Fluorescent body, light source including fluorescent body, and novel inorganic oxide

Abstract

To provide a novel fluorescent body showing red fluorescence by excitation of light in a blue light wavelength region which is particularly a fluorescent body using inexpensive and highly safe and stable manganese as an activator.SOLUTION: A fluorescent body contains inorganic oxide which is expressed by La1.5 Na1.5-xMxTe1-xNbxO6, in which M denotes Mg, Ca, Sr or Ba, x is 0.01 to 1.0, the inorganic oxide has a double perovskite structure, and the inorganic oxide is doped by manganese ion. By using the fluorescent body, an illumination device having color rendering properties suitable for use indoor, and a wavelength conversion material which converts ultraviolet ray in sunlight into red light can be provided.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a phosphor, a light source containing the phosphor, and a novel inorganic oxide. More specifically, the present invention relates to a phosphor containing an inorganic oxide having a double-perovskite structure, a light source containing the phosphor, and a novel inorganic oxide having a double-perovskite structure. [Background technology]

[0002] Light sources that use LEDs as their light source are considered to be a new generation of light source with many advantages, including high efficiency, long life, and high environmental friendliness. White light sources are generally made up of combinations of blue, green, and red LEDs, as well as combinations of ultraviolet to blue light emitting LEDs and various phosphors. An example of a white light source currently in practical use is Ce. 3+ One example is a combination of a YAG yellow phosphor activated with InGaN blue LED chip. However, this white light source lacks red components, so the color rendering is not sufficient for indoor use. From this perspective, various red phosphors have been explored in recent years to improve the color rendering of white light sources.

[0003] Red light is also suitable for photosynthesis and is thought to promote plant growth, so materials that emit red fluorescence when excited by ultraviolet light in sunlight are also in demand in the agricultural sector.

[0004] Red phosphor is Eu 2+ Phosphors containing rare earth ions such as arsenic-containing oxide phosphors, sulfide phosphors, and oxynitride phosphors have been developed as phosphors that do not contain rare earth elements, but they are not sufficient in terms of safety, stability, ease of synthesis, and the like.

[0005] Meanwhile, in recent years, various phosphors using manganese have been reported as red phosphors with excellent safety. Manganese is inexpensive, so it also contributes to reducing the cost of red phosphors. For example, Non-Patent Document 1 reports that Ba2LaNbO6 with a double perovskite structure is doped with Mn 4+ or Cr 3+ In addition, Non-Patent Document 2 reports a deep red phosphor in which Mn is doped into La2LiTaO6 with a double perovskite structure. 4+ Non-Patent Document 3 discloses a phosphor doped with Mn in Gd2ZnTiO6 with a double perovskite structure. 4+ Patent Document 1 discloses a phosphor in which manganese ions are doped into an inorganic oxide having a double perovskite structure, the constituent elements of which are one or more elements selected from the group consisting of Sb, Nb, Ta, Te, W, and I, La, and Na. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2019-048931 A [Non-patent literature]

[0007] [Non-Patent Document 1] PATanner et al, Inorg. Chem. 2009, 48, 11142-11146 [Non-Patent Document 2] Lei Wang et al, Appl. Phys. A, 2014, 117, 1777-1783 [Non-Patent Document 3] Hui Chen et al, J. Mater. Chem. C 2016, 4, 2374-2381 Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a novel phosphor that exhibits red fluorescence when excited by light in the blue wavelength range. In particular, an object of the present invention is to provide a phosphor that uses manganese, which is inexpensive, safe, and highly stable, as an activator. Another object of the present invention is to provide a light source and a wavelength conversion material that can provide a lighting device or the like having color rendering properties suitable for indoor use. [Means for solving the problem]

[0009] Among the phosphors described in Patent Document 1, the present inventors have focused on La 1.5 Na 1.5 The present invention was completed by attempting to develop a cheaper and more stable phosphor based on the TeO6 host phosphor. That is, the present invention provides the following.

[0010] [1] La 1.5 Na 1.5-x M x Te 1-x Nb x Represented by O6, A phosphor comprising an inorganic oxide, in which M represents Mg, Ca, Sr, or Ba and x is 0.01 to 1.0, the inorganic oxide having a double perovskite structure, and the inorganic oxide is doped with manganese ions. [2] The phosphor according to [1], wherein the manganese ion is a tetravalent manganese ion. [3] The phosphor according to [1] or [2], wherein M is Ca. [4] La 1.5 Na 1.5 The phosphor according to any one of [1] to [3], which shows an XRD pattern similar to that of Te1O6 and emits red fluorescence when excited by blue light. [5] The phosphor according to any one of [1] to [4], wherein the inorganic oxide is doped with manganese ions in an amount of 0.1 atom % to 1 atom % relative to the total atom number of Nb and Te.

[0011] [6] A light source comprising a light-emitting element that emits light in the blue light region or the ultraviolet light region, and the phosphor according to any one of [1] to [5]. [7] The light source according to [6], wherein the light emitting element is a light emitting diode. [8] The light source according to [7], wherein the light emitting diode comprises InGaN. [9] Ce 3+ The light source according to any one of [6] to [8], comprising a YAG phosphor activated with , and the light-emitting element is a light-emitting element that emits light in the blue light region.

[10] La 1.5 Na 1.5-x M x Te 1-x Nb x An inorganic oxide represented by O6, where M is Mg, Ca, Sr, or Ba, and x is 0.01 to 1.0, and has a double perovskite structure. Effect of the Invention

[0012] The present invention provides a novel red phosphor in which a matrix made of an inorganic oxide having a double perovskite structure is doped with manganese ions. By utilizing the phosphor of the present invention, it is possible to provide a lighting device having color rendering properties suitable for indoor use, and a wavelength conversion material that converts ultraviolet light in sunlight to red light. The present invention also provides a novel inorganic oxide having a double perovskite structure. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram showing a double perovskite structure. [Diagram 2] FIG. 2 is a diagram showing XRD patterns of phosphors prepared in the examples. [Diagram 3] FIG. 2 is a diagram showing the excitation spectrum and the fluorescence spectrum of the phosphor prepared in the example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The present invention will be described in detail below. In this specification, "LED" means light-emitting diode, "OLED" means organic electroluminescence, and "YAG" means a crystal of a garnet structure of a composite oxide of yttrium and aluminum. "XRD" means X-ray diffraction. In this specification, "~" is used to mean that the numerical values ​​before and after it are included as the lower and upper limits. In this specification, numerical values ​​or numerical ranges are interpreted as including the generally acceptable range of error for inorganic substances and crystals. In addition, the expression "similar" indicates something that can be interpreted as the same within the generally acceptable range of error.

[0015] <Phosphor> The phosphor of the present invention is La 1.5 Na 1.5-x M x Te 1-x Nb x O6, where M is Mg, Ca, Sr, or Ba, and x is 0.01 to 1.0.

[0016] As described above, the present inventors have found that, among the phosphors described in Patent Document 1, La 1.5 Na 1.5 We focused on phosphors based on TeO6 and investigated replacing Te (tellurium) with a less expensive metal. As a result, we found that phosphors using Nb (niobium) as a less expensive metal to replace some or all of Te were La 1.5 Na 1.5 It was found that it gives fluorescence with brightness comparable to that of TeO6. By replacing a larger proportion of Te with Nb, it is possible to reduce costs. In addition, Nb is more chemically stable than Te, so it is possible to provide a more stable phosphor.

[0017] The inorganic oxide in the phosphor of the present invention has a double perovskite structure. In the phosphor of the present invention, the inorganic oxide is doped with manganese ions. That is, the phosphor of the present invention has the inorganic oxide as a host, and the host is activated by being doped with manganese ions to exhibit fluorescence. It is preferable that the phosphor that is an inorganic oxide doped with manganese ions also has a double perovskite structure.

[0018] The valence of Nb contained in the inorganic oxide or phosphor is not limited, but is preferably a pentavalent ion. The valence of Te is not limited, but is preferably a hexavalent ion.

[0019] [Double perovskite structure] A typical example of a double perovskite structure is shown in FIG. 1. Perovskite compounds can generally be represented as ABX3, but compounds having a double perovskite structure have heteroatoms at both or only one of the A and B sites of the perovskite structure, and generally have a composition that can be represented as A'A"B'B"X6. The eight spheres depicted in FIG. 1 are A sites, and the center of an octahedron with an X site at its vertex is the B site. In a double perovskite structure, generally, two types of ions are arranged alternately at the A site or the B site. In the double perovskite structure shown in FIG. 1, the B site is arranged alternately. However, those that vary from such an arrangement are also included in the double perovskite structure. For example, the above alternating arrangement does not have to be a strict alternating arrangement, and two types of ions may be present at both the A site and the B site. Further, as the double perovskite structure, a structure in which a distortion is added to the structure shown in FIG. 1 is also known (for example, J. Cryt. Growth 2008. 310, 240-244), and in this specification, when the double perovskite structure is referred to, it also includes such a structure having a distortion.

[0020] The number of elements (preferably O) present at the X site in the double perovskite structure may vary slightly from 6 (e.g., 5.0 to 6.0), but all such variations are considered to be within the scope of the double perovskite structure having a composition that can be represented as A'A''B'B''X6.

[0021] In the double perovskite structure of the phosphor of the present invention, La is preferably present in the A site and O is preferably present in the X site. Na may further be present in the A site. It is preferable that Na or M and Nb or Te are alternately arranged in the B site.

[0022] The inorganic oxide contained in the phosphor of the present invention is La 1.5 Na 1.5-x M x Te 1-x Nb x O6. M represents Mg, Ca, Sr, or Ba, and is preferably Ca. x is 0.01 to 1.0. From the viewpoint of suppressing the amount of Te and further reducing costs, x may be 0.1 or more, preferably 0.2 or more, more preferably 0.3 or more, even more preferably 0.4 or more, and particularly preferably 0.5 or more. The phosphor of the present invention in which x is 1.0 provides sufficient brightness, but from the viewpoint of obtaining higher brightness, x is preferably 0.9 or less, more preferably 0.8 or less, even more preferably 0.7 or less, and particularly preferably 0.6 or less.

[0023] La 1.5 Na 1.5-x M x Te 1-x Nb x An example of O6 is La 1.5 NaCa 0.5 Te 0.5 Nb 0.5 O6, La 1.5 Na 0.9 Ca 0.6 Te 0.4 Nb 0.6 O6, La 1.5 Na 0.7 Ca 0.8 Te 0.2 Nb 0.8O6, etc. It is well known to those skilled in the art that there may be some error in the amount of each element. In addition, the number of O (oxygen) is 6, and the above-mentioned variation in the elements present at the X site in the double perovskite structure may occur. 1.5 Na 1.5-x M x Te 1-x Nb x The ranges defined by O6 etc. encompass such ranges of error and variation.

[0024] La doped with manganese ions 1.5 Na 1.5-x M x Te 1-x Nb x O6 is "La 1.5 Na 1.5-x M x Te 1-x Nb x It can be expressed by the formula "O6:Mn", and further, it can be expressed by a formula taking into account the doping amount, as described later.

[0025] [Manganese ion] In the phosphor of the present invention, it is believed that the doped manganese ions have a structure in which they are substituted for M at the B site. 1.5 Na 1.5-x M x Te 1-x Nb x In the double perovskite structure with the O6 composition, Na or M and Nb or Te are arranged alternately at the B site, so the substituted manganese ions tend to be isolated in the matrix, which makes it easier to increase the fluorescence intensity.

[0026] The manganese ions may be doped into the host as divalent to pentavalent ions, preferably divalent, tetravalent or pentavalent ions, and more preferably tetravalent ions. It is believed that the fluorescence intensity is higher when doped as tetravalent ions. Manganese ions with different valences may be mixed in the phosphor of the present invention.

[0027] In general, in phosphors doped with manganese ions, the manganese added during synthesis is thought to contain manganese ions that are not substituted with Nb or Te or that are not incorporated into the host crystal. However, in the phosphor of the present invention, it is thought that most of the manganese ions are substituted for Nb or Te in the host crystal structure, resulting in high fluorescence intensity.

[0028] When the total atom number of elements Nb and Te is taken as 1, the doping amount of manganese ions is preferably 0.0005 to 0.02 (0.05 atom % to 2 atom % with respect to the total atom number of Nb and Te), more preferably 0.001 to 0.01 (0.1 atom % to 1 atom % with respect to the total atom number of Nb and Te), and further preferably 0.002 to 0.005 (0.2 atom % to 0.5 atom % with respect to the atom number of M).

[0029] [Other dopant ions] The phosphor of the present invention may be doped with dopant ions (codopants) other than manganese ions in addition to manganese ions. The other dopant ions may or may not be substituted for elements in the host crystal structure, but are preferably substituted. The other dopant ions may be contained in the phosphor of the present invention as ions for charge compensation. Additionally, other dopant ions are preferably incorporated into the host crystal.

[0030] Other dopant ions include calcium ions (Ca 2+ ), strontium ion (Sr 2+ ), barium ion (Ba 2+ ), magnesium ion (Mg 2+ ), tungsten ions (W 6+ ) are mentioned.

[0031] When other dopant ions are present, the doping amount may be the doping amount necessary for charge compensation, but it does not have to be the strictly necessary doping amount, and may be more or less than the doping amount necessary for charge compensation. For example, when the total atom number of elements Nb and Te is 1, it is preferably 0.0001 to 0.05 (0.01 atom% to 5 atom% with respect to the total atom number of Nb and Te), more preferably 0.0005 to 0.02 (0.05 atom% to 2 atom% with respect to the total atom number of Nb and Te), and even more preferably 0.001 to 0.01 (0.1 atom% to 1 atom% with respect to the total atom number of Nb and Te). It is also preferable that the doping amount is 1 to 3 times (atom number) the doping amount of manganese ions.

[0032] Examples of the phosphor of the present invention include the following. La 1.5 Na 0.994 Ca 0.506 Te 0.497 Nb 0.5 O6: 0.003Mn La 1.5 Na 0.894 Ca 0.606 Te 0.397 Nb 0.6 O6: 0.003Mn It is well known to those skilled in the art that there may be some error in the amount of each element.

[0033] The shape of the phosphor of the present invention is not particularly limited, but may be, for example, particulate, and preferably has a particle size of 0.1 μm to 100 μm. It is believed that a phosphor with a larger particle size provides higher brightness.

[0034] <Method of manufacturing phosphor> The phosphor of the present invention can be produced by a solid-state reaction method including a step of firing a raw material mixture. The firing can be carried out, for example, at 400°C to 1300°C, but a phosphor with high purity can be produced particularly at a temperature of less than 1000°C. The firing may be carried out preferably at 500°C to 990°C, more preferably at 800°C to 980°C, and even more preferably at 900°C to 970°C. The firing time is generally one hour or more, preferably 3 hours to 72 hours, and more preferably 5 hours to 18 hours. The temperature during firing may be raised over a period of 30 minutes to 6 hours, and preferably 1 hour to 5 hours. The calcination can be carried out under atmospheric conditions, but may also be carried out in an oxygen atmosphere, if necessary.

[0035] It is also preferable that the firing process includes a calcination step and a firing step. 1.5 Na 1.5-x M x Te 1-x Nb x A highly pure phosphor of the double perovskite oxide represented by O6 can be obtained. The calcination step may be performed at 400°C to 800°C, preferably 500°C to 700°C, for 2 to 12 hours, preferably 3 to 9 hours. The firing step may be performed at 500°C to 990°C, preferably 800°C to 980°C, for 2 to 24 hours, preferably 8 to 18 hours. It is preferable to include a step of cooling the intermediate product to the ambient temperature between the calcination step and the firing step. This is because the intermediate product can be crushed and mixed by cooling. In other words, it is preferable to include a step of crushing, mixing, or crushing and mixing before reheating after cooling. This is because a pure product can be obtained by promoting a solid-phase reaction. After cooling, the temperature is raised again for 30 minutes to 6 hours, preferably 1 to 5 hours, and firing is performed.

[0036] The firing is preferably carried out by the powder bed method. The powder bed method is a method in which a powdered material to be fired is placed around a pellet-shaped material to be fired and then fired. This method makes it difficult for evaporation from the pellet to occur, and a product that maintains the molar ratio of each element in the material to be fired can be obtained in the pellet. The material to be fired may be a mixture of raw materials, or an intermediate product obtained by calcining a mixture of raw materials. The mass ratio of powder to pellets may be approximately 1:2 or more, preferably 1:3 or more. The pellets can be produced by applying a pressure of, for example, 5 to 10 tons to the material to be fired. The pellets may be produced to have a size of, for example, 7 mm×7 mm to 10 mm×10 mm and a thickness of about 1 to 2 mm.

[0037] After firing, an annealing treatment may be performed. The annealing treatment may be performed at 400° C. to 1300° C., preferably 600° C. to 1000° C., for 2 hours to 42 hours, preferably 12 hours to 36 hours. The annealing treatment may be performed in an oxygen atmosphere or a nitrogen atmosphere.

[0038] In the raw material mixture, the manganese source may be, for example, manganese carbonate (MnCO3), manganese oxide, or manganese acetate, and it is preferable to use MnCO3. In the raw material mixture, the sources of LaNb and Te may be, for example, the oxides of each of them. As a source of Na, for example, carbonate (Na2CO3) can be used. As a source of M (e.g., Ca), for example, carbonate (CaCO3) can be used. All raw materials are preferably in powder form, with as high a purity (99.9% or higher) and as small a particle size as possible to enhance reactivity.

[0039] The raw materials may be mixed in a molar ratio according to the stoichiometric ratio of the desired phosphor, although the above ratio may be appropriately modified in consideration of the amount of evaporation during production. The mixing method is not particularly limited. For example, a mortar or a ball mill may be used. The mixing may be performed by a dry method, a wet method, or both. For example, mixing by a dry method may be followed by mixing by a wet method. Mixing by a wet method may be performed, for example, by mixing ethanol and mixing in a mortar.

[0040] <Applications of phosphors> The phosphor of the present invention can be used as a red phosphor. The fluorescence emitted by the red phosphor may be light that gives a peak (peak of the fluorescence spectrum) in the wavelength range of 620 to 730 nm. The red phosphor can be used to manufacture various light sources, and can be used in combination with a light-emitting element that emits light in the light wavelength region that excites the phosphor to form a light source. The light-emitting element can be a light-emitting diode (LED).

[0041] The phosphor of the present invention has the property of emitting red fluorescence when excited by blue light or ultraviolet light. There are no particular limitations on the blue LED that emits light in the blue light region, but it is sufficient if it has a peak (peak of the excitation spectrum) in the wavelength range of 390 to 480 nm, and elements containing InGaN, GaN, AlGaN, or the like can be used. There are no particular limitations on the ultraviolet LED that emits light in the ultraviolet region, but it is sufficient that it has a peak (peak of the excitation spectrum) in the wavelength range of 200 to 350 nm, and elements containing InAlGaN or AlGaN can be used.

[0042] The phosphor of the present invention can be combined with a blue LED and a green phosphor that fluoresces green light when excited by blue light to form a white light source, or can be combined with an ultraviolet LED, a blue phosphor that fluoresces blue light when excited by ultraviolet light, and a green phosphor that fluoresces green light when excited by ultraviolet light to form a white light source.

[0043] It is also preferable to use the phosphor of the present invention to adjust the color rendering of a white light source that combines a blue LED with a yellow phosphor that shows yellow fluorescence when excited by blue light. For example, YAG is used as a phosphor that shows very high intensity yellow fluorescence when excited by the wavelength emitted by a blue LED. 3+ Although phosphors activated by fluorine are known, the phosphor of the present invention exhibits sufficient fluorescence intensity in the red wavelength range that is clearly different from the fluorescence of YAG phosphors. Therefore, the phosphor of the present invention may be used in a white light source containing a blue LED and a YAG phosphor. The light of the white light source containing the phosphor of the present invention contains a sufficient amount of red components, and can realize a warm white light suitable for indoor lighting devices. In addition, the white light source can also be used as a backlight for other lighting devices and various image display devices such as liquid crystal display devices.

[0044] Furthermore, the phosphor of the present invention can be applied to lighting devices for plant growth. Red light is suitable for photosynthesis, and plant growth can be promoted by using the phosphor of the present invention together with a lighting device formed by combining an ultraviolet LED or a blue LED as a light source.

[0045] The phosphor of the present invention can be used as a wavelength conversion material by utilizing the property of giving red fluorescence when excited by blue light or ultraviolet light. For example, it can be used as a material that converts ultraviolet light in sunlight that is unnecessary for plant growth into useful red light, or as a material for efficiently utilizing sunlight in solar cells with low sensitivity to ultraviolet light. In use, for example, a wavelength conversion film is produced from a composition containing the phosphor of the present invention, a binder resin, and necessary additives, and can be used as a vinyl sheet for a vinyl house or a sealing sheet for a solar cell. In addition, the phosphor of the present invention can be used as a heating element that does not require a power source by using a natural light source or an artificial light source by being contained in a highly thermally conductive resin or a heat storage material and made into a sheet or molded body. EXAMPLES

[0046] The present invention will be described in more detail below with reference to examples. The materials, reagents, amounts of substances and their ratios, operations, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the following examples.

[0047] <Synthesis of phosphor> The synthesis was carried out by the solid-state reaction method. The starting materials used were La(OH)3 powder obtained by leaving La2O3 powder (99.99%) available from Wako Pure Chemical Industries in air for 3 days, Na2CO3 powder (99.5%), TeO2 powder (99.9%) available from Kojundo Kagaku Kenkyusho, MnCO3 powder (99.9%), Nb2O5 powder (99.9%) available from Wako Pure Chemical Industries, and CaCO3 powder (99.99%) available from Kanto Kagaku. Each powder was weighed out so that the atomic ratio was La:Na:Ca:Te:Nb:Mn=1.5:(1.494-x):0.006+x:(0.997-x):x:0.003.

[0048] In addition, Na2CO3, which is highly volatile, was weighed out at a high ratio to the amount of the final product. The weighed out starting materials were mixed in an agate mortar for 10 minutes by the dry method and for 20 minutes by the wet method (ethanol), and calcined at 600°C for 4 hours under atmospheric conditions. They were then mixed again and some were pelletized. The powdered product was placed around the pellets produced, and fired by the powder bed method at 1000°C or 950°C for 12 hours under atmospheric conditions. The fired pellets were then annealed at 800°C for 24 hours in a nitrogen atmosphere to obtain a phosphor. The gas flow rate during annealing was 60mL / min.

[0049] The Rietveld analysis of the products confirmed that all compositions had a double perovskite structure with the space group P21 / c (No. 14-1).

[0050] <XRDパターン> The measurements were performed using a RINT-2200 X-ray diffractometer (Rigaku Corporation) with a CuKα monochromatic light source (λ = 0.15418 nm). The obtained XRD pattern is shown in Figure 2. All of the examples where x=0, 0.2, 0.4, 0.5, 0.6, 0.8, and 1.0 are the same as those described in Patent Document 1 (La doped with manganese ions and calcium ions). 1.5 Na 1.5 It was found that the XRD pattern was similar to that of TeO6) and that it had a similar crystal structure. In addition, in the cases where x = 0.2, 0.4, 0.5, 0.6, 0.8, and 1.0, peaks due to impurities were observed in the cases where firing was performed at 1000°C, but not in the cases where firing was performed at 950°C (arrows).

[0051] <Excitation and Emission Spectra> Measurements were performed at room temperature using a JASCO FP-6500 fluorescence spectrophotometer (150 W xenon light source, JASCO ISF-513 integrating sphere). La 1.5 Na 1.5-x Ca x Te 1-x Nb x The excitation and fluorescence spectra of O6:Mn (x=0, 0.5, 0.6, 0.8, 1.0) are shown in Figure 3 and Table 1. The excitation spectra were measured at a fluorescence wavelength of 700 nm. As a result, an excitation band located at wavelengths of 250 to 450 nm with a peak wavelength at 315 nm and an excitation band located at wavelengths of 440 to 550 nm with a peak wavelength at 500 nm were observed. In addition, the fluorescence spectra excited with blue light of about 315 nm showed a fluorescence band located at 650 to 750 nm with a peak located at about 700 nm.

[0052] [Table 1]

[0053] <Quantum efficiency> When the external and internal quantum efficiencies were calculated for the phosphors with x=0, 0.5, and 0.6 based on the measurement results using the FP-6500 fluorescence spectrophotometer, the values ​​obtained were all approximately the same.

Claims

1. No 1.5 Yes 1.5-x M x Yes 1-x Nb x Oh 6 It is expressed as M represents Mg, Ca, Sr, or Ba; x includes an inorganic oxide having a value of 0.01 to 1.0; The inorganic oxide has a double perovskite structure, The phosphor wherein the inorganic oxide is doped with manganese ions.

2. 2. The phosphor according to claim 1, wherein the manganese ion is a tetravalent manganese ion.

3. 2. The phosphor according to claim 1, wherein M is Ca.

4. La 1.5 Na 1.5 Te 1 O 6 2. The phosphor according to claim 1, which exhibits an XRD pattern similar to that shown in FIG. 1 and gives red fluorescence when excited by blue light.

5. 2. The phosphor according to claim 1, wherein the inorganic oxide is doped with manganese ions in an amount of 0.1 atom % to 1 atom % relative to the total atom number of Nb and Te.

6. A light source comprising a light emitting element that emits light in the blue light region or the ultraviolet light region and the phosphor according to any one of claims 1 to 5.

7. 7. The light source of claim 6, wherein the light emitting element is a light emitting diode.

8. The light source of claim 7 , wherein the light emitting diode comprises InGaN.

9. C 3+ 7. The light source according to claim 6, comprising a YAG phosphor activated with 1, and the light emitting element is a light emitting element that emits light in the blue light region.

10. No 1.5 Yes 1.5-x M x Yes 1-x Nb x Oh 6 It is expressed as M represents Mg, Ca, Sr, or Ba; x is 0.01 to 1.0; An inorganic oxide with a double perovskite structure.

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