JP2005226000A - Nitride phosphor, manufacturing method of nitride phosphor, white light emitting element and pigment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a red nitride phosphor having an emission peak wavelength in 600 nm or longer, especially 650-690 nm and having a high emission intensity, a manufacturing method of the nitride phosphor, and a pigment. <P>SOLUTION: The nitride phosphor has a chemical composition represented by general formula (1): Ca<SB>m-x</SB>Eu<SB>x</SB>Si<SB>9</SB>Al<SB>y</SB>N<SB>(12+2/3m+y)</SB>(1), wherein the following expressions hold: 0.5≤m≤5.0, 0.1<x/m≤1.0, and 0≤y≤3.0. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a red light emitting nitride phosphor having a light emission peak in a long wavelength region of 600 nm or more (especially 650 to 690 nm) and high emission intensity, a method for producing the nitride phosphor, a white light emitting element, and a pigment.

Currently, many red-emitting phosphors having an emission peak in a long wavelength region of 600 nm or more are sulfide-based, and oxides are activated by europium (Eu) used in three-wavelength fluorescent lamps. Examples thereof include yttrium oxide phosphors (Y ₂ O ₃ : Eu, YVO ₄ : Eu). However, the emission peak wavelength of these red phosphors is 650 nm or less, and it is said that there are few that show strong emission intensity at wavelengths longer than this.

In addition, many nitride-based phosphors absorb ultraviolet to blue light and exhibit a relatively long-wavelength yellow to orange fluorescent color, and are attracting attention as phosphors suitable for white light-emitting elements. . The white light emitting element converts a part of light emitted from a blue semiconductor light emitting element (blue LED) such as a GaN system with a photoluminescence phosphor, and converts the wavelength of the blue LED light into the wavelength converted light (mainly a yellow light emitting element). It is a light emitting element that emits a light emission color different from that of LED light, particularly white light, by mixing with light. Since such a light emitting element is small and has high power efficiency, it is used as various light sources such as a signal lamp, an in-vehicle illumination, a liquid crystal backlight, and a display board such as a station destination guide plate. As a photoluminescence phosphor used in a white light emitting element in combination with a blue LED, an yttrium / aluminum / garnet phosphor activated with cerium (Ce) (hereinafter referred to as “YAG phosphor”). However, nitride-based phosphors that emit yellow to orange light are expected as photoluminescent phosphors for white light-emitting elements that replace YAG-based phosphors.
On the other hand, the light emitted from the YAG phosphor is yellow-green to yellow, and the light emission color of the white light-emitting element is slightly bluish-white, which is good for simple lighting but requires high color rendering properties. In addition, when used as a backlight of a color liquid crystal display (LCD), the output light has a short red component. For this reason, it has also been proposed to use the nitride phosphor together with the YAG phosphor in order to correct the emission color, that is, to supplement the red component.

Examples of such nitride-based red phosphors include calcium (Ca) -α-sialon phosphors (see Patent Document 1) and nitridosilicates such as Ca ₂ Si ₅ N ₈ and Sr ₂ Si ₅ N. ₈ , Ba ₂ Si ₅ N ₈ , Ba ₂ Si ₇ N ₁₀ , and Ba _2−x Eu _x Si ₅ N ₈ type phosphors (see Patent Documents 2 and 3).
JP 2002-363554 A Special table 2003-515655 gazette Special table 2003-515665 gazette

However, the Ca-α-sialon-based phosphor described in Patent Document 1 has an emission peak wavelength of 500 to 600 nm, and in the nitridosilicate described in Patent Documents 2 and 3, the Ca-based phosphor is 600. Although it is ˜630 nm, the luminance is low, and there are few practical phosphors whose emission peak wavelength is particularly longer than 650 nm.
The present invention has been made in view of the above circumstances, and has a light emission peak wavelength of 600 nm or more, particularly 650 to 690 nm, and a light emission color of red. It aims at providing a manufacturing method, a white light emitting element, and a pigment.

In order to solve the above-mentioned problems, the present inventors have conducted extensive research. As a result, the present inventors have a novel nitride fluorescent light having a light emission peak wavelength at 600 nm or more, particularly 650 to 690 nm, and a high emission intensity. I found my body.
That is, the nitride phosphor of the invention described in claim 1 has a chemical composition represented by the following general formula (1).
_{Ca mx Eu x Si 9 Al y} N (12 + 2 / 3m + y) ... (1)
(However, in the general formula (1), 0.5 ≦ m ≦ 5.0, 0.1 <x / m ≦ 1.0, and 0 ≦ y ≦ 3.0.)

The invention according to claim 2 is the nitride phosphor according to claim 1,
The main crystal phase is orthorhombic.

The invention according to claim 3 is a method for producing the nitride phosphor according to claim 1 or 2,
A compound of a metal element other than silicon constituting the nitride and silicon nitride are dissolved or dispersed in molten urea and / or a molten urea derivative to form a nitride precursor, and the nitride precursor is A nitride phosphor is produced by heating in an inert or reducing atmosphere.

  The white light emitting device according to claim 4 is a semiconductor light emitting device that emits blue light, and a phosphor that emits fluorescence in the green to yellow wavelength region by absorbing part of the light from the semiconductor light emitting device. And the nitride phosphor according to claim 1 or 2.

  The white light-emitting device according to claim 5 is a semiconductor light-emitting device that emits light in the ultraviolet to blue-violet region, and a phosphor that absorbs light from the semiconductor light-emitting device and emits blue fluorescence, or It comprises at least one of phosphors emitting green fluorescence and the nitride phosphor according to claim 1 or 2.

The pigment of the invention described in claim 6 has a chemical composition represented by the following general formula (1).
_{Ca mx Eu x Si 9 Al y} N (12 + 2 / 3m + y) ... (1)
(However, in the general formula (1), 0.5 ≦ m ≦ 5.0, 0.1 <x / m ≦ 1.0, and 0 ≦ y ≦ 3.0.)

The nitride phosphor according to the present invention has a light emission peak wavelength in a long wavelength region of 650 to 690 nm which is 600 nm or more, particularly not so practical, and exhibits high light emission intensity. Further, it emits light by being excited by light in a wide wavelength region from the ultraviolet region to the yellow-green light region, and also by an electron beam or an electric field. Therefore, it is useful as a phosphor used for ordinary illumination, various display tubes, white LEDs, and the like. Further, since the object color is yellow red (orange red) to red, it can be applied to various uses as a pigment not containing heavy metal.
Furthermore, according to the method for producing a nitride phosphor according to the present invention, a nitride precursor having a uniform composition can be formed by dissolving or dispersing each raw material in molten urea and / or a molten urea derivative. it can. Then, by heating such a nitride precursor in an inert or reducing atmosphere, a nitride phosphor having excellent characteristics and crystallinity with a uniform particle diameter can be obtained. Further, since nitriding and crystal growth of the raw material can be performed in the same reaction vessel, it can be efficiently produced by a simple process, and can be produced at normal pressure and at a relatively low temperature.

Hereinafter, the nitride phosphor according to the present invention, a white light-emitting element or pigment as an application, and a method for producing the nitride phosphor will be described in detail.
(Nitride phosphor)
The nitride phosphor according to the present invention has a chemical composition represented by the following general formula (1).
_{Ca mx Eu x Si 9 Al y} N (12 + 2 / 3m + y) ... (1)
In the general formula (1), 0.5 ≦ m ≦ 5.0, 0.1 <x / m ≦ 1.0, and 0 ≦ y ≦ 3.0.

In the general formula (1), the range of m is preferably 1.0 ≦ m ≦ 4.0.
The present invention is characterized in that the activator Eu serving as the emission center has a large amount of doping, and the emission intensity increases as the Eu doping amount increases. The range of x / m is preferably 0.2 ≦ x / m ≦ 0.9, and more preferably 0.3 ≦ x / m ≦ 0.9. In particular, the light emission intensity is maximum near x / m = 0.5.
Further, even if the amount of Eu doping increases, the emission intensity due to concentration quenching does not decrease so much, and even if Ca is replaced by 100%, it can be used as a phosphor.

Further, the crystal structure changes depending on x / m which is the ratio of Eu and (Ca + Eu), and is monoclinic when the doping amount of Eu is small, but is orthorhombic with increasing Eu doping amount. And the ratio becomes approximately orthorhombic only with x / m = 0.5 as a boundary.
The nitride phosphor according to the present invention tends to have a longer emission wavelength and a higher intensity as the crystal phase has a higher orthorhombic proportion, and therefore the main crystal phase is orthorhombic. preferable. In particular, it is preferable that the monoclinic system is not detected and only the orthorhombic system is used because the emission intensity can be improved.

  In the nitride phosphor of the present invention, it is not essential to contain aluminum (Al), but it is considered that the structure is stabilized by adding Al even when the doping amount of Eu is increased. Further, from the examples described later, it can be presumed that an orthorhombic system is likely to be formed by Al, and since the emission intensity is high and the emission peak tends to be sharp, it is desirable to contain Al. However, since the emission intensity decreases conversely as the Al content increases, y needs to be 3.0 or less. The value of y is preferably in the range of 0 <y ≦ 2.0, most preferably 0.1 ≦ y ≦ 1.5.

  The nitride phosphor of the present invention is not an oxynitride containing a controlled amount of oxygen such as α-sialon or β-sialon. However, in general, oxygen often inevitably enters nitrides. The present invention does not exclude such a nitride containing a small amount of oxygen that inevitably enters.

  The nitride phosphor of the present invention includes an element that acts as a coactivator such as a rare earth metal element, such as cerium (Ce), terbium (Tb), in order to adjust emission intensity, afterglow, and other fluorescence characteristics. ), Dysprodium (Dy), samarium (Sm), praseodymium (Pr), neodymium (Nd), erbium (Er), holmium (Ho), thulium (Tm), manganese (Mn), etc. may be appropriately doped. .

  The nitride phosphor according to the present invention emits fluorescence having an emission peak wavelength in the range of 600 nm or more, particularly 650 nm to 690 nm, which has hardly existed in the past, when excited by light in the ultraviolet to yellow-green light region, electron beam, or electric field. Long-wavelength red light emitting phosphor. Further, this nitride phosphor has a yellow-red (orange-red) color to a red color, and has a very high emission intensity.

  Such nitride phosphors can be used as long-wavelength red phosphors, which have not been so practical in the past, as illumination phosphors such as lamps, cold cathode tubes, CRTs, PDPs, FEDs, It can be used as a red phosphor for display tubes such as inorganic EL.

Further, it is excited by ultraviolet light and visible light in a purple to yellow-green wavelength region, and these light can be converted into light having a longer wavelength, so that it is very effective for producing a white light emitting element.
Specifically, the blue LED absorbs a part of the blue light from the LED, converts the wavelength, emits green to yellow light, and the nitride of the present invention as the second phosphor. By combining with a phosphor, a white light emitting device with excellent color balance can be obtained.
For example, a white light emitting device including a GaN-based or InGaN-based blue LED having a light emission peak wavelength of 400 nm to 460 nm and a YAG phosphor that emits yellow-green to yellow light when excited by blue light is used. The color rendering property and color sensitivity can be improved by adding the nitride phosphor of the present invention for the red component complementary color.
In addition, by combining the blue LED, the first phosphor that emits green light with the blue light, and the red light emitting nitride phosphor of the present invention, white light emission by mixing three primary colors of blue, green, and red light. An element can also be obtained. Since the nitride phosphor of the present invention can be excited by light in a wide wavelength region from ultraviolet light to yellow-green light, it emits light not only from the light from the blue LED but also from light emitted by the first phosphor. High efficiency.
Further, instead of the blue LED, for example, a semiconductor element (ultraviolet LED) that emits light in an ultraviolet to blue-violet region having a peak wavelength of 360 to 400 nm is used, and the emitted light is absorbed to emit red, green, or blue fluorescence. A light emitting device that emits white light by mixing these three primary colors in combination with a photoluminescent phosphor that emits light is also known, but the nitride phosphor of the present invention is used as a red component of such a white light emitting device. You can also.
Furthermore, as a phosphor combined with an ultraviolet LED, a blue LED, or an LED emitting blue-green to green, the nitride phosphor of the present invention is used alone, and various light sources such as white light, purple, magenta, pink, and red are used. A light-emitting element that emits colored light can also be obtained.

Furthermore, since the nitride phosphor of the present invention has an object color of yellow-red to red, as an alternative material for pigments containing heavy metals such as iron, copper, manganese, and chromium, such as bengara (iron oxide), paint and Applicable to ink and the like. It can also be used as a red pigment that emits deep red light using ultraviolet light and visible light as an excitation source, for phosphor toning and cosmetics, and as a pigment for anti-counterfeiting ink such as banknotes and securities. It is.
Furthermore, it can be used for a wide range of applications as an ultraviolet and visible light absorbing material.

(Nitride phosphor manufacturing method)
Next, a method for producing a nitride phosphor according to the present invention will be described.
As the method for producing a nitride phosphor according to the present invention, a known solid phase reaction method, spray pyrolysis method, liquid phase reaction method, and other methods can be applied, but the urea precursor shown below is used. The most preferable method is that it is easy to obtain a nitride having a uniform composition and a uniform crystal size and good crystallinity. Furthermore, this method is preferable in that the raw material can be nitrided and grown in the same reaction vessel, and can be produced at normal pressure and at a relatively low temperature.
Hereinafter, an example of the method using the urea precursor suitably used in the present invention will be described. First, urea and / or a urea derivative (hereinafter sometimes referred to as “urea or the like”) is heated to a temperature equal to or higher than these melting points to be in a molten state. However, if the heating temperature is too high, another product may be generated. Therefore, after the urea or the like is dissolved and the Ca compound, Eu compound, Al compound, or silicon nitride described later is added, the molten state is kept for a predetermined time. It is preferable that the temperature is such that it can be maintained. For example, when urea is used, its melting point is 132 ° C., so it is sufficient to heat it to a slightly higher temperature.

  As the urea derivative, various compounds such as urea compounds as carbamate compounds, urea complex compounds, and urea adduct compounds can be used as substitutes of various organic groups for nitrogen atoms in urea. As urea or the like, urea is preferably used from the viewpoints of availability, ease of handling, and the like.

  Next, a Ca compound, an Eu compound, and an Al compound, which are constituents of the final product, are dissolved in molten urea or the like, and silicon nitride is dispersed to form a nitride precursor. The Ca compound and the Al compound may be added according to the nitride phosphor to be generated, and are not necessarily essential. When the coactivator is doped, a predetermined amount of a metal element compound that acts as a coactivator is added and dissolved.

  A compound of a metal element other than silicon constituting the nitride, that is, a Ca compound, Eu compound, Al compound, or a coactivator element compound is not particularly limited as long as it is dissolved in molten urea or the like. For example, chlorides, nitrates and the like can be mentioned. As silicon nitride, either crystalline or amorphous silicon can be used as appropriate. For example, amorphous silicon nitride is considered preferable in terms of reactivity, but crystalline silicon nitride is advantageous in terms of easy availability, easy handling, and yield. is there.

The nitride precursor thus obtained is allowed to cool, for example, and dried to form a solid. This solid material is mechanically pulverized as necessary, and heated using a heating furnace to produce a nitride. As a heating furnace, well-known things, such as a batch furnace, a belt furnace, a tubular furnace, a rotary kiln, can be used.
However, it is necessary to perform heating under an inert atmosphere or a reducing atmosphere.
Further, the target product may be formed by one-step heating (firing) in an inert atmosphere or a reducing atmosphere, or the target nitride is obtained by heating (firing) in multiple stages. Also good. For example, if heating is performed in two stages, a product having characteristics that cannot be obtained by heating in one stage can be obtained. Various conditions such as the heating temperature and the heating time may be appropriately set according to the type of the desired product and the required characteristics. The conditions may be set from the range of 0.5 to 12 hours at a temperature of. In the case of two-stage heating, it is desirable to set the second stage heating temperature higher than the first stage heating temperature. For example, the first stage heating is performed at about 300 to 900 ° C., Preferably, it is carried out at a temperature in the range of about 400-800 ° C for 0.5-4 hours, and the second stage heating is carried out at a temperature in the range of about 1200-1650 ° C, preferably 1350-1600 ° C for about 0.000. It is desirable to perform for 5 to 12 hours. Multi-stage heating is advantageous in that a product with a more uniform composition can be obtained with good reproducibility.

  Further, as other heating means, the finely powdered precursor powder having a uniform and fine particle diameter is obtained by heating the precursor powder that has been mechanically pulverized, preferably after adjusting the particle size and then dispersing in the gas phase. A nitride powder can be obtained.

Furthermore, a spray pyrolysis method may be used as another heating means. In this spray pyrolysis method, the liquid precursor is made into fine droplets using an atomizer such as an ultrasonic type or a two-fluid nozzle type or other atomizing means, and this is subjected to an inert atmosphere or a reducing atmosphere condition. Under heating, the precursor can be decomposed and reacted to obtain fine and uniform nitride powder.
In the above production example, the method of dissolving or dispersing each compound etc. in the molten urea etc. has been described, but the urea etc. and the compound etc. are mixed in advance and then heated to melt the urea etc. It doesn't matter.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, the embodiment of this invention is not limited to this.
Samples 1 to 25 were prepared according to the following method, and then the following measurements were performed for each sample 1 to 25 for evaluation.
[Preparation of Sample 7]
Urea was melted at 134 ° C. to obtain molten urea. In 36 g of this molten urea, 2.09 g of EuCl ₃ .6H ₂ O, 0.345 g of AlCl ₃ .6H ₂ O and 0.63 g of CaCl ₂ are added and dissolved, and further ₂ g of Si ₃ N ₄ powder (SN manufactured by Ube Industries) -E10) was added, stirred and dispersed uniformly. This was air-cooled while stirring to produce a solid nitride precursor having an element molar ratio of Ca: Eu: Si: Al = 2: 2: 9: 0.5. The obtained precursor was placed on a carbon boat with a lid, fired in an N ₂ atmosphere containing 4% H ₂ at 800 ° C. for 2 hours, and then pulverized. This was sandwiched between Mo plates and heated in a 4% H ₂ / N ₂ atmosphere at 1500 ° C. for 2 hours to produce a nitride phosphor.

[Preparation of Samples 1-6, 8-25]
Samples 1 to 6 and 8 to 25 were obtained in the same manner as Sample 7 by appropriately changing the molar ratio of the raw materials in the preparation of Sample 7. Table 1 shows the chemical composition of each sample 1-25.
Samples 1 to 11 are fixed at m = 4 and y = 0.5 in the above general formula (1), samples 12 to 16 are fixed at m = 4 and x = 2, and samples 17 to 18 are fixed. Is fixed at m = 4, y = 1.5, samples 19-23 are fixed at m = 3, y = 0.5, samples 24-25 are fixed at x = m / 2, y = 0.5, Each other parameter is changed. Samples 1 to 3 and 19 are outside the present invention.

<< X-ray diffraction pattern >>
About the obtained phosphor powder (samples 1 to 25), an X-ray diffraction pattern was measured using Cu-Kα ray as an X-ray source using a powder X-ray diffractometer manufactured by Rigaku Corporation. A representative one is shown in FIGS. 1 shows the X-ray diffraction pattern of Sample 2, FIG. 2 shows Sample 6, FIG. 3 shows Sample 7, and FIG. 3 and 4 are similar X-ray diffraction patterns, and it can be seen that the crystal structure has only an orthorhombic system. Also, FIG. 2 has a crystal structure with more orthorhombic system than monoclinic system, and FIG. 1 confirms that it has a crystal structure with more monoclinic system than orthorhombic system. did it. For other samples, the crystal structure was confirmed from the X-ray diffraction pattern, and the results are shown in Table 1.

<Fluorescence characteristics>
With respect to each sample 1 to 25, a fluorescence spectrum was measured in the range of 470 nm to 900 nm using a spectrofluorometer (FP-6600 type) manufactured by JASCO Corporation, using 400 nm monochromatic light as an excitation light source. Table 1 shows the measurement results (measurement values) for the emission peak wavelength and emission intensity of each sample 1-25. The emission intensity in Table 1 is the relative intensity when the emission intensity of the sample 7 at the emission peak wavelength of 677 nm is 100. 5 to 6 show typical spectrum diagrams. FIG. 5 shows fluorescence spectra of samples 2, 6, and 7, and FIG. 6 shows fluorescence spectra of samples 21, 24, and 25. Moreover, the excitation spectrum in each emission peak wavelength about these samples was measured in the range of 250 nm to 620 nm, and is shown in FIGS. 7 shows the excitation spectra of Samples 2, 6, and 7. FIG. 8 shows the excitation spectra of Samples 21, 24, and 25.
Rhodamine B was used for correcting the excitation spectrum, and a xenon lamp and a tungsten lamp were used for correcting the fluorescence spectrum.

表１の結果から明らかなように、上記一般式（１）で表される窒化物蛍光体において、Ｅｕと（Ｃａ＋Ｅｕ）の割合であるｘ／ｍの範囲が０．１＜ｘ／ｍ≦１．０である試料４〜１８、２０〜２５は、６５０ｎｍ〜６８２ｎｍに発光ピークが見られ、発光強度も大きかった。一方、上記範囲外である試料１〜３、１９は、６１１ｎｍ〜６１５ｎｍに発光ピークが見られるが、強度が非常に弱いものであった。

As is clear from the results in Table 1, in the nitride phosphor represented by the general formula (1), the range of x / m, which is the ratio of Eu and (Ca + Eu), is 0.1 <x / m ≦ 1. Samples 4 to 18 and 20 to 25 having an emission peak of 0.0 showed an emission peak at 650 nm to 682 nm, and the emission intensity was also high. On the other hand, Samples 1 to 3 and 19 outside the above range showed emission peaks at 611 nm to 615 nm, but were very weak in intensity.

  Further, since the emission peak wavelength is greatly shifted to a long wavelength around x / m = 0.2 and around 0.3, it can be seen that the emission peak wavelength can be controlled by the amount of Eu doped. Furthermore, as shown in Samples 7, 12 to 16, 21, 24, 25, it can be seen that when x / m = 0.5, the emission intensity is high and the phosphor is very excellent. For example, as shown in Samples 8 to 11, the emission intensity tended to decrease as x / m was increased from 0.5 to increase the amount of Eu doping, but this was caused by concentration quenching. Can be guessed.

  Further, when the value of x / m is changed as 0 ≦ x / m ≦ 1.0, and when 0 ≦ x / m ≦ 0.1 shown in Samples 1 to 3, the main crystal phase is monoclinic. Although it is a crystal system, the proportion of orthorhombic system increases with increasing Eu doping amount (increasing x / m), and orthorhombic system with x / m = 0.5 (sample 7) as a boundary. Only will be detected. From this and the relationship between the emission characteristics, it can be seen that if the main crystal phase is orthorhombic, a phosphor having an emission peak in the long wavelength region and having a high emission intensity can be obtained.

  Further, as shown in Sample 12, when the composition ratio of Al was y = 0, the emission peak was at 651 nm and the emission intensity was 51. Therefore, even if Al is not particularly added, it is at a level that does not cause a problem in practice. However, as shown in Samples 13 to 16, by adding in the range of 0 <y ≦ 3.0, the emission wavelength is longer. Since the emission intensity is also increased, it can be seen that an advantageous effect can be obtained by adding Al.

  For Samples 7, 21, 24, and 25, the emission characteristics when 460 nm monochromatic light was used as the excitation light were also examined. Sample 7 had an emission peak at 676 nm. Samples 7, 21, 24, and 25 have emission peaks at 674 nm, 681 nm, and 676 nm, respectively. The emission intensity is relative intensity when the intensity at the emission peak wavelength of sample 7 is 100, and is 102. 65, 86.

"appearance"
The appearance of the obtained phosphor powder (samples 1 to 25) was observed, and the object colors are shown in Table 1.
As shown in Samples 1 to 3, 19, the smaller the amount of Eu, the less reddish yellow, and Sample 1 to which no Eu was added was gray. It was confirmed that the redness was increased as the amount of Eu was increased.

2 is an X-ray diffraction pattern of Sample 2. 2 is an X-ray diffraction pattern of Sample 6. 3 is an X-ray diffraction pattern of Sample 7. 2 is an X-ray diffraction pattern of a sample 21. FIG. It is a fluorescence spectrum of Samples 2, 6, and 7. It is a fluorescence spectrum of samples 21, 24, and 25. It is an excitation spectrum of Samples 2, 6, and 7. It is an excitation spectrum of samples 21, 24, and 25.

Claims (6)

A nitride phosphor having a chemical composition represented by the following general formula (1).
_{Ca mx Eu x Si 9 Al y} N (12 + 2 / 3m + y) ... (1)
(However, in the general formula (1), 0.5 ≦ m ≦ 5.0, 0.1 <x / m ≦ 1.0, and 0 ≦ y ≦ 3.0.) The nitride phosphor according to claim 1, wherein
A nitride phosphor characterized in that the main crystal phase is orthorhombic. A method for producing the nitride phosphor according to claim 1, comprising:
A compound of a metal element other than silicon constituting the nitride and silicon nitride are dissolved or dispersed in molten urea and / or a molten urea derivative to form a nitride precursor, and the nitride precursor is A method for producing a nitride phosphor, comprising producing a nitride phosphor by heating in an inert or reducing atmosphere.   3. A semiconductor light emitting device that emits blue light, a phosphor that absorbs part of light from the semiconductor light emitting device and emits fluorescence in a green to yellow wavelength region, and the nitride fluorescence according to claim 1. A white light emitting element comprising: a body.   A semiconductor light emitting device that emits light in the ultraviolet to blue-violet region, and at least one of a phosphor that emits blue fluorescence by absorbing light from the semiconductor light emitting device, or a phosphor that emits green fluorescence, A white light-emitting element comprising the nitride phosphor according to claim 1. A pigment having a chemical composition represented by the following general formula (1).
_{Ca mx Eu x Si 9 Al y} N (12 + 2 / 3m + y) ... (1)
(However, in the general formula (1), 0.5 ≦ m ≦ 5.0, 0.1 <x / m ≦ 1.0, and 0 ≦ y ≦ 3.0.)

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