TW201716544A - Fluorescent body, production method therefor and light-emitting device - Google Patents

Abstract

A fluorescent body which includes a crystalline phase represented by a composition in formula (1), wherein the fluorescent body is characterized by also containing 100-2500ppm of boron. SraM1bAlcSidNeOf: Eux1Cey1...(1) (where: M1 is at least one metal element selected from the group consisting of Ca, Ba and Mg; 2≤a≤8; 0≤b≤3; 2≤c≤7; 10≤d≤25; 15≤e37; 0≤f≤3; and 0<x1+y1≤0.6).

Description

Phosphor, manufacturing method thereof and illuminating device

The present invention relates to a phosphor, a method of manufacturing the same, and a light-emitting device, and more particularly to a phosphor that exhibits green light, a method of manufacturing the same, and a light-emitting device.

In the past, white light-emitting diodes (white LEDs) have been widely used to combine a blue-emitting semiconductor light-emitting element with a yellow phosphor, and a two-color mixed type of white light is obtained by mixing colors of blue and yellow. However, the white light emitted by the two-color mixed type white LED has a problem of poor color rendering. Therefore, as another configuration, a white LED having a three-color mixed color type in which a semiconductor light-emitting element that emits blue light and two kinds of phosphors of green and red are combined is used, and a semiconductor LED is used. The light of the light-emitting element excites the respective phosphors, thereby obtaining white light by using a mixed color of blue, green, and red.

As a phosphor that exhibits green light emission, a green phosphor having various compositions has been developed. For example, in Patent Document 1 and Non-Patent Document 1, a green phosphor used for an LED or the like is described as having Sr _5-yza M _y Si _23-x Al _3+x O _x+2a N _37-x-2a. A phosphor composed of Eu _z Ce _z1 , in particular, an embodiment having a composition of Sr _4.9 Al ₅ Si ₂₁ O ₂ N ₃₅ :Eu _0.1 is described in the embodiment of Patent Document 1.

Further, for example, Patent Document 2 discloses a phosphor comprising Sr ₃ Si ₁₃ Al ₃ O ₂ N activated by Eu, which contains a ratio of an oxygen concentration in an outer side region of a predetermined crystal to an oxygen concentration in an inner region. _{The 21-} genus crystal particles exhibit light emission with a luminescence peak between 490 and 580 nm when excited by light having a wavelength of 250 to 500 nm.

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2011-505451

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2013-43937

[Non-patent literature]

[Non-Patent Document 1] Chemistry-A European Journal 2009, 15, 5311-5319

However, the green phosphors described in Patent Document 1 and Non-Patent Document 1 have insufficient light-emitting characteristics, and particularly have a problem that the light-emitting intensity is low. Further, as described in Non-Patent Document 1, since the orange-red phosphor such as SrAlSi ₄ N ₇ or Sr ₂ Si ₅ N ₈ is formed in a different phase, it must be mechanically removed. Further, although the phosphor described in Patent Document 2 has high luminous stability against heat, it is expected that the luminous characteristics of the phosphor itself are further improved.

Further, as for the phosphor for white LEDs, it has been known that when the particle diameter is too large, it is difficult to uniformly disperse in the resin, and the color tone varies, and it is necessary to control the specific particle size range. Further, when pulverization and classification are carried out in order to reduce the particle size, fine particles are generated and the main cause of the decrease in brightness is required. Therefore, it is necessary to control the specific particle diameter without a pulverization step.

The present invention has been made in view of the above problems, and an object thereof is to provide a particle size controlled to be specific and the generation of a heterogeneous phase is suppressed, and the luminescence property, particularly the luminescence intensity, is A conventional phosphor, a method for producing the same, and a light-emitting device.

In order to achieve the above object, the inventors of the present invention have repeatedly conducted intensive studies, and as a result, have found that by allowing a green phosphor activated by ruthenium and/or osmium to contain a specific amount of boron, it can be controlled to a specific particle diameter and suppress the heterogeneous phase. The present invention is completed by greatly increasing the luminous intensity.

That is, the present invention relates to a phosphor comprising a crystal phase represented by the composition of the following formula (1), which further contains 100 to 2,500 ppm of boron.

Sr _a M1 _b Al _c Si _d N _e O _f :Eu _x1 Ce _y1 (1)

(here, M1 is one or more metal elements selected from the group consisting of Ca, Ba, and Mg, 2≦a≦8, 0≦b≦3, 2≦c≦7, 10≦d≦25, 15≦e≦37,0≦f≦3,0<x1+y1≦0.6).

Further, the present invention relates to a phosphor comprising at least a crystal phase of a structure of Sr ₅ Al ₅ Si ₂₁ N ₃₅ O ₂ characterized by: Sr ₅ Al ₅ Si ₂₁ N ₃₅ O in an X-ray diffraction pattern when the phosphor of structure ₂ from the diffraction peak intensity of (021) plane is a, and the phosphor structure of SrAlSi ₄ N ₇ from the (221) diffraction peak intensity of the set B, B / A<0.03.

Further, the present invention relates to a phosphor comprising a crystal phase represented by the composition of the following formula (2).

Sr _g M2 _h B _i Al _j Si _k N _l O _m :Eu _x2 Ce _y2 (2)

(here, M2 is one or more metal elements selected from the group consisting of Ca, Ba, and Mg, 2≦g≦8, 0≦h≦3, 0.02≦i≦0.8, 2≦j≦7, 10≦k≦25,15≦l≦37,0≦m≦3,0<x2+y2≦0.6).

Moreover, the present invention relates to a method of manufacturing a phosphor, which has the following steps Step: a step of obtaining a raw material mixture by mixing an Sr-containing compound, an Al-containing compound, an Si-containing compound, an Eu-containing compound and/or a Ce-containing compound, and a B-containing compound; and in an inert gas atmosphere or a reducing gas atmosphere The step of firing the raw material mixture is characterized in that the amount of the B-containing compound added is from 250 to 10,000 ppm of the raw material mixture.

Furthermore, the present invention relates to a light-emitting device comprising: the phosphor; and a light source that emits excitation light to the phosphor and emits light.

According to the present invention, it is possible to provide a phosphor, a method for producing the same, and a light-emitting device which are controlled to have a specific particle diameter and which suppress generation of a different phase, and which have excellent light-emitting characteristics, in particular, an emission intensity superior to those of the prior art.

Fig. 1 is a view showing an X-ray diffraction (XRD) pattern of a phosphor obtained in Example 5 and Comparative Example 1.

Fig. 2 is a graph showing the emission spectra of the phosphors obtained in Example 5 and Comparative Example 1.

Fig. 3 is a scanning electron micrograph of the phosphor obtained in Example 5 and Comparative Example 1.

Fig. 4 is a view showing a B-depth depth profile of the phosphor obtained in Example 5.

Fluorescent body

The phosphor of the present invention contains a crystal phase represented by the composition of the following formula (1).

Sr _a M1 _b Al _c Si _d N _e O _f :Eu _x1 Ce _y1 (1)

(here, M1 is one or more metal elements selected from the group consisting of Ca, Ba, and Mg, 2≦a≦8, 0≦b≦3, 2≦c≦7, 10≦d≦25, 15≦e≦37,0≦f≦3,0<x1+y1≦0.6).

That is, the fluorescent system of the present invention is activated by europium (Eu) and/or cerium (Ce), and is a green fluorescent light having a peak between 500 and 560 nm when excited by light having a wavelength of 330 to 500 nm. Light body.

In the phosphor of the present invention, lanthanum (Eu) and/or cerium (Ce) are activators and have a property of emitting light in the form of luminescent atoms in the phosphor. The molar ratio of the krypton in the phosphor is in the range of 0 ≦ x 1 ≦ 0.3, preferably 0.001 ≦ x 1 ≦ 0.25, more preferably 0.1 ≦ x 1 ≦ 0.15. When the value of x1 exceeds 0.3, the luminescence atoms become high in concentration and close to each other to cancel the luminescence, and thus the luminescence intensity is likely to be weak. Further, the molar ratio of the krypton in the phosphor, that is, the value of the above y1 is in the range of 0 ≦ y1 ≦ 0.3, preferably in the range of 0 ≦ y1 ≦ 0.1, more preferably in the range of 0 ≦ y1 ≦ 0.0001. Inside. The value of x1 + y1 is in the range of 0 < x1 + y1 ≦ 0.6, preferably in the range of 0.001 ≦ x 1 + y1 ≦ 0.25, more preferably in the range of 0.1 ≦ x 1 + y1 ≦ 0.15. Also included in the present invention is the case where the composition of Eu is not contained, that is, the case where the value of x1 is 0; or the case where the composition of Ce is not contained, that is, the value of y1 is 0, but it must be at least containing Eu or The composition of any element in Ce, that is, the composition of x1+y1>0.

Further, in the phosphor of the present invention, the molar ratio of strontium (Sr) in the phosphor is in the range of 2 ≦ a ≦ 8, preferably in the range of 4 ≦ a ≦ 8, more preferably 4.5. Within the range of ≦a≦6, it is more preferably in the range of 4.75 ≦ a ≦ 5.25. When the value of a is in the range of 2≦a≦8, a green phosphor having a half-value width and a high brightness can be obtained.

Further, in the phosphor of the present invention, the M1 is one or more metal elements selected from the group consisting of calcium (Ca), barium (Ba), and magnesium (Mg), and the value of b is preferably 0. Within the range of ≦b≦3. Also included in the present invention is a case where the composition of any of Ca, Ba, and Mg is not contained, that is, the case where the value of b is zero.

Further, in the phosphor of the present invention, the molar ratio of aluminum (Al) in the phosphor is in the range of 2 ≦ c ≦ 7, preferably in the range of 3 ≦ c ≦ 7, preferably 4 Within the range of ≦c≦6. When the value of c is in the range of 2 ≦ c ≦ 7, a green phosphor having a half-value width and a high brightness can be obtained.

Further, in the phosphor of the present invention, the molar ratio of cerium (Si) in the phosphor is in the range of 10 ≦d ≦ 25, preferably in the range of 15 ≦ d ≦ 25, more preferably 19.5. Within the range of ≦d≦22.5, more preferably within the range of 20.5≦d≦21.5. When the value of d is in the range of 10 ≦d ≦ 25, a green phosphor having a half-value width and a high brightness can be obtained.

Further, in the phosphor of the present invention, the molar ratio of nitrogen (N) in the phosphor is in the range of 15 ≦e ≦ 37, preferably in the range of 32 ≦ e ≦ 37, more preferably 34. Within the range of ≦e≦36, it is more preferably within the range of 34.5 ≦e ≦ 35.5. When the value of e is in the range of 15 ≦e ≦ 37, a green phosphor having a half-value width and a high brightness can be obtained.

Further, in the phosphor of the present invention, the molar ratio of oxygen (O) in the phosphor is in the range of 0 ≦ f ≦ 3, preferably in the range of 0.1 ≦ f ≦ 2.3. When the value of f is in the range of 0 ≦ f ≦ 3, a green phosphor having a high half-value width and high brightness can be obtained.

Here, the phosphor of the present invention is characterized by further containing boron. The content of boron relative to the entire phosphor is 100 to 2,500 ppm, preferably 200 to 1,500 ppm, more preferably 300 to 1,500 ppm. If the boron content is less than 100 ppm, the luminescence intensity will not increase, even if it is much more At 2500 ppm, the luminescence intensity also became low. The boron content can be measured using an inductively coupled plasma emission spectroscopy (ICP-AES) apparatus.

Further, in the phosphor of the present invention, the boron element concentration on the outermost surface of the phosphor is preferably from 20,000 to 100,000 ppm, more preferably from 30,000 to 60,000 ppm. In the present invention, the concentration of the boron element on the outermost surface of the phosphor may be defined as the concentration of the boron element measured at a depth of several nm from the outer side when the X-ray is irradiated to the outermost surface of the phosphor. The concentration of boron element on the outermost surface of the phosphor can be measured using an X-ray photoelectron spectroscopy (XPS) apparatus.

In many cases, the composition of the phosphor particles differs from the inside of the particle surface in the vicinity of the particle surface, and the composition variation is confirmed. In the present invention, a depth region of 100 nm (outside ~100 nm) from the outermost surface of the phosphor may be defined as a phosphor surface, and a depth region exceeding the surface of the phosphor (more than 100 nm from the outside) may be defined as fluorescence. Inside the body. No composition changes were observed inside the phosphor.

Preferably, the phosphor of the present invention has a boron element concentration on the outermost surface of the phosphor higher than a boron element concentration in the phosphor. If the concentration of the boron element on the outermost surface of the phosphor is higher than the concentration of the boron element in the phosphor, a green phosphor having a half-value width and a high brightness can be obtained. Specifically, the concentration of the boron element on the outermost surface of the phosphor is preferably about 5 to 8 times the concentration of the element of boron existing inside the inner surface of 200 nm from the outermost surface of the phosphor. The concentration of boron in the interior of 200 nm from the outermost surface of the phosphor can be defined as the number of surfaces after etching from the surface of the phosphor to 200 nm after the surface of the phosphor is irradiated with X-rays. The elemental concentration of boron measured at the depth can be measured using an X-ray photoelectron spectroscopy (XPS) apparatus.

Further, the phosphor of the present invention preferably has a half value width of the emission spectrum of 70 nm or less. Here, the half value width means that when the vertical axis is the light emission intensity and the horizontal axis is the wavelength, when the measurement emission spectrum is measured and the light emission intensity at the peak is set to I, the time becomes I/2. wavelength width. When the half value width is relatively narrow as described above, high luminous intensity can be obtained.

Further, the phosphor of the present invention is derived from a phosphor of a structure of Sr ₅ Al ₅ Si ₂₁ N ₃₅ O _{2 in an} X-ray diffraction pattern measured by an X-ray diffraction (XRD) apparatus. 021) The diffraction peak intensity of the surface is set to A, and when the diffraction peak intensity of the (221) plane of the phosphor of the SrAlSi ₄ N ₇ structure is B, B/A < 0.03, preferably B/A <0.01, more preferably B/A=0. The structure of Sr ₅ Al ₅ Si ₂₁ N ₃₅ O ₂ is a crystal structure having the same shape as ICSD Coll Code: 420168, and also contains a metal of one or more selected from the group consisting of Ca, Ba, and Mg. The crystalline structure of the phosphor substituted by the element. Further, the SrAlSi ₄ N ₇ structure is a crystal structure having the same shape as ICSD Coll Code: 163667, and also contains a part of Sr which is replaced by one or more metal elements selected from the group consisting of Ca, Ba, and Mg. The crystal structure of the light body. In the present invention, B/A < 0.03 means that the amount of crystals of the SrAlSi ₄ N ₇ structure contained in the phosphor of the present invention in the form of a hetero phase (impurity) is small. Since the amount of crystals of the SrAlSi ₄ N ₇ structure is small, a high-luminance green phosphor having a half-value width of the emission spectrum can be obtained.

Further, the phosphor of the present invention preferably has a D ₁₀ diameter of 20 to 30 μm as measured by a laser diffraction/scattering type particle size distribution measuring apparatus. When the diameter of D ₁₀ is 20 to 30 μm, the number of particles is small and the luminous intensity is increased. When the D ₁₀ diameter exceeds 30 μm, it is difficult to uniformly disperse in the resin when the light-emitting device is formed, specifically, a white light-emitting LED, and the color tone is likely to vary.

Further, it is preferable that the phosphor of the present invention has an average value of the Heywood diameter (circular equivalent diameter) measured by a scanning electron microscope photograph of less than 32 μm. For example, the Heywood Trail can be calculated by reading the powder image using the image analysis type particle size distribution measuring software "Mac-View" manufactured by Mountech Co., Ltd. If the average value of the Heywood diameter is less than 32 μm, it can be obtained without pulverization when used especially as a light-emitting element of a white LED. It is preferred to obtain the desired particle size.

Further, the phosphor of the present invention contains a crystal phase represented by the composition of the following formula (2).

Sr _g M2 _h B _i Al _j Si _k N _l O _m :Eu _x2 Ce _y2 (2)

(here, M2 is one or more metal elements selected from the group consisting of Ca, Ba, and Mg, 2≦g≦8, 0≦h≦3, 0.02≦i≦0.8, 2≦j≦7, 10≦k≦25,15≦l≦37,0≦m≦3,0<x2+y2≦0.6).

The value of x2 above is in the range of 0 ≦ x 2 ≦ 0.3, preferably in the range of 0.001 ≦ x 2 ≦ 0.25, more preferably in the range of 0.1 ≦ x 2 ≦ 0.15. When the value of x2 exceeds 0.3, the luminescent atoms become high in concentration and close to each other to cancel the luminescence, so that the luminescence intensity is likely to be weak. Further, the value of y2 is in the range of 0 ≦ y 2 ≦ 0.3, preferably in the range of 0 ≦ y 2 ≦ 0.1, more preferably in the range of 0 ≦ y 2 ≦ 0.0001. The value of x2+y2 is in the range of 0<x2+y2≦0.6, preferably in the range of 0.001≦x2+y2≦0.25, more preferably in the range of 0.1≦x2+y2≦0.15. Also included in the present invention is a case where the composition of Eu is not contained, that is, the case where the value of x2 is 0; or the case where the composition of Ce is not contained, that is, the value of y2 is 0, but it must be at least containing Eu or The composition of any element in Ce, that is, the composition of x2+y2>0.

Further, in the phosphor of the present invention, the molar ratio of strontium (Sr) in the phosphor is in the range of 2 ≦ g ≦ 8 , preferably in the range of 4 ≦ g ≦ 8 , more preferably 4.5. Within the range of ≦g≦6, it is more preferably in the range of 4.75≦g≦5.25. When the value of g is in the range of 2 ≦ g ≦ 8 , a green phosphor having a half-value width and a high brightness can be obtained.

Further, in the phosphor of the present invention, the M2 is one or more metal elements selected from the group consisting of calcium (Ca), barium (Ba), and magnesium (Mg), and the value of h is preferably 0. ≦h Within the range of ≦3. Also included in the present invention is a case where the composition of any one of Ca, Ba, and Mg is not contained, that is, the value of h described above is zero.

Further, in the phosphor of the present invention, the molar ratio of boron (B) in the phosphor is in the range of 0.02 ≦ i ≦ 0.8, preferably 0.04 ≦ i ≦ 0.4. When the value of i is in the range of 0.04 ≦ i ≦ 0.4, a green phosphor having a half-value width and a high brightness can be obtained.

Further, in the phosphor of the present invention, the molar ratio of aluminum (Al) in the phosphor is in the range of 2≦j≦7, preferably in the range of 3≦j≦7, more preferably 4 Within the scope of ≦j≦6. When the value of j is in the range of 2≦j≦7, a green phosphor having a half-value width and a high brightness can be obtained.

Further, in the phosphor of the present invention, the molar ratio of cerium (Si) in the phosphor is in the range of 10 ≦ k ≦ 25, preferably in the range of 15 ≦ k ≦ 25, more preferably 19.5. Within the range of ≦k≦22.5, more preferably within the range of 20.5≦k≦21.5. When the value of k is in the range of 10 ≦ k ≦ 25, a green phosphor having a half-value width and a high brightness can be obtained.

Further, in the phosphor of the present invention, the molar ratio of nitrogen (N) in the phosphor is in the range of 15 ≦ ≦ 37, preferably in the range of 32 ≦ ≦ 37, more preferably 34. Within the range of ≦l≦36, more preferably within the range of 34.5 ≦l ≦ 35.5. When the value of l is in the range of 15 ≦l ≦ 37, a green phosphor having a half-value width and a high brightness can be obtained.

Further, in the phosphor of the present invention, the molar ratio of oxygen (O) in the phosphor is in the range of 0 ≦ m ≦ 3, preferably in the range of 0.1 ≦ m ≦ 2.3. In the case where the value of m is in the range of 0 ≦ m ≦ 3, a green phosphor having a half-value width and a high luminance can be obtained.

2. Method of manufacturing phosphor

The phosphor of the present invention can be produced, for example, by a production method having Preparation: mixing the Sr-containing compound, the Al-containing compound, the Si-containing compound, the Eu-containing compound and/or the Ce-containing compound, and the B-containing compound, and further mixing the M-containing compound as needed (here, the M system is selected from Ca, Ba) a step of obtaining a raw material mixture (mixing step) with one or more metal elements of the group consisting of Mg; and a step of firing the raw material mixture in an environment containing an inert gas or a reducing gas atmosphere ( The firing step); and the step of pulverizing and classifying as needed.

(1) mixing step

Each of the raw material-containing compounds containing an Sr compound, an Al-containing compound, a Si-containing compound, an Eu-containing compound, a Ce-containing compound, a B-containing compound, and an M-containing compound is separately decomposed from a nitride, an oxynitride, an oxide, or by thermal decomposition. Be selected as the precursor material for the oxide.

Specific examples of the antimony-containing (Sr) compound are not particularly limited, and for example, a group selected from the group consisting of strontium nitride (Sr ₃ N ₂ ), strontium carbonate (SrCO ₃ ), and strontium oxide (SrO) can be preferably used. A powder of cerium nitride (Sr ₃ N ₂ ) can be preferably used as the powder of one or more kinds.

Specific examples of the aluminum-containing (Al) compound are not particularly limited, and for example, aluminum nitride (AlN), aluminum oxide (Al ₂ O ₃ ), or aluminum carbonate (Al ₂ (CO ₃ ) ₃ ) can be preferably used. A powder of aluminum nitride (AlN) can be preferably used as the powder of one or more of the groups.

The specific example of the cerium (Si)-containing compound is not particularly limited, and for example, it can be preferably selected from amorphous tantalum nitride (Si ₃ N ₄ ), crystalline tantalum nitride (Si ₃ N ₄ ), and As the powder of one or more kinds of the group consisting of cerium oxide (SiO ₂ ), a powder of amorphous tantalum nitride (Si ₃ N ₄ ) or crystalline tantalum nitride (Si ₃ N ₄ ) can be preferably used.

Specific examples of the ruthenium-containing (Eu) compound are not particularly limited, and for example, ruthenium (III) oxide (Eu ₂ O ₃ ), ruthenium (II) oxide (EuO), or tantalum nitride (EuN) can be preferably used. And one or more kinds of powders of the group consisting of metal ruthenium (Eu).

The specific example of the cerium-containing (Ce) compound is not particularly limited, and for example, one selected from the group consisting of cerium nitride (CeN), cerium oxide (CeO ₂ ), and metal cerium (Ce) can be preferably used. More than one kind of powder.

Further, the present invention is characterized in that a B-containing compound is added in the range of 250 to 10,000 ppm of the raw material mixture in addition to the above-mentioned raw material-containing compound. By adding 250 to 10,000 ppm of the B-containing compound, 100 to 2,500 ppm of boron can be contained in the obtained phosphor. Further, when the B-containing compound is not added, the obtained phosphor contains a large amount of crystals of a SrAlSi ₄ N ₇ structure which is a hetero phase (impurity), but it is understood that by adding a B-containing compound of 250 to 10000 ppm, The amount of crystallization of the SrAlSi ₄ N ₇ structure can be reduced. The amount of the compound containing B is preferably from 750 to 10,000 ppm, more preferably from 1,000 to 5,000 ppm.

Specific examples of the boron-containing (B) compound are not particularly limited, and for example, boron nitride (BN), boron oxide (B ₂ O ₃ ), or boron oxyhydroxide (B(OH) ₃ ) can be preferably used. One or more kinds of powders of the group formed.

Further, in the present invention, the M-containing compound (here, M is selected from one or more metal elements selected from the group consisting of Ca, Ba, and Mg) may be mixed as needed.

Specific examples of the calcium-containing (Ca) compound in the M-containing compound are not particularly limited, and for example, calcium hydride (Ca ₃ N ₂ ), calcium carbonate (CaCO ₃ ), calcium oxide (CaO) can be preferably used. One or more kinds of powders of the group consisting of.

Specific examples of the cerium (Ba)-containing compound in the M-containing compound are not particularly limited, and for example, barium nitride (Ba ₃ N ₂ ), barium carbonate (BaCO ₃ ), barium oxide (BaO) can be preferably used. One or more kinds of powders of the group consisting of.

Specific examples of the magnesium-containing (Mg) compound in the M-containing compound are not particularly limited, and for example, magnesium oxynitride (Mg ₃ N ₂ ), magnesium carbonate (MgCO ₃ ), and magnesium oxide (MgO) can be preferably used. One or more kinds of powders of the group consisting of.

These raw material-containing compounds may be used alone or in combination of two or more. Each of the raw material-containing compounds preferably has a purity of 99% by mass or more. In the above-mentioned raw material-containing compound, since the mixing ratio is substantially directly equal to the composition ratio of the formula (1), the mixing ratio is adjusted so as to have a desired composition ratio. However, since the amount of oxygen and the amount of nitrogen are not always fixed, the mixing ratio of the raw materials can be set in consideration of the oxygen content and the nitrogen content contained in the raw materials, thereby adjusting the target oxygen amount and nitrogen amount.

Further, in the firing, in order to promote sintering and to form at a lower temperature, a Li-containing compound to be a sintering aid may be added. Examples of the Li-containing compound to be used include lithium oxide, lithium carbonate, lithium metal, and lithium nitride, and each of these powders may be used alone or in combination. In addition, the amount of the Li-containing compound to be added is preferably 0.01 to 0.5 mol, based on the Li element, per mol of the fired product obtained in the calcination step described below. The Li-containing compound is easily volatilized in the firing step and is hardly contained in the phosphor powder.

The mixing method of the raw material powder is not particularly limited, and a method known per se, for example, a method of dry mixing, a method of removing the solvent after wet mixing in an inert solvent which does not substantially react with each component of the raw material, and the like may be employed. . As the mixing device, a V-type mixer, a rolling mixer, a ball mill, a vibrating machine, a medium agitating mill or the like is preferably used.

(2) firing step

Next, the raw material mixture is fired. The firing of the raw material mixture is preferably carried out in an inert gas atmosphere or in a reducing gas atmosphere. The inert gas atmosphere can be made of nitrogen or argon. A rare gas or an inert gas such as a mixed gas. In order to be an inert gas atmosphere, it is preferable to contain no oxygen, but it may contain oxygen as an impurity to the extent of not more than 0.1 vol% (and further less than 0.01 vol%). Further, the reducing gas atmosphere may be composed of a mixed gas of a rare gas such as nitrogen or argon and hydrogen or carbon monoxide gas. In order to be a reducing gas atmosphere, it is preferable to contain no oxygen, but it is also possible to contain oxygen as an impurity to a level of less than 0.1 vol% (and further less than 0.01 vol%). The firing temperature is in the range of 1500 to 2000 ° C, more preferably 1600 to 1800 ° C. The firing time is usually in the range of 0.5 to 100 hours, preferably in the range of 0.5 to 20 hours. The firing pressure may be at least normal pressure, preferably less than 0.92 MPa. The amount of oxygen and the amount of nitrogen in the target phosphor can be adjusted by changing the type of the ambient gas, the oxygen concentration and the nitrogen concentration in the ambient gas, the firing temperature, and the firing time.

(3) Smashing and grading steps

The phosphor obtained by firing does not need to be pulverized, for example, in the case of being used as a light-emitting element of a white LED, the desired particle size can be obtained, but further, pulverization is carried out as needed, and is classified as necessary as necessary. Particle size range. In this case, the pulverization method may be any one of wet pulverization and dry pulverization, and, for the classification method, any one of the operation methods generally used for grading the powder such as the sieving operation and the application of the fluid may be used. . Further, the phosphor obtained by firing may be subjected to an acid cleaning treatment or a baking treatment using a mineral acid such as hydrochloric acid or nitric acid as needed.

3. Light-emitting device

The phosphor of the present invention can be used in various light-emitting devices. The light-emitting device of the present invention includes at least a phosphor of the present invention containing 100 to 2,500 ppm of boron in the composition represented by the above formula (1), and a light source that emits excitation light to the phosphor. Specific examples of the light-emitting device include a white light-emitting diode (white LED), a fluorescent lamp, and a fluorescent display tube (VFD). Cathode ray tube (CRT), plasma display panel (PDP), field emission display (FED), and the like. The white LED is a light-emitting device including a blue phosphor, a red phosphor, a phosphor (green phosphor) of the present invention, and a semiconductor light-emitting device that emits ultraviolet light having a wavelength of 350 to 430 nm, for example, and utilizes The ultraviolet light from the light-emitting element excites the blue phosphor, the green phosphor, and the red phosphor, and white light is obtained by using a mixture of blue, red, and green. Further, the other configuration may be applied to a light-emitting device including a red phosphor, a phosphor (green phosphor) of the present invention, and a semiconductor element emitting blue light having a wavelength of 430 to 500 nm, and using a light-emitting element. The blue light excites the green phosphor and the red phosphor, and the white, red, and green colors are used to obtain white light.

Examples of the blue light-emitting phosphor include (Ba, Sr, Ca) ₃ MgSi ₂ O ₈ :Eu, (Ba, Sr, Ca) MgAl ₁₀ O ₁₇ :Eu, (Ba, Sr, Mg, Ca ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Eu and the like. Further, examples of the red light-emitting phosphor include (Ba, Sr, Ca) ₃ MgSi ₂ O ₈ : Eu, Mn, Y ₂ O ₂ S: Eu, La ₂ O ₃ S: Eu, (Ca, Sr, Ba) ₂ Si ₅ N ₈ :Eu, CaAlSiN ₃ :Eu, Eu ₂ W ₂ O ₉ , (Ca, Sr, Ba) ₂ Si ₅ N ₈ :Eu, Mn, CaTiO ₃ :Pr, Bi, (La , Eu) ₂ W ₃ O _12, etc. Examples of the semiconductor light-emitting device include an AlGaN-based semiconductor light-emitting device.

[Examples]

Hereinafter, the present invention will be specifically described based on examples, but these are not intended to limit the object of the present invention. First, each measurement method used in the present embodiment is disclosed.

(identification of crystalline phase)

The crystal phase was identified using an X-ray diffraction (XRD) apparatus (Ultima IV, manufactured by Rigaku Corporation).

(particle size distribution measurement)

The particle size distribution measurement was performed using a laser diffraction/scattering particle size distribution measuring apparatus (MT3300EX II manufactured by Nikkiso Co., Ltd.).

(Scanning Electron Microscope Photo, Heywood Trail)

A scanning electron microscope photograph was taken using a scanning electron microscope (JSM-6510 manufactured by JEOL Ltd.). Further, the image analysis type particle size distribution measurement software "Mac-View" (manufactured by Mountech Co., Ltd.) was used, and a scanning electron microscope photograph was read to calculate the Heywood diameter.

(fluorescence peak wavelength, luminescence intensity, half value width of the spectrum)

Using a spectrofluorometer (manufactured by JASCO Corporation, FP-6500), a fluorescence spectrum at an excitation wavelength of 450 nm was measured, and the peak wavelength of the fluorescence, the intensity of the emission at the wavelength, and the half value width of the spectrum were determined. The luminescence intensity was expressed as 100% of the luminescence intensity of the peak wavelength of 522.0 nm of Comparative Example 1.

(boron content)

The boron content in the phosphor powder was quantitatively analyzed using an inductively coupled plasma emission spectrometry (ICP-AES) apparatus (Seiko Electronics Nanotechnology Co., Ltd., SPS3250UV).

(The concentration of the most surface element of the phosphor of boron, the concentration of elements inside)

X-ray photoelectron spectroscopy (XPS) device (PHI1800 manufactured by Ulvac-Phi Co., Ltd.), under the condition of X-ray source: Al-K α, sweep angle: 45° from the surface, investigates the presence of fluorescence The element on the outermost surface of the body (available from the outer side up to several nm), and the elemental concentration of the outermost surface of the phosphor of boron is estimated from the peak intensity of each element.

(Comparative Example 1)

Oxide (Eu ₂ O ₃ ) powder (purity: 99.9%), tantalum nitride (Sr ₃ N ₂ ) powder (purity: 99%), amorphous tantalum nitride (Si ₃ N ₄ ) powder (purity : 99%), aluminum nitride (AlN) powder (purity: 99.9%), lithium carbonate (Li ₂ CO ₃ ) powder (purity: 99.9%) in the form of a mixed composition of Table 1 in a nitrogen-washed glove box The inside was weighed and mixed using a dry vibrator for 1 hour to obtain a mixed powder. The obtained mixed powder is placed in a crucible made of tantalum nitride, and added to a graphite resistance heating type electric furnace, and while nitrogen gas is passed through the electric furnace, the temperature is raised to 1,650 ° C while maintaining normal pressure. The temperature was maintained at 1650 ° C for 7 hours, and further heated to 1730 ° C, and kept at 1730 ° C for 10 hours to obtain a fired product. The obtained sample was crushed by a mortar made of tantalum nitride until it passed through a sieve having a mesh size of 32 μm. The evaluation results obtained by measuring XRD, particle size distribution, fluorescence spectrum, ICP, and XPS (PHI1800) of the obtained powder are shown in Table 2. Further, an XRD pattern is shown in Fig. 1, an emission spectrum is shown in Fig. 2, and a scanning electron microscope photograph is shown in Fig. 3.

As a result of XRD measurement, the XRD pattern shown in Fig. 1 was obtained. The synthetic powder is a mixed phase of the Sr ₅ Al ₅ Si ₂₁ N ₃₅ O ₂ structure with the SrAlSi ₄ N ₇ structure. The intensity of the diffraction peak from the (021) plane near the 25.8° of the Sr ₅ Al ₅ Si ₂₁ N ₃₅ O ₂ structure (A) and the diffraction of the (221) plane near the 24.9° of the SrAlSi ₄ N ₇ structure The ratio (B/A) of the peak intensity (B) was 2.75. Further, as a result of measuring the particle size distribution, the D ₁₀ diameter was 13.8 μm. As a result of measurement by ICP and XPS, boron was not detected. When excited at a wavelength of 450 nm, the emission spectrum shown in Fig. 2 was obtained. Although the peak wavelength is 522.0 nm and is green, the half-value width is 111.1 nm, and it becomes a light-emitting component containing a red component. Further, according to the scanning electron micrograph shown in Fig. 3, the primary particle diameter before the pulverization of Comparative Example 1 was large, and the average value of the Heywood diameter was 35.9 μm, and it was necessary to pulverize when grading by a sieve having a mesh size of 32 μm. Therefore, the smashing debris increases.

(Examples 1 to 6)

Examples 1 to 6 were carried out in the same manner as in Comparative Example 1, except that boron nitride (BN) powder (purity: 99%) was added as in Table 1. The evaluation results of the synthetic powder are shown in Table 2. As a result of XRD measurement, the intensity of the diffraction peak from the (021) plane of the Sr ₅ Al ₅ Si ₂₁ N ₃₅ O ₂ structure located near 25.8° (A) and the structure of the SrAlSi ₄ N ₇ structure located near 24.9° (from 221) The ratio (B/A) of the intensity (B) of the diffraction peak of the surface is less than 0.03, especially the B/A of the examples 2 to 6 is 0, and the structure of the structure of Sr ₅ Al ₅ Si ₂₁ N ₃₅ O ₂ is obtained. phase. Further, as a result of measuring the particle size distribution, the D ₁₀ diameter was 14.6 to 24.5 μm. The XRD pattern of Example 5 is shown in FIG.

As a result of ICP measurement, the boron content increases with the amount of boron added, and is 110 to 2300 ppm. Further, as a result of XPS measurement, the elemental concentration of boron on the outermost surface of the phosphor is 14,000 to 92,000 ppm. Further, the emission peak wavelength when excited at a wavelength of 450 nm was green at 520.5 to 524.0 nm, and the relative luminescence intensity at 13% when Comparative Example 1 was 100% was 132.5 to 194.9%. The half value width of the emission spectrum is 67.3 to 76.4 nm. The emission spectrum of Example 5 is shown in Fig. 2, and the scanning electron micrograph of Example 5 is shown in Fig. 3.

In Examples 1 to 6, the boron content was in the range of 100 to 2,500 ppm, so that a single phase having a structure of Sr ₅ Al ₅ Si ₂₁ N ₃₅ O ₂ and having few particles and a high-intensity fluorescence with a narrow half-value of the emission spectrum were obtained. body. Further, according to the scanning electron micrograph before the pulverization of Example 5 shown in Fig. 3, it was confirmed that Example 5 was that the primary particle diameter was smaller than that of Comparative Example 1, and the average value of the Heywood diameter at this time was 26.8. Μm, and it is not necessary to pulverize when grading by a sieve having a mesh size of 32 μm, so that the number of particles is small and the particle diameter is uniform.

Further, with respect to the sample of Example 5, an X-ray photoelectron spectroscopy (XPS) apparatus (PHI5000 manufactured by Ulvac-Phi Co., Ltd.) was used, and the X-ray source: Al-K α, plucking angle: 45° to the surface. The element concentration of boron on the surface after argon etching to a depth of 200 nm was measured in terms of SiO _{2 in} the condition of SiO ₂ . The results are shown in Table 3 and Figure 4. The concentration of boron on the outermost surface of the phosphor using XPS is 55000 ppm. The concentration of boron element decreases toward the inside of the particle, and the concentration of boron element at a depth of 100 nm or more from the outermost surface of the phosphor (measures the surface after etching) , asymptotic to about 9000ppm.

(Comparative examples 2 to 4)

Comparative Examples 2 to 4 were carried out in the same manner as in Example 1 except that the amount of boron nitride (BN) powder (purity: 99%) was changed as shown in Table 1. The evaluation results of the synthetic powder are shown in Table 2. As a result of XRD measurement, the intensity of the diffraction peak from the (021) plane (A) and the structure of the SrAlSi ₄ N ₇ structure near the 25.8° of the Sr ₅ Al ₅ Si ₂₁ N ₃₅ O ₂ structure are from 24.9°. The ratio (B/A) of the intensity (B) of the diffraction peak of the (221) plane is 0.04 to 0.21, and becomes a mixed phase of the structure of Sr ₅ Al ₅ Si ₂₁ N ₃₅ O _{2 and the} structure of SrAlSi ₄ N ₇ . As a result of the measurement of the particle size distribution, the D ₁₀ diameter was 11.5 to 17.0 μm. As a result of ICP measurement, the boron content was 54 ppm in Comparative Example 2, 84 ppm in Comparative Example 3, and 3600 ppm in Comparative Example 4. Further, as a result of XPS measurement, the element concentration of boron on the outermost surface of the phosphor of Comparative Example 2 was 8000 ppm, and the element concentration of boron on the outermost surface of the phosphor of Comparative Example 3 was 12,000 ppm, and boron of Comparative Example 4 was used. The elemental concentration on the outermost surface of the phosphor was 120000 ppm. The luminescence peak wavelength was green at 523.0 to 524.0 nm, and the relative luminescence intensity at the time when Comparative Example 1 was 100% was 113.4 to 120.1%. The half value width of the emission spectrum is 78.5 to 90.9 nm.

In Comparative Examples 2 to 4, since the boron content was outside the range of 100 to 2,500 ppm, a high-luminance phosphor having a half-value width of the emission spectrum could not be obtained.

Claims (10)

A phosphor comprising a crystal phase represented by the composition of the following formula (1), characterized in that it further contains 100 to 2,500 ppm of boron; and Sr _a M1 _b Al _c Si _d N _e O _f :Eu _x1 Ce _y1 (1) (here, M1 is one or more metal elements selected from the group consisting of Ca, Ba, and Mg, 2≦a≦8, 0≦b≦3, 2≦c≦7, 10≦d≦25 , 15≦e≦37,0≦f≦3,0<x1+y1≦0.6). For example, the phosphor of claim 1 is 4, a ≦ 8, 3 ≦ c ≦ 7, 15 ≦ d ≦ 25, 32 ≦ e ≦ 37. A phosphor according to claim 1 or 2, wherein the concentration of boron element on the outermost surface of the phosphor measured by an X-ray photoelectron spectroscopy (XPS) device is 20,000 to 100,000 ppm. The phosphor according to any one of claims 1 to 3, wherein a half value width of the emission spectrum is 70 nm or less. A phosphor comprising at least a crystalline phase of a structure of Sr ₅ Al ₅ Si ₂₁ N ₃₅ O ₂ , characterized by: X-ray diffraction of a phosphor of a structure of Sr ₅ Al ₅ Si ₂₁ N ₃₅ O _{2 in a} pattern The diffraction peak intensity from the (021) plane is set to A, and when the diffraction peak intensity from the (221) plane of the phosphor of the SrAlSi ₄ N ₇ structure is B, B/A < 0.03. A phosphor comprising a crystal phase represented by the composition of the following formula (2): Sr _g M2 _h B _i Al _j Si _k N _l O _m : Eu _{x 2} Ce _y2 (2) (here, M2 is selected One or more metal elements of a group consisting of free Ca, Ba, and Mg, 2≦g≦8, 0≦h≦3, 0.02≦i≦0.8, 2≦j≦7,10≦k≦25,15 ≦l≦37,0≦m≦3,0<x2+y2≦0.6). For example, the phosphor of claim 6 is 4, g≦8, 3≦j≦7, 15≦k≦25, 32≦l≦37. A method for producing a phosphor, comprising the steps of: mixing a Sr-containing compound, an Al-containing compound, an Si-containing compound, an Eu-containing compound and/or a Ce-containing compound, and a B-containing compound to obtain a raw material mixture; The step of firing the raw material mixture in an inert gas atmosphere or a reducing gas atmosphere is characterized in that the B-containing compound is added in an amount of from 250 to 10,000 ppm of the raw material mixture. The method for producing a phosphor according to claim 8, wherein the Sr-containing compound is Sr ₃ N ₂ , the Al-containing compound is AlN, and the Si-containing compound is Si ₃ N ₄ . A light-emitting device comprising the phosphor of any one of claims 1 to 7 and a light source that emits excitation light to the phosphor to emit light.