JP2007046004A - Method for producing nitride phosphor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new, industrially useful method for producing a phosphor which can be excited by an electron beam and a near ultraviolet to blue light and shows high luminance. <P>SOLUTION: The nitride phosphor comprises a host crystal composed of a compound represented by the formula: M<SP>1</SP><SB>a</SB>M<SP>2</SP><SB>b</SB>N<SB>c</SB>(wherein M<SP>1</SP>represents one or more elements selected from the group consisting of Mg, Ca, Sr, Ba and Zn; M<SP>2</SP>represents one or more elements selected from the group consisting of Al, Ga and In; and c=(2a/3)+b, 0≤a and 0<b) and one or more activating agents selected from the group consisting of the rare earth metals, Cr, Mn and Zn. An alkali metal or an alkali metal nitride, M<SP>1</SP>, M<SP>2</SP>, and an activating agent are charged into a reaction vessel and allowed to react in a nitrogen-containing gas, to produce the nitride phosphor. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a nitride phosphor.

  The phosphor is a visible light excitation light emitting element such as a white LED that combines a blue light emitting LED and a phosphor, a near ultraviolet light to blue violet light excitation light emitting that combines a near ultraviolet to blue violet light emitting LED and a phosphor. Ultraviolet-excited light-emitting elements such as elements, liquid crystal backlights and fluorescent lamps, vacuum ultraviolet-excited light-emitting elements such as plasma display panels and rare gas lamps, electron-beam-excited light-emitting elements such as cathode ray tubes and field emission displays (FEDs), and X-ray imaging It is used for various light emitting elements such as an X-ray excited light emitting element such as an apparatus and an electric field excited light emitting element such as an inorganic EL display.

  For example, as a near-ultraviolet to blue-violet light excitation light-emitting element formed by combining an LED that emits near-ultraviolet to blue-violet light and a phosphor, the light-emitting element emits light on a light-emitting surface of the light-emitting element that emits near-ultraviolet to blue-violet light. A phosphor that is excited by light and capable of wavelength conversion is arranged, and emits light of various colors (see, for example, Patent Document 1), or a light-emitting element that emits white light by visual observation (for example, a patent). Reference 2) has been proposed.

As phosphors used in the light emitting element, Y ₂ O ₃ : Eu is used as a red phosphor, Zn _0.6 Cd _0.4 S: Ag is used as a green phosphor, and (Sr, Ca) ₁₀ (PO ₄ ) is used as a blue phosphor. ₆ Cl ₂ : Eu, Y ₃ Al ₅ O ₁₂ : Ce as a yellow phosphor (see, for example, Patent Document 1), and Eu-activated α-sialon as a yellow phosphor, Eu _0.5 Si _9.75 Al _2.25 N _15.25 O _0.75 has been proposed.

JP-A-9-153645 JP 2002-363554 A

However, the brightness of any phosphor is still insufficient.
In addition, since white LEDs are used at temperatures close to 100 ° C. or higher, thermal and chemical stability are also required, but none of them satisfy this temperature characteristic sufficiently.
Most of the phosphors in practical use are oxides, but recently nitride phosphors have been developed. Nitride has a stronger covalent bond than the oxide of the same typical element, tends to have a narrow band gap, and is similar to sulfide. However, it is mechanically strong and chemically stable compared to sulfides. These characteristics indicate that the potential as a phosphor for white LED is high. Nitride is also excellent as a phosphor for FED because it has a narrower band gap and higher conductivity than an oxide.
However, one of the reasons why nitride phosphors have not yet been put to practical use is the difficulty in synthesis in which the conventional manufacturing method requires a high temperature of about 1800 ° C. and a high pressure of about 1 GPa.
An object of the present invention is to provide a novel and industrially useful production method of a phosphor that can be excited by an electron beam or near ultraviolet to blue light and exhibits high luminance.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be achieved by using an alkali metal as a flux, and have completed the present invention.

That is, the present invention provides [1] formula ^{_{M 1 a M 2 b N c}} ( however, M ¹ is, Mg, Ca, Sr, at least one element selected from the group consisting of Ba and Zn, M ² is , One or more elements selected from the group consisting of Al, Ga, and In, c = (2a / 3) + b, and 0 ≦ a and 0 <b) In addition, when producing a nitride phosphor containing at least one selected from the group consisting of rare earth metals, Cr, Mn and Zn as an activator, an alkali metal or an alkali metal and an alkali metal are contained in the reaction vessel. The present invention relates to a method for producing a nitride phosphor, which is charged with nitride, M ¹ , M ² , and an activator, and is produced in a gas containing nitrogen.
The present invention is also characterized in that [2] the molar ratio M _A / M _S of the total number of moles M _S of the nitride phosphor starting material and the number of moles M _A of the alkali metal is 2 to 5. 1] A method for producing a nitride phosphor according to the above
[3] The method for producing a nitride phosphor according to [1] or [2], wherein the alkali metal is Na or a mixture of Na and Li,
[4] The method for producing a nitride phosphor according to any one of [1] to [3], wherein the alkali metal nitride is Li ₃ N;
[5] The method for producing a nitride phosphor according to any one of [1] to [4], wherein the pressure of the gas containing nitrogen is 1 MPa to 20 MPa,
[6] The method for producing a nitride phosphor according to any one of [1] to [5], wherein the maximum temperature during production is 600 ° C. to 850 ° C.,
[7] The method for producing a nitride phosphor according to [6], wherein the cooling rate from the maximum temperature described in [6] to a predetermined temperature is 5 ° C./hour to 200 ° C./hour,
[8] The method for producing a nitride phosphor according to any one of [1] to [7], wherein M ² is Ga.
[9] is one or more elements M ¹ is selected from the group consisting of Ca, Sr and Ba, and wherein the M ² is Ga [1] to of any one of [8] Manufacturing method of nitride phosphor,
[10] M ¹ is one or more elements selected from the group consisting of Ca, Sr and Ba, M ² is Ga, and the inactive agent is Mn, Zn, Ce, Pr, Sm, Eu, Tb The method for producing a nitride phosphor according to any one of [1] to [8], wherein the nitride phosphor is one or more elements selected from the group consisting of Dy, Ho, Er, Tm, and Yb,
[11] M ¹ is one or more elements selected from the group consisting of Ca, Sr and Ba, M ² is Ga, and the inactive agent is Mn, Zn, Ce, Eu, Tb, Ho, Er The method for producing a nitride phosphor according to any one of [1] to [8], wherein the nitride phosphor is one or more elements selected from the group consisting of Tm, Yb,
[12] The nitride phosphor according to any one of [1] to [11], wherein the content of the inactive agent is 0.00001 or more and 0.3 or less with respect to the molar amount a + b. Manufacturing method,
[13] A white light emitting device using a nitride semiconductor, emitting light having a wavelength of near ultraviolet to blue light, and an LED made of a nitride semiconductor, and any one of [1] to [12] A white light emitting device comprising: a nitride phosphor manufactured by the method;
It is related to.

  According to the method for producing a nitride phosphor of the present invention, the nitride phosphor can be produced under conditions of lower temperature and lower pressure than in the prior art, so that the present invention is extremely useful industrially.

An embodiment of the method for producing a nitride phosphor of the present invention will be described in detail.
A method using an alkali metal as a flux proposed as a GaN single crystal growth method is called Na flux method because Na is often used. Compared with the melt method requiring 6GPa, 2200 ° C, and the solution method using metal Ga requiring high temperature and high pressure of 1-2GPa, 1600 ° C, the Na flux method produces a GaN single crystal at about 10MPa and 800 ° C. it can. The role of Na is considered to facilitate the dissolution of nitrogen in the Na—Ga mixed melt.

The Na flux method is suitable for the synthesis of M ³ GaN (M ³ is an alkaline earth metal) to which GaN, alkaline earth metal, or the like is added. However, since the Na flux method is a crystal growth method, it is considered undesirable even if rare earth elements or the like coexist in the Na flux as activators because the rare earth elements segregate and do not have a uniform composition. Attempts to dope rare earth elements have not been made.
The Na flux method is intended to produce a single crystal having a large nitride, and originally there was no idea of producing a powdery phosphor.
However, surprisingly, the present inventors have found that a nitride containing a rare earth element as an activator can be suitably produced by allowing a raw material containing a rare earth element as an activator to coexist in the Na flux. I found it.

A preferred method for producing the nitride phosphor of the present invention will be described with reference to FIG.
First, M ¹ and M ² as starting materials, and one or more selected from the group consisting of rare earth metals, Cr, Mn and Zn as activators are put in the crucible 3. As the crucible material, BN, alumina, niobium or the like is used. After a predetermined amount of alkali metal is added thereto, a crucible is set in the reaction vessel 1 and nitrogen gas is introduced to bring the internal pressure of the vessel to a predetermined pressure of about 5 MPa.
Here, regarding the molar ratio between the alkali metal and the starting material, if the total number of moles of the starting material is M _S and the number of moles of the alkaline earth metal is M _A , M _A / M _S is preferably 2-5. 0.5 to 3.2 is more preferable, and 3 is most preferable.

Next, the crucible is heated by the heater 6 and held at a temperature of 600 ° C. to 850 ° C. for about 24 hours. The temperature of the crucible can be measured by setting a thermocouple near the crucible as shown in the figure. When the temperature is raised, the pressure in the reaction vessel becomes about 6 MPa.
The form of nitride synthesized is determined by the holding temperature and pressure. When the pressure is less than 1 MPa, it is not preferable because it is difficult to synthesize a nitride phosphor. Although there is no big problem for the high pressure, it is preferably up to about 20 MPa in view of the pressure resistance of the reaction vessel and the production cost.
Further, even if the temperature is lower than 600 ° C., it is not preferable because it is difficult to synthesize nitride. When the temperature is higher than 850 ° C., the boiling point of Na is 883 ° C., and thus the amount of Na volatilizing increases, which is not preferable. If the pressure is 1 to 20 MPa at a temperature of 600 ° C. to 850 ° C., a nitride phosphor can be suitably synthesized. Depending on the production conditions, it becomes a fine powder, or it becomes a plate or columnar single crystal. When a large single crystal is formed, it can be used as a laser material as a single crystal phosphor, or it can be crushed and used as a powder phosphor.

  After holding at a predetermined temperature, it is cooled to room temperature. The cooling rate is preferably 5 ° C./hour to 200 ° C./hour, more preferably 6 ° C. to 100 ° C. If the cooling rate is high, more metal remains without being nitrided, and the yield decreases. If the cooling rate is slow, the throughput decreases. Unlike the single crystal growth, the synthesis of the nitride phosphor powder does not require the production of large particles, so that the cooling rate can be made relatively fast. The cooling method may be a constant rate, a method of slowing the cooling rate to a certain temperature, and then increasing the cooling rate.

  After cooling, remove the crucible from the reaction vessel. If an alkali metal such as Na remains, the nitride phosphor can be obtained by washing with ethanol or the like. If the nitride phosphor reacts with moisture or the like in the atmosphere, the reaction vessel is opened with a glow box filled with argon gas. Liquid ammonia may be used for washing the alkali metal.

Next, a preferred embodiment of the nitride phosphor produced according to the present invention will be described.
The nitride phosphor has the formula (1)
M ¹ _a M ² _b N _c (1)
Wherein the phosphor comprises a near-ultraviolet to blue-colored phosphor containing at least one selected from the group consisting of rare earth metal elements, Cr, Mn and Zn as an activator. It becomes a phosphor exhibiting high luminance when excited by light in the above wavelength range.

  The phosphor binder in the present invention is preferably at least one selected from the group consisting of Zn, Ce, Pr, Sm, Eu, Tb, Dy, Ho, Er, Tm, and Yb. Zn, Ce, Eu, One or more selected from the group consisting of Tb, Ho, Er, and Tm is more preferable.

The content of the activator in the phosphor in the present invention is preferably in the range of 0.00001 or more and 0.3 or less with respect to the total molar amount a + b of M ¹ and M ² in the formula (1). The range of 0.1 to 0.1 is more preferable, and the range of 0.0005 to 0.01 is more preferable.

M ¹ is a Group 2 metal element, and includes at least one selected from the group consisting of Mg, Ca, Sr, Ba and Zn, preferably at least one selected from the group consisting of Ca, Sr and Ba is there. M ² is a Group 3 metal element, and includes at least one selected from the group consisting of Al, Ga and In, preferably at least one selected from the group consisting of Ga and In, more preferably Is Ga.

In the formula (1), a, b, and c have a relationship of c = (2a / 3) + b, and 0 ≦ a and 0 <b. The molar ratio a / b between M ¹ and M ² is preferably 0 or more and 2 or less, and more preferably 0 or more and 1.5 or less.

Among the above preferred embodiment, M ¹ is Ca, an M ²¹ is at least one selected from the group consisting of Sr and Ba, at least one M ²² that M ² is selected from the group consisting of Ga and In Yes, the activator L ²¹ is at least one selected from the group consisting of Zn, Ce, Pr, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, and 0 ≦ a and 0 <b Yes, when a / b is in the range of 0 to 2, and the activator content x is in the range of 0.0001 × (a + b) to 0.1 × (a + b), the following (2 A nitride phosphor comprising a compound represented by the formula is preferred. However, when p is the number of moles of a divalent one of L ²¹ , p is (2u / 3) + (1-u) because the trivalent one of L ²¹ is 1-u mole.
M ²¹ _a M ²² _b N _c · xL ²¹ N _p (2)

Furthermore, it consists of a compound represented by the formula (2), M ²¹ is one or more selected from the group consisting of Ca and Sr, M ²² is Ga, and the activator L is Zn, Ce, Eu. , Tb, Ho, Er, Tm, and Yb, 0 ≦ a and 0 <b, a / b is in the range of 0 to 1, and x is 0. 0005 × (a + b) or 0.01 × (a + b) if it is the range (However, p is the number of moles of divalent ones of L ²¹ and u, as trivalent of L ²¹ 1- Since it is u mol, p = (2u / 3) + (1-u)) is more preferable.

  In addition, if the fluorescent substance in this invention is substantially nitride, it may contain about 2 weight% of oxygen which is an impurity grade.

  Among such phosphors according to the present invention, a phosphor having an excitation spectrum peak between 360 nm and 480 nm is preferable because it is efficiently excited by light in the near ultraviolet to blue wavelength range and exhibits high luminance. When combined with an LED made of a nitride semiconductor that emits light in the near-ultraviolet to blue wavelength range, a light-emitting device exhibiting high luminance is obtained.

Next, a specific example of a light emitting element that emits near ultraviolet to blue light for exciting the nitride phosphor will be described. Basically, a light-emitting element has a structure in which an n-type compound semiconductor crystal layer, a light-emitting layer made of a compound semiconductor crystal, and a p-type compound semiconductor crystal layer are stacked on a substrate. By disposing the light-emitting layer between the n-type layer and the p-type layer, a highly efficient light-emitting element with a low driving voltage can be obtained. If necessary, several layers having different compositions, conductivity, and doping concentrations may be inserted between the n-type layer and the light-emitting layer and between the light-emitting layer and the p-type layer. For example, a layer in which at least two layers having different compositions represented by the general formula In _x Ga _y Al _z N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ z ≦ 1, X + Y + Z = 1) are stacked. It may be introduced. The layer may be doped with n-type and / or p-type impurities.

Next, the light emitting layer will be described. In order to realize a light emitting element using band edge light emission, the amount of impurities contained in the light emitting layer must be kept low. Specifically, it is preferable that each of Si, Ge, and Group 2 elements has a concentration of 10 ¹⁷ cm ⁻³ or less. In the case of band edge emission, the emission color is determined by the composition of the Group 3 element in the emission layer. The light emitting layer may have a single quantum well structure or a multiple quantum well structure. The thickness of the light emitting layer is preferably 5 mm to 300 mm. More preferably, it is 10 to 90 cm. When the film thickness is smaller than 5 mm or larger than 300 mm, a light emitting element using the compound semiconductor is not preferable because the luminous efficiency is not sufficient.

In order to efficiently recombine the charges injected into the light emitting layer, a so-called double heterostructure in which the light emitting layer is sandwiched between layers having a larger band gap can be preferably used. Hereinafter, a layer having a larger band gap than the light emitting layer in contact with the light emitting layer may be referred to as a charge injection layer. The difference in band gap between the charge injection layer and the light emitting layer is preferably 0.1 eV or more. When the difference in band gap between the charge injection layer and the light emitting layer is smaller than 0.1 eV, the carriers are not sufficiently confined in the light emitting layer, and the light emission efficiency is lowered. More preferably, it is 0.3 eV or more. However, if the band gap of the charge injection layer exceeds 5 eV, the voltage required for charge injection becomes high. Therefore, the band gap of the charge injection layer is preferably 5 eV or less. The thickness of the charge injection layer is preferably 10 to 5000 mm. Even if the thickness of the charge injection layer is smaller than 5 mm or larger than 5000 mm, the luminous efficiency is lowered, which is not preferable. More preferably, it is 10 to 2000 cm.
While the embodiments of the present invention have been described above, the embodiments of the present invention disclosed above are merely examples, and the scope of the present invention is not limited to these embodiments. The scope of the present invention is defined by the terms of the claims, and further includes meanings equivalent to the description of the claims and all modifications within the scope.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited to the following Example.

Example 1
A phosphor of formula M ¹ _a M ² _b N _c was synthesized as follows. In glove box filled with argon gas, the Sr as M ^1, a Ga as M ^2, using Eu as Fukatsuzai, the respective molar ratio of Sr: Ga: Eu = 0.1: 3: 0.01 The BN crucible was charged. Next, Na as an alkali metal was weighed so that M _A / M _S = 2.5, and placed in a crucible. Here, M _S is the total number of moles of starting materials, and M _A is the number of moles of alkali metal. A crucible was set in the reaction vessel, and the inside of the vessel was pressurized to 4 MPa with nitrogen gas, and then heated to 760 ° C. over 15 hours. The pressure inside the reaction vessel became 5.5 MPa as the temperature rose. After maintaining in this state for 24 hours, cooling was performed to 100 ° C. over 100 hours at a cooling rate of 6.6 ° C./hour, and energization to the electric furnace was terminated. The crucible was taken out from the reaction vessel cooled to room temperature, and the remaining Na was washed away with ethanol to obtain a nitride phosphor.
The obtained phosphor was mainly a columnar crystal having a height of about 1 mm, and its color was slightly reddish and transparent. When this phosphor was irradiated with light having a peak wavelength of 400 nm emitted from the light emitting element, clear red light emission was exhibited. The crystal was pulverized in an agate mortar and the luminescence characteristics were measured as shown in FIG. It has an excitation spectrum from near ultraviolet to about 450 nm, and particularly strong absorption was observed at 400 nm. In the emission spectrum, red emission having a sharp peak around 622 nm was observed.

Example 2
Similar to the embodiment, the Ca as M ¹ of formula _{^{M 1 a M 2 b N c}} , Ga as M ^2, using Ce as Fukatsuzai, the respective molar ratio of Ca: Ga: Ce = 0.1 : 3: It charged to the crucible made from BN so that it might be set to 0.05. Next, Na as an alkali metal was weighed so that M _A / M _S = 2.5, and a nitride phosphor was obtained in the same manner.
The obtained phosphor was mainly composed of columnar crystals having a height of about 1 mm, and the color was transparent with a slight bluish tinge. When this phosphor was irradiated with light having a peak wavelength of 365 nm emitted from an ultraviolet lamp, clear blue light emission was exhibited. The crystals were pulverized in an agate mortar and the luminescence characteristics were measured as shown in FIG. A broad blue emission having an excitation spectrum from near ultraviolet to about 400 nm and a peak in the vicinity of 480 nm was observed in the emission spectrum.

Example 3
As in Example 1, the Sr as M ¹ of formula _{^{M 1 a M 2 b N c}} , Ga as M ^2, with Yb as Fukatsuzai, the respective molar ratio of Sr: Ga: Yb = 0. A BN crucible was charged so that the ratio was 1: 3: 0.01. Next, Na as an alkali metal was weighed so that M _A / M _S = 2.5, and a nitride phosphor was obtained in the same manner.
The obtained phosphor was mainly composed of columnar crystals having a height of about 1 mm, and the color was slightly yellowish and transparent. When this phosphor was irradiated with light having a peak wavelength of 365 nm emitted from an ultraviolet lamp, clear yellow light emission was exhibited. The crystals were pulverized in an agate mortar and the luminescence characteristics were measured as shown in FIG. A broad yellow light emission having an excitation spectrum from near ultraviolet to about 400 nm and a peak in the vicinity of 550 nm was observed.

Example 4
As in Example 1, the Sr as M ¹ of formula _{^{M 1 a M 2 b N c}} , Ga as M ^2, using Eu as Fukatsuzai, the respective molar ratio of Sr: Ga: Eu = 3: 2: A BN crucible was charged so that the ratio was 0.05. Next, as an alkali metal, Na was weighed so that M _A / M _S = 2.5, and a nitride phosphor was obtained in the same manner.
The obtained phosphor was a columnar crystal having a height of about 1 mm, a hexagonal plate crystal having a side of about 0.5 mm, and the like, and the color was yellowish and transparent. Since this phosphor decomposes while absorbing moisture in the air, it was set in the sample chamber of a scanning electron microscope so as not to touch the air, and light emission (CL: cathode luminescence) by electron beam excitation was measured.
The result is shown in FIG. In the emission spectrum, green emission having a broad peak around 525 nm was observed.

Example 5
As in Example 1, a Ba as M ¹ of formula _{^{M 1 a M 2 b N c}} , Ga as M ^2, using Eu as Fukatsuzai, the respective molar ratio of Ba: Ga: Eu = 3: 2: Charged to a crucible made of BN to be 0.02. Next, as an alkali metal, Na was weighed so that M _A / M _S = 2.5, and a nitride phosphor was obtained in the same manner.
The obtained phosphor was a columnar crystal having a height of about 1 mm, a hexagonal plate crystal having a side of about 0.5 mm, and the like, and the color was yellowish and transparent. Since this phosphor decomposes while absorbing moisture in the air, it was set in the sample chamber of the scanning electron microscope so as not to touch the air, and the cathodoluminescence was measured.
The result is shown in FIG. In the emission spectrum, blue emission having a broad peak around 445 nm was observed.

The conceptual diagram of the manufacturing apparatus used with the manufacturing method of this invention. Excitation / emission spectrum when starting composition is Sr: Ga: Eu = 0.1: 3: 0.01 Excitation / emission spectrum when starting composition Sr: Ga: Ce = 0.1: 3: 0.05 Excitation / emission spectrum when starting composition Sr: Ga: Yb = 0.1: 3: 0.01 CL spectrum when starting composition Sr: Ga: Eu = 3: 2: 0.05 CL spectrum when the starting composition is Ba: Ga: Eu = 3: 2: 0.02.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Reaction container 2 ... Crucible support 3 ... Crucible 4 ... Melt 5 ... Thermocouple 6 ... Electric furnace 7 ... Regulator

Claims (13)

Formula M ¹ _a M ² _b N _c (where M ¹ is one or more elements selected from the group consisting of Mg, Ca, Sr, Ba and Zn, and M ² consists of Al, Ga and In) A rare earth metal as an activator in a mother crystal composed of a compound represented by one or more elements selected from the group, c = (2a / 3) + b, 0 ≦ a and 0 <b) In producing a nitride phosphor containing at least one selected from the group consisting of Cr, Mn, and Zn, an alkali metal or an alkali metal and an alkali metal nitride, M ¹ , M ² are contained in the reaction vessel. A method for producing a nitride phosphor, comprising charging an activator and producing in a gas containing nitrogen. The total number of moles M _S and the number of moles M _A of the alkali metal of the nitride phosphor starting material molar ratio M _A / M _S is the nitride phosphor of claim 1, wherein the 2 to 5 Production method.   3. The method for producing a nitride phosphor according to claim 1, wherein the alkali metal is Na or a mixture of Na and Li. Manufacturing method of the nitride phosphor according to any one of claims 1 to 3, wherein the alkali metal nitrides are Li ₃ N.   The method for producing a nitride phosphor according to any one of claims 1 to 4, wherein the pressure of the gas containing nitrogen is 1 MPa to 20 MPa.   The method for producing a nitride phosphor according to any one of claims 1 to 5, wherein a maximum temperature during production is 600 ° C to 850 ° C.   The method for producing a nitride phosphor according to claim 6, wherein the cooling rate from the maximum temperature according to claim 6 to a predetermined temperature is 5 ° C./hour to 200 ° C./hour. The method for producing a nitride phosphor according to claim 1, wherein M ² is Ga. M ¹ is Ca, is one or more elements selected from the group consisting of Sr and Ba, M ² is the nitride phosphor according to claim 1, characterized in that the Ga Production method. M ¹ is one or more elements selected from the group consisting of Ca, Sr and Ba, M ² is Ga, and the inactive agent is Mn, Zn, Ce, Pr, Sm, Eu, Tb, Dy, The method for producing a nitride phosphor according to claim 1, wherein the nitride phosphor is one or more elements selected from the group consisting of Ho, Er, Tm, and Yb. M ¹ is one or more elements selected from the group consisting of Ca, Sr and Ba, M ² is Ga, and the inactive agent is Mn, Zn, Ce, Eu, Tb, Ho, Er, Tm, The method for producing a nitride phosphor according to claim 1, wherein the nitride phosphor is one or more elements selected from the group consisting of Yb.   The method for producing a nitride phosphor according to any one of claims 1 to 11, wherein a content of the inactive agent is 0.00001 or more and 0.3 or less with respect to the molar amount a + b.   A white light emitting device using a nitride semiconductor, which emits light having a wavelength of near ultraviolet to blue light, and manufactured by the method according to any one of claims 1 to 12 and an LED made of a nitride semiconductor. A white light emitting device comprising a nitride phosphor.

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