TW201625774A - Phosphor, light emitting device, illumination device and image display device - Google Patents

Abstract

To provide a novel phosphor, which is effectively used for LED, having a narrow full-width at half-maximum of an emission spectrum and having a different crystal structure from those of conventional phosphors. The phosphor comprising an element M, an element A, Al, Si and N and comprising a monoclinic crystalline phase, Wherein each lattice constant of the crystalline phase satisfies in the axis a, 7.7 Å ≤ a ≤ 8.51 Å in the axis b, 8.64 Å ≤ b ≤ 9.55 Å, in the axis c, 8.53 Å ≤ c ≤ 9.43 Å, in the angle [beta], 97.6 DEG ≤ [beta] ≤ 115.6 DEG. (wherein the element M represents one or more kinds selected from activation elements and the element A represents one or more kinds selected from alkali earth metal elements).

Description

Phosphor, illuminating device, illuminating device and image display device

The present invention relates to a phosphor, a light-emitting device, a lighting device, and an image display device.

In recent years, due to the trend of energy saving, the demand for using LEDs (Light Emitting Diodes) as illumination or backlights has been increasing. The LED used herein is a white light-emitting LED in which a phosphor is disposed on an LED chip emitting light of blue or near-ultraviolet wavelength. As a white light-emitting LED of this type, in recent years, a nitride phosphor that emits red light by using blue light from a blue LED chip as excitation light and green light is used. Fluorescent body. Especially in the display application, among the three colors of blue, green and red, the visibility of the green to the human eye is particularly high, which greatly contributes to the overall brightness of the display, and therefore is particularly important compared with the other two colors. Developed a green phosphor with excellent luminescence properties. As a phosphor that emits green light, for example, a composite oxynitride represented by a composition formula of Ba ₃ Si ₆ O ₁₂ N ₂ :Eu,Ce has been developed as a broadband-based phosphor (Patent Document 1).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] International Publication No. 2007/088966

Although various types of phosphors have been developed as described above, for example, in the case of display applications, in view of color rendering properties, a phosphor having a narrow half-value width of an emission spectrum is desired. The present invention has been made in view of the above problems, and provides a novel phosphor having a narrow half-value width of an emission spectrum and having a crystal structure different from that of a conventional phosphor, and can be effectively used for LED applications.

In view of the above problems, the inventors of the present invention have diligently studied the novel exploration of phosphors, and as a result, it has been conceived to have a novel phosphor having a crystal structure different from that of a conventional phosphor and which can be effectively used for LED applications. this invention. The invention is as follows.

<1> A phosphor comprising a crystal phase containing monoclinic crystals such as M element, A element, Al, Si, N, etc.; wherein a lattice constant of the crystal phase satisfies an a-axis of 7.7 Å, respectively. ≦a≦8.51Å, the b-axis is 8.64 Åb≦9.55Å, the c-axis is 8.53 Åc≦9.43Å, and the β angle is 97.6°≦β≦115.6°, (wherein the M element is selected from the activating element) One or more elements, and the A element means one or more elements selected from the group consisting of alkaline earth metal elements).

The phosphor described in the above [1], wherein the crystal phase has a composition represented by the following formula [1], and M _m A _a Al _b Si _c N _d [1] (the above formula [1] In the above, the M element represents one or more elements selected from the group consisting of active elements, and the A element represents one or more elements selected from the group consisting of alkaline earth elements, and m, a, b, c, and d are each independently satisfying the following formula. Value, 0 < m ≦ 0.2 m + a = 1 0.8 ≦ b ≦ 1.2 3.2 ≦ c ≦ 4.8 5.6 ≦ d ≦ 8.4).

<3> The phosphor described in <1> or <2>, wherein the A element contains Ca and/or Sr.

The phosphor described in any one of <1> to <3> wherein the M element contains Eu.

The phosphor described in any one of <1> to <4> which has excitation light having a wavelength of 350 nm or more and 460 nm or less, and has a range of 500 nm or more and 560 nm or less. Luminous peak wavelength.

<6> A light-emitting device comprising: a first light-emitting body; and a second light-emitting body that emits visible light by irradiation of light from the first light-emitting body, wherein the second light-emitting body The phosphor includes the phosphor described in any one of <1> to <5>.

<7> A lighting device comprising the light-emitting device described in <6> as a light source.

<8> An image display device comprising the light-emitting device described in <6> as a light source.

The novel phosphor of the present invention has a narrow half-value width of an emission spectrum and has a crystal structure different from that of a conventional phosphor, and can be effectively used for LED applications. Therefore, the light-emitting device using the novel phosphor of the present invention is excellent in color rendering property. Further, the illumination device and the image display device including the light-emitting device of the present invention have high quality.

Fig. 1 is a view showing a powder X-ray diffraction (XRD) pattern of the phosphor obtained in Example 1.

2 is an image obtained by using a scanning electron microscope (photograph of a substitute image) of the phosphor obtained in Example 1. FIG.

Fig. 3 is a graph showing the results of measurement by electron probe micro analysis (EPMA) of the phosphor obtained in Example 1. Furthermore, the C peak is due to the coating.

4 is a view showing an XRD pattern obtained by simulation of the phosphor obtained in Example 1 and a powder X-ray diffraction pattern obtained by a transmission method.

Figure 5 is a graph showing the excitation-luminescence spectrum of the phosphor obtained in Example 1. Figure. The dotted line indicates the excitation spectrum, and the solid line indicates the luminescence spectrum.

Fig. 6 is a graph showing the temperature characteristics (relative intensity when the luminescence peak intensity at 25 ° C is 100%) of the phosphor obtained in Example 1 and the phosphor of Comparative Example 1.

Fig. 7 is a view showing the XRD pattern of the phosphor obtained in Examples 2 and 4.

Fig. 8 is a graph showing the luminescence spectra of the phosphors obtained in Examples 2 to 4.

Fig. 9 is a view showing the XRD pattern of the phosphor obtained in Example 5.

Fig. 10 is a view showing the luminescence spectrum of the phosphor obtained in Example 5.

Fig. 11 is a view showing the XRD pattern of the phosphor obtained in Example 7.

Fig. 12 is a view showing the luminescence spectra of the phosphors obtained in Examples 7 and 8.

Fig. 13 is a luminescence spectrum calculated by simulation in the light-emitting device of Example 10.

Fig. 14 is a chart showing the luminescence spectrum calculated by simulation in the light-emitting device of Example 11.

Fig. 15 is a luminescence spectrum calculated by simulation in the light-emitting device of Example 12.

Fig. 16 is a luminescence spectrum calculated by simulation in the light-emitting device of Example 13.

Fig. 17 is a chromaticity range calculated by simulation in the light-emitting device of the thirteenth embodiment.

Fig. 18 is a luminescence spectrum calculated by simulation in the light-emitting device of Example 14.

Fig. 19 is a chromaticity range calculated by simulation in the light-emitting device of the fourteenth embodiment.

In the following, the present invention is not limited to the embodiments and the examples, and the present invention is not limited to the embodiments described below, and the invention can be carried out without departing from the spirit and scope of the invention. In addition, the numerical range represented by the "~" in this specification means the numerical value contained in the before and after "~" as a range of a lower limit and an upper limit. Further, in the composition formula of the phosphor in the present specification, the division of each composition formula is represented by a dot (,). Further, when a plurality of elements are arranged by a comma (,), it is indicated that one or two or more elements including the listed elements can be arbitrarily combined and composed. For example, the composition formula of "(Ca,Sr,Ba)Al ₂ O ₄ :Eu" is considered to generally represent the following: "CaAl ₂ O ₄ :Eu", "SrAl ₂ O ₄ :Eu", "BaAl ₂ O ₄ :Eu", "Ca _1-x Sr _x Al ₂ O ₄ :Eu", "Sr _1-x Ba _x Al ₂ O ₄ :Eu", "Ca _1-x Ba _x Al ₂ O ₄ :Eu", And "Ca _1-xy Sr _x Ba _y Al ₂ O ₄ :Eu" (wherein, where 0 < x < 1, 0 < y < 1, 0 < x + y < 1).

The present invention includes a phosphor as a first embodiment, a light-emitting device as a second embodiment, an illumination device as a third embodiment, and a video display device as a fourth embodiment.

<About phosphor>

The fluorescent system according to the first embodiment of the present invention comprises a crystal phase containing monoclinic crystals such as M element, A element, Al, Si, N, etc., and the lattice constant of the crystal phase satisfies the a-axis of 7.7 Å, respectively. a ≦ 8.51 Å, the b-axis is 8.64 Å ≦ b ≦ 9.55 Å, the c-axis is 8.53 Å ≦ c ≦ 9.43 Å, and the β angle is 97.6 ° ≦ β ≦ 115.6 °. In the above, the M element represents one or more elements selected from the group consisting of active elements, and the A element represents one or more elements selected from the group consisting of alkaline earth metal elements.

The M element is selected from the group consisting of Eu (Eu), Manganese (Mn), Ce (Ce), and Pr (Pr). One or more elements selected from the group consisting of Nd, Sm, Tb, Dy, Ho, Er, Tm, and Yb . M preferably contains at least Eu, more preferably Eu.

Further, Eu may be replaced by at least one element selected from the group consisting of Ce, Pr, Sm, Tb, and Yb, and is more preferably Ce in terms of luminescence quantum efficiency. That is, M is further preferably Eu and/or Ce, and more preferably Eu.

The ratio of Eu to the entire active element is preferably 50 mol% or more, more preferably 70 mol% or more, and particularly preferably 90 mol% or more.

The A element represents one or more elements selected from the group consisting of alkaline earth metal elements. The alkaline earth metal element is preferably magnesium (Mg), calcium (Ca), strontium (Sr) or barium (Ba), further preferably Ca, Sr, Ba, more preferably Ca and/or Sr, and particularly preferably Sr. These elements may also be replaced with other divalent metals, such as zinc (Zn). These elements may also be replaced with a rare earth element. The rare earth element to be substituted is preferably lanthanum (La), yttrium (Y) or lanthanum (Lu), more preferably lanthanum (La) or yttrium (Y), and particularly preferably lanthanum (La).

Al represents aluminum. Al can also utilize other trivalent elements that are chemically similar, such as boron (B), gallium (Ga), indium (In), strontium (Sc), ytterbium (Y), lanthanum (La), yttrium (Gd), yttrium. Part of the replacement of (Lu).

Si means 矽. Si may also be substituted with a chemically similar other tetravalent element such as germanium (Ge), tin (Sn), titanium (Ti), zirconium (Zr), hafnium (Hf) or the like.

In the formula (1), N represents a nitrogen element. N may be substituted with a part of other elements such as oxygen (O), a halogen atom (fluorine (F), chlorine (Cl), bromine (Br), iodine (I)).

Further, as for oxygen, it is conceivable that it is mixed as an impurity in the raw material metal, when it is introduced in a manufacturing process such as a pulverization step, a nitridation step, or the like, In the phosphor of this embodiment, it is an inevitable incorporation. Further, in the case where a halogen atom is contained, it is conceivable to be mixed as an impurity in the raw material metal, or introduced in a manufacturing process such as a pulverization step or a nitridation step, and the like, particularly in the case where a halide is used as a flux. There are cases included in the phosphor.

The phosphor of the first embodiment of the present invention is preferably one of the above-mentioned phosphors, and the crystal phase thereof has a composition represented by the following formula [1].

M _m A _a Al _b Si _c N _d [1]

(In the above formula [1], the M element represents one or more elements selected from the group consisting of active elements, and the A element represents one or more elements selected from the group consisting of alkaline earth elements, and m, a, b, c, and d are independent. To satisfy the value of the following formula; 0<m≦0.2

m+a=1

0.8≦b≦1.2

3.2≦c≦4.8

5.6≦d≦8.4)

The aspects of the M element, the A element, the Al, Si, N in the formula [1] and preferred aspects are as described above.

m represents the content of the activating element M, and the range thereof is usually 0 < m ≦ 0.2, the lower limit value is preferably 0.001, more preferably 0.02, and the upper limit thereof is preferably 0.15, more preferably 0.1, particularly preferably Is 0.08.

a represents the content of the A element. The relationship between m and a usually satisfies m+a=1.

b represents the content of Al, and its range is usually 0.8≦b≦1.2, the lower limit The value is preferably 0.9, and the upper limit is preferably 1.1.

c represents the content of Si, and the range thereof is usually 3.2 ≦ c ≦ 4.8, the lower limit value is preferably 3.6, more preferably 3.8, and the upper limit value is preferably 4.4, more preferably 4.2.

d represents the content of N, and the range thereof is usually 5.6 ≦ d ≦ 8.4, the lower limit value is preferably 6, more preferably 6.3, and the upper limit value is preferably 8, more preferably 7.7.

If the content of any of the above ranges is in the above range, it is preferable in terms of the light-emitting characteristics of the obtained phosphor, particularly in terms of good light-emitting luminance.

In the case where the phosphor of the present embodiment is mixed with oxygen, the crystal structure can be maintained by replacing a part of Si-N in the crystal structure with Al-O. That is, it is considered that as long as it is within the above range, the crystal structure is maintained.

<About physical properties of phosphors> [light color]

The luminescent color of the phosphor of the present embodiment can be excited by light of a near-ultraviolet region to a blue region having a wavelength of 300 nm to 500 nm by adjusting a chemical composition or the like, thereby setting blue, cyan, green, and yellow. Green, yellow, orange, red, etc.

[luminescence spectrum]

When the phosphor of the present embodiment is used to measure the luminescence spectrum when excited by light having a wavelength of 350 nm or more and 460 nm or less (especially, a wavelength of 400 nm or 450 nm), the following characteristics are preferable. In the phosphor of the present embodiment, the peak wavelength in the above-mentioned luminescence spectrum is usually 500 nm or more, preferably 510 nm or more, and more preferably 520 nm or more. Further, it is usually 560 nm or less, preferably 550 nm. Hereinafter, it is more preferably 545 nm or less. If it is within the above range, the obtained phosphor exhibits a good green color, and thus is preferable.

[half-value width of luminescence spectrum]

In the phosphor of the present embodiment, the half value width of the luminescence peak in the luminescence spectrum is usually 90 nm or less, preferably 80 nm or less, more preferably 70 nm or less, and usually 30 nm or more, more preferably 40 nm or more. . In other words, the "fluorescent body having a narrower half-value width" in the present embodiment means a phosphor having a half-value width of a light-emitting peak of 90 nm or less. By setting it as the said range, the color reproduction range of a video display device can be enlarged, when it is used in the image display apparatus, such as a liquid-

Further, the phosphor of the present embodiment can be excited by light having a wavelength of 400 nm, and for example, a GaN-based LED can be used. Further, in the measurement of the luminescence spectrum of the phosphor of the present embodiment, and the calculation of the luminescence peak wavelength, the peak relative intensity, and the peak half value width, for example, a 150 W xenon lamp can be used as the excitation light source, and a multi-channel charge coupled device can be used. CCD, Charge Coupled Device) A fluorescence measuring device (manufactured by JASCO Corporation) manufactured by Detector C7041 (manufactured by Hamamatsu Photonics Co., Ltd.) was used as a spectrometer.

[Temperature characteristics (luminous intensity maintenance rate)]

The phosphor of this embodiment is also excellent in temperature characteristics. Specifically, when light having a wavelength of 450 nm is irradiated, the ratio of the luminescence peak intensity value in the luminescence spectrum at 200 ° C to the luminescence peak intensity value in the luminescence spectrum at 25 ° C is usually 50% or more. It is preferably 60% or more, and particularly preferably 70% or more. Moreover, since the normal phosphor decreases in temperature as the temperature rises, it is difficult to think that the ratio will exceed 100%, but there may be more than 100% for some reasons. However, if it exceeds 100%, there is a tendency for color shift due to temperature change. In the case of measuring the temperature characteristics, the method described in JP-A-2008-138156 can be used.

[excitation wavelength]

The phosphor of the present embodiment is usually 300 nm or more, preferably 350 nm or more, more preferably 400 nm or more, and usually 500 nm or less, preferably 480 nm or less, more preferably 460 nm or less, and particularly preferably 450 nm or less. There are excitation peaks in the range. That is, excitation can be performed using light in the near ultraviolet to blue region.

[CIE, Commission Internationale de L'Eclairage Chroma Coordinates]

The value of the CIE chromaticity coordinate of the phosphor of the present embodiment is usually 0.275 or more, preferably 0.300 or more, more preferably 0.320 or more, still more preferably 0.340 or more, and usually 0.425 or less, preferably 0.400. Hereinafter, it is more preferably 0.380 or less, further preferably 0.360 or less. Further, the y value of the CIE chromaticity coordinates of the phosphor of the present embodiment is usually 0.550 or more, preferably 0.575 or more, and usually 0.675 or less, preferably 0.650 or less, more preferably 0.625 or less. By using the CIE chromaticity coordinate within the above range, when a blue LED and another yellow phosphor or a red phosphor are used in combination, a luminescent color having a good color rendering property, preferably a white color to a light bulb color, can be obtained. A light-emitting device that emits light.

[quantum efficiency]

The external quantum efficiency (η _o ) of the phosphor of the present embodiment is usually 40% or more, preferably 45% or more, more preferably 50% or more, and still more preferably 55% or more. The higher the external quantum efficiency, the higher the luminous efficiency, and thus it is preferable. The internal quantum efficiency (η _i ) of the phosphor of the present embodiment is usually 60% or more, preferably 65% or more, more preferably 70% or more, still more preferably 75% or more, and particularly preferably 80% or more. . Internal quantum efficiency means the ratio of the number of photons emitted to the photon number of the excitation light absorbed by the phosphor. Therefore, the higher the internal quantum efficiency, the higher the luminous efficiency or the luminous intensity, and thus it is preferable.

[lattice constant]

The lattice constant of the phosphor of the present embodiment varies depending on the type of the element constituting the crystal, and the lattice constants a, b, and c each have the following ranges. The a-axis is usually in the range of 7.7 Å or more and 8.51 Å or less, and the lower limit is preferably 7.86 Å, more preferably 8.02 Å, and the upper limit is preferably 8.35 Å, more preferably 8.18 Å. The b-axis is usually in the range of 8.64 Å or more and 9.55 Å or less, and the lower limit is preferably 8.82 Å, more preferably 9 Å, and the upper limit is preferably 9.37 Å, more preferably 9.18 Å. The c-axis is usually in the range of 8.53 Å or more and 9.43 Å or less, and the lower limit is preferably 8.71 Å, more preferably 8.89 Å, and the upper limit is preferably 9.25 Å, more preferably 9.07 Å.

Further, the ratio (a/c) of the a-axis to the c-axis is preferably 0.85 or more, more preferably 0.88 or more, still more preferably 0.96 or less, still more preferably 0.92 or less.

The β angle is in the range of 97.6° or more and 115.6° or less, and the lower limit is preferably 99.6°, more preferably 106.02°, and the upper limit is preferably 113.6°, more preferably 112.16°.

In addition, in any case, the phosphor of the present embodiment is stably produced, and the generation of the impurity phase is suppressed, so that the luminance of the obtained phosphor is good.

[unit lattice volume]

The present embodiment is calculated by the lattice constant of the unit lattice volume of the aspects of the phosphor of (V) is preferably 522.9Å ³ or more, more preferably 553.6Å ³ or more, and further more preferably 612.0Å ^3, and, It is preferably 707.4 Å ³ or less, more preferably 676.6 Å ³ or less, and further preferably 645.9 Å ³ or less. If the unit lattice volume is too large or the unit lattice volume is too small, the skeleton structure is destabilized and impurities of other structures are produced by-products, resulting in a decrease in luminous intensity or a decrease in color purity.

[Crystal system and space group]

The space group of the phosphor of the present embodiment is not particularly limited as long as it exhibits a repetition period of the above-described length in a statistically considered average structure within a range distinguishable by single-crystal X-ray diffraction, and preferably belongs to Based on the "Crystalline International Table (Third Revision), volume A space group symmetry" No. 4 (P2 ₁ ). Here, the lattice constant and the space group can be obtained by a usual method. The lattice constant can be obtained by analyzing the results of X-ray diffraction and neutron ray diffraction by Rietveld, and the space group can be obtained by electron beam diffraction. Further, the crystal of the phosphor of the present embodiment is monoclinic.

[Powder X-ray diffraction (XRD) pattern]

The phosphor of the present embodiment has a peak in the region 1 to 5 shown below in the powder X-ray diffraction pattern measured by CuKα ray (1.5418 Å). Furthermore, there are at least two peaks in region 4. Further, the region 5 also has at least two peaks, and one of the peaks has the highest peak intensity in the powder X-ray diffraction pattern. It is defined as the strongest peak intensity: I _max . Here, the peak intensity is a value obtained by performing background correction.

Area 1 14.73°≦2θ≦15.77°

Area 2 19.37°≦2θ≦20.95°

Area 3 26.00°≦2θ≦28.25°

Area 4 28.26°≦2θ≦30.29°

Area 5 30.30°≦2θ≦33.21°

In the present embodiment, the regions 1 to 5 have peaks, which means that the peaks are located in the range of the regions 1 to 5. In the present embodiment, the reason for the specific separation regions 1 to 5 is only to select the peaks unique to the phosphor of the present embodiment. Further, in the phosphor of the present embodiment, depending on the shape of the crystal, there are cases where alignment occurs during measurement, and peaks which can be confirmed in the X-ray diffraction pattern and peaks which cannot be confirmed are generated. The peaks appearing in the regions 1, 2, and 5 in the present embodiment can be characteristically confirmed peaks even if alignment occurs.

In the crystal structure identified by the diffraction method such as X-ray diffraction or neutron beam diffraction, the phosphor of the present embodiment may also have a stacking period and order of the inclusion layer in the crystal structure. Irregular structures such as chaos and chaos that arise from chaos, and partially contain structurally confusing parts. The presence or absence of the disorder or the like can be confirmed by the presence or absence of streaks in the X-ray diffraction pattern image or by observation by a transmission electron microscope (TEM) in the analysis of the single crystal structure. In the case of such a local irregular structure, it is represented by a repetition of the statistically considered average construction display period within a range distinguishable by X-ray diffraction. The presence or absence of the local irregular structure in the structure is not particularly limited, and it is preferable to have an irregular structure locally in the structure and to perform averaging within the structure. The reason is due to compositional variation caused by volatilization of elements generated during calcination, etc., due to localization in the crystal structure. By adopting an irregular structure and mitigating and averaging, the phase purity of the phosphor of the present embodiment is improved, and the by-products of other structures are also suppressed, so that the luminescence intensity is improved and the temperature characteristics are improved.

The ratio (I ₁ /I _max ) of the peak intensity (I ₁ ) to the strongest peak intensity (I _max ) of at least one of the peaks of the region 1 is usually 0.10 or more, preferably 0.15 or more, and more preferably 0.20 or more, particularly preferably 0.25 or more. The ratio (I ₂ /I _max ) of the peak intensity (I ₂ ) to the strongest peak intensity (I _max ) of at least one of the peaks of the region 2 is usually 0.10 or more, preferably 0.15 or more, and more preferably 0.20 or more. The ratio (I ₃ /I _max ) of the peak intensity (I ₃ ) to the strongest peak intensity (I _max ) of at least one of the peaks of the region 3 is usually 0.05 or more, preferably 0.10 or more, and more preferably 0.20 or more, particularly preferably 0.30 or more. The ratio of the peak intensities (I _4a , I _4b ) of at least two of the peaks of the region 4 to the strongest peak intensity (I _max ) (I _4a /I _max ), (I _4b /I _max ) is usually 0.05. The above is preferably 0.10 or more, more preferably 0.15 or more, still more preferably 0.20 or more, and still more preferably 0.30 or more. Region 5 having the peaks, in addition to the strongest peak intensity (I _max) of the at least the peak intensity (the I ₅₎ other than one of relative the strongest peak intensity (I _max) ratio (I ₅ / I _max) is usually 0.35 or more, It is preferably 0.40 or more, and more preferably 0.45 or more. Further, the ratio of the peak intensity (I ₆ ) of at least one of the peaks of the phosphor region 6 (16.50 ° ≦ 2θ ≦ 19.00 °) of the present embodiment to the strongest peak intensity (I _max ) (I ₆ /I _max ) is usually 0.30 or less, preferably 0.20 or less, more preferably 0.10 or less, and still more preferably 0.05 or less.

<Manufacturing method of phosphor>

The raw material for obtaining the phosphor of the present embodiment, the method for producing a phosphor, and the like are as follows. The method for producing the phosphor of the present embodiment is not particularly limited, and for example, It is produced by the raw material of the element M (hereinafter referred to as "M source" as appropriate), the raw material of the element A (hereinafter referred to as "A source" as appropriate), and the raw material of the element Al (hereinafter referred to as appropriate) The "Al source") and the raw material of the element Si (hereinafter referred to as "Si source" as appropriate) are mixed (mixing step), and the obtained mixture is calcined (calcination step). In the following, for example, the raw material of the element Eu may be referred to as "Eu source", and the raw material of the element Sm may be referred to as "Sm source".

[fluorescent material]

Examples of the phosphor raw material (i.e., M source, A source, Al source, and Si source) for producing the phosphor of the present embodiment include metals and alloys of elements of M element, A element, Al, and Si. , quinone imine compounds, nitrogen oxides, nitrides, oxides, hydroxides, carbonates, nitrates, sulfates, oxalates, carboxylates, halides, and the like. The reactivity with respect to the composite nitrogen oxides, or the amount of generation of NOx, SOx, or the like at the time of calcination may be considered as appropriate, and may be appropriately selected from the compounds.

(M source)

Specific examples of the Eu source in the M source include Eu ₂ O ₃ , Eu ₂ (SO ₄ ) ₃ , and Eu ₂ (C ₂ O ₄ ) ₃ . 10H ₂ O, EuCl ₂ , EuCl ₃ , Eu(NO ₃ ) ₃ . 6H ₂ O, EuN, EuNH, and the like. Among them, Eu ₂ O ₃ , EuN, and the like are preferable, and EuN is particularly preferable. Further, specific examples of the raw material of the other active elements such as the Sm source, the Tm source, and the Yb source are exemplified by the respective compounds exemplified as the Eu source, and Eu is replaced by Sm, Tm, and Yb, respectively. Compound.

(A source)

Specific examples of the Sr source in the A source include SrO and Sr(OH) ₂ . 8H ₂ O, SrCO ₃ , Sr(NO ₃ ) ₂ , SrSO ₄ , Sr(C ₂ O ₄ ). H ₂ O, Sr(OCOCH ₃ ) ₂ . 0.5H ₂ O, SrCl ₂ , Sr ₃ N ₂ , SrNH, and the like. Wherein, preferably _{SrO, SrCO 3, Sr 2 N} , Sr 3 N 2, particularly preferably _{Sr 2 N, Sr 3 N 2} . Further, in terms of reactivity, the particle diameter is preferably small; and in terms of luminous efficiency, it is preferably higher in purity. Further, specific examples of the raw material of other alkaline earth metal elements such as a Ba source, a Ca source, and a Mg source include each compound exemplified as a specific example of the Sr source, and Sr is replaced by, for example, Ba, Ca, Mg, or the like. a compound.

(Al source)

Specific examples of the Al source include AlN, Al ₂ O ₃ , Al(OH) ₃ , AlOOH, and Al(NO ₃ ) ₃ . Among them, AlN, Al ₂ O _{3 is} preferable, and AlN is particularly preferable. Further, as the AlN, the particle size is preferably small in terms of reactivity, and it is preferably higher in terms of luminous efficiency. Specific examples of the raw material of the other trivalent element include each of the compounds exemplified as the specific examples of the Al source, and the Al is replaced by B, Ga, In, Sc, Y, La, Gd, and Lu. Compound. Furthermore, the Al source can also use the elemental Al.

(Si source)

As a specific example of the Si source, SiO ₂ or Si ₃ N _{4 is} preferably used. Further, a compound which is SiO ₂ can also be used. Specific examples of such a compound include SiO ₂ , H ₄ SiO ₄ , Si(OCOCH ₃ ) ₄ and the like. Further, as Si ₃ N ₄ , the particle size is preferably small in terms of reactivity, and it is preferably higher in terms of luminous efficiency. Further, it is preferable that the content ratio of the carbon element as an impurity is small. Specific examples of the raw material of the other tetravalent element include a compound in which Si is replaced by Ge, Ti, Zr, Hf or the like, which is a specific example of the Si source. Furthermore, the Si source can also use the Si of the element.

Further, the M source, the A source, the Al source, and the Si source may be used singly or in combination of two or more kinds in any combination.

[mixing step]

The phosphor material can be weighed and obtained by a ball mill or the like, and then filled in a crucible, and then calcined at a predetermined temperature and environment, and the calcined product is pulverized and washed to obtain the present embodiment. Fluorescent body.

The mixing method is not particularly limited, and may be either a dry mixing method or a wet mixing method. Examples of the dry mixing method include ball milling and the like. The wet mixing method is, for example, a method in which a solvent or a dispersion medium such as water is added to the phosphor raw material, and the mixture is mixed with a crucible to form a solution or a slurry, and then spray-dried and heated. Dry it, or dry it naturally.

[calcination step]

The obtained mixture is filled in a heat-resistant container such as a crucible or a tray made of a material having low reactivity with each of the phosphor materials. The material of the heat-resistant container used in the calcination is not particularly limited as long as the effect of the present embodiment is not impaired, and examples thereof include boron nitride.

The calcination temperature varies depending on other conditions such as pressure, and can usually be calcined in a temperature range of 1800 ° C or higher and 2200 ° C or lower. As the highest temperature reached in the calcination step, it is usually 1800 ° C or higher, preferably 1900 ° C or higher, and, usually, It is 2200 ° C or less, preferably 2150 ° C or less, more preferably 2100 ° C or less. When the calcination temperature is too high, nitrogen gas scatters and tends to be colored in the mother crystal to cause coloring. When the temperature is too low, the solid phase reaction tends to be slow, and it is difficult to obtain the target phase as the main phase.

Although it varies depending on the calcination temperature and the like, it is usually 0.2 MPa or more, preferably 0.4 MPa or more, and usually 200 MPa or less, preferably 190 MPa or less. When the volatilization of the constituent element, particularly the alkaline earth metal element, is suppressed, and the occurrence of defects is suppressed, it is preferably 0.8 MPa or more, more preferably 10 MPa or more, further preferably 50 MPa or more, further preferably 100 MPa or more, and particularly preferably It is 150 MPa or more. Further, in the case of obtaining a phosphor having a high absorption efficiency, it is preferably 190 MPa or less, more preferably 50 MPa or less, further preferably 10 MPa or less, and particularly preferably 1.0 MPa or less.

When the pressure in the calcination step is 10 MPa or less, the highest temperature at the time of calcination is usually 1800 ° C or higher, preferably 1900 ° C or higher, more preferably 2000 ° C or higher, and usually 2200 ° C or lower. Preferably, it is 2150 ° C or less, more preferably 2100 ° C or less. If the calcination temperature is less than 1800 ° C, the solid phase reaction does not proceed, so that only an impurity phase or an unreacted phase occurs, and it is difficult to obtain a target phase as a main phase.

Further, even if the target crystal phase is obtained in a very small amount, there is a possibility that the element which becomes the center of the luminescence in the crystal, in particular, the Eu element is not diffused, and the quantum efficiency is lowered. Further, when the calcination temperature is too high, the element constituting the crystal of the target phosphor is easily volatilized, and it is highly likely that crystal lattice defects or decomposition will occur and other phases will be generated as impurities.

The temperature increase rate in the calcination step is usually 2 ° C / min or more, preferably 5 ° C / min or more, more preferably 10 ° C / min or more, and usually 30 ° C / min or less. It is preferably 25 ° C / min or less. If the temperature increase rate is lower than the range, there is a possibility that the calcination time becomes long. Further, when the temperature increase rate is higher than the above range, the calcination apparatus, the container, and the like may be damaged.

The calcination atmosphere in the calcination step is arbitrary as long as the phosphor of the present embodiment can be obtained, and it is preferably an environment containing nitrogen. Specifically, a nitrogen atmosphere, a nitrogen atmosphere containing hydrogen, and the like are exemplified, and among them, a nitrogen atmosphere is preferred. Further, the oxygen content in the calcination atmosphere is usually preferably 10 ppm or less, preferably 5 ppm or less.

The calcination time varies depending on the temperature, pressure, and the like at the time of calcination, and is usually 10 minutes or longer, preferably 30 minutes or longer, and usually 72 hours or shorter, preferably 12 hours or shorter. If the calcination time is too short, crystal growth and grain growth cannot be promoted, so that a phosphor having excellent properties cannot be obtained. If the calcination time is too long, the volatilization of the constituent elements is promoted, and thus the atomic vacancies are caused in the crystal structure. A case where a defect is induced and a fluorescent body having good characteristics cannot be obtained.

Furthermore, the calcination step can be repeated several times as needed. At this time, in the first calcination and the second calcination, the calcination conditions may be the same or different.

In the case where the phosphor is uniformly diffused while the phosphor is generated and the phosphor having a high internal quantum efficiency is calcined, or when a large particle of several μm is obtained, the reverse calcination is effective. The highest temperature of the first calcination step in this case is preferably lower than the highest temperature in the second calcination step.

[post-processing steps]

The obtained calcined product is crushed, pulverized, and/or classified to produce a powder of a predetermined size. Here, it is preferable to carry out the treatment so that D ₅₀ becomes about 30 μm or less. Specific examples of the treatment include a method of subjecting a composition to a sieve classification process of about 45 μm in a mesh and transferring the powder passing through the sieve to the next step; or using a general pulverization such as a ball mill or a vibrating mill or a jet mill. The method of pulverizing the composition into a predetermined particle size. In the latter method, excessive pulverization not only generates fine particles which easily scatter light, but also causes crystal defects on the surface of the particles, which may cause a decrease in luminous efficiency.

Further, a step of cleaning the phosphor (calcined material) may be provided as needed. After the washing step, the phosphor is dried until the adhering moisture disappears and is used for use. Further, it is also possible to perform dispersion and classification processing for understanding the agglutination as needed. Further, the phosphor of the present embodiment can also be formed by a so-called alloy method in which a constituent metal element is alloyed and nitrided in advance.

<Composition containing a phosphor>

The phosphor of the first embodiment of the present invention can also be used by mixing with a liquid medium. In particular, when the phosphor of the first embodiment of the present invention is used for a light-emitting device or the like, it is preferably used in such a manner as to be dispersed in a liquid medium. The phosphor of the first embodiment of the present invention is dispersed in a liquid medium, and is appropriately referred to as "a composition containing a phosphor in an embodiment of the present invention" as an embodiment of the present invention. Wait.

[fluorescent body]

The type of the phosphor of the first embodiment of the present invention contained in the phosphor-containing composition of the present embodiment is not limited, and may be arbitrarily selected from the above. Further, the first embodiment of the present invention contained in the composition containing the phosphor of the present embodiment The phosphor of the aspect may be used alone or in combination of two or more kinds in any combination and in any ratio. Further, the phosphor-containing composition of the present embodiment may contain a phosphor other than the phosphor of the first embodiment of the present invention as long as the effects of the present embodiment are not impaired.

[Liquid medium]

The liquid medium used in the phosphor-containing composition of the present embodiment is not particularly limited as long as the performance of the phosphor is not impaired within the target range. For example, any inorganic substance may be used as long as the phosphor of the first embodiment of the present invention is preferably dispersed in a liquid state under the desired use conditions, and no adverse reaction occurs. Examples of the material and/or the organic material include a polyoxymethylene resin, an epoxy resin, and a polyamidene polyoxymethylene resin.

[Liquid medium and phosphor content]

The content ratio of the phosphor and the liquid medium in the phosphor-containing composition of the present embodiment is arbitrary as long as the effect of the present embodiment is not significantly impaired, and the liquid medium contains the fluorescein with respect to the present embodiment. The composition of the light body is usually 50% by weight or more, preferably 75% by weight or more, and usually 99% by weight or less, preferably 95% by weight or less.

[Other ingredients]

Further, in the phosphor-containing composition of the present embodiment, other components may be contained in addition to the phosphor and the liquid medium as long as the effects of the present embodiment are not significantly impaired. Further, the other components may be used alone or in combination of any ratio and ratio. More than one species.

<Lighting device>

A second embodiment of the present invention includes a first illuminant (excitation light source), and a illuminating device that emits a second illuminant of visible light by irradiation of light from the first illuminator, and the second illuminator A phosphor comprising the first embodiment of the present invention. Here, the phosphors according to the first embodiment of the present invention may be used singly or in combination of two or more kinds in any combination and in any ratio.

The phosphor according to the first embodiment of the present invention is, for example, a phosphor that emits blue or green region fluorescence under irradiation of light from an excitation light source. Specifically, in the case of constituting the light-emitting device, the blue or green phosphor in the first embodiment of the present invention preferably has a light-emitting peak in a wavelength range of 500 nm or more and 560 nm or less.

Further, regarding the excitation source, it is possible to have a luminescence peak in a wavelength range of less than 420 nm. Hereinafter, the phosphor of the first embodiment of the present invention has a light-emitting peak in a wavelength range of 500 nm or more and 560 nm or less, and the first light-emitting system has a light-emitting peak in a wavelength range of 350 nm or more and 460 nm or less. The aspect of the light-emitting device in the case is described, but the embodiment is not limited to these.

In the above case, the light-emitting device of the present embodiment can be set, for example, in the following manner. In other words, at least one type of phosphor having an emission peak in a wavelength range of 500 nm or more and 560 nm or less can be used as the first illuminant in a wavelength range of 350 nm or more and 460 nm or less (the present invention) The phosphor of one embodiment is used as the first phosphor of the second illuminant, and is used at 580 nm or more. In addition, a phosphor having a light-emitting peak (red phosphor) in the wavelength range of 680 nm or less is used as the second phosphor of the second light-emitting body.

(red phosphor)

As the red phosphor in the above aspect, for example, the following phosphor can be preferably used. Examples of the Mn-activated fluoride phosphor include K ₂ (Si, Ti) F ₆ : Mn, K ₂ Si _1-x Na _x Al _x F ₆ : Mn (0 < x < 1) (together KSF) Fluorescent body; examples of the sulfide phosphor include (Sr, Ca) S: Eu (CAS phosphor), La ₂ O ₂ S: Eu (LOS phosphor); and garnet fluorescence Examples of the body include (Y, Lu, Gd, Tb) ₃ Mg ₂ AlSi ₂ O ₁₂ :Ce; examples of the nanoparticle include CdSe; and examples of the nitride or oxynitride phosphor include (Sr , Ca) AlSiN ₃ : Eu (S/CASN phosphor), (CaAlSiN ₃ ) _1-x . (SiO ₂ N ₂ ) _x :Eu (CASON phosphor), (La,Ca) ₃ (Al,Si) ₆ N ₁₁ :Eu (LSN phosphor), (Ca,Sr,Ba) ₂ Si ₅ ( N,O) ₈ :Eu (258 phosphor), (Sr,Ca)Al _1+x Si _4-x O _x N _7-x :Eu (1147 phosphor), M _x (Si,Al) ₁₂ (O,N) ₁₆ :Eu (M is Ca, Sr, etc.) (α-Sialon phosphor), Li(Sr,Ba)Al ₃ N ₄ :Eu (the above x is 0<x<1), etc. . As the red phosphor, a KSF phosphor or an S/CASN phosphor is preferred in the above.

(yellow phosphor)

In the above aspect, a phosphor having a luminescence peak (yellow phosphor) in the range of 550 to 580 nm may be used as needed. As the yellow phosphor, for example, the following phosphor can be preferably used. Examples of the garnet-based phosphor include (Y, Gd, Lu, Tb, La) ₃ (Al, Ga) ₅ O ₁₂ : (Ce, Eu, Nd); and as the orthosilicate, for example, Ba, Sr, Ca, Mg) ₂ SiO ₄ : (Eu, Ce); as the nitrogen (oxygen) phosphor, for example, (Ba, Ca, Mg) Si ₂ O ₂ N ₂ : Eu (SION) Light body), (Li, Ca) ₂ (Si, Al) ₁₂ (O, N) ₁₆ : (Ce, Eu) (α-Sialon phosphor), (Ca, Sr) AlSi ₄ (O, N) ₇ : (Ce, Eu) (1147 phosphor), (La, Ca, Y) ₃ (Al, Si) ₆ N ₁₁ : Ce (LSN phosphor), and the like. Further, among the above-mentioned phosphors, a garnet-based phosphor is preferable, and among them, a YAG-based phosphor represented by Y ₃ Al ₅ O ₁₂ :Ce is preferable.

(green phosphor)

In the above aspect, the green phosphor may include a phosphor other than the phosphor of the first embodiment of the present invention. For example, the following phosphor may be preferably used. Examples of the garnet-based phosphor include (Y, Gd, Lu, Tb, La) ₃ (Al, Ga) ₅ O ₁₂ : (Ce, Eu, Nd), and Ca ₃ (Sc, Mg) ₂ Si _{3 .} O ₁₂ : (Ce, Eu) (CSMS phosphor); examples of the citrate-based phosphor include (Ba, Sr, Ca, Mg) ₃ SiO ₁₀ : (Eu, Ce), (Ba, Sr , Ca, Mg) ₂ SiO ₄ : (Ce, Eu) (BSS phosphor); as the oxide phosphor, for example, (Ca, Sr, Ba, Mg) (Sc, Zn) ₂ O ₄ : ( Ce, Eu) (CASO phosphor); as the nitrogen (oxygen) phosphor, for example, (Ba, Sr, Ca, Mg) Si ₂ O ₂ N ₂ : (Eu, Ce), Si _6-z Al _z O _z N _8-x : (Eu, Ce) (β-Sialon phosphor) (0<z≦1), (Ba, Sr, Ca, Mg, La) ₃ (Si, Al) ₆ O ₁₂ N ₂ : (Eu, Ce) (BSON phosphor); as the aluminate phosphor, for example, (Ba, Sr, Ca, Mg) ₂ Al ₁₀ O ₁₇ : (Eu, Mn) (GBAM system) Fluorescent) and so on.

[Composition of light-emitting device]

The light-emitting device of the present embodiment has a first light-emitting body (excitation light source) and at least the phosphor of the first embodiment of the present invention is used as the second light-emitting body, and the configuration thereof is not limited, and may be arbitrary. It is constructed by a known device. As a device and illuminate The embodiment of the device is described in, for example, Japanese Laid-Open Patent Publication No. 2007-291352. Further, examples of the form of the light-emitting device include a shell type, a cup type, an on-wafer, and a non-contact type phosphor.

<Use of light-emitting device>

The use of the light-emitting device according to the second embodiment of the present invention is not particularly limited, and can be used in various fields in which a general light-emitting device can be used, and particularly preferably in terms of a wide color reproduction range and high color rendering property. The ground is used as a light source for a lighting device or an image display device.

[lighting device]

A third embodiment of the present invention is an illumination device characterized by comprising a light-emitting device according to a second embodiment of the present invention as a light source. In the case where the light-emitting device according to the second embodiment of the present invention is applied to a lighting device, the above-described light-emitting device may be appropriately incorporated into a known lighting device and used. For example, a surface-emitting illumination device or the like in which a plurality of light-emitting devices are arranged on the bottom surface of the holding case can be cited. The average color rendering evaluation Ra of the luminescent color of the illumination device according to the third embodiment of the present invention is usually 60 or more, preferably 65 or more, more preferably 70 or more, and still more preferably 75 or more. When Ra is in the above range, a light-emitting device having good color rendering properties can be obtained. Further, the special color rendering evaluation number R9 of the illuminating color of the illuminating device according to the third embodiment of the present invention is usually negative 10 or more, preferably negative 5 or more, further preferably 0 or more, and particularly preferably 5 or more. By setting the special color rendering number R9 within the above range, an illumination device having good color rendering properties can be obtained.

[Image display device]

A fourth embodiment of the present invention is an image display device characterized by comprising a light-emitting device according to a second embodiment of the present invention as a light source. In the case where the light-emitting device of the second embodiment of the present invention is used as the light source of the image display device, the specific configuration of the image display device is not limited, and is preferably used together with the color filter. For example, when it is used as a video display device and a color image display device using a color liquid crystal display device, the light-emitting device can be used as a backlight, and the shutters using liquid crystals can be red, green, and blue. The color filters of the pixels are combined to form an image display device.

[Examples]

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to the following examples as long as they do not depart from the gist of the invention.

<Measurement method> [Luminescence characteristics]

The sample was placed in a copper sample holder, and an excitation luminescence spectrum and an luminescence spectrum were measured using a fluorescence spectrophotometer FP-6500 (manufactured by JASCO Corporation). In the measurement, the slit width of the light-receiving side spectroscope was set to 1 nm, and the measurement was performed. Further, the luminescence peak wavelength (hereinafter sometimes referred to as "peak wavelength") and the half value of the luminescence peak are read from the obtained luminescence spectrum.

[chromaticity coordinates]

The chromaticity coordinates of the x, y color system (CIE 1931 color system) are based on the data of the wavelength range of 360 nm to 800 nm of the luminescence spectrum obtained by the above method, and are determined in accordance with JIS Z8724 as specified in JIS Z8701. The chromaticity coordinates CIEx and CIEy in the XYZ color system are calculated.

[Using EPMA Elemental Analysis]

In order to investigate the composition of the phosphor obtained in the first embodiment of the present invention, the following elemental division was carried out. After several crystals were selected by observation with a scanning electron microscope (SEM), analysis of each element was carried out using an electron probe microanalyzer (wavelength dispersion type X-ray analyzer: EPMA) JXA-8200 (manufactured by JEOL Co., Ltd.). .

[Elemental analysis using energy dispersive X-ray (EDX)]

The following elemental analysis was carried out in order to investigate the composition of the obtained phosphor. The analysis of the constituent metal elements (Sr, Ca, La, Ba, Si, Al, Eu) uses an energy dispersive X-ray spectroscopy. Specifically, crystals of several examples were selected under SEM observation, and analyzed using an energy dispersive X-ray analyzer EMAX ENERGY (EMAX x-act detector specification) manufactured by Horiba.

[Powder X-ray diffraction measurement]

The powder X-ray diffraction system was precisely measured by a powder X-ray diffraction device D2 PHASER (manufactured by BRUKER). The measurement conditions are as follows.

Use CuKα tube

X-ray output = 30KV, 10mA

Scan range 2θ=5°~80°

Read width = 0.025°

[Using the powder X-ray diffraction of the transmission method]

Powder X-ray diffraction using the transmission method, using an imaging plate and Ji Nie (Guinier) camera powder X-ray diffraction device (manufactured by HUBER) for precise measurement. The measurement was carried out by loading the sample into a capillary at the time of measurement and rotating the capillary. The measurement conditions are as follows.

Use CuKα tube

X-ray output = 40KV, 30mA

Scan range 2θ=4°~100°

Read width = 0.005°

[Crystal Structure Analysis]

The X-ray diffraction data of the single crystal particles were measured using a single crystal X-ray diffraction apparatus (Rigaku, R-AXIS RAPID-H) equipped with an imaging plate and a graphite single photometer and using Mo Kα as an X-ray source. The data collection and the precision of the lattice constant are PROCESS-AUTO, and the X-ray shape absorption correction system uses NUMABS. For the data of F ^2, the crystal structure parameters were refined using SHELXL-97. Further, the drawing of the crystal structure uses VESTA.

[Time-of-flight secondary ion mass spectrometry (TOF-SIMS, time of flight-secondary ion mass spectrometry) elemental analysis]

For the crystals selected under the SEM observation, time-of-flight secondary ion mass spectrometry (TOF-SIMS) was carried out under the following conditions to confirm the presence or absence of boron.

(instrument)

TOF.SIMS5 (ION.ToF GmbH)

(polar mode)

Positive and negative

(primary ion)

Type: Bi ₁ ⁺ , Energy: 25kV, Current: 1.25pA, Field of view: 120×120μm ²

(sputtering ions)

Type: O ₂ ⁺ (positive), Cs ⁺ (negative) energy: 2kV

Current: 360.0nA (positive), 135.0nA (negative) pit size: 450 × 450μm ²

(period time)

80μs

(scanning)

1024

<Manufacture of phosphors> (Example 1)

Using Sr ₃ N ₂ (manufactured by Shellac Co., Ltd.), EuN (manufactured by Shellac Co., Ltd.), Si ₃ N ₄ (manufactured by Ube Industries, Ltd.), and AlN (manufactured by Tokuyama Co., Ltd.) as phosphor raw materials, phosphors were prepared as described below. . The raw materials were weighed by an electronic balance so as to have the respective weights shown in the following Table 1, and placed in an alumina mortar, and pulverized and mixed until uniform. Further, 0.43 g of Mg ₃ N ₂ (manufactured by Shellac Co., Ltd.) was added to the mixed powder, and further pulverized and mixed. These operations were carried out in a glove box filled with argon.

About 0.5 g of the raw material mixed powder obtained was weighed and directly filled into a boron nitride crucible. This crucible was placed in a vacuum press calciner (manufactured by Shimadzu Mectem Co., Ltd.). Then, after depressurizing to 8 × 10 ^-3 Pa or less, it was heated from room temperature to 800 ° C under vacuum. At 800 ° C, nitrogen gas was maintained and introduced at this temperature for 5 minutes until the pressure in the furnace became 0.85 MPa. After the introduction of nitrogen gas, the pressure in the furnace was maintained at 0.85 MPa, and the temperature was further raised to 1600 ° C for 1 hour. Further, it was heated to 2050 ° C and maintained at 2050 ° C for 4 hours. After calcination, it was cooled to 1200 ° C and then left to cool. The phosphor of Example 1 was obtained by picking up only green crystals from the obtained product.

The phosphor of Example 1 was subjected to powder X-ray diffraction measurement, and the obtained X-ray diffraction pattern is shown in Fig. 1. It was confirmed that the XRD pattern of the phosphor of Example 1 was not present in the powder diffraction file (PDF) and was a novel phosphor.

Further, the phosphor of Example 1 was observed by SEM, and the obtained results are shown in Fig. 2 . Further, elemental analysis (EPMA measurement) was carried out in order to investigate constituent elements and their ratios. The qualitative results of the composition analysis are shown in Fig. 3, and the quantitative results (average values) are shown in Table 2 below.

As shown in Table 2, in the phosphor of Example 1, it was confirmed that the mixing of Mg and oxygen was below the detection limit. Further, the TOF-SIMS analysis of the phosphor of Example 1 revealed that boron (B) was not contained. From the above results, the single crystal structure analysis was carried out by setting the ratio of (Sr, Eu):Al:Si:N to 1:1:4:7. For the single crystal structure analysis of the obtained single crystal, the lattice constant, the space group, and each are determined as follows. The coordinates of the atom.

[Crystal Structure Analysis]

The basic reflection obtained by the single crystal X-ray diffraction of Example 1 can be indexed into a simple lattice (P lattice a = 8.031 (5) Å, b = 9.0936 (7) Å, c = 8.9797 ( 5) Å, β = 111.6221 (17) °). Furthermore, the numbers in parentheses indicate the standard deviation. Further, the reflection point of the obtained basic reflection is studied according to the extinction rule, and as a result, the space group obtained by using the crystal of this time to obtain the crystal structure model is P2 ₁ . The analysis results are summarized in Table 3.

Further, based on the result of the composition analysis, the Si/Al portion was assumed to be a ratio of 0.8/0.2 and was set as the atomic coordinate of the current time. Further, it is presumed that Eu replaces a part of the Sr site in the crystal structure. The results of the obtained atomic coordinates are shown in Table 4. Furthermore, the numbers in parentheses indicate the standard deviation.

Further, the X-ray diffraction pattern was simulated based on the coordinates obtained by the structural analysis, and the chemical composition of the phosphor obtained in Example 1 was determined to be Sr _0.97 with reference to the composition analysis result and the composition ratio calculated from the electron density. Eu _0.03 AlSi ₄ N ₇ .

The lattice constant obtained by structural analysis of the single crystal of the phosphor of Example 1 was set to an initial value, and the crystal lattice of the phosphor of Example 1 was powdered according to the XRD pattern of FIG. The constant was refined, and the results obtained are shown in Table 5. It was confirmed that a value substantially coincident with the lattice constant obtained by diffraction of single crystal X-rays was obtained, and the variation per crystal was small.

Further, with respect to the phosphor of Example 1, a pattern obtained by simulating a powder X-ray diffraction pattern measured by a transmission method and a crystal structure determined by single crystal structure analysis is shown in FIG. .

At the time of measurement, in order to suppress the influence of the selective alignment, the phosphor of Example 1 was placed in a capillary tube, and the capillary was rotated at the time of measurement to carry out measurement. From the measurement results, it was confirmed that the crystal structure determined by the single crystal structure analysis was the phosphor of Example 1. Further, when compared with the pattern of Fig. 4 measured by the reflection method, the intensity ratio of a part of the peak changes, suggesting the influence of the selective alignment derived from the crystal.

The measurement results of the excitation-luminescence spectrum of the phosphor of Example 1 are shown in Fig. 5 . The excitation spectrum was monitored for luminescence at 540 nm, and the luminescence spectrum was measured at 450 nm. It was confirmed that the phosphor of Example 1 exhibited an emission spectrum having an emission peak wavelength of 541 nm and a half-value width of 66 nm, and showed green light emission. Further, an excitation spectrum was shown which had a peak at 460 nm and exhibited excitation in a wide wavelength range of 300 nm to 480 nm.

(Comparative Example 1)

Sr ₃ N ₂ (manufactured by Shellac Co., Ltd.), EuN (manufactured by Shellac Co., Ltd.), Si ₃ N ₄ (manufactured by Ube Industries, Ltd.), AlN (manufactured by Tokuyama Co., Ltd.), and Al ₂ O ₃ (manufactured by RARE METALLIC Co., Ltd.) were used as the fluorescent material. The bulk material was prepared as described below. The raw materials were weighed by an electronic balance so as to have the respective addition compositions and weights shown in Table 6, and placed in an alumina mortar to be pulverized and mixed until uniform. These operations were carried out in a glove box filled with nitrogen.

About 1.5 g of the raw material mixed powder obtained was weighed and directly filled into a boron nitride crucible. The crucible was placed in a vacuum pressurized calciner. Then, after depressurizing to 8 × 10 ^-3 Pa or less, it was heated from room temperature to 800 ° C under vacuum. When the temperature reached 800 ° C, high-purity nitrogen gas (99.9995%) was maintained and introduced at this temperature for 5 minutes until the pressure in the furnace became 0.85 MPa. After introducing high-purity nitrogen gas, the pressure in the furnace was maintained at 0.85 MPa, and the temperature was further raised to 1600 ° C at a temperature increase rate of 20 ° C /min, and held for 2 hours. Further, it was heated to 1850 ° C and maintained at 1850 ° C for 6 hours. After calcination, it was cooled to 1200 ° C and then left to cool. Thereafter, the product was crushed to obtain a phosphor of Comparative Example 1 represented by (Sr _0.97 Eu _0.03 ) ₅ Si ₂₁ Al ₅ O ₂ N ₃₅ .

[Measurement result of temperature characteristics]

The temperature characteristics of the phosphor obtained in Example 1 and the phosphor obtained in Comparative Example 1 were measured. In the luminescence spectrum in the case of irradiating light having a wavelength of 450 nm, the relative intensity (%) at each temperature with respect to the luminescence peak intensity value at 25 ° C is shown in Fig. 6 and Table 7 below.

As shown in FIG. 6 and Table 7, it was confirmed that the phosphor of Example 1 has better temperature characteristics than the phosphor obtained in Comparative Example 1, and in particular, the luminance retention rate at a high temperature is high. More specifically, as shown in Table 7, the phosphor of Example 1 has a temperature characteristic improvement in the temperature region reached when it is used in an LED at 200 ° C or the like as compared with the conventional phosphor. The extremely remarkable effect of 20 points.

[Examples 2 to 4]

In the same manner as in Example 1, except that the weight of the raw material was changed in the manner shown in the following Table 8, and the amount of Mg ₃ N ₂ was changed from 0.43 g to 0.22 g, the same procedure as in Example 1 was carried out. The phosphors of Examples 2 to 4 were synthesized.

The phosphors of Examples 2 to 4 were measured by XRD. The results of measuring the phosphors of Examples 2 and 4 by XRD are shown in Fig. 7. It was confirmed that the phosphors of Examples 2 to 4 obtained a phase having the same crystal structure as that of the phosphor of Example 1. Further, according to the powder XRD patterns of the phosphors of Examples 2 and 4, the respective lattice constants and unit lattices were obtained for the phases having the same crystal structure as in Example 1. The volume was refined, and the results obtained are shown in Table 9.

Further, in Table 10, the peak intensity (I) of the strongest peak in the regions 1 to 5 (excluding the strongest peak intensity (I _max ) in the region 3) in the region 1 to 5 when the XRD measurement of the phosphor of Example 4 is performed is summarized. The ratio of the strongest peak intensity (I _max ) (I/I _max ). Further, in the region 4, the ratio of the two peak intensities I _4a and I _4b to the strongest peak intensity (I _max ) is described.

Further, the atomic ratio of Sr:Ca:Al:Si and the substitution amount of Ca obtained by measuring the phosphors of Examples 2 to 4 by EPMA are shown in Table 11.

As shown in Tables 9 to 11, the phosphors of Examples 2 to 4 were obtained and implemented. The crystal phase of the phosphor of Example 1 was the same. From this, it was confirmed that a phosphor having the same crystal structure as in Example 1 and replacing a part of Sr in the structure with Ca was obtained. Further, the luminescence spectrum when the phosphors of Examples 2 to 4 were excited by light of 400 nm was measured. The luminescence spectra of the phosphors of Examples 2 to 4 are summarized in Fig. 8, and the luminescence peak wavelength, half value width, and chromaticity are summarized in Table 12. As shown in Table 12, it was found that the luminescent color can be adjusted by replacing one part of Sr with Ca.

[Examples 5 and 6]

In Example 1, the weights of the raw materials and the raw materials were changed in the manner shown in Table 13 below, and the "maintaining at 2080 ° C" was changed to "maintained at 2000 ° C", and the amount of Mg ₃ N ₂ was added. The phosphors of Examples 5 and 6 were obtained by the same procedure as in Example 1 except that 0.43 g was changed to 0.22 g.

The phosphors of Examples 5 and 6 were measured by XRD. The result of measuring the phosphor of Example 5 by XRD is shown in FIG. It was confirmed that the phosphor of Example 5 obtained a phase having the same crystal structure as that of the phosphor of Example 1. Further, according to the powder XRD pattern of the phosphor of Example 5, The phase of the same crystal structure as in Example 1 was corrected for each lattice constant and unit lattice volume, and the results obtained are shown in Table 14.

Further, in Table 15, the peak intensity (I) of the strongest peak in the regions 1 to 5 in the XRD measurement of the phosphor of Example 5 is excluded (excluding the strongest peak intensity (I _max ) in the region 3). The ratio of the strongest peak intensity (I _max ) (I/I _max ). Further, in the region 4, the ratio of the two peak intensities I _4a and I _4b to the strongest peak intensity (I _max ) is described.

Further, the atomic ratio of Sr:Ba:Al:Si and the substitution amount of Ba obtained by measuring the phosphors of Examples 5 and 6 by EDX are shown in Table 16.

As shown in Tables 14 to 16, the phosphors of Examples 5 and 6 were obtained and obtained. The same crystalline phase of Example 1 was used. From this, it was confirmed that a crystal structure having the same crystal structure as that of the phosphor of Example 1 was obtained, and a part of Sr in the structure was replaced with a phosphor of Ba. Further, the luminescence spectrum when the phosphors of Examples 5 and 6 were excited by light of 400 nm was measured. The luminescence spectrum of the phosphor of Example 5 is summarized in Fig. 10, and the luminescence peak wavelength, half value width, and chromaticity are summarized in Table 17. As shown in Table 17, it was found that the luminescent color can be adjusted by substituting a part of Sr with Ba.

[Examples 7, 8]

In the first embodiment, the weights of the raw materials and the raw materials were changed as shown in the following Table 18, and the "maintained at 2080 ° C" was changed to "maintained at 2000 ° C", and the amount of Mg ₃ N ₂ was added. The phosphors of Examples 7 and 8 were obtained by the same procedure as in Example 1 except that 0.43 g was changed to 0.22 g.

The phosphors of Examples 7 and 8 were measured by XRD. The result of measuring the phosphor of Example 7 by XRD is shown in Fig. 11 . It was confirmed that the phosphors of Examples 7 and 8 obtained a phase having the same crystal structure as that of the phosphor of Example 1. Further, according to the powder XRD pattern of the phosphor of Example 7, each lattice constant and unit lattice were obtained for the phase having the same crystal structure as in Example 1. The product was refined, and the results obtained are shown in Table 19.

Further, in Table 20, the peak intensity (I) of the strongest peak in the regions 1 to 5 in the XRD measurement of the phosphor of Example 7 (excluding the strongest peak intensity (I _max ) in the region 3) is relatively The ratio of the strongest peak intensity (I _max ) (I/I _max ). Further, in the region 4, the ratio of the two peak intensities I _4a and I _4b to the strongest peak intensity (I _max ) is described.

Further, the atomic ratio of Sr:La:Al:Si and the substitution amount of La obtained by measuring the phosphors of Examples 7 and 8 by EPMA are shown in Table 21.

As shown in Tables 19 to 21, the phosphors of Examples 7 and 8 obtained the same crystal phase as in Example 1. From this, it was confirmed that the same crystal having the same as that of Example 1 was obtained. A portion of Sr within the structure is constructed and replaced with a phosphor of La. Further, the luminescence spectrum when the phosphors of Examples 7 and 8 were excited by light of 400 nm was measured. The luminescence spectra of the phosphors of Examples 7 and 8 are summarized in Fig. 12, and the luminescence peak wavelength, half value width, and chromaticity are summarized in Table 22. As shown in Table 22, it was found that the luminescent color can be adjusted by replacing one part of Sr with La.

<Manufacture of light-emitting device> [Embodiment 9]

First, a composition containing a phosphor is prepared. The dimethyl-based polyfluorene oxide resin, the oxidized cerium oxide, and the phosphor obtained in Example 1 were mixed by a stirring defoaming device to prepare a composition containing a phosphor. Further, the amount ratio of each member is adjusted such that the chromaticity of the luminescence spectrum displayed by the illuminating device described below becomes CIEy=0.100 to 0.150.

Then, a light-emitting device was produced using the composition containing the phosphor prepared above. The phosphor-containing composition obtained above was injected into a 5050-size (5 mm square) ceramic package equipped with a 35 mil square InGaN blue LED using a manual pipette. Thereafter, the light-emitting device was kept at 100 ° C for 1 hour, and then held at 150 ° C for 5 hours, whereby the composition containing the phosphor was cured to obtain a light-emitting device. The durability of the obtained light-emitting device was evaluated by the lighting test described below.

[lighting test]

A current of 350 mA was applied to the light-emitting device, and the luminescence spectrum was measured by a spectroscopic measuring device equipped with an integrating sphere. Then, the light-emitting device is continuously energized at a driving current of 150 mA in a constant temperature bath set at 85 ° C, and the light-emitting device is taken out from the constant temperature bath at each time point of 20 hours, 100 hours, 500 hours, and 1000 hours from the start of energization, and The luminescence spectrum was measured in the same manner as in the case of time 0. The durability of the phosphor of Example 1 was evaluated by the difference (Δy) between the chromaticity coordinates y calculated from the luminescence spectra obtained after each elapsed time and the chromaticity coordinates y at time 0. The results are shown in Table 23.

As shown in Table 23, the light-emitting device using the phosphor of the first embodiment of the present invention has a very small Δy. That is, the light-emitting device using the phosphor of the first embodiment of the present invention is excellent in durability.

<About simulation of light-emitting device>

The phosphor of the first embodiment, the SCASN phosphor BR102/Q (manufactured by Mitsubishi Chemical Corporation), and the blue LED (luminous peak wavelength of 451 nm) were combined to produce a light-emitting device having color temperatures of 3000 K, 4000 K, and 5000 K. The fabricated illuminator simulates a white LED spectrum.

Specifically, separately prepare the measured data of the blue LED, and self-reality The luminescence spectrum obtained by subtracting the spectrum of the excitation source from the measured luminescence spectrum of the above-mentioned phosphor when excited at a wavelength of 450 nm. The intensity of the blue LED and the intensity of the luminescence peak of each phosphor are multiplied by an arbitrary ratio by the color temperature of the illuminating device to display the color temperature of 3000K, 4000K, and 5000K, and are calculated as one luminescence spectrum, and the obtained person is regarded as white. Exported from the spectrum.

The calculation method of each optical characteristic evaluation item is as follows.

(i) The xy chromaticity coordinates on the CIE 1931 chromaticity diagram are calculated in accordance with JIS Z8724: 1997 (Title: Method of Color Measurement - Source Color -).

(ii) converted to the uv chromaticity coordinate on the CIE 1960 UCS chromaticity diagram according to the result of (i) above, and calculated according to JIS Z8725:1999 (title: measurement method of distribution temperature and color temperature of light source, correlation color temperature) Correlated color temperature (Kelvin) and Duv.

(iii) According to JIS Z8726: 1990 (title: color rendering evaluation method of light source), the color evaluation number (Ra, R1 to R15) is calculated from the white spectrum.

[Embodiment 10]

The white LED spectrum of the light-emitting device of Example 10 was obtained by adjusting the intensity of the emission spectrum of each of the phosphors so as to display a color temperature of 3000K. The white LED spectrum of the light-emitting device of Example 10 is shown in Fig. 13. Ra shows 78. Further, the absorption efficiency of the phosphor of Example 1 excited by excitation at 455 nm was assumed to be 85%, the internal quantum efficiency was assumed to be 89%, and the D50 was assumed to be 15.4 μm, and the luminescence of the illuminating device of Example 10 was obtained. The efficiency is 181.2 lm / W. The results of these simulations are summarized in Table 24.

[Example 11]

The white LED spectrum of the light-emitting device of Example 11 was obtained by adjusting the intensity of the emission spectrum of each of the phosphors so as to display a color temperature of 4000K. The white LED spectrum of the light-emitting device of Example 11 is shown in Fig. 14. Ra shows 76. Further, the absorption efficiency of the phosphor of Example 1 excited by excitation at 455 nm was assumed to be 85%, the internal quantum efficiency was assumed to be 89%, and the D50 was assumed to be 15.4 μm, and the luminescence of the illuminating device of Example 11 was obtained. The efficiency is 192.6 lm/W. The results of these simulations are summarized in Table 24.

[Embodiment 12]

The white LED spectrum of the light-emitting device of Example 12 was obtained by adjusting the intensity of the emission spectrum of each of the phosphors at a display color temperature of 5000K. The white LED spectrum of the light-emitting device of Example 12 is shown in Fig. 15. Ra shows 75. Further, the absorption efficiency of the phosphor of Example 1 excited by excitation at 455 nm was assumed to be 85%, the internal quantum efficiency was assumed to be 89%, and the D50 was assumed to be 15.4 μm, and the luminescence of the illuminating device of Example 12 was assumed. The efficiency is 196.1 lm/W. The results of these simulations are summarized in Table 24.

As shown in Table 24, according to the simulation results, the light-emitting device including the phosphor of the present invention has high color rendering property and high luminous efficiency.

[Example 13]

The phosphor of the first embodiment, the CASN phosphor BR101/J (manufactured by Mitsubishi Chemical Corporation), and the blue LED (luminous peak wavelength of 450 nm) were combined to prepare a light-emitting device, and the white LED spectrum was simulated for the produced light-emitting device. . The derived spectrum is shown in Fig. 16. The chromaticity is CIEx=0.262 CIEy=0.219. Further, the chromaticity range of the light-emitting device of Example 13 is shown in Fig. 17. As shown in Fig. 17, the light-emitting device using the phosphor of the first embodiment of the present invention is suitable for use in, for example, an image display device because of a wide range of chromaticity.

[Embodiment 14]

For the phosphor of the above Example 1, KSF phosphor BR301/C (Mitsubishi Chemical) A light-emitting device that combines a blue LED (luminous peak wavelength of 450 nm) to simulate a white LED spectrum. The derived white LED spectrum is shown in Fig. 18. The chromaticity of the illuminating device is CIEx=0.260 CIEy=0.216. Further, the chromaticity range of the light-emitting device of Example 14 is shown in Fig. 19. As shown in Fig. 19, the light-emitting device using the phosphor of the first embodiment of the present invention is suitable for, for example, an image display device or the like because of a wide range of chromaticity.

According to the above, the phosphor of the first embodiment of the present invention can provide not only a bright light-emitting device with good color reproducibility, but also a higher light-emitting intensity in a region where the normal use temperature is higher and the light-emitting intensity is lowered. Light emitting device. That is, the light-emitting device including the phosphor of the first embodiment of the present invention and the high-quality illumination device and the liquid crystal display device including the same are of high quality.

The present invention has been described in detail with reference to the preferred embodiments thereof. The present application is based on Japanese Patent Application No. Hei. No. Hei. No. Hei.

Claims (8)

A phosphor comprising a phosphor having a crystal phase of a monoclinic crystal of M element, A element, Al, Si, N; characterized in that the lattice constant of the crystal phase satisfies the a-axis of 7.7 Å, respectively. ≦a≦8.51Å, the b-axis is 8.64 Åb≦9.55Å, the c-axis is 8.53 Åc≦9.43Å, and the β angle is 97.6°≦β≦115.6°, (wherein the M element is selected from the activating element) One or more elements, and the A element means one or more elements selected from the group consisting of alkaline earth metal elements). The phosphor of claim 1, wherein the crystal phase has a composition represented by the following formula [1], M _m A _a Al _b Si _c N _d [1] (in the above formula [1], the M element represents One or more elements selected from the group consisting of active elements, and the A element is one or more elements selected from the group consisting of alkaline earth metal elements, and m, a, b, c, and d are each independently satisfying the value of the following formula, 0 < m ≦0.2 m+a=1 0.8≦b≦1.2 3.2≦c≦4.8 5.6≦d≦8.4). A phosphor according to claim 1 or 2, wherein the A element comprises Ca and/or Sr. The phosphor of any one of claims 1 to 3, wherein the M element comprises Eu. The phosphor according to any one of claims 1 to 4, which has an emission peak wavelength in a range of 500 nm or more and 560 nm or less by irradiating excitation light having a wavelength of 350 nm or more and 460 nm or less. A light-emitting device comprising: a first light-emitting body; and a second light-emitting body that emits visible light by irradiation of light from the first light-emitting body, wherein the second light-emitting body includes the claims 1 to 5 Any of the phosphors. A lighting device characterized by comprising the light-emitting device of claim 6 as a light source. An image display device comprising the light-emitting device of claim 6 as a light source.