JP2019116615A - Oxynitride phosphor, light emitting device and method for producing oxynitride phosphor - Google Patents

Abstract

To provide an oxynitride phosphor having high light emitting properties, a light emitting device and a method for producing an oxynitride phosphor.SOLUTION: An oxynitride phosphor has a composition represented by the following formula (I): (BaEu)MSiON(where M is at least one element selected from the group consisting of rare earth elements excluding Eu and Sm; a, b, c and d are numbers satisfying 0<a≤1.0, 0<b≤0.07, -0.3<c<0.3, -0.3<d<0.3).SELECTED DRAWING: Figure 2

Description

  The present invention relates to an oxynitride phosphor, a light emitting device, and a method of manufacturing an oxynitride phosphor.

  A light emitting device combining a light emitting diode (Light Emitting Diode, hereinafter also referred to as “LED”) or a light emitting element of a laser diode (Laser Diode, hereinafter also referred to as “LD”) and a phosphor has a light source with high conversion efficiency. Because of its low power consumption, long life and small size, it is used as a light source to replace incandescent bulbs and fluorescent lamps.

As a fluorescent substance used for a light-emitting device, for example, in Patent Document 1, Ba _p Si _q O _r N _{((2/3) p + (4/3) q− (2/3) r)} : Eu (0. An oxynitride phosphor represented by the formula 5 <p <1.5, 1.5 <q <2.5, 1.5 <r <2.5) is disclosed. The oxynitride phosphor is excited by an excitation light source in the ultraviolet to visible light range to emit bluish green to yellowish light.

Unexamined-Japanese-Patent No. 2004-277547

However, the above-described oxynitride phosphor is required to improve emission intensity and further improve temperature characteristics.
Therefore, it is an object of one embodiment of the present invention to provide an oxynitride phosphor having high emission intensity and a favorable temperature characteristic, a light emitting device, and a method for producing an oxynitride phosphor.

  The means for solving the problems includes the following aspects.

A first aspect of the present invention is an oxynitride phosphor containing a composition represented by the following formula (I).
_{(Ba 1-a Eu a)} 1-b M b Si 2 O 2 + c N 2 + d (I)
In the formula (I), M is at least one element selected from the group consisting of rare earth elements other than Eu and Sm, and a, b, c and d each satisfy 0 <a ≦ 1.0, 0 <b ≦ 0.07, −0.3 <c <0.3, −0.3 <d <0.3.

  A second aspect of the present invention is a light emitting device including the oxynitride phosphor and an excitation light source having an emission peak wavelength in the range of 380 nm to 485 nm.

  A third aspect of the present invention is a method for producing an oxynitride phosphor according to the first aspect, which comprises a compound containing Ba, a compound containing Eu, and a rare earth element other than Eu and Sm. A mixture comprising a compound containing at least one element M to be selected, a compound containing Si, any of the aforementioned compounds being a compound containing oxygen, and optionally, any of the compounds being a compound containing nitrogen And baking the mixture, which is a method of producing an oxynitride phosphor.

  According to one aspect of the present invention, it is possible to provide an oxynitride phosphor having high emission intensity and good temperature characteristics, a light emitting device, and a method for producing an oxynitride phosphor.

FIG. 1 is a schematic cross-sectional view showing an example of a light emitting device. FIG. 2 is a view showing the emission spectrum of relative emission energy (%) with respect to the wavelength (nm) of the oxynitride phosphors according to Examples 2 to 5 and Comparative Example 1. FIG. 3 is a graph showing emission spectra of the oxynitride phosphors according to Examples 2 and 14 and Comparative Examples 1 and 3. FIG. 4 is a SEM photograph of an oxynitride phosphor according to Example 2. FIG. 5 is a SEM photograph of an oxynitride phosphor according to Comparative Example 1. FIG. 6 is a view showing emission spectra of light emitting devices according to Examples 2 to 5 and Comparative Example 1. FIG. 7 is a graph showing fluctuation values of Δy after continuous lighting for 1000 hours from the beginning of the light emitting devices according to Examples 2 to 5 and Comparative Example 1. FIG. 8 is a graph showing variation values of Δy after continuous lighting for 1000 hours from the beginning of the light emitting devices according to Examples 2 and 14 and Comparative Examples 1 and 3. FIG. 9 shows relative emission energy (%) of the oxynitride phosphors according to Examples 14 to 17 and Comparative Example 1 when light is emitted at each temperature ranging from room temperature (about 25 ° C.) to 300 ° C. It is a graph.

  Hereinafter, an oxynitride phosphor, a light emitting device, and a method for producing an oxynitride phosphor according to the present invention will be described based on embodiments. However, the embodiments shown below are exemplifications for embodying the technical concept of the present invention, and the present invention is limited to the following oxynitride phosphor, light emitting device, and method of producing oxynitride phosphor. I will not. The relationship between the color name and the chromaticity coordinates, the relationship between the wavelength range of light and the color name of monochromatic light, etc. conform to JIS Z8110.

Oxynitride Phosphor The oxynitride phosphor according to the first embodiment of the present invention has a composition represented by the following formula (I).
_{(Ba 1-a Eu a)} 1-b M b Si 2 O 2 + c N 2 + d (I)
In the formula (I), M is at least one element selected from the group consisting of rare earth elements other than Eu and Sm, and a, b, c and d each satisfy 0 <a ≦ 1.0, 0 <b ≦ 0.07, −0.3 <c <0.3, −0.3 <d <0.3.

  The oxynitride phosphor including the composition represented by the formula (I) according to the first embodiment of the present invention may be in the range of 380 nm to 485 nm (hereinafter, referred to as “near ultraviolet to blue region”. ) Can be efficiently excited by light from a light emitting element having a light emission peak wavelength to emit bluish green light, thereby providing an oxynitride phosphor having high light emission intensity as described later. The oxynitride phosphor according to the first embodiment of the present invention is also excellent in temperature characteristics. That is, an oxynitride phosphor having good temperature characteristics capable of suppressing color tone fluctuation even when operated at high temperature or continuously lit for a long time at high temperature. Can be provided.

  In the formula (I), M is at least one element selected from the group consisting of rare earth elements other than Eu and Sm (hereinafter may be referred to as “element M”). The oxynitride phosphor having the composition represented by the above formula (I) contains Eu as an activating element and at least one element M selected from the group consisting of rare earth elements excluding Eu and Sm, and a phosphor The element M is partially taken into the crystal structure of the phosphor while maintaining the balance between the negative charges of oxygen and nitrogen and the positive charges of Ba, Eu, element M and Si in the composition of Although the production method will be described later, a part of the compound of the element M contained in the raw material of the oxynitride phosphor of this embodiment functions as a flux when firing the mixture of the raw materials, and a part of the element M is fluorescent It is considered to be incorporated into the crystal structure of the body. Therefore, the oxynitride phosphor of the present embodiment is a phosphor particle having few defects and high crystallinity, and is efficiently excited by light from a light emitting element having a light emission peak wavelength in the near ultraviolet to blue region, and is bluish green It emits light and has higher emission intensity than in the case of not containing the element M.

  In the above formula (I), the element M is more preferably at least one member selected from the group consisting of Y, La, Ce, Pr, Nd, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. It is a rare earth element. In the formula (I), the element M is more preferably at least one element selected from the group consisting of Y, La, Ce, Pr, Nd, Tb and Dy. By containing the element M, the oxynitride phosphor having the composition represented by the formula (I) is efficiently excited by the light from the light emitting element having a light emission peak wavelength in the near ultraviolet to blue region, and is high An oxynitride phosphor having emission intensity can be provided.

  In the formula (I), the element M is particularly preferably at least one element selected from the group consisting of La, Ce, Pr and Nd. The oxynitride phosphor including the composition represented by the formula (I) contains Eu and at least one element M selected from the group consisting of La, Ce, Pr and Nd. Among them, the element M having an ion radius closer to the ion radius of Ba ion is more likely to be included in the oxynitride phosphor by replacing Ba and Eu, and becomes phosphor particles with few defects and high crystallinity. The light is efficiently excited by the light from the light emitting element having a light emission peak wavelength in the near ultraviolet to blue region, and a bluish green light having a high light emission intensity is emitted. In the above formula (I), the element M is at least one element selected from the group consisting of La, Ce, Pr and Nd, even when operated at high temperature, It is possible to provide an oxynitride phosphor capable of suppressing color tone fluctuation even when lighted continuously for a long time under high temperature.

  In the formula (I), the variable a represents the activation amount of Eu of the oxynitride phosphor including the composition represented by the formula (I) in molar ratio. In the present specification, “molar ratio” refers to the molar ratio of each element in 1 mol of the chemical composition represented by the formula (I). In the formula (I), the variable a is a number that satisfies 0 <a ≦ 1.0. In the formula (I), when the variable a is 0, Eu does not exist as an activator in the oxynitride, and the oxynitride does not emit light even when irradiated with excitation light. In the formula (I), when the variable a is 1.0, it means that all Ba sites are replaced with Eu in the crystal structure, but even if all Ba sites are replaced with Eu in this way, excitation light An oxynitride phosphor that emits light upon irradiation is obtained. In the formula (I), the variable a is preferably 0.001 ≦ a <1.0, more preferably 0.001 ≦ a ≦ 0.5, still more preferably 0.001 ≦ a ≦ 0.3. More preferably, it is a number satisfying 0.001 ≦ a ≦ 0.1. When the molar ratio of the activating element, Eu, is increased, the emission intensity increases up to a certain range, but the increase in Eu may cause concentration quenching, which may lower the emission intensity.

  In the formula (I), the variable b is at least one element selected from the group consisting of rare earth elements excluding Eu and Sm of the oxynitride phosphor containing the composition represented by the formula (I) It is a molar ratio of M. In the formula (I), the variable b is a number satisfying 0 <b ≦ 0.07, and when the variable b is 0, the element M is not present in the oxynitride phosphor, and the oxynitridation is carried out It is not possible to improve the emission intensity of the substance phosphors to a high degree. In the formula (I), when the variable b exceeds 0.07, that is, when the element M to be incorporated into the crystal structure is increased, the energy that should contribute to the light emission of the activator Eu is absorbed by the element M It is inferred that the light emission characteristics are degraded. In the formula (I), the variable b preferably satisfies 0.001 ≦ b ≦ 0.06, more preferably 0.001 ≦ b ≦ 0.05, and still more preferably 0.001 ≦ b ≦ 0.045. It is a number.

  In the oxynitride phosphor containing the composition represented by the formula (I), the element M is at least one element selected from the group consisting of La, Ce, Pr and Nd in the formula (I) In the formula (I), it is preferable that the variable a and the variable b be numbers satisfying 0.001 ≦ a <0.1 and 0.001 ≦ b ≦ 0.05, respectively. The oxynitride phosphor containing the composition represented by the formula (I) contains at least one element M selected from the group consisting of La, Ce, Pr and Nd together with Eu, and the oxynitride phosphor In the composition contained in, the variable a representing the molar ratio of Eu is a number satisfying 0.001 ≦ a <0.1, and the variable b representing the molar ratio of the element M is 0.001 ≦ b ≦ 0. By being a number satisfying 05, the oxynitride phosphor can improve the emission intensity highly and improve the temperature characteristics. The oxynitride phosphor containing at least one element M selected from the group consisting of La, Ce, Pr and Nd in the composition represented by the above formula (I) is a case where it is operated under high temperature. Also, it is possible to provide an oxynitride phosphor capable of suppressing color tone fluctuation even when the lamp is continuously lit for a long time under high temperature.

In the formula (I), the variable c is a value which is variable with respect to the molar ratio of oxygen (O) when the molar ratio of Si is 2 in the composition represented by the formula (I). Show. Furthermore, in the formula (I), the variable d is a numerical value which fluctuates with respect to 2 which is the molar ratio of nitrogen (N) when the molar ratio of Si is 2 in the composition represented by the above-mentioned formula (I) Indicates
If the variable c is a number satisfying −0.3 <c <0.3 and the variable d is a number satisfying −0.3 <d <0.3, negative charges of oxygen and nitrogen, Ba, and The balance with the positive charge of Eu, element M and Si can be easily adjusted, and the crystal structure of the oxynitride represented by BaSi ₂ O ₂ N ₂ , which is the basic composition of the present phosphor, can be maintained and is stable. The crystalline structure can contribute to the improvement of the light emission characteristics. On the other hand, BaSi ₂ O ₂ N ₂ indicates that the variable c is −0.3 or less or the variable d is −0.3 or less, or the variable c is 0.3 or more or the variable d is 0.3 or more. The tetrahedral structure represented by SiON ₃ constituting the crystal structure to be changed may change, and the crystal structure may partly change to reduce the light emission intensity.

  The oxynitride phosphor containing the composition represented by the formula (I) preferably has an average particle diameter in the range of 3 μm to 50 μm, more preferably in the range of 5 μm to 40 μm, and still more preferably 6 μm. More preferably, it is in the range of 7 μm to 20 μm. When the average particle diameter of the oxynitride phosphor having the composition represented by the formula (I) is in the range of 3 μm to 50 μm, the light from the light emitting element having the emission peak wavelength in the near ultraviolet to blue region is well absorbed And have high light emission intensity. The average particle diameter of the oxynitride phosphor containing the composition represented by the above-mentioned formula (I) is a particle whose volume cumulative frequency from the small diameter side reaches 50% in the volume-based particle size distribution by laser diffraction scattering particle size distribution measurement The diameter (median diameter) is said. The laser diffraction / scattering particle size distribution measurement method can be measured, for example, using a laser diffraction particle size distribution measuring apparatus (manufactured by MALVERN, product name: MASTER SIZER (master sizer) 3000).

Light Emitting Device An example of a light emitting device using an oxynitride phosphor containing the composition represented by the formula (I) according to the second embodiment of the present invention will be described based on the drawings. FIG. 1 is a schematic cross-sectional view showing a light emitting device 100 according to a second embodiment of the present invention.

  The light emitting device 100 includes the molded body 40, the light emitting element 10, and the fluorescent member 50. The molded body 40 is formed by integrally molding the first lead 20 and the second lead 30 and the resin portion 42 containing a thermoplastic resin or a thermosetting resin. The molded body 40 forms a recess having a bottom surface and a side surface, and the light emitting element 10 is disposed on the bottom surface of the recess. The light emitting element 10 has a pair of positive and negative electrodes, and the pair of positive and negative electrodes are electrically connected to the first lead 20 and the second lead 30 through the wires 60 respectively. The light emitting element 10 is covered by a fluorescent member 50. The fluorescent member 50 includes, for example, a phosphor 70 for converting the wavelength of light from the light emitting element 10 and a resin. The phosphor 70 further includes a first phosphor 71 and a second phosphor 72. The first lead 20 and the second lead 30 connected to the pair of positive and negative electrodes of the light emitting element 10 are directed to the outside of the molded body 40 constituting the light emitting device 100 to form the first lead 20 and the second lead. A part of the lead 30 is exposed. Power can be supplied from the outside via the first lead 20 and the second lead 30 to cause the light emitting device 100 to emit light.

  The light emitting element 10 is used as an excitation light source, and preferably has a light emission peak in a wavelength range of 380 nm to 485 nm. The emission peak wavelength of the light emitting element 10 is more preferably in the range of 390 nm to 480 nm, and still more preferably in the range of 420 nm to 470 nm. The half width of the emission spectrum of the light emitting element 10 can be, for example, 30 nm or less.

Light emitting element 10, for example, it is preferable to use a semiconductor light emitting device using nitride semiconductor _{(In X Al Y Ga 1-} X-Y N, 0 ≦ X, 0 ≦ Y, X + Y ≦ 1). By using a semiconductor light emitting element as a light source, it is possible to obtain a stable light emitting device with high efficiency, high output linearity with respect to input, and resistance to mechanical shock.

The light emitting device 100 includes an oxynitride phosphor including the composition represented by the formula (I) according to at least the first embodiment, and an excitation light source having an emission peak wavelength in the range of 380 nm to 485 nm. Is preferred.
The first phosphor 71 preferably includes an oxynitride phosphor including the composition represented by the formula (I) according to the first embodiment of the present invention. When the first phosphor 71 is an oxynitride phosphor including the composition represented by the formula (I), it is efficiently excited by light from an excitation light source having a light emission peak wavelength within the range of 380 nm to 485 nm. It is possible to constitute the light emitting device 100 emitting mixed color light of the light from the light emitting element 10 and the fluorescence from the fluorescent substance 70 including the first fluorescent substance 71 by the oxynitride fluorescent substance having high luminous intensity. .

  The first phosphor 71 includes an oxynitride phosphor including the composition represented by the formula (I) according to the first embodiment, and is contained in, for example, the fluorescent member 50 covering the light emitting element 10. In the light emitting device 100 in which the light emitting element 10 is covered with the fluorescent member 50 containing the first fluorescent substance 71, an oxynitride including a part of the light emitted from the light emitting element 10 having the composition represented by the formula (I) It is absorbed by the phosphor and emitted as blue-green light. By using the light emitting element 10 that emits light having a light emission peak wavelength in the range of 380 nm to 485 nm, a light emitting device with high light emission efficiency can be provided.

  The fluorescent member 50 preferably includes a second phosphor 72 having a light emission peak wavelength different from that of the first phosphor 71. For example, the light emitting device 100 appropriately includes the light emitting element 10 that emits light having a light emission peak wavelength in the range of 380 nm to 485 nm, and the first phosphor 71 and the second phosphor 72 excited by this light. Thus, a wide color reproduction range and high color rendering can be obtained.

What is necessary is to absorb the light from the light emitting element 10 and perform wavelength conversion to light of a wavelength different from that of the first phosphor 71 as the second phosphor 72. For example, (Ca, Sr, Ba) ₂ SiO ₄ : Eu, (Ca, Sr, Ba) ₈ MgSi ₄ O ₁₆ (F, Cl, Br) ₂ : Eu, Si _6-z Al _z O _z N _{8-z : Eu (0 <z ≦ 4.2} ), (Sr, Ba, Ca) Ga 2 S 4: Eu, (Lu, Y, Gd, Lu) 3 (Ga, Al) 5 O 12: Ce, (La, Y, Gd) ₃ Si ₆ N ₁₁ : Ce, Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce, CaSc ₄ O ₄ : Ce, K ₂ (Si, Ge, Ti) F ₆ : Mn, (Ca, Sr, Ba) ) ₂ Si ₅ N ₈ : Eu, CaAlSiN ₃ : Eu, (Ca, Sr) AlSiN ₃ : Eu, (Sr, Ca) LiAl ₃ N ₄ : Eu, (Ca, Sr) ₂ Mg ₂ Li ₂ Si ₂ N ₆ : Eu, 3.5MgO.0.5MgF ₂ .GeO ₂ : Mn Sr ₃ SiO ₅ : Eu, (Ca, Sr, Li, Y) _x (Si, Al) ₁₂ (O, N) ₁₆ : Eu (0 ≦ x ≦ 3), etc. may be mentioned. In the present specification, in a formula representing the composition of a phosphor, a plurality of elements described by being separated by commas (,) contain at least one element of the plurality of elements in the composition. means. Further, in the present specification, in the formula representing the composition of the phosphor, the host crystal is shown before the colon (:), and the activating element is shown after the colon (:).

  The fluorescent substance 70 containing the 1st fluorescent substance 71 and the 2nd fluorescent substance 72 comprises the fluorescence member 50 which coat | covers a light emitting element with a sealing material. As a sealing material which comprises the fluorescence member 50, a silicone resin and an epoxy resin can be mentioned.

  The light emitting device according to the second embodiment of the present invention has high emission intensity by including the oxynitride phosphor according to the first embodiment of the present invention, and is operated at high temperature. Even in the case where the light emitting device is continuously lit for a long time under high temperature, however, it is possible to suppress color tone fluctuation, and it is possible to provide a light emitting device excellent in color rendering property and color reproducibility. .

Method for Producing Oxynitride Phosphor The method for producing an oxynitride phosphor according to the third embodiment of the present invention is a method for producing an oxynitride phosphor containing a composition represented by the following formula (I) A compound containing Ba, a compound containing Eu, a compound containing at least one element M selected from the group consisting of Eu and rare earth elements excluding Sm, a compound containing Si, and any of the compounds mentioned above contains oxygen Preparing a mixture containing the compound, wherein any one of the compounds is a compound containing nitrogen, if necessary, and calcining the mixture.
_{(Ba 1-a Eu a)} 1-b M b Si 2 O 2 + c N 2 + d (I)
In the formula (I), M is at least one element selected from the group consisting of rare earth elements other than Eu and Sm, and a, b, c and d each satisfy 0 <a ≦ 1.0, 0 <b ≦ 0.07, −0.3 <c <0.3, −0.3 <d <0.3.

  In the formula (I), the element M is at least one element selected from the group consisting of rare earth elements other than Eu and Sm, preferably Y, La, Ce, Pr, Nd, Gd, Tb, Dy. At least one rare earth element selected from the group consisting of Ho, Er, Tm, Yb and Lu, more preferably at least one selected from the group consisting of Y, La, Ce, Pr, Nd, Tb and Dy It is one kind of element, more preferably at least one kind of element selected from the group consisting of La, Ce, Pr and Nd.

Mixture The method for producing an oxynitride phosphor according to the third embodiment of the present invention comprises at least one selected from the group consisting of a compound containing Ba, a compound containing Eu, and a rare earth element other than Eu and Sm as raw materials. A compound containing the element M of a species and a compound containing Si are included. The compound of any of the above compounds is a compound containing oxygen. The compound containing oxygen is preferably a carbonate or an oxide. Further, at least one selected from the group consisting of a compound containing Ba, a compound containing Eu, a compound containing at least one element M selected from the group consisting of Eu and rare earth elements excluding Sm, and a compound containing Si The compound of the type is a compound in which any of the compounds mentioned above contains nitrogen, if necessary, and preferably, any of the compounds is a nitride. The compound containing nitrogen includes, for example, a nitride containing Ba, a nitride containing Si, and a nitride containing Eu.

  In the method for producing an oxynitride phosphor according to the third embodiment of the present invention, since the oxynitride phosphor has oxygen and nitrogen in a constant molar ratio, Ba, Eu, element M and Si are used. In addition, it is necessary to include a compound containing oxygen and a compound containing nitrogen in a fixed molar ratio. The compound containing oxygen may be a compound containing Ba, a compound containing Eu, or a compound containing an element M, as described later. The compound containing nitrogen may be a compound containing Si as described later.

  In the method for producing an oxynitride phosphor according to the third embodiment of the present invention, the molar ratio of the element M contained in the mixture containing the raw material of the oxynitride phosphor is the molar ratio of Si contained in the mixture Is preferably greater than 0 and less than 0.15. In the method for producing an oxynitride phosphor, the molar ratio of the element M contained in the mixture is more preferably 0.001 or more and 0.13 or less, where the molar ratio of Si contained in the mixture is 2. More preferably, it is 0.001 or more and 0.12 or less. The molar ratio of the element M contained in the mixture is, if the molar ratio of Si contained in the mixture is 2, if it is more than 0 and less than 0.15, the obtained formula (I) is obtained An oxynitride phosphor containing a composition can be obtained, and in the composition represented by the formula (I), the element M in a molar ratio satisfying a variable b of 0 <b ≦ 0.07 is added to the oxynitride phosphor. It can be contained. The molar ratio of each element in the mixture containing the raw material of the oxynitride phosphor may be expressed as a charged composition or a charged molar ratio.

As the compound containing Ba, a nitride containing Ba, an oxide, a carbonate, a hydride or the like can be used. Moreover, barium may use a single substance of barium metal, and examples of the compound containing Ba include Ba ₃ N ₂ , BaO, BaCO ₃ , BaH ₂ and BaNH ₂ .

As a compound containing Si, an oxide containing Si and / or a nitride containing Si can be used. Examples of the compound containing Si include SiO ₂ and Si ₃ N ₄ . As silicon, a single substance of silicon metal may be used, or an alloy in which part of Si is replaced by at least one element selected from Ge and Sn of Group 14 may be used.

The compound containing the element M is an oxide, hydroxide, nitride, oxynitride, fluoride or chloride containing at least one rare earth element selected from the group consisting of rare earth elements other than Eu and Sm. Etc. can be used. The compound containing the element M is preferably an oxide which is easy to obtain and a stable compound and thus easy to handle. The compound containing the element M is Y ₂ O ₃ , La ₂ O ₃ , CeO ₂ , CeO ₂ , Pr ₆ O ₁₁ , Nd ₂ O ₃ , Gd ₂ O ₃ , Tb ₄ O ₇ , Dy ₂ O ₃ , Ho ₂ O ₃ , Er ₂ O ₃ , Tm ₂ O ₃ , Yb ₂ O ₃ , and Lu ₂ O ₃ .

As the compound containing Eu, an oxide containing Eu, a hydroxide, a nitride, an oxynitride, a fluoride, a hydride, or a chloride can be used. Specific examples of the compound containing Eu include Eu ₂ O ₃ , EuN, and EuF ₃ .

  The mixture is a compound containing Ba, a compound containing Eu, a compound containing at least one element M selected from the group consisting of Eu and rare earth elements other than Sm, and a compound containing Si weigh each compound, Be prepared.

  The measured raw materials may be prepared by wet or dry mixing using a mixer. A mixer can also be ground using a pulverizer such as a vibration mill, a roll mill, a jet mill or the like in addition to a ball mill generally used industrially to increase the specific surface area. Also, in order to set the specific surface area of the powder within a certain range, classification is carried out using a settling tank, a wet separator such as a hydrocyclone, a centrifugal separator, a dry classifier such as a cyclone, an air separator, etc. You can also

The mixture is placed on a crucible or a boat made of carbon such as graphite, boron nitride (BN), alumina (Al ₂ O ₃ ), tungsten (W), molybdenum (Mo), etc., heat-treated in the furnace and fired. You can get things.

Firing Step In the method for producing an oxynitride phosphor according to the third embodiment of the present invention, the mixture is preferably fired in a reducing atmosphere. The reducing atmosphere preferably contains nitrogen. The reducing atmosphere contains nitrogen, and may contain at least one or more of hydrogen, argon, carbon dioxide, carbon monoxide or ammonia as another gas. The reducing atmosphere is preferably an atmosphere containing hydrogen as well as nitrogen, and preferably contains 1% by volume or more, more preferably 5% by volume or more, and still more preferably 10% by volume or more in the reducing atmosphere.

  The manufacturing method according to the third embodiment of the present invention can obtain an oxynitride phosphor having a desired composition by firing the mixture in a reducing atmosphere. When the reducing atmosphere is an atmosphere containing nitrogen gas and hydrogen gas, an oxynitride phosphor having higher emission intensity can be obtained. In the oxynitride phosphor according to the present invention, the activating element is Eu, and by firing the mixture in a reducing atmosphere, the proportion of divalent Eu contributing to light emission increases in the oxynitride phosphor. It is due to. Divalent Eu is likely to be oxidized to be trivalent Eu, but it is obtained because calcination of it in a reducing atmosphere with high reducing power including hydrogen and nitrogen reduces trivalent Eu to divalent Eu. The proportion of divalent Eu in the oxynitride phosphor is increased, and an oxynitride phosphor having high emission intensity is obtained.

  The firing temperature for obtaining a fired product is preferably in the range of 1300 ° C. or more and 1600 ° C. or less, more preferably in the range of 1400 ° C. or more and 1600 ° C. or less. If the firing temperature is in the range of 1300 ° C. or more and 1600 ° C. or less, an oxynitride phosphor having a target composition, a stable crystal structure, and sufficient light emission intensity can be obtained. Firing is performed by firing the first stage at a temperature in the range of 800 ° C. to 1000 ° C., and gradually heating to perform the second stage firing at a temperature in the range of 1100 ° C. to 1300 ° C. You may perform the multistep baking which arrives. When the first firing temperature is in the range of 800 ° C. or more and 1000 ° C. or less, a fired product having a target composition can be easily obtained. When the second baking temperature is in the range of 1100 ° C. or more and 1300 ° C. or less, the decomposition of the obtained oxynitride phosphor is suppressed, and the oxynitride fluorescent light having a stable crystal structure and sufficient luminous intensity It is because it is easy to get a body.

  Firing can use a horizontal tubular furnace or a box atmosphere furnace. The pressure at the time of firing may be a gauge pressure, preferably in an atmosphere in the range of 0.1 MPa to 200 MPa. In the oxynitride phosphor obtained by firing, the crystal structure is more easily decomposed as the firing temperature becomes higher, but the decomposition of the crystal structure is suppressed by using the pressure atmosphere, and the decrease in light emission intensity is suppressed. Can. The pressure of the firing atmosphere may be, for example, atmospheric pressure (standard pressure about 0.1 MPa), more preferably in the range of 0.1 MPa or more and 100 MPa or less, and further preferably 1 in view of ease of production. .0 MPa or less.

  The firing time can be appropriately selected depending on the firing temperature or the pressure of the atmosphere at the time of firing, and is preferably 0.5 hours or more and 20 hours or less. The firing time is preferably 0.5 hours or more and 20 hours or less. When the baking time is 0.5 hours or more and 20 hours or less, the decomposition of the obtained oxynitride phosphor is suppressed, and an oxynitride phosphor having a stable crystal structure and a sufficient emission intensity can be obtained. . In addition, when the firing time is 0.5 hours or more and 20 hours or less, the production cost can be reduced, and the production time can be relatively shortened. The heat treatment time is more preferably 1 hour or more and 15 hours or less, and still more preferably 1.5 hours or more and 12 hours or less.

Post-Treatment after Firing In the manufacturing method according to the third embodiment of the present invention, the fired product obtained after firing is pulverized and mixed using a ball mill, a vibration mill, a hammer mill, a mortar, a pestle, etc. Processing may be performed. In the post-treatment, in addition to grinding and mixing, classification may be performed by sieving or settling to further adjust the particle size. Classification can be performed by a method usually used in industry, such as sedimentation classification, mechanical classification, hydraulic classification, wet classification such as centrifugal classification, and sieving classification. In addition to the grinding, mixing, and classification, post-treatment may be, for example, acid washing after classification. The acid cleaning treatment removes impurities attached to the surface of the fired product. It is preferable to use a hydrochloric acid aqueous solution for the acid washing treatment because it is easy to obtain and inexpensive. The concentration of hydrochloric acid contained in the aqueous hydrochloric acid solution is preferably a concentration that removes impurities on the surface of the calcined product and does not affect the crystal structure of the calcined product.

  By the manufacturing method according to the third embodiment of the present invention, it is possible to obtain an oxynitride phosphor including the composition represented by the formula (I). The obtained oxynitride phosphor having the composition represented by the above-mentioned formula (I) has high emission intensity and is excellent in temperature characteristics, and even when operated under high temperature, also under high temperature Even when the lamp is continuously turned on for a long time, the color tone fluctuation can be suppressed.

  Hereinafter, the present invention will be specifically described by way of examples. The present invention is not limited to these examples.

Example 1
Preparation step of mixture Barium carbonate (BaCO ₃ ), silicon oxide (SiO ₂ ), silicon nitride (Si ₃ N ₄ ), europium oxide (Eu ₂ O ₃ ), and yttrium oxide (Y ₂ O ₃ ), which are raw materials, The feed composition is weighed so that the molar ratio of Ba: Si: Eu: Y is 0.98: 2: 0.02: 0.074, and the weighed raw materials are mixed by a dry ball mill to obtain a mixture. The In Table 1, the preparation molar ratio of each element which comprises the oxynitride fluorescent substance which concerns on Example 1 is shown. Here, the preparation composition or the preparation molar ratio indicates the molar ratio of each element of Ba, Eu, element M and Si in the mixture containing the raw material of the oxynitride phosphor.
Firing Step The obtained mixture is formed into a block on a boat of boron nitride, and in a reducing atmosphere containing nitrogen and hydrogen gas (4% by volume of hydrogen gas, 96% by volume of nitrogen gas), atmospheric pressure (standard pressure about 0. Baking was performed at 1450 ° C. for 10 hours under 1 MPa) to obtain a baked product. The obtained baked product is crushed in a mortar, then coarse particles exceeding the mesh size are removed by a sieve having a mesh size of 50 μm, and the crushed baked product is acid-washed with a hydrochloric acid aqueous solution and then washed with water The individual particles were separated and dried to obtain the oxynitride phosphor of Example 1.

Example 2 to Example 13
Raw materials barium carbonate (BaCO ₃ ), silicon oxide (SiO ₂ ), silicon nitride (Si ₃ N ₄ ), europium oxide (Eu ₂ O ₃ ), and oxides containing each rare earth element were weighed and weighed. The raw materials were mixed in a dry ball mill to obtain a mixture. Specifically, oxides containing a rare earth element are, for example, lanthanum oxide (La ₂ O ₃ ), cerium oxide (CeO ₂ ), praseodymium oxide (Pr ₆ O ₁₁ ), neodymium oxide (Nd ₂ O ₃ ), gadolinium oxide ( Gd ₂ O ₃ ), terbium oxide (Tb ₄ O ₇ ), dysprosium oxide (Dy ₂ O ₃ ), holmium oxide (Ho ₂ O ₃ ), erbium oxide (Er ₂ O ₃ ), thulium oxide (Tm ₂ O ₃ ) Ytterbium oxide (Yb ₂ O ₃ ) or lutetium oxide (Lu ₂ O ₃ ) was used. An oxynitride phosphor according to Examples 2 to 13 was obtained in the same manner as Example 1 except that each of these mixtures was used. Table 1 shows the preparation molar ratio of each element of Ba, Eu, element M and Si in the mixture containing the raw material of the oxynitride phosphor according to Examples 2 to 13.

Comparative Example 1
The raw materials barium carbonate (BaCO ₃ ), silicon oxide (SiO ₂ ), silicon nitride (Si ₃ N ₄ ), and europium oxide (Eu ₂ O ₃ ) are weighed, and the weighed raw materials are mixed in a dry ball mill, A mixture was obtained. An oxynitride phosphor of Comparative Example 1 was obtained in the same manner as Example 1 except that this mixture was used. Table 1 shows the feed molar ratio of each element of Ba, Eu, and Si in the mixture containing the raw material of the oxynitride phosphor according to Comparative Example 1.

Comparative example 2
Raw materials barium carbonate (BaCO ₃ ), silicon oxide (SiO ₂ ), silicon nitride (Si ₃ N ₄ ), europium oxide (Eu ₂ O ₃ ), and samarium oxide (Sm ₂ O ₃ ) were weighed and weighed. The raw materials were mixed in a dry ball mill to obtain a mixture. An oxynitride phosphor according to Comparative Example 2 was obtained in the same manner as Example 1, except that this mixture was used. Table 1 shows the preparation molar ratios of Ba, Eu, element M and Si in the mixture containing the raw material of the oxynitride phosphor according to Comparative Example 2.

Example 14 to Example 17
Raw materials barium carbonate (BaCO ₃ ), silicon oxide (SiO ₂ ), silicon nitride (Si ₃ N ₄ ), europium oxide (Eu ₂ O ₃ ), and oxides containing each rare earth element were weighed and weighed. The raw materials were mixed in a dry ball mill to obtain a mixture. Specifically, the oxide containing each rare earth element used lanthanum oxide (La ₂ O ₃ ), cerium oxide (CeO ₂ ), praseodymium oxide (Pr ₆ O ₁₁ ), neodymium oxide (Nd ₂ O ₃ ) . The oxynitride phosphors according to Examples 14 to 17 were obtained in the same manner as in Example 1 except that each of these mixtures was used. Table 1 shows the preparation molar ratio of each element of Ba, Eu, element M and Si in the mixture containing the raw material of the oxynitride phosphor according to Examples 14 to 17.

Comparative Examples 3 and 4
Raw materials barium carbonate (BaCO ₃ ), silicon oxide (SiO ₂ ), silicon nitride (Si ₃ N ₄ ), europium oxide (Eu ₂ O ₃ ), and lanthanum oxide (La ₂ O ₃ ) were weighed and weighed. The raw materials were mixed in a dry ball mill to obtain a mixture. An oxynitride phosphor according to Comparative Examples 3 and 4 was obtained in the same manner as Example 1 except that each of these mixtures was used. In the oxynitride phosphors according to Comparative Examples 3 and 4, when the molar ratio of Si contained in the mixture is 2 in the feed composition, the molar ratio of La, which is the rare earth element contained in the mixture, is 0. Obtained using a mixture of 15 or more. Table 1 shows the preparation molar ratio of each element of Ba, Eu, element M and Si in the mixture containing the raw material of the oxynitride phosphor according to Comparative Examples 3 and 4.

Compositional analysis The obtained oxynitride phosphors according to Examples 1 to 17 and Comparative Examples 1 to 4 were subjected to ICP emission analysis using an inductively coupled plasma emission analyzer (manufactured by Perkin Elmer (Perkin Elmer)). The molar ratio of each element of Ba, Eu, each rare earth element M, Si, O and N was measured. The results are shown in Table 2. The molar ratio of each element in each of the oxynitride phosphors analyzed is the molar ratio calculated with the molar ratio of Si being 2.

Average Particle Size With respect to the oxynitride phosphors of Examples 1 to 17 and Comparative Examples 1 to 4 obtained, the average particle size was measured by a laser diffraction type particle size distribution measuring apparatus (manufactured by MALVERN, product name: MASTER SIZER 3000). Was measured. In the present specification, the average particle diameter of the oxynitride phosphor is a particle diameter (D50: median diameter) at which the volume cumulative frequency from the small diameter side reaches 50%. The results are shown in Table 2.

Luminescent Properties: Measurement of Emission Spectrum The luminescent properties of the obtained oxynitride phosphors of Examples 1 to 17 and Comparative Examples 1 to 4 were measured. The emission characteristics of the powder of the oxynitride phosphor were measured by setting a wavelength of excitation light to 450 nm with a spectrofluorimeter (product name: QE-2000, manufactured by Otsuka Electronics Co., Ltd.). The oxynitride phosphors of each example and comparative example emitted bluish green by the light from the excitation light source having an emission peak wavelength of 450 nm. The oxynitride phosphors of Examples 1 to 17 and Comparative Examples 1 and 3 had an emission peak wavelength of 494 nm, and the oxynitride phosphors of Comparative Examples 2 and 4 had an emission peak wavelength of 493 nm.

Relative luminescence energy (%)
From the emission spectra measured for the oxynitride phosphors according to Examples 1 to 17 and Comparative Examples 1 to 4, assuming that the emission energy value of the oxynitride phosphor of Comparative Example 1 is 100%, each Example and Comparative Example Relative luminescence energy values were determined. Note that the emission energy value is an integral value of a spectrum in a wavelength range of 470 nm or more and 550 nm or less in the emission spectrum. The results are shown in Table 2. FIG. 2 is a view showing the emission spectra of the oxynitride phosphors according to Examples 2 to 5 and Comparative Example 1. FIG. 3 is a view showing emission spectra of the oxynitride phosphors according to Examples 2 and 14 and Comparative Examples 1, 3 and 4.

SEM photograph A SEM photograph of the oxynitride phosphor according to Example 2 and Comparative Example 1 was obtained using a scanning electron microscope (SEM). FIG. 4 is a SEM photograph of the oxynitride phosphor of Example 2, and FIG. 5 is a SEM photograph of the oxynitride phosphor of Comparative Example 1.

Consideration of Oxynitride Phosphor As shown in Table 2, the oxynitride fluorescence according to Examples 1 to 17 containing Eu and at least one rare earth element selected from the group consisting of rare earth elements excluding Eu and Sm. The body was efficiently excited by the light from the light emitting element having a light emission peak wavelength at 450 nm, and the relative light emission energy was increased as compared with Comparative Example 1 containing no rare earth element other than Eu. The oxynitride phosphor according to Examples 1 to 17 has a composition represented by the above-mentioned formula (I), and is at least one selected from the group consisting of an activating element Eu and a rare earth element other than Eu and Sm. Contains the element M of the species. It was surmised that the compound M of the element M functions as a flux in the firing step, thereby obtaining an oxynitride phosphor with few defects and high crystallinity.

  As shown in Table 2, in the oxynitride phosphor according to Comparative Example 2, the relative emission energy was reduced as compared to the oxynitride phosphor according to Comparative Example 1 including Sm and not including a rare earth element other than Eu. Although the mechanism by which the relative light emission energy of the oxynitride phosphor containing Sm according to Comparative Example 2 decreases is not clear, the element is apt to easily become a positive charge with the same bivalent charge as that for Eu and a trivalent positive charge. Compared to M, it is difficult to balance the negative charge of oxygen or nitrogen and the positive charge of Ba, Eu, Sm and Si in the composition of the phosphor, and it is difficult to be incorporated in the composition of the phosphor. Therefore, it is presumed that a phosphor having high crystallinity can not be obtained because the compound of Sm has a weak function as a flux in the firing step. As shown in Table 1, in the oxynitride phosphors according to Comparative Examples 3 and 4, since the preparation molar ratio of La which is a rare earth element contained in the mixture as the raw material was 0.15 or more, the obtained comparison In the oxynitride phosphors according to Examples 3 and 4, the variable b representing the molar ratio of the element M exceeded 0.07 in the composition represented by the formula (I). Therefore, the oxynitride phosphors according to Comparative Examples 3 and 4 are relative to each other because the energy which should contribute to the light emission of the activator Eu is absorbed by the element M because the element M incorporated into the crystal structure is too much. It was estimated that the light emission energy decreased.

  As shown in FIG. 2, the emission spectra of the oxynitride phosphors according to Examples 2 to 5 had a relative intensity higher than that of the oxynitride phosphor according to Comparative Example 1.

  As shown in FIG. 3, in the oxynitride phosphors according to Examples 2 and 14, the variable b representing the molar ratio of La, which is the element M, exceeds 0 in the composition represented by the formula (I). It was in the range of .07 or less, and the relative strength tended to be higher than that of Comparative Example 1. On the other hand, as shown in FIG. 3, in the oxynitride phosphors according to Comparative Examples 3 and 4, the variable b representing the molar ratio of the element M exceeds 0.07 in the composition represented by the formula (I). The energy to contribute to light emission was absorbed by La when the amount of La incorporated into the crystal structure was too large, and the relative intensity was lower than in Comparative Example 1.

  As shown in the SEM photograph of FIG. 4, the oxynitride phosphor according to Example 2 has a relatively smooth surface, and the particle diameter tends to be larger than that of the oxynitride phosphor according to Comparative Example 1. It was done. As shown in Table 2, except for Example 12, the oxynitride phosphors according to Examples 2 to 11 and Examples 13 to 17 have a larger average particle diameter than the oxynitride phosphor according to Comparative Example 1. became. The relatively smooth surface of the oxynitride phosphor in Example 2 is presumed to be due to the fact that phosphor particles with few defects and high crystallinity are obtained.

  On the other hand, as shown in the SEM photograph of FIG. 5, in the oxynitride phosphor according to Comparative Example 1, it was confirmed that fine pores were formed on the surface of the phosphor particles. Fine vacancies on the particle surface of the oxynitride phosphor according to Comparative Example 1 are formed by incorporating a large amount of unstable Ba into the crystal structure and removing the unstable Ba by post-treatment or the like. Is presumed to be a void.

Production of light emitting devices according to Examples 1 to 5 and Examples 14 to 17 and Comparative Examples 1 to 4 As shown in FIG. 1, an LED chip made of a nitride semiconductor having a light emission peak wavelength of 450 nm as a light emitting element 10 is formed. The light emitting element 10 was connected to the first lead 20 and the second lead 30 by wires 60, respectively. Oxynitriding according to Examples 1 to 5, 14 to 17 and Comparative Examples 1 to 4 so that the CIE chromaticity coordinates x of mixed light emitted from the light emitting device are around 0.128 and y is around 0.150 A substance fluorescent substance was added to a silicone resin as a first fluorescent substance 71, mixed and dispersed to obtain a composition for a fluorescent member. An appropriate amount of the composition for a phosphor member was injected into the recess of the molded body 40, and the resin in the composition for a fluorescent material was cured to form a fluorescent member 50. Thus, a light emitting device 100 was obtained.

Evaluation Luminescent Properties of Light Emitting Device The emission spectrum of each of the light emitting devices according to Examples 2 to 5 and Comparative Example 1 was measured using a spectrofluorimeter (Hitachi High-Technologies Corporation, product name: F-4500). The results are shown in FIG.

Reliability evaluation of light emitting device 1
Relative luminous flux (Po) after continuous lighting
The light emitting devices according to Examples 1 to 5 and Examples 14 to 17 and Comparative Examples 1 to 4 were continuously lit at 85 ° C. and a current of 150 mA for 1000 hours. The luminous flux of the light emitting device of Comparative Example 1 after continuous lighting for 1000 hours is measured by a total luminous flux measuring device using an integrating sphere, and the luminous flux of the light emitting device of Comparative Example 1 after this continuous lighting is 100% The relative luminous flux (%) of the light emitting device according to each of Examples 1 to 5 and Examples 14 to 17 and Comparative Examples 1 to 4 was calculated. The results are shown in Table 3.

Evaluation of reliability of light emitting devices 2
Fluctuation value and relative fluctuation rate (%) of difference Δy of CIE chromaticity coordinate y value before and after storage
The light emitting devices according to Examples 1 to 5 and Examples 14 to 17 and Comparative Examples 1 to 4 were continuously lit at 85 ° C. and a current of 150 mA for 1000 hours. Measure y1 value in CIE chromaticity coordinates before continuous lighting and y2 value in CIE chromaticity coordinates after continuous lighting for 1000 hours using a multi-channel spectroscope (Hamamatsu Photonics Co., Ltd., product name: PMA-12) The difference Δy between the y1 value and the y2 value was calculated as an absolute value. The results are shown in Table 3. Assuming that the difference Δy of the light emitting device of Comparative Example 1 before and after continuous lighting for 1000 hours is 100%, the relative fluctuation rate (%) of Δy of the light emitting device according to each of Examples 1 to 5, 14 to 17 and Comparative Examples 1 to 4 Expressed as). The results are shown in Table 3. FIG. 7 is a graph showing Δy fluctuation values after 1000 hours of continuous lighting from the beginning of the light emitting devices according to Examples 2 to 5 and Comparative Example 1. FIG. 8 is a graph showing Δy fluctuation values after continuous lighting for 1000 hours from the beginning of the light emitting devices according to Examples 2 and 14 and Comparative Examples 1 and 3.

Reliability Evaluation Temperature Characteristic Evaluation of Oxynitride Phosphors: Relative Emission Energy (%)
The oxynitride phosphors according to Examples 14 to 17 and Comparative Example 1 were excited by light from an excitation light source having an emission peak wavelength of 450 nm at each temperature in a temperature range of room temperature (25 ° C.) to 300 ° C. The emission spectrum of the oxynitride phosphor was measured by a spectrofluorimeter (manufactured by Hitachi High-Tech Science, product name: F-4500E). The relative emission spectra of the oxynitride phosphors of each Example and Comparative Example at each temperature, where the energy value of the emission spectrum measured at 25 ° C. of the oxynitride fluorescence according to each Example and Comparative Example is 100% The energy value (relative luminescence energy (%)) was determined. Note that the energy value is a relative integral value within the wavelength range of 470 nm or more and 550 nm or less in the emission spectrum obtained at each temperature. FIG. 9 is a graph showing relative emission energy (%) with respect to each temperature in the temperature range of room temperature (25 ° C.) to 300 ° C. for the oxynitride phosphors according to Examples 14 to 17 and Comparative Example 1.

Discussion of Light-Emitting Device As shown in Table 3, the acid according to Examples 1 to 5 and Examples 15 to 17 containing Eu and at least one rare earth element selected from the group consisting of Eu and rare earth elements excluding Sm. In the light emitting device using the nitride phosphor, the relative luminous flux became high. Although the relative luminous flux of the light emitting device according to Example 14 was slightly lower than that of the light emitting device according to Comparative Example 1, the fluctuation value of Δy after storage for 1000 hours was the light emission according to Examples 1 to 5 and Examples 15 to 17. It is smaller than the apparatus, and the Δy relative fluctuation rate is also the smallest as 58.9%, and the color tone fluctuation is suppressed even when continuous lighting is continued at a relatively high temperature of 85 ° C. for a long time.

On the other hand, as shown in Table 3, the light emitting device according to Comparative Example 2 contains Sm, and the crystallinity of the phosphor is low, so if it is kept continuously lit at a relatively high temperature of 85 ° C. for a long time, Comparative Example The fluctuation value of Δy becomes large beyond 1 and the relative fluctuation rate of Δy also becomes large, and the color tone fluctuates.
In the light emitting devices according to Comparative Examples 3 and 4, the oxynitride phosphor according to Comparative Examples 3 and 4 included in the light emitting device has a variable b representing a molar ratio of La in the composition represented by the formula (I). The relative luminous flux is lower than that of Comparative Example 1 because it is estimated that the light flux exceeds .07 and the energy contributing to the light emission is absorbed by La because too much La is incorporated into the crystal structure.

  As shown in FIG. 6, in the emission spectra of the light emitting devices according to Examples 2 to 5, the relative intensity of the wavelength range of 480 nm or more and 520 nm or less is a wavelength of 480 nm or more and 520 nm or less of the emission spectrum of the light emitting device according to Comparative Example 1 The light emission characteristics were improved because the relative intensity of the range was higher.

  As shown in FIG. 7, from Example 2 using the oxynitride phosphors of Examples 2 to 5 containing Eu and at least one rare earth element selected from the group consisting of La, Ce, Pr and Nd. The light emitting device of No. 5 has a variation of Δy as compared with the light emitting device of Comparative Example 1 in which the continuous lighting is continued under the same conditions even when the lighting is continued continuously for a long time of 1000 hours under a relatively high temperature of 85 ° C. It was confirmed that the value was small, color tone fluctuation was suppressed, and the temperature characteristics were good. It was speculated that this is because the film contains an oxynitride phosphor with few defects and high crystallinity.

  As shown in FIG. 8, in the light emitting devices according to Examples 2 and 14, in the composition represented by the formula (I), the variable b representing the molar ratio of La which is the element M exceeds 0 and is 0.07 or less If the lamp is continuously lit for a long time of 1000 hours at a relatively high temperature of 85 ° C., the fluctuation value of Δy becomes small, the color tone fluctuation is further suppressed, and the temperature characteristic is further improved. Was confirmed. On the other hand, in the light emitting devices according to Comparative Examples 3 and 4, when the variable b representing the molar ratio of La, which is the element M in the composition represented by the formula (I), becomes larger than 0.07, The color tone variation was not suppressed as much as the light emitting device.

Discussion of Oxynitride Phosphors As shown in FIG. 9, the oxynitride phosphors according to Examples 14 to 17 emit light at temperatures ranging from 25 ° C. to 300 ° C. at room temperature. Compared to the oxynitride phosphor according to Comparative Example 1, the decrease in relative emission energy is suppressed, and the color tone variation is suppressed. Since the oxynitride phosphors according to Examples 14 to 17 have few defects and high crystallinity, they can suppress color tone fluctuation even when operated at a high temperature of 300 ° C., and have temperature characteristics It was good.

  The oxynitride phosphor of the present invention can be combined with an excitation light source to constitute a light emitting device. The light emitting device of the present invention can be suitably used for a light source for illumination, an LED display, a backlight light source for liquid crystal, a traffic light, an illumination switch, various sensors, various indicators, and the like.

  10: light emitting element, 40: molded body, 42: resin part, 50: fluorescent member, 71: first phosphor, 72: second phosphor, 100: light emitting device.

Claims (10)

The oxynitride fluorescent substance containing the composition shown by following formula (I).
_{(Ba 1-a Eu a)} 1-b M b Si 2 O 2 + c N 2 + d (I)
In the formula (I), M is at least one element selected from the group consisting of rare earth elements other than Eu and Sm, and a, b, c and d each satisfy 0 <a ≦ 1.0, 0 <b ≦ 0.07, −0.3 <c <0.3, −0.3 <d <0.3.   In the formula (I), M is at least one element selected from the group consisting of Y, La, Ce, Pr, Nd, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, The oxynitride phosphor according to claim 1.   The oxynitride phosphor according to claim 1, wherein in the formula (I), M is at least one element selected from the group consisting of Y, La, Ce, Pr, Nd, Tb and Dy.   In the formula (I), M is at least one element selected from the group consisting of La, Ce, Pr and Nd, and a and b are each 0.001 ≦ a <0.1, 0. The oxynitride phosphor according to claim 1, wherein the number satisfies 001 ≦ b ≦ 0.05.   A light emitting device comprising the oxynitride phosphor according to any one of claims 1 to 4 and an excitation light source having an emission peak wavelength in the range of 380 nm to 485 nm. It is a manufacturing method of the oxynitride fluorescent substance as described in any one of Claim 1 to 4, Comprising:
A compound containing Ba, a compound containing Eu, a compound containing at least one element M selected from the group consisting of Eu and rare earth elements other than Sm, a compound containing Si, any of the aforementioned compounds contain oxygen A method of producing an oxynitride phosphor, which comprises preparing a mixture which is a compound, and, if necessary, any of the compounds is a compound containing nitrogen, and firing the mixture.   The oxynitride phosphor according to claim 6, wherein the molar ratio of the element M contained in the mixture is greater than 0 and less than 0.15 when the molar ratio of Si contained in the mixture is 2. Manufacturing method.   The manufacturing method of the oxynitride fluorescent substance of Claim 6 or 7 whose compound containing the said element M is an oxide.   The manufacturing method of the oxynitride fluorescent substance as described in any one of Claim 6 to 8 whose baking temperature exists in the range of 1300 degreeC or more and 1600 degrees C or less.   The method for producing an oxynitride phosphor according to any one of claims 6 to 9, wherein the firing is performed in a reducing atmosphere.