallium nitride-based compound semiconductor with an emission peak wavelength of 420 nm was placed on the bottom surface of the recess as the first lead. Then, the composition for forming a wavelength conversion member was injected and filled onto the light-emitting element, and the resin in the composition for forming a wavelength conversion member was cured by heating. The full width at half maximum of the emission spectrum of the light-emitting element was 15 nm. A light-emitting device according to the example was fabricated by this process.

[0091] Measurement of emission spectrum For the light-emitting device according to the embodiment, the emission spectrum at room temperature (25°C ± 5°C) was measured using an optical measurement system combining a spectrophotometer and an integrating sphere.

[0092] [Table 2]

[0093] Figure 14 shows the emission spectrum of the light-emitting device according to the embodiment. As shown in Figure 14, the emission spectrum of the light-emitting device according to the embodiment was continuous within the range of the emission peak wavelength of the light-emitting element (420 nm) to 1600 nm. [Industrial applicability]

[0094] The oxide phosphors relating to this disclosure can also be used in medical light-emitting devices for obtaining information from within living organisms, light-emitting devices for monitoring health conditions when mounted on small mobile devices such as smartphones, light-emitting devices for analytical devices that non-destructively measure information from inside foods such as fruits, vegetables, and rice, and light-emitting devices for reflectance spectrometers used to measure film thickness, etc. Light-emitting devices using the oxide phosphors relating to this disclosure can be used in medical devices, small mobile devices, analytical devices, and reflectance spectrometers. [Explanation of Symbols]

[0095] 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 converter, 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: Coating member, 100, 200: Light-emitting device.

Claims

1. An oxide phosphor having the composition contained in the composition formula shown in the following formula (1). (Li １－ｔ M １ ｔ ) ｕ (G １－ｖ M ２ ｖ ) ５ O ｗ :Cr ｘ , Ni ｙ , M ３ ｚ (1) (In the above formula (1), M １ is at least one element selected from the group consisting of Na, K, Rb, and Cs, and M ２ is at least one element selected from the group consisting of B, Al, Sc, In and rare earth elements, and M ３ (where is at least one element selected from the group consisting of Si, Ge, Sn, Ti, Zr, Hf, Bi, V, Nb, and Ta, and t, u, v, w, x, y, and z satisfy the following conditions, respectively: 0 ≤ t ≤ 1.0, 0.7 ≤ u ≤ 1.6, 0 ≤ v < 1.0, 7.85 ≤ w ≤ 11.5, 0.05 ≤ x ≤ 1.2, 0 < y ≤ 0.5, y < x, 0 ≤ z ≤ 0.5.)

2. The oxide phosphor according to claim 1, wherein in formula (1), x and y satisfy 1.5 ≤ x / y ≤ 50.

3. The oxide phosphor according to claim 1 or 2, wherein in formula (1), x and y satisfy 0.08 ≤ x ≤ 0.8 and 0.001 ≤ y ≤ 0.

3.

4. The oxide phosphor according to claim 1 or 2, wherein in formula (1), x and y satisfy 0.1 ≤ x ≤ 0.5 and 0.005 ≤ y ≤ 0.

2.

5. The oxide phosphor according to any one of claims 1 to 4, wherein the oxide phosphor has an emission spectrum with an emission peak wavelength and a full width at half maximum of 150 nm or more.

6. The oxide phosphor according to any one of claims 1 to 5, wherein the oxide phosphor has an emission peak wavelength in the range of 1150 nm to 1300 nm.

7. The oxide phosphor according to any one of claims 1 to 6, wherein in formula (1), x and y satisfy 0.25 < x + y ≤ 1.

2.

8. A light-emitting device comprising an oxide phosphor according to any one of claims 1 to 7, and a light-emitting element having an emission peak wavelength in the range of 365 nm to 500 nm, for irradiating the oxide phosphor.

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