JP2013227527A - Phosphor and light emitting device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a yellow light-emitting phosphor which has high color rendering characteristics and can be stably produced.SOLUTION: The phosphor contains a crystalline phase which has the composition shown by formula [1]: XYO:Ce(wherein Xis an alkaline earth metal element essentially containing Ca; Yis a tetravalent metallic element essentially containing Si; a1, b1 and c1 are the numbers satisfying 1.9≤a1≤2.2, 3.8≤b1≤4.3 and 0.001≤c1≤0.1, respectively) and which is a γ phase. The phosphor contains a trivalent metallic element essentially containing Al and has a light emission peak in the wavelength region of 530-600 nm.

Description

  The present invention relates to a yellow light-emitting phosphor that has high color rendering properties and can be stably produced, and a light-emitting device using the phosphor.

  White light-emitting diodes (hereinafter also referred to as “LEDs”) are one of next-generation light-emitting elements that can replace conventional light sources for general illumination. The white LED has an advantage that it consumes much less power than a conventional light source, exhibits high efficiency and high brightness, has a long life, and has a fast response speed.

  As a method for producing a white LED, a method for producing a combination of red, green and blue LEDs, a method for producing a combination of red, green and blue light emitting phosphors with ultraviolet or near ultraviolet LEDs, and a yellow light emitting phosphor for blue LEDs. The method of producing in combination is mentioned.

  Among these, the method of manufacturing a blue LED in combination with a yellow light-emitting phosphor not only has a simple structure and is easy to manufacture, but also has the advantage that high-intensity white light can be obtained. Currently, it is most widely used.

Examples of yellow light emitting phosphors to be combined with blue LEDs include yttrium aluminum garnet (Y ₃ Al ₅ O ₁₂ : Ce ³⁺ ; hereinafter abbreviated as “YAG”). However, YAG-based yellow light-emitting phosphors have a relatively weak emission intensity in the red region due to the characteristics of the emission wavelength, so it is difficult to obtain a high color rendering characteristic and are sensitive to the color temperature. Therefore, there is a problem that it is not suitable as a color background light source for illumination and liquid crystal display (LCD).

In order to solve these problems, several phosphors have been studied, and a Ca ₂ SiO ₄ : Ce phosphor has been reported as an example (Patent Document 1).

JP 2009-084552 A

When a phosphor is put into practical use, it is necessary to be able to produce it stably. As a result of the inventors trying out Patent Document 1, a phosphor emitting blue light instead of yellow light was obtained. This is because the Ca ₂ SiO ₄ crystal has γ-type and β-type crystal phases, and the yellow light-emitting phosphor has a γ-type crystal phase, while the phosphor is in the process of firing in the manufacturing process. This is probably because a phosphor having a β-type crystal phase was produced.
In addition, the Ca ₂ SiO ₄ crystal is easily hydrated in the β-type, whereas the γ-type is not easily hydrated. Therefore, when Ca ₂ SiO ₄ is studied as the host crystal of the phosphor, the stability to moisture is referred to. In terms of the point, it is desirable to reliably generate the γ-type host crystal.

  An object of the present invention is to provide a yellow light-emitting phosphor that has high color rendering properties and can be produced stably.

The present inventors have result of intensive studies to solve this _problem, Ca 2 SiO ₄ by adding Al to Si site of the crystal, and Al composition ratio and ^Ce 0.49c ^-0.35 ≦ d the composition ratio of When satisfying / c ≦ 15, it was found that a γ phase was stably obtained, and the present invention was completed.

That is, the gist of the present invention is the following [1] to [7].
[1] A phosphor containing a crystal phase having a composition represented by the following formula [1], wherein the crystal phase is a γ phase,
A phosphor containing a trivalent metal element essentially containing Al and having an emission peak in a wavelength range of 530 nm to 600 nm.
^{_{X 1 a1 Y 1 O b1:}} Ce c1 ... [1]
(In the above formula [1],
X ¹ is an alkaline earth metal element in which Ca is essential,
Y ¹ is a tetravalent metal element in which Si is essential,
Represents.
A1 to c1 are respectively
1.9 ≦ a1 ≦ 2.2
3.8 ≦ b1 ≦ 4.3
0.001 ≦ c1 ≦ 0.1
Represents a number that satisfies )

[2] The phosphor according to [1], wherein the crystal phase has a composition represented by the following formula [2].
_{X a (Si 1-d,} Z d) O b: Ce c, A e ... [2]
(In the above equation [2],
X is an alkaline earth metal element in which Ca is essential,
Z is a trivalent metal element in which Al is essential,
A represents an alkali metal element.
A to e are respectively
1.9 ≦ a ≦ 2.2
3.8 ≦ b ≦ 4.3
0.001 ≦ c ≦ 0.1
0.49c ^-0.35 ≦ d / c ≦ 15
0 ≦ e ≦ 0.1
Represents a number that satisfies )

[3] The phosphor according to [1], wherein the crystal phase has a composition represented by the following formula [3].
_{X a (Si 1-d,} W d) O b: Ce c, A e ... [3]
(In the above equation [3],
X is an alkaline earth metal element in which Ca is essential,
W requires Al, and an element containing at least one selected from trivalent metal elements other than Al, Ge, and Sn A represents an alkali metal element.
A to e are respectively
1.9 ≦ a ≦ 2.2
3.8 ≦ b ≦ 4.3
0.001 ≦ c ≦ 0.1
0.49c ^-0.35 ≦ d / c ≦ 15
0 ≦ e ≦ 0.1
Represents a number that satisfies )

[4] The phosphor according to any one of [1] to [3], which has a peak top at 60 to 75 ppm when a solid ²⁷ Al-MAS-NMR spectrum is measured after moisture absorption treatment.

[5] When measuring the solid ²⁷ Al-MAS-NMR spectrum after the moisture absorption treatment, the integrated intensity area of the signal intensity of 0 to 60 ppm is 300% or less with respect to the integrated intensity area of the signal intensity of 60 to 75 ppm. The phosphor according to any one of [1] to [4].

[6] In the X-ray diffraction pattern, the black angle is 15.72-15.90, 20.50-20.70, 23.16-23.36, 29.50-29.78, 32.38-32. The phosphor according to any one of [1] to [5], which has peaks in the ranges of 64, 32.70-32.86, 35.56-35.76, and 47.36-47.76, respectively.

[7] A light emitting device having a first light emitter (excitation light source) and a second light emitter that can emit visible light by converting light from the first light emitter, The second light emitter contains at least one of the phosphors according to any one of [1] to [6] as a first phosphor.

  According to the present invention, it is possible to provide a yellow phosphor that has high color rendering properties and can be manufactured stably. In addition, when the phosphor of the present invention is combined with an LED or the like, a light emitting device having excellent light emission characteristics can be provided.

Is a graph illustrating the parameters ^{"0.49c -0.35} ≦ d / c ≦ 15" in the present invention. It is a perspective view which shows typically one Embodiment of the light-emitting device of this invention. It is sectional drawing which shows typically another embodiment of the light-emitting device of this invention. In FIG. 3, (a) shows a shell-type light emitting device, and (b) shows a surface-mounted light emitting device. It is sectional drawing which shows typically the one aspect | mode of the illuminating device of this invention. 6 is a chart showing an X-ray diffraction pattern of the phosphor obtained in Example 5. FIG. 6 is a chart showing an emission spectrum of the phosphor obtained in Example 5. 6 is a chart showing an X-ray diffraction pattern of a phosphor obtained in Comparative Example 2. It is a chart which shows the solid ²⁷ Al-MAS-NMR spectrum of the fluorescent substance obtained in Examples 21-23, 25, 26, 28, 29, and the comparative example 1. FIG.

Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist of the present invention. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value. Further, in the phosphor composition formula in this specification, each composition formula is delimited by a punctuation mark (,). In addition, when a plurality of elements are listed separated by commas (,), one or two or more of the listed elements may be included in any combination and composition. For example, the composition formula “(Ca, Sr, Ba) Al ₂ O ₄ : Eu” has “CaAl ₂ O ₄ : Eu”, “SrAl ₂ O ₄ : Eu”, and “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”, _{"Ca 1-x-y Sr x} Ba y Al 2 O 4: Eu " (. in the formula, 0 <x <1,0 <y <1,0 < a x + y <1) all the comprehensive It shall be shown in

[1. Phosphor]
The phosphor of the present invention contains a crystal phase having a composition represented by the following formula [1], and the crystal phase is a γ-phase phosphor. And having an emission peak in a wavelength range of 530 nm to 600 nm.
^{_{X 1 a1 Y 1 O b1:}} Ce c1 ... [1]
(In the above formula [1],
X ¹ is an alkaline earth metal element in which Ca is essential,
Y ¹ is a tetravalent metal element in which Si is essential,
Represents.
A1 to c1 are respectively
1.9 ≦ a1 ≦ 2.2
3.8 ≦ b1 ≦ 4.3
0.001 ≦ c1 ≦ 0.1
Represents a number that satisfies )
Here, the trivalent metal element in which Al is essential corresponds to “Z” in the following formula [2].

Moreover, it is preferable that the said crystal phase has a composition represented by following formula [2] or following formula [3].
_{X a (Si 1-d,} Z d) O b: Ce c, A e ... [2]
(In the above equation [2],
X is an alkaline earth metal element in which Ca is essential,
Z is a trivalent metal element in which Al is essential,
A represents an alkali metal element.
A to e are respectively
1.9 ≦ a ≦ 2.2
3.8 ≦ b ≦ 4.3
0.001 ≦ c ≦ 0.1
0.49c ^-0.35 ≦ d / c ≦ 15
0 ≦ e ≦ 0.1
Represents a number that satisfies )

_{X a (Si 1-d,} W d) O b: Ce c, A e ... [3]
(In the above equation [3],
X is an alkaline earth metal element in which Ca is essential,
W requires Al, and an element containing at least one selected from trivalent metal elements other than Al, Ge, and Sn A represents an alkali metal element.
A to e are respectively
1.9 ≦ a ≦ 2.2
3.8 ≦ b ≦ 4.3
0.001 ≦ c ≦ 0.1
0.49c ^-0.35 ≦ d / c ≦ 15
0 ≦ e ≦ 0.1
Represents a number that satisfies )

<Composition of phosphor>
As described above, in the formula [1], “X ¹ ” represents an alkaline earth metal element in which Ca is essential, and is synonymous with “X” in the formula [2] or the formula [3] described later. .
In the formula [1], “Y ¹ ” represents a tetravalent metal element in which Si is essential.
In the formula [1], “O” represents oxygen and has the same meaning as “O” in the formula [2] or the formula [3] described later.
In the formula [1], “Ce” represents cerium as an activator element and is synonymous with “Ce” in the formula [2] or the formula [3] described later.
In the formula [1], “a1” represents the molar ratio of the X element (an alkaline earth metal element in which Ca is essential). a1 is a number that usually satisfies 1.9 ≦ a1 ≦ 2.2, preferably 1.91 or more, more preferably 1.92 or more, particularly preferably 1.94 or more, and preferably 2.1. It is 19 or less, more preferably 2.18 or less, and particularly preferably 2.16 or less. When a1 is in the above range, the γ phase can be stably synthesized.

  In the formula [1], “b1” represents a molar ratio of O element (oxygen). b1 is a number that usually satisfies 3.8 ≦ b1 ≦ 4.3, preferably 3.82 or more, more preferably 3.85 or more, particularly preferably 3.9 or more, and preferably 4. 28 or less, more preferably 4.25 or less, and particularly preferably 4.2 or less. When b1 is in the above range, the γ phase can be stably synthesized.

  In the above formula [1], “c1” represents the molar ratio of Ce as an activator element. c1 is usually a number satisfying 0.001 ≦ c1 ≦ 0.1, preferably 0.002 or more, more preferably 0.003 or more, particularly preferably 0.004 or more, and preferably 0.09. Below, it is more preferably 0.08 or less, particularly preferably 0.07 or less. If the value of c1 is too large, concentration quenching tends to occur and the brightness tends to decrease. If it is too small, the absorption efficiency tends to decrease, and accordingly, the brightness tends to decrease.

Further, the crystal phase having the composition represented by the formula [1] may contain other elements within the range in which the effect of the present invention can be obtained. For example, Li, Na, K, Rb and Cs An alkali metal element selected from the group consisting of may be contained.
The crystal phase having the composition represented by the formula [1] preferably has the composition represented by the formula [2] or the formula [3].

Further, Al is essential in the crystal phase having the composition represented by the formula [1]. By containing Al, it is possible not only to compensate for the charge shift caused by Ce ³⁺ activation, but also to stabilize the γ phase. In this sense, Al may exist in any form as long as the crystal phase of the phosphor is maintained. In other words, Al is not only present at the Si position in the γ phase that compensates for the deviation of the charge of Ce ³⁺ activated by Ca, but also in a desirable bonding state of Al at lattice defects such as the interface of crystal grain boundaries and the crystal surface. Arrangement stabilizes the γ phase. The desirable Al arrangement state can be confirmed by, for example, solid ²⁷ Al-MAS-NMR.

  In the formula [2] and the formula [3], “X” represents an alkaline earth metal element in which calcium (Ca) is essential. The proportion of Ca to the entire X element is preferably 50 mol% or more, more preferably 70 mol% or more, and particularly preferably 90 mol% or more. When the ratio of Ca to the entire A element is equal to or more than the above lower limit, the lattice volume becomes a more appropriate size, and a stable state without distortion in the skeleton structure can be obtained. The X element may contain alkaline earth metal elements such as strontium (Sr) and barium (Ba) in addition to Ca.

  In the formula [2] and the formula [3], “Si” represents a silicon (Si) element.

  In the formula [2], “Z” represents a trivalent metal element in which Al is essential. The Z element may contain boron (B), gallium (Ga), or the like within a range that does not affect the properties of the obtained phosphor. The proportion of Al to the entire Z element is preferably 50 mol% or more, more preferably 70 mol% or more, and particularly preferably 90 mol% or more. If the ratio of Al to the entire Z element is too small, impurities are generated and it tends to be difficult to obtain a phosphor having the target composition.

In the above formula [3], “W” represents an element containing Al as an essential element and containing at least one selected from trivalent metal elements other than Al, Ge, and Sn (hereinafter referred to as “trivalent metal other than Al”). “One or more elements selected from metal elements, Ge, and Sn” may be referred to as “in-W coexisting elements”).
The proportion of Al to the entire W element is preferably 50 mol% or more, more preferably 70 mol% or more, and particularly preferably 90 mol% or more. When W element contains Al and coexisting elements in W, the effect that γ phase can be generated stably is produced. However, if the proportion of Al to the entire W element is too small, impurities are generated and the target composition is produced. It tends to be difficult to obtain a phosphor of this type.

In the above formulas [2] and [3], “A” is an alkali metal element selected from the group consisting of Li, Na, K, Rb, and Cs, and among these, Li is easily substituted with the Ca position. And / or Na is preferred, and Li is more preferred.
As the A element, any one of these elements may be contained alone, or two or more kinds may be contained in any combination and ratio, but the phosphor of the present invention is the A element. When element A is contained, it is preferable that element A contains at least Li. By containing Li as the A element, it is possible to compensate for the charge shift caused by Ce ³⁺ activation.

  In the above formulas [2] and [3], “O” represents an oxygen element. The O element only needs to contain oxygen as a main component, and may contain F, Cl, or the like within a range that does not affect the characteristics of the obtained phosphor.

  In the above formulas [2] and [3], “Ce” represents cerium as an activator element. The Ce element only needs to contain cerium as a main component, and may contain other rare earth elements such as Eu within a range not affecting the characteristics of the obtained phosphor.

  The phosphor of the present invention is inevitably mixed in addition to the above-described constituent elements of X, Si, Z, W, O, Ce and A within a range that does not affect the effects of the present invention. It may contain an element such as an impurity element.

  In the above formulas [2] and [3], “a” represents the molar ratio of the X element (an alkaline earth metal element in which Ca is essential). a is usually a number satisfying 1.9 ≦ a ≦ 2.2, preferably 1.91 or more, more preferably 1.92 or more, particularly preferably 1.94 or more, and preferably 2. It is 19 or less, more preferably 2.18 or less, and particularly preferably 2.16 or less. When a is in the above range, the γ phase can be stably synthesized.

  In the above formulas [2] and [3], “b” represents the molar ratio of the O element (oxygen). b is a number that usually satisfies 3.8 ≦ b ≦ 4.3, preferably 3.82 or more, more preferably 3.85 or more, particularly preferably 3.9 or more, and preferably 4. 28 or less, more preferably 4.25 or less, and particularly preferably 4.2 or less. When b is in the above range, the γ phase can be stably synthesized.

  In the above formulas [2] and [3], “c” represents the molar ratio of Ce as the activator element. c is a number that usually satisfies 0.001 ≦ c ≦ 0.1, preferably 0.002 or more, more preferably 0.003 or more, particularly preferably 0.004 or more, and preferably 0.09. Below, it is more preferably 0.08 or less, particularly preferably 0.07 or less. If the value of c is too large, concentration quenching tends to occur and the brightness tends to decrease. If it is too small, the absorption efficiency tends to decrease, and accordingly, the brightness tends to decrease.

In the present invention, after the value of “c” in the formula [2] satisfies the above range, “d” indicating the molar ratio of the Z element (a trivalent metal element in which Al is essential) is: 0.49C ^-0.35 there is a large feature on meeting ≦ d / c ≦ ^15, by a ^{0.49c -0.35 ≦ d / c ≦ 15} , the deviation of the charge due to Ce-activated is "Z ”Promotes Ce activation and promotes the formation of a γ-phase structure, so that it is possible to stably produce a yellow light-emitting phosphor excellent in color rendering. d / c is small, the β phase than ^{0.49C -0.35} is the main phase. Also, a large d / c means that c is small and d is large, the activator element Ce is small and the light emission intensity is lowered, and since d is large, the content ratio of Si element is relatively high. By decreasing, it becomes easy to generate | occur | produce different phases other than (gamma) phase.
Similarly, after the value of “c” in the formula [3] satisfies the above range, “d” indicating the molar ratio of the W element (an element in which Al is essential and includes the coexisting element in W) is 0.49C ^-0.35 there is a large feature on meeting ≦ d / c ≦ ^15, by a ^{0.49c -0.35 ≦ d / c ≦ 15} , the deviation of the charge due to Ce-activated is "W ”Promotes Ce activation and promotes the formation of a γ-phase structure, so that it is possible to stably produce a yellow light-emitting phosphor excellent in color rendering. d / c is small, the β phase than ^{0.49C -0.35} is the main phase. Also, a large d / c means that c is small and d is large, the activator element Ce is small and the light emission intensity is lowered, and since d is large, the content ratio of Si element is relatively high. By reducing the number, a different phase other than the γ phase is likely to occur.

In the present invention, the lower limit of the ^{"0.49c -0.35} ≦ d / c", "d / c", as shown in FIG. 1, a phosphor composition was variously changed, the value of "c" When the value of “d / c” is taken on the x-axis and the y-axis is taken as the value of “d / c”, an approximate expression of “c” and “d / c” is obtained in the case where a phosphor having a crystal phase of γ-phase is surely obtained. It was decided by this. That is, in FIG. 1, the points indicated by white circles indicate the minimum d / c values at which γ-phase phosphors can be obtained for each c value, and from these points, “y = 0.915x− ^0. approximation formula that ^{3476 (R} 2 = 0.8711) "is obtained. Accordingly, in the present invention, the ^{"0.49C -0.35"} and the lower limit of "d / c value".

In the above formulas [2] and [3], “e” represents the molar ratio of element A (alkali metal element), and is usually 0 ≦ e ≦ 0.1, preferably 0.001 or more, more preferably 0. 0.005 or more, particularly preferably 0.01 or more, and preferably 0.1 or less, more preferably 0.08 or less, and particularly preferably 0.06 or less. The phosphor composition of the present invention may be e = 0 (not containing an alkali metal element). However, when the Ce element is contained as an activator element, Ce ³⁺ ions are contained by including the alkali metal element. It works as a charge compensator and has the effect of making Ce elements easier to enter. However, in that case, if there is too much alkali metal element, chemical stability as a phosphor may be impaired, so e is set to the upper limit or less.

The crystal phase of the phosphor of the present invention desirably has a peak top at 60 to 75 ppm (around 70 ppm) in a solid ²⁷ Al-MAS-NMR spectrum measured after moisture absorption treatment. In particular, it is desirable that the integrated intensity area of the signal intensity of 0 to 60 ppm (near 55 ppm) is 300% or less, for example, 100 to 200%, with respect to the integrated intensity area of the signal intensity of 60 to 75 ppm (near 70 ppm). This condition characterizes the γ phase structure yellow phosphor.
In addition, the specific measuring method of the solid ²⁷ Al-MAS-NMR spectrum after the moisture absorption treatment of the phosphor is as described in the section of the examples described later.

<Characteristics of phosphor>
(Peak emission wavelength)
The phosphor of the present invention is usually 530 nm or more, preferably 540 nm or more, more preferably 545 nm or more, particularly preferably 550 nm or more, and usually 600 nm or less, preferably 595 nm or less, more preferably 590 nm or less. Has an emission peak. That is, the phosphor of the present invention has a yellow to orange light emission color.

  Since the phosphor of the present invention has a wide half-value width of the emission peak, when used in combination with a blue LED, light emission with good color rendering can be obtained with only one type of phosphor. In addition to the phosphor of the present invention, if a light emitting device is formed by combining a blue to yellow-green phosphor, a red phosphor, or the like, a light emitting device that emits light of higher color rendering can be obtained.

(CIE chromaticity coordinates)
The x value of the CIE chromaticity coordinate of the phosphor of the present invention is usually 0.40 or more, preferably 0.41 or more, more preferably 0.42 or more, particularly preferably 0.43 or more, and usually 0.56. In the following, it is preferably 0.55 or less, more preferably 0.54 or less, more preferably 0.53 or less, and particularly preferably 0.52 or less. The y value of the CIE chromaticity coordinates of the phosphor of the present invention is usually 0.45 or more, preferably 0.46 or more, more preferably 0.47 or more, further preferably 0.48 or more, and usually 0. .60 or less, preferably 0.58 or less, more preferably 0.56 or less, and particularly preferably 0.55 or less.
When the CIE chromaticity coordinates are in the above range, a light emission color with good color rendering can be obtained.

(XRD black angle)
The phosphor of the present invention has a black angle of 15.72-15.90, 20.50-20.70, 23.16-23.36, 29.50-29.78 in an X-ray diffraction (XRD) pattern. , 32.38-32.64, 32.70-32.86, 35.56-35.76, and 47.36-47.76, respectively. For example, a γ phase structure is obtained, and a desired yellow fluorescent color can be obtained by Ce activation.

(Excitation wavelength)
The phosphor of the present invention has an excitation peak in a wavelength range of usually 300 nm or more, preferably 330 nm or more, more preferably 360 nm or more, and usually 500 nm or less, preferably 480 nm or less, more preferably 460 nm or less. That is, it is excited by light in the ultraviolet to blue region.

(Particle size)
The phosphor of the present invention usually has a fine particle form. Specifically, the mass median diameter _{D 50} is usually 2μm or more, preferably 5μm or more, and usually 30μm or less, preferably fine particles of the range 20 [mu] m. When the mass median diameter D ₅₀ is too large, for example, tend to dispersibility becomes poor in the liquid medium in the preparation of which will be described later phosphor-containing composition tends to be too small and the low luminance.

Mass median diameter D ₅₀ is, for example, obtained by measuring particle size distribution by laser diffraction scattering method, is a value determined from the mass-standard particle size distribution curve. The median diameter D ₅₀ is in this mass-standard particle size distribution curve, the accumulated value refers to the particle size value when the 50%.

[2. Method for producing phosphor]
In the phosphor of the present invention, each phosphor material is added with the composition of the crystal phase represented by the formula [1] (however, a trivalent metal element containing Al as essential is added as necessary) And a phosphor raw material mixture prepared by weighing compounds and metals as raw materials so that the composition of the crystal phase represented by the formula [2] or the formula [3] is obtained. It can manufacture by baking a raw material mixture.

As the phosphor material, a metal compound, a metal, or the like is used. Therefore, in order to produce the phosphor of the present invention having the composition of the crystal phase represented by the formula [1], the formula [2], or the formula [3], the X ¹ element and the raw material of the X element (hereinafter referred to as “X ¹ element”) (Hereinafter referred to as “X source”), Y ¹ element and Si element raw materials (hereinafter referred to as “Y source” and “Si source” as appropriate), Z element raw materials (hereinafter referred to as “Z source” as appropriate), W element raw materials (hereinafter referred to as “Z source”) (Hereinafter referred to as “W source”), O element material (hereinafter referred to as “O source”), Ce element material (hereinafter referred to as “Ce source”), A element material (hereinafter referred to as “A source”) The necessary combination is mixed (mixing step), the obtained mixture is fired (firing step), and the obtained fired product is crushed, pulverized, and washed (post-treatment step) as necessary. Can be manufactured.

<Phosphor material>
As the phosphor material used, known materials can be used. For example, the X source is a Ca source such as Ca ₃ N ₂ , CaO and CaCO ₃ , and the Y source is SiC, Si ₃ N ₄ and SiO. Si source such as ₂ ; Z source as Al source such as AlN, Al ₂ O ₃ and Al ₄ C ₃ ; W source as the Al source, GeO ₂ , Li ₄ GeO ₄ , Na ₄ GeO ₄ , K ₄ GeO ₄ , SnO ₂ , Li ₄ SnO ₄ , Na ₄ SnO ₄ , K ₄ SnO _4, etc., raw materials for coexisting elements in W (hereinafter referred to as “internal W coexisting element source” as appropriate), Ce source is Ce metal A Ce compound selected from oxides, carbonates, chlorides, fluorides, nitrides or oxynitrides can be used.

Examples of the A source include Li ₂ O, LiOH · H ₂ O, Li ₂ CO ₃ , LiHCO ₃ , LiNO ₃ , Li ₂ SO ₄ , Li (OCOCH ₃ ), LiF, LiCl, LiBr, and LiI. Of these, carbonates and hydrogen carbonates are preferable. In addition, specific examples of other A sources such as Na source, K source, Rb source, Cs source, etc., in each of the compounds mentioned as specific examples of Li source, Li represents each of Na, K, Rb, Cs, etc. Examples include compounds replaced with elements.

  The O source (oxygen) in the formula [1], the formula [2] or the formula [3] is an X source (Ca source), a Y source (Si source), a Z source (Al source), or a W source. (Al source and coexisting element source in W), Ce source, A source (Li source), or from a firing atmosphere. Each raw material may contain inevitable impurities.

<Mixing process>
The phosphor raw materials are weighed so as to obtain the target composition, and sufficiently mixed using a ball mill or the like to obtain a phosphor raw material mixture (mixing step).
Although it does not specifically limit as said mixing method, Specifically, the following methods (i) and (ii) are mentioned.

  (I) Dry pulverizer such as hammer mill, roll mill, ball mill, jet mill, etc., or pulverization using mortar and pestle, etc., and mixer such as ribbon blender, V-type blender, Henschel mixer, etc., or mortar and pestle And a dry mixing method in which the above phosphor raw materials are pulverized and mixed.

  (Ii) After adding a solvent or dispersion medium such as water to the above-mentioned phosphor raw material, for example, using a pulverizer, a mortar and a pestle, or an evaporating dish and a stirring rod, A wet mixing method in which drying is performed by spray drying, heat drying, or natural drying.

  The mixing of the phosphor raw material may be either the wet mixing method or the dry mixing method, but in order to avoid contamination of the phosphor raw material with moisture, a dry mixing method or a wet mixing method using a water-insoluble solvent is more preferable. .

<Baking process>
Subsequently, the phosphor material mixture obtained in the mixing step is fired (firing step).
Firing is carried out using a firing furnace, a pressure furnace or the like after the above-described phosphor raw material mixture is dried, if necessary, and filled in a container such as a crucible.

  Examples of the material of the firing container (such as a crucible) used in the firing step include alumina, boron nitride, and carbon. Among these, phosphors with good crystallinity are particularly obtained by using alumina. Is preferable.

  Although the firing temperature varies depending on other conditions such as pressure, the firing can be usually performed in a temperature range of 600 ° C. or more and 1700 ° C. or less. The maximum temperature reached in the firing step is usually 1000 ° C. or higher, preferably 1200 ° C. or higher, more preferably 1300 ° C. or higher, particularly preferably 1400 ° C. or higher, and usually 1700 ° C. or lower, preferably 1650 ° C. or lower. Preferably it is 1600 degrees C or less. If the firing temperature is too high, volatilization of the low boiling point metal element cannot be avoided or melting occurs, so that defects tend to be generated and colored in the base crystal, and impurities are likely to be generated. . If it is too low, the progress of the solid phase reaction tends to be slow.

  The temperature rising rate in the firing step is usually 2 ° C./min or more, preferably 5 ° C./min or more, more preferably 8 ° C./min or more, and usually 30 ° C./min or less, preferably 25 ° C./min or less. It is. If the rate of temperature rise is below this range, the firing time may be long. In addition, if the rate of temperature rise exceeds this range, the firing device, container, etc. may be damaged.

  The firing atmosphere in the firing step is arbitrary as long as the phosphor of the present invention is obtained, but a reducing gas-containing atmosphere is preferable. Specific examples include an argon gas atmosphere, a nitrogen gas atmosphere, a hydrogen-containing argon gas atmosphere, a hydrogen-containing nitrogen gas atmosphere, a hydrogen gas atmosphere, and the like. Among these, an argon gas atmosphere is preferable.

  The firing time (maximum temperature holding time) varies depending on the temperature and pressure during firing, but is usually 10 minutes or longer, preferably 30 minutes or longer, and usually 24 hours or shorter, preferably 12 hours or shorter.

  Although the pressure in the firing step varies depending on the firing temperature and the like, the pressure in the furnace can be set to atmospheric pressure (0.1013 MPa) or a pressurized state. The pressure in the firing step is usually 0.1013 MPa or more, preferably 0.2 MPa or more, more preferably 0.4 MPa or more, and usually 100 MPa or less, preferably 50 MPa or less, more preferably 20 MPa or less, particularly preferably 10 MPa. It is as follows. If the pressure is too high, by-products tend to increase, and if the pressure is too low, the obtained phosphor may be decomposed or colored, so adjustment of the pressure is important.

  In addition, you may repeat a baking process in multiple times as needed. In that case, the firing conditions may be the same or different between the first firing and the second firing.

<Post-processing process>
The fired product obtained by the firing is granular or massive. This is pulverized, pulverized and / or classified into a powder of a predetermined size. _Here, it is preferable to process as _{D 50} is less than about 30 [mu] m.

  As an example of the specific treatment, the baked product is subjected to a sieve classification process with an opening of about 45 μm, and the powder that has passed through the sieve is passed to the next process, or the composite is a common product such as a ball mill, a vibration mill, a jet mill, or the like. The method of grind | pulverizing to a predetermined particle size using a grinder is mentioned. In the latter method, excessive pulverization not only generates fine particles that easily scatter light, but also generates crystal defects on the particle surface, which may cause a decrease in luminous efficiency.

  Moreover, you may provide the process of wash | cleaning fluorescent substance (baked material) as needed. After the cleaning step, the phosphor is dried until it has no adhering moisture and is used. Further, if necessary, dispersion / classification treatment may be performed to loosen the aggregation.

[3. Use of phosphor]
The phosphor of the present invention can be used for any application using the phosphor. In addition, the phosphor of the present invention can be used alone, but two or more kinds of phosphors can be used together, or a phosphor mixture of any combination using the phosphor of the present invention and other phosphors in combination. Can also be used.

The phosphor of the present invention can be used as a phosphor-containing composition by mixing with a known liquid medium (for example, a silicone compound).
In addition, the phosphor obtained by the present invention can be suitably used for various light-emitting devices by combining with a light source that emits ultraviolet light, taking advantage of the property that it can be excited by ultraviolet light.

  The emission color of the light-emitting device is not limited to purple or white, but by appropriately selecting the combination and content of phosphors, light emission that emits light in any color, such as light bulb color (warm white) or pastel color The device can be manufactured. The light-emitting device thus obtained can be used as a light-emitting portion (particularly a liquid crystal backlight) or an illumination device of an image display device.

[4. Phosphor-containing composition]
The phosphor of the present invention can be used by mixing with a liquid medium. In particular, when the phosphor of the present invention is used for applications such as a light emitting device, it is preferably used in a form dispersed in a liquid medium. The phosphor of the present invention dispersed in a liquid medium will be referred to as “the phosphor-containing composition of the present invention” as appropriate.

<Phosphor>
There is no restriction | limiting in the kind of fluorescent substance of this invention contained in the fluorescent substance containing composition of this invention, It can select arbitrarily. Moreover, the fluorescent substance of this invention contained in a fluorescent substance containing composition may be only 1 type, and may use 2 or more types together by arbitrary combinations and a ratio. Furthermore, the phosphor-containing composition may contain a phosphor other than the phosphor of the present invention as long as the effects of the present invention are not significantly impaired.

<Liquid medium>
The kind of the liquid medium used for the phosphor-containing composition of the present invention is not particularly limited, and a curable material that can be molded over the semiconductor light emitting element can be used. The curable material is a fluid material that is cured by performing some kind of curing treatment. Here, the fluid state means, for example, a liquid state or a gel state. The curable material is not particularly limited as long as it secures the role of guiding the light emitted from the solid light emitting element to the phosphor. Moreover, only 1 type may be used for a curable material and it may use 2 or more types together by arbitrary combinations and a ratio. Therefore, as the curable material, any of inorganic materials, organic materials, and mixtures thereof can be used.

  As the inorganic material, for example, a solution obtained by hydrolytic polymerization of a solution containing a metal alkoxide, a ceramic precursor polymer or a metal alkoxide by a sol-gel method, or a combination thereof is solidified (for example, a siloxane bond). Inorganic materials having

  On the other hand, examples of the organic material include a thermosetting resin and a photocurable resin. Specific examples include (meth) acrylic resins such as poly (meth) acrylic acid methyl; styrene resins such as polystyrene and styrene-acrylonitrile copolymers; polycarbonate resins; polyester resins; phenoxy resins; butyral resins; Cellulose resins such as cellulose acetate and cellulose acetate butyrate; epoxy resins; phenol resins; silicone resins and the like.

  Among these curable materials, it is preferable to use a silicon-containing compound that is less deteriorated with respect to light emitted from the semiconductor light-emitting element and is excellent in alkali resistance, acid resistance, and heat resistance. The silicon-containing compound is a compound having a silicon atom in the molecule, organic materials such as polyorganosiloxane (silicone compound), inorganic materials such as silicon oxide, silicon nitride, silicon oxynitride, borosilicate, phosphosilicate Examples thereof include glass materials such as salts and alkali silicates. Among these, silicone materials are preferable from the viewpoints of transparency, adhesion, ease of handling, and excellent mechanical and thermal stress relaxation characteristics.

  The silicone-based material usually refers to an organic polymer having a siloxane bond as a main chain, and for example, condensation-type, addition-type, improved sol-gel type, photo-curing type silicone-based materials can be used.

  As the condensed silicone material, for example, semiconductor light-emitting device members described in JP-A-2007-112973 to 112975, JP-A-2007-19459, JP-A-2008-34833, and the like can be used. Condensation-type silicone materials have excellent adhesion to packages, electrodes, and light-emitting elements used in semiconductor light-emitting devices, so the addition of adhesion-improving components can be minimized, and crosslinking is mainly due to siloxane bonds. There is an advantage of excellent heat resistance and light resistance.

  Examples of the addition-type silicone material include potting silicone materials described in JP-A-2004-186168, JP-A-2004-221308, JP-A-2005-327777, JP-A-2003-183881, Organically modified silicone materials for potting described in JP-A-2006-206919, silicone materials for injection molding described in JP-A-2006-324596, silicone materials for transfer molding described in JP-A-2007-231173, etc. Can be suitably used. The addition-type silicone material has advantages such as a high degree of freedom of selection such as a curing rate and a hardness of a cured product, a component that does not desorb during curing, hardly shrinking due to curing, and excellent deep part curability.

  Moreover, as an improved sol-gel type silicone material that is one of the condensation types, for example, the silicone materials described in JP-A-2006-077234, JP-A-2006-291018, JP-A-2007-119569 and the like can be used. It can be used suitably. The improved sol-gel type silicone material has an advantage that it has a high degree of crosslinking, heat resistance, light resistance and durability, and is excellent in the protective function of a phosphor having low gas permeability and low moisture resistance.

  As the photocurable silicone material, for example, silicone materials described in JP2007-131812A, JP2007-214543A, and the like can be suitably used. The ultraviolet curable silicone material has advantages such as excellent productivity because it cures in a short time, and it is not necessary to apply a high temperature for curing, so that the light emitting element is hardly deteriorated.

  These silicone materials may be used alone, or a mixture of a plurality of silicone materials may be used if curing inhibition does not occur when mixed.

<Content of liquid medium and phosphor>
The content of the liquid medium in the phosphor-containing composition of the present invention is arbitrary as long as the effects of the present invention are not significantly impaired. Is 40% by mass or more, and is usually 99% by mass or less, preferably 95% by mass or less, more preferably 80% by mass or less. When the amount of the liquid medium is large, no particular problem occurs. However, in order to obtain a desired chromaticity coordinate, color rendering index, luminous efficiency, etc. in the case of a semiconductor light emitting device, it is usually at a blending ratio as described above. It is desirable to use a liquid medium. On the other hand, when there is too little liquid medium, fluidity | liquidity falls and it may become difficult to handle.

  The liquid medium mainly serves as a binder in the phosphor-containing composition of the present invention. The liquid medium may be used alone or in combination of two or more in any combination and ratio. For example, when using a silicon-containing compound for the purpose of improving heat resistance, light resistance, etc., other thermosetting resins such as an epoxy resin are contained so as not to impair the durability of the silicon-containing compound. Also good. In this case, the content of the other thermosetting resin is usually 25% by mass or less, preferably 10% by mass or less, based on the total amount of the liquid medium as the binder.

  The phosphor content in the phosphor-containing composition of the present invention is arbitrary as long as the effects of the present invention are not significantly impaired, but usually 1% by mass or more with respect to the entire phosphor-containing composition of the present invention, Preferably it is 5 mass% or more, More preferably, it is 20 mass% or more, and is 75 mass% or less normally, Preferably it is 60 mass% or less. The proportion of the phosphor of the present invention in the phosphor in the phosphor-containing composition is also arbitrary, but is usually 30% by mass or more, preferably 50% by mass or more, and usually 100% by mass or less. If the phosphor content in the phosphor-containing composition is too high, the flowability of the phosphor-containing composition may be inferior and difficult to handle, and if the phosphor content is too low, the light emission efficiency of the light-emitting device decreases. There is a tendency.

<Other ingredients>
In the phosphor-containing composition of the present invention, in addition to the phosphor and the liquid medium, other components such as a metal oxide for adjusting the refractive index, a diffusing agent, and a filler are used unless the effects of the present invention are significantly impaired. Further, additives such as a viscosity modifier and an ultraviolet absorber may be contained. Only 1 type may be used for another component and it may use 2 or more types together by arbitrary combinations and a ratio.

[5. Light emitting device]
A light-emitting device of the present invention includes a first light-emitting body (excitation light source) and a second light-emitting body that can emit visible light by converting light from the first light-emitting body into visible light. The above-mentioned [1. It contains a first phosphor containing one or more of the phosphors of the present invention described in the section [Phosphor].

  Preferable specific examples of the phosphor of the present invention used in the light emitting device of the present invention include [1. Examples thereof include the phosphor of the present invention described in the “Phosphor” column and the phosphors used in the respective Examples in the “Example” column described later. In addition, any one of the phosphors of the present invention may be used alone, or two or more may be used in any combination and ratio.

  The light-emitting device of the present invention has a first light emitter (excitation light source), and at least the phosphor of the present invention is used as the second light emitter. It is possible to arbitrarily adopt the apparatus configuration. A specific example of the device configuration will be described later.

  Among the light emitting devices of the present invention, in particular, as a white light emitting device, specifically, an excitation light source as described later is used as the first light emitter, and in addition to the phosphor of the present invention, blue fluorescence as described later is emitted. Phosphor that emits light (hereinafter referred to as “blue phosphor” as appropriate), phosphor that emits green fluorescence (hereinafter referred to as “green phosphor” as appropriate), phosphor that emits red fluorescence (hereinafter referred to as “red phosphor” as appropriate) And a known phosphor such as a phosphor that emits yellow fluorescence (hereinafter referred to as “yellow phosphor” as appropriate) is used in any combination, and a known apparatus configuration is obtained.

  Here, the white color of the white light emitting device means all of (yellowish) white, (greenish) white, (blueish) white, (purple) white and white defined by JIS Z 8701 Of these, white is preferred.

<Configuration of light emitting device>
(First luminous body)
The 1st light-emitting body in the light-emitting device of this invention light-emits the light which excites the 2nd light-emitting body mentioned later.
The emission peak wavelength of the first illuminant is not particularly limited as long as it overlaps with the absorption wavelength of the second illuminant described later, and an illuminant having a wide emission wavelength region can be used. Usually, a light emitter having an emission wavelength from the ultraviolet region to the blue region is used.

  The specific value of the emission peak wavelength of the first illuminant is usually 300 nm or more, preferably 330 nm or more, more preferably 360 nm or more, and usually 500 nm or less, preferably 480 nm or less, more preferably 460 nm or less. It is desirable to use a light emitter having a wavelength.

  As the first light emitter, a semiconductor light emitting element is generally used, and specifically, a light emitting diode (LED), a laser diode (LD), or the like can be used. In addition, as a light-emitting body which can be used as a 1st light-emitting body, an organic electroluminescent light emitting element, an inorganic electroluminescent light emitting element, etc. are mentioned, for example. However, what can be used as a 1st light-emitting body is not restricted to what is illustrated by this specification.

Among these, as the first light emitter, a GaN LED or LD using a GaN compound semiconductor is preferable. This is because GaN-based LEDs and LDs have significantly higher emission output and external quantum efficiency than SiC-based LEDs that emit light in this region, and emit very bright light with low power when combined with the phosphor. It is because it is obtained. For example, for a current load of 20 mA, GaN-based LEDs and LDs usually have a light emission intensity 100 times or more that of SiC-based. As the GaN-based LED and LD, those having an Al _X Ga _Y N light emitting layer, a GaN light emitting layer, or an In _X Ga _Y N light emitting layer are preferable. Among them, since the emission intensity is very high, the GaN-based LED is particularly preferably one having an In _X Ga _Y N light emitting layer, and more preferably a multiple quantum well structure having an In _X Ga _Y N layer and a GaN layer. preferable.

  In the above, the value of X + Y is usually a value in the range of 0.8 to 1.2. In the GaN-based LED, those in which the light emitting layer is doped with Zn or Si or those without a dopant are preferable for adjusting the light emission characteristics.

A GaN-based LED has these light-emitting layer, p-layer, n-layer, electrode, and substrate as basic components, and the light-emitting layer is an n-type and p-type Al _X Ga _Y N layer, GaN layer, or In _X Those having a heterostructure sandwiched between Ga _Y N layers and the like are preferable because of high light emission efficiency, and those having a heterostructure having a quantum well structure are more preferable because of high light emission efficiency.
Note that only one first light emitter may be used, or two or more first light emitters may be used in any combination and ratio.

(Second light emitter)
The second light emitter in the light emitting device of the present invention is a light emitter that emits visible light when irradiated with light from the first light emitter described above, and one or more phosphors of the present invention are used as the first phosphor. A second phosphor (a blue phosphor, a green phosphor, a yellow phosphor, an orange phosphor, a red phosphor, etc.), which will be described later, is contained as appropriate depending on the application. Further, for example, in the second luminous body, the first and second phosphors are dispersed in a sealing material (cured material of a curable material as a liquid medium of the phosphor-containing composition of the present invention described above). Configured.

  As a phosphor other than the phosphor of the present invention (that is, the second phosphor) used in the second light emitter, the phosphor directly emits light emitted from the first light emitter such as the semiconductor light emitting element described above. The substance is not particularly limited as long as it is a substance that is excited by light or indirectly and emits light of a different wavelength, and can be an inorganic phosphor or an organic phosphor. For example, the type and content of phosphor used to obtain a desired emission color of one or more of blue phosphor, green phosphor, yellow phosphor, orange to red phosphor as exemplified below The amount is preferably adjusted appropriately.

<Blue phosphor>
The blue phosphor preferably has an emission peak wavelength of usually 420 nm or more, particularly 430 nm or more, more preferably 440 nm or more, and usually 490 nm or less, especially 480 nm or less, and more preferably 470 nm or less.
Specifically, (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Eu, (Ba, Ca, Mg, Sr) ₂ SiO ₄ : Eu, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Eu, (Ba, Ca, Sr) ₃ MgSi ₂ O ₈ : Eu are preferred, Ba, Sr) MgAl ₁₀ O ₁₇ : Eu, (Ca, Sr, Ba) ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Eu, and Ba ₃ MgSi ₂ O ₈ : Eu are more preferable.

<Green phosphor>
As the green phosphor, those having an emission peak wavelength of usually 500 nm or more, particularly 510 nm or more, more preferably 515 nm or more, and usually 550 nm or less, especially 542 nm or less, further 535 nm or less are preferred.
_{Specifically, Y 3 (Al, Ga)} 5 O 12: Ce, CaSc 2 O 4: Ce, Ca 3 (Sc, Mg) 2 Si 3 O 12: Ce, (Sr, Ba) 2 SiO 4: Eu Β-sialon, (Ba, Sr) ₃ Si ₆ O ₁₂ : N ₂ : Eu, SrGa ₂ S ₄ : Eu, and BaMgAl ₁₀ O ₁₇ : Eu, Mn are preferable.

<Yellow phosphor>
As the yellow phosphor, those having an emission peak wavelength of usually 530 nm or more, particularly 540 nm or more, more preferably 550 nm or more, and usually 620 nm or less, particularly 600 nm or less, and further 580 nm or less are suitable.
The yellow _{phosphor, Y 3 Al 5 O 12:} Ce, (Y, Gd) 3 Al 5 O 12: Ce, (Sr, Ca, Ba, Mg) 2 SiO 4: Eu, (Ca, Sr) Si 2 N ₂ O ₂ : Eu, (La, Y, Gd, Lu) ₃ (Si, Ge) ₆ N ₁₁ : Ce are preferable.

<Orange to red phosphor>
As the orange to red phosphors, those having an emission peak wavelength of usually 570 nm or more, particularly 580 nm or more, more preferably 585 nm or more, and usually 780 nm or less, particularly 700 nm or less, and further 680 nm or less are preferable.
Specifically, (Ca, Sr, Ba) ₂ Si ₅ (N, O) ₈ : Eu, (Ca, Sr, Ba
) Si (N, O) ₂ : Eu, (Ca, Sr, Ba) AlSi (N, O) ₃ : Eu, (Sr, Ba) ₃ SiO ₅ : Eu, (Ca, Sr) S: Eu, (La , Y) ₂ O ₂ S: Eu, Eu (dibenzoylmethane) ₃ · 1,10-phenanthroline complex and other β-diketone Eu complexes, carboxylic acid Eu complexes, K ₂ SiF ₆ : Mn are preferred, (Ca , Sr, Ba) ₂ Si ₅ (N, O) ₈ : Eu, (Sr, Ca) AlSi (N, O): Eu, (La, Y) ₂ O ₂ S: Eu, K ₂ SiF ₆ : Mn More preferred.

As the orange phosphor, (Sr, Ba) ₃ SiO ₅ : Eu, (Sr, Ba) ₂ SiO ₄ : Eu, (Ca, Sr, Ba) ₂ Si ₅ (N, O) ₈ : Eu, ( Ca, Sr, Ba) AlSi (N, O) ₃ : Ce is preferred.

Second phosphor mass median diameter D ₅₀ that is used for the light emitting device of the present invention is usually 2μm or more and preferably 5μm or more, and usually 30μm or less is preferably in a range of inter alia 20μm or less. When the mass median diameter D ₅₀ is too small, and the luminance decreases tends to phosphor particles tend to aggregate. On the other hand, when the mass median diameter is too large, there is a tendency for coating unevenness and blockage of a dispenser to occur.

[6. Embodiment of Light Emitting Device]
<Embodiment of Light Emitting Device>
Hereinafter, the light-emitting device of the present invention will be described in more detail with reference to specific embodiments. However, the present invention is not limited to the following embodiments, and does not depart from the gist of the present invention. It can be implemented with arbitrary modifications.

  FIG. 2 is a schematic perspective view showing a positional relationship between a first light emitter serving as an excitation light source and a second light emitter configured as a phosphor-containing portion having a phosphor in an example of the light emitting device of the present invention. Shown in In FIG. 2, reference numeral 1 denotes a phosphor-containing portion (second light emitter), reference numeral 2 denotes a surface-emitting GaN LD as an excitation light source (first light emitter), and reference numeral 3 denotes a substrate. In order to create a state in which they are in contact with each other, the excitation light source (LD) 2 and the phosphor-containing portion 1 (second light emitter) are separately manufactured, and their surfaces are brought into contact with each other by an adhesive or other means. Alternatively, the phosphor-containing portion 1 (second light emitter) may be formed (molded) on the light emitting surface of the excitation light source (LD) 2. As a result, the excitation light source (LD) 2 and the phosphor-containing part 1 (second light emitter) can be brought into contact with each other.

When such an apparatus configuration is employed, the light loss is such that light from the excitation light source (first light emitter) is reflected by the film surface of the phosphor-containing portion (second light emitter) and oozes out. Therefore, the light emission efficiency of the entire device can be improved.
FIG. 3A is a typical example of a light emitting device of a form generally referred to as a shell type, and has a light emission having an excitation light source (first light emitter) and a phosphor-containing portion (second light emitter). It is typical sectional drawing which shows one Example of an apparatus. In the light emitting device 4, reference numeral 5 is a mount lead, reference numeral 6 is an inner lead, reference numeral 7 is an excitation light source (first light emitter), reference numeral 8 is a phosphor-containing portion, reference numeral 9 is a conductive wire, and reference numeral 10 is a mold. Each member is indicated.

  FIG. 3B is a representative example of a light-emitting device of a form called a surface-mount type, and light emission having an excitation light source (first light emitter) and a phosphor-containing portion (second light emitter). It is typical sectional drawing which shows one Example of an apparatus. In the figure, reference numeral 22 is an excitation light source (first light emitter), reference numeral 23 is a phosphor-containing portion (second light emitter), reference numeral 24 is a frame, reference numeral 25 is a conductive wire, reference numerals 26 and 27 are electrodes. Respectively.

<Applications of light emitting device>
The use of the light-emitting device of the present invention is not particularly limited, and can be used in various fields in which ordinary light-emitting devices are used. However, since the color rendering property is high and the color reproduction range is wide, the illumination device is particularly preferable. And as a light source for image display devices.

(Lighting device)
When the light-emitting device 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. For example, as shown in FIG. 4, a surface emitting illumination device 11 incorporating the above-described light emitting device 4 can be cited.
FIG. 4 is a cross-sectional view schematically showing an embodiment of the illumination device of the present invention. As shown in FIG. 4, the surface-emitting illumination device has a large number of light-emitting devices 13 (on the light-emitting device 4 described above) on the bottom surface of a rectangular holding case 12 whose inner surface is light-opaque such as a white smooth surface. Is provided with a power source and a circuit (not shown) for driving the light-emitting device 13 on the outside, and a milky white acrylic plate or the like is provided at a position corresponding to the lid portion of the holding case 12. The diffusion plate 14 is fixed for uniform light emission.

  Then, the surface-emitting illumination device 11 is driven to emit light by applying a voltage to the excitation light source (first light emitter) of the light-emitting device 13, and a part of the light emission is converted to the phosphor-containing portion (first The phosphor in the phosphor-containing resin part as the second phosphor) absorbs and emits visible light, while light emission with high color rendering is obtained by color mixing with blue light or the like not absorbed by the phosphor. The light passes through the diffusion plate 14 and is emitted upward in the drawing, and illumination light with uniform brightness is obtained within the surface of the diffusion plate 14 of the holding case 12.

(Image display device)
When the light emitting device of the present invention is used as a light source of an image display device, the specific configuration of the image display device is not limited, but it is preferably used together with a color filter. For example, when the image display device is a color image display device using color liquid crystal display elements, the light emitting device is used as a backlight, a light shutter using liquid crystal, and a color filter having red, green, and blue pixels; By combining these, an image display device can be formed.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to a following example, unless the summary is exceeded. In addition, the values of various production conditions and evaluation results in the following examples have meanings as preferable values of the upper limit or the lower limit in the embodiment of the present invention, and the preferable range is the value of the upper limit or the lower limit. It may be a range defined by a combination of values of the following examples or values of the examples.

[Examples 1 to 29 and Comparative Examples 1 to 8]
{Phosphor material}
As the phosphor material, the following were used.

<Examples 1-18, Comparative Examples 1-8>
As a raw material compound of the phosphor, CaCO ₃ (manufactured by Alfa Aesar, purity 99.95%), SiO ₂ (manufactured by Alfa Aesar, purity 99.95%, particle size 500 μm or less), CeO ₂ (manufactured by Alfa Aesar, purity 99) 0.9%, particle size 5 μm), Al ₂ O ₃ (Alfa Aesar, purity 99.997%, particle size 100 μm or less), Li ₂ CO ₃ (Alfa Aesar, purity 99.998%), respectively.

<Examples 19 to 29>
As a raw material compound of the phosphor, CaCO ₃ (manufactured by Hakuho Chemical Laboratory, purity 99.9%), SiO ₂ (manufactured by Admafine, purity 99.9%), CeO ₂ (manufactured by Shin-Etsu Chemical, purity 99.9). %), Al ₂ O ₃ (manufactured by Sumitomo Chemical Co., Ltd., purity 99.99%), basic MgCO ₃ (manufactured by Hakuho Chemical Laboratory), SrCO ₃ (manufactured by Rare Metallic, purity 99.99%), GeO ₂ (high Purity Chemical Laboratory, purity 99.995%) was used.

{Synthesis of phosphor}
The phosphor was synthesized as follows.

<Examples 1-18, Comparative Examples 1-8>
CaCO ₃ , SiO ₂ , CeO ₂ , and Al ₂ O ₃ were weighed in such amounts that a to e in the formula [2] are values shown in Table 1. The weighed raw material compounds were mixed and stirred in ethanol for 20 minutes using an agate pestle and an agate mortar, then transferred to an alumina crucible (purity 99%) and dried at 150 ° C. for 3 hours. Thereafter, the alumina crucible was placed in a tubular furnace (Elite TSH 15/75/450). A reducing gas of 0.1 liter / min was allowed to flow there. Argon gas was used as the reducing gas. The temperature was raised from 150 ° C. to 400 ° C. at 4 ° C./min, and from 400 ° C. to 1450 ° C. at 8 ° C./min. Thereafter, it was held at 1450 ° C. (maximum temperature reached) under normal pressure for 6 hours. Cooling was performed at 1 ° C./min from 1450 ° C. to 1350 ° C. at 3 ° C./min from 1350 ° C. to 150 ° C. Thereafter, the fired product was taken out into the room. The fired product was again pulverized in air using an agate pestle and an agate mortar, and refired in a normal pressure argon atmosphere using the same firing temperature program as described above to obtain a phosphor.
In Example 17, an inner lid of a ZrO ₂ plate was used for the alumina crucible during firing, and in Example 18, an inner lid of Al ₂ O ₃ powder was provided for the alumina crucible during firing.

<Examples 19 to 27 (Ge-containing, Sr-containing, Mg-containing)>
CaCO ₃ , SiO ₂ , CeO ₂ , Al ₂ O ₃ , MgCO ₃ , SrCO ₃ , GeO ₂ were weighed in such amounts that a to e in the above formulas [2] to [3] are values shown in Tables 2 to 4 . The weighed raw material compounds were mixed and stirred in ethanol for 20 minutes using an agate pestle and an agate mortar, then transferred to an alumina crucible (purity 99%) and dried at 150 ° C. for 3 hours. After that, the alumina crucible was turned into a tubular furnace (Siliconit Koyo Kogyo Co., Ltd. BTEXSH-1165 type PCR
Model No. 9637-H). A reducing gas of 0.1 liter / min was allowed to flow there. Argon gas was used as the reducing gas. The temperature was raised from 150 ° C. to 850 ° C. at 4 ° C./min, and from 850 ° C. to 1450 ° C. at 1 ° C./min. Thereafter, it was held at 1450 ° C. (maximum temperature reached) under normal pressure for 6 hours. Cooling was performed at 1 ° C./min from 1450 ° C. to 1350 ° C. at 3 ° C./min from 1350 ° C. to 150 ° C. Thereafter, the fired product was taken out into the room to obtain a phosphor.

<Examples 28 and 29 (refired)>
The phosphor obtained in Example 27 was annealed as follows to obtain the phosphors of Examples 28 and 29.
First, the phosphor obtained in Example 27 was sufficiently mixed in a wet manner using ethanol in an alumina mortar and closely packed in an alumina crucible (purity 99%). This was heated at 4 ° C./min up to 500 ° C. in a mixed gas stream consisting of a mixed gas of 96 vol% nitrogen and 4 vol% hydrogen using an atmosphere-controlled high-temperature heating electric furnace. The mixture was held at 500 ° C. for 12 hours and refired, and then allowed to cool. Thereafter, the fired product was taken out into the room, and the phosphor of Example 28 was obtained.
In addition, the phosphor obtained in Example 27 was sufficiently mixed in a wet manner using ethanol in an alumina mortar, and each was closely packed in an alumina crucible (purity 99%). This was heated up to 700 ° C. at a rate of 4 ° C./min in a mixed gas stream consisting of a mixed gas of 96 vol% nitrogen and 4 vol% hydrogen using an atmosphere-controlled high-temperature heating electric furnace. The mixture was held at 700 ° C. for 12 hours and refired, and then allowed to cool. Thereafter, the fired product was taken out into the room, and the phosphor of Example 29 was obtained.

{Analysis and evaluation of phosphor}
<Powder X-ray pattern analysis>
About the obtained fluorescent substance, the powder X-ray pattern analysis was performed with the following method. Powder X-ray diffraction was precisely measured with a powder X-ray diffractometer D8 ADVANCE manufactured by Bruker. The measurement conditions are as follows.
・ Uses CuKα tube
・ X-ray output 40KV 40mA
・ Divergent slit 0.25 °
・ Detector 1D position sensitive streamer mode counter ・ Scanning range 2θ = 10 ° -80 °
・ Reading width 0.02 °
・ Counting time 0.5-2 seconds
About the obtained pattern, it compared and identified using the following reference patterns, respectively.
γ phase: ICSD-082995
β phase: ICSD-081096

<Emission peak intensity / emission peak wavelength>
About the obtained phosphor, a module type fluorescence spectrophotometer SPEX Fluorolog-3 (manufactured by Horiba) equipped with a 450 W xenon lamp as an excitation light source and a photomultiplier tube R928 (manufactured by Hamamatsu Photonics) as a spectrum measuring device was used. The emission peak intensity in the wavelength range of 550 to 590 nm was measured.
Specifically, the light from the excitation light source was passed through a diffraction grating spectrometer having a focal length of 32 cm, and only the excitation light having a wavelength of 450 nm was irradiated onto the phosphor. The light generated from the phosphor by the irradiation of excitation light is dispersed by a diffraction grating spectrometer, the emission intensity of each wavelength is measured by a spectrum measuring device in the wavelength range of 300 nm to 800 nm, and signal processing such as sensitivity correction by a personal computer After that, an emission spectrum was obtained. During the measurement, the slit width of the light-receiving side spectroscope was set to 1 nm and the measurement was performed.

<Emission spectrum>
For the phosphors obtained in Examples 15 to 29, a fluorescence measuring apparatus (manufactured by JASCO Corporation) equipped with a 150 W xenon lamp as an excitation light source and a multichannel CCD detector C7041 (manufactured by Hamamatsu Photonics) as a spectrum measuring apparatus. Used to measure the emission spectrum.
Specifically, the light from the excitation light source was passed through a diffraction grating spectrometer having a focal length of 10 cm, and only the excitation light having a wavelength of 450 nm was irradiated to the phosphor through the optical fiber. The light generated from the phosphor by the irradiation of the excitation light is dispersed by a diffraction grating spectroscope having a focal length of 25 cm, the emission intensity of each wavelength is measured by a spectrum measuring device in a wavelength range of 300 nm to 800 nm, and a personal computer is used. An emission spectrum was obtained through signal processing such as sensitivity correction. During the measurement, the slit width of the light-receiving side spectroscope was set to 1 nm and the measurement was performed.

  Further, for the phosphors obtained in Examples 15 to 29, XYZ defined in JIS Z8701 is obtained from data in the wavelength region of 360 nm to 800 nm of the emission spectrum obtained by the above method, according to JIS Z8724. As the chromaticity coordinates x and y in the color system, the chromaticity coordinates of the x, y color system (CIE 1931 color system) were calculated.

  These results are shown in Tables 1-4. In Tables 1 to 4, Examples showing peak intensities of 550 nm to 590 nm had emission peaks in the wavelength range of 550 nm to 590 nm.

Further, FIG. 5 shows an X-ray diffraction pattern of the phosphor obtained in Example 5, and FIG. 6 shows an emission spectrum thereof. Moreover, the X-ray diffraction pattern of the phosphor obtained in Comparative Example 2 is shown in FIG.
From the X-ray diffraction pattern of FIG. 5, the phosphor of Example 5 has a black angle of 15.72-15.90, 20.50-20.70, 23.16-23.36, 29.50-29. 78, 32.38-32.64, 32.70-32.86, 35.56-35.76, and 47.36-47.76, respectively. .
On the other hand, from the X-ray diffraction pattern of FIG. 7, the phosphor of Comparative Example 2 is β-phase.

D / c has the smallest d / c among Comparative Example 1 in which c = 0.005 and d / c = 2.00 and Examples 1 to 3 in which d / c = 4.00 to 8.00. = 4.00 In Example 1, the relationship between c and d / c is plotted on the x-axis and d / c on the y-axis as shown in FIG. ○ mark.
Similarly, in Comparative Example 3 where c = 0.010 and d / c = 2.00, and Examples 4-8 where d / c = 3.00 to 10.00, d / c is the smallest d / c. The relationship between c and d / c in Example 4 where c = 3.00 is plotted on the x-axis and d / c on the y-axis as shown in FIG. ○ marked.
Similarly, in Comparative Example 4 where c = 0.015 and d / c = 2.00 and Examples 9 and 10 where d / c = 2.67 or 3.33, d / c is the smallest d / c. The relationship between c and d / c in Example 9 with c = 2.67 is plotted on the x-axis and d / c on the y-axis as shown in FIG. ○ marked.
Similarly, in Comparative Example 5 where c = 0.020 and d / c = 1.50 and Examples 11-13 where d / c = 2.00 to 3.00, d / c is the smallest d / c. The relationship between c and d / c of Example 11 with c = 2.00 is plotted on the x-axis and d / c on the y-axis as shown in FIG. ○ marked.
This ◯ mark indicates an intermediate d / c value between the d / c value of the comparative example that becomes the β phase and the lowest value of the d / c value of the example that becomes the γ phase. If the value is c, it is considered that a γ phase is formed.
An approximate expression: y = 0.4915x− ^0.3476 (R ² = 0.8711) is obtained from the four circles.

From the above _results, by adding Al to Si site Ca 2 SiO ₄ crystal and a composition ratio of Al and ^Ce, to satisfy ^{0.49c -0.35 ≦ d / c ≦ 15} , stable As a result, it is understood that a γ phase is obtained, and a high color rendering yellow light emitting phosphor can be reliably produced.

<Quantum efficiency>
The absorption efficiency αq, internal quantum efficiency ηi, and external quantum efficiency ηo of the phosphors obtained in Examples 25 to 29 were measured as follows.
First, the phosphor sample to be measured was packed in a cell with a sufficiently smooth surface so that the measurement accuracy was maintained, and was attached to an integrating sphere.
Light was introduced into this integrating sphere from an emission light source (150 W Xe lamp) for exciting the phosphor using an optical fiber. The emission peak wavelength of light from the light emitting light source was adjusted using a monochromator (diffraction grating spectrometer) or the like so as to be monochromatic light of 395 nm. Using this monochromatic light as excitation light, the phosphor sample to be measured was irradiated, and the spectrum was measured for the emission (fluorescence) and reflected light of the phosphor sample using a spectrometer (MCPD7000 manufactured by Otsuka Electronics Co., Ltd.). The light in the integrating sphere was guided to a spectroscopic measurement device using an optical fiber.

The absorption efficiency αq is a value obtained by dividing the number of photons _Nabs of excitation light absorbed by the phosphor sample by the total number of photons N of excitation light.

First, the total number of photons N of the latter excitation light is proportional to the numerical value obtained by the following (formula A). Therefore, a “Spectralon” manufactured by Labsphere (having a reflectance R of 98% with respect to the excitation light having a wavelength of 450 nm), which is a reflector having a reflectance R of almost 100% with respect to the excitation light, is measured. A reflection spectrum I _ref (λ) was measured by attaching to the integrating sphere with the same arrangement as the phosphor sample, irradiating with excitation light, and measuring with a spectroscopic measurement device, and the following value (Equation A) was obtained. .

Here, the integration interval was 435 m to 465 nm.
The number N _abs of the photons in the excitation light that is absorbed in the phosphor sample is proportional to the amount calculated by the following equation (B).

Therefore, the reflection spectrum I (λ) was obtained when the phosphor sample for which the absorption efficiency αq is to be obtained was attached. The integration range of (Formula B) was the same as the integration range defined in (Formula A). Since the actual spectrum measurement value is generally obtained as digital data divided by a certain finite bandwidth with respect to λ, the integration of (Equation A) and (Equation B) was obtained by the sum based on the bandwidth. .
From the above, αq = _Nabs / N = (Formula B) / (Formula A) was calculated.

Next, the internal quantum efficiency ηi was determined as follows. Internal quantum efficiency ηi is a value obtained by dividing the number N _abs of photons number N _PL of photons originating from the fluorescence phenomenon absorbed by the phosphor sample.
Here, N _PL is proportional to the amount obtained by the following (formula C). Therefore, the amount required by the following (formula C) was determined.

The integration interval was 466 nm to 780 nm.
As described above, ηi = (formula C) / (formula B) was calculated, and the internal quantum efficiency ηi was obtained.

It should be noted that the integration from the spectrum that was converted to digital data was performed in the same manner as when the absorption efficiency αq was obtained.
And the external quantum efficiency (eta) o was calculated | required by taking the product of absorption efficiency (alpha) q calculated | required as mentioned above and internal quantum efficiency (eta) i.
Table 5 shows the measurement results. From Table 5, it can be seen that re-firing (annealing) has an effect of improving internal quantum efficiency and external quantum efficiency.

<Solid ²⁷ Al-MAS-NMR spectrum>
For the phosphors obtained in Examples 21 to 23, 25, 26, 28, 29, and Comparative Example 1, solid ²⁷ Al-MAS-NMR spectra after moisture absorption treatment were measured by the following method.
First, the phosphor sample was sampled in a solid NMR sample tube, allowed to stand in a desiccator with saturated ammonium chloride aqueous solution for one night or longer, and sufficiently absorbed, and then sealed and an aluminum chloride aqueous solution as a standard substance. It measured on the conditions of Table 6. Since ²⁷ Al is a quadrupole nucleus, the peak width and the peak intensity vary depending on the measurement conditions such as the magnetic field strength and the pulse width.

The measurement results are shown in FIG. As is clear from FIG. 8, the phosphors of Examples 21 to 23, 25, 26, 28, and 29 all have a spectrum having a maximum peak near 70 ppm, whereas the phosphor of Comparative Example 1 Is a spectrum having a maximum peak around 60 ppm.
In addition, the phosphors of Examples 21 to 23, 25, 26, 28, and 29 all have an integrated intensity area of signal intensity of 0 to 60 ppm with respect to an integrated intensity area of signal intensity of 60 to 75 ppm. On the other hand, the phosphor of Comparative Example 1 had an integrated intensity area of 0 to 60 ppm of signal intensity of about 330% with respect to an integrated intensity area of signal intensity of 60 to 75 ppm.

  The phosphor of the present invention can be used in any field where light is used. For example, in addition to indoor and outdoor lighting, image display of various electronic devices such as mobile phones, household appliances, and outdoor installation displays. It can be suitably used for an apparatus or the like.

1 Phosphor-containing part (second light emitter)
2 Excitation light source (first light emitter) (LD)
3 Substrate 4 Light-emitting device 5 Mount lead 6 Inner lead 7 Excitation light source (first light emitter)
DESCRIPTION OF SYMBOLS 8 Fluorescent substance containing part 9 Conductive wire 10 Mold member 11 Surface light-emitting illuminating device 12 Holding case 13 Light-emitting device 14 Diffusing plate 22 Excitation light source (1st light-emitting body)
23 Phosphor-containing part (second light emitter)
24 frame 25 conductive wire 26 electrode 27 electrode

Claims (7)

A phosphor containing a crystal phase having a composition represented by the following formula [1], wherein the crystal phase is a γ phase,
A phosphor containing a trivalent metal element essentially containing Al and having an emission peak in a wavelength range of 530 nm to 600 nm.
^{_{X 1 a1 Y 1 O b1:}} Ce c1 ... [1]
(In the above formula [1],
X ¹ is an alkaline earth metal element in which Ca is essential,
Y ¹ is a tetravalent metal element in which Si is essential,
Represents.
A1 to c1 are respectively
1.9 ≦ a1 ≦ 2.2
3.8 ≦ b1 ≦ 4.3
0.001 ≦ c1 ≦ 0.1
Represents a number that satisfies ) The phosphor according to claim 1, wherein the crystal phase has a composition represented by the following formula [2].
_{X a (Si 1-d,} Z d) O b: Ce c, A e ... [2]
(In the above equation [2],
X is an alkaline earth metal element in which Ca is essential,
Z is a trivalent metal element in which Al is essential,
A represents an alkali metal element.
A to e are respectively
1.9 ≦ a ≦ 2.2
3.8 ≦ b ≦ 4.3
0.001 ≦ c ≦ 0.1
0.49c ^-0.35 ≦ d / c ≦ 15
0 ≦ e ≦ 0.1
Represents a number that satisfies ) The phosphor according to claim 1, wherein the crystal phase has a composition represented by the following formula [3].
_{X a (Si 1-d,} W d) O b: Ce c, A e ... [3]
(In the above equation [3],
X is an alkaline earth metal element in which Ca is essential,
W requires Al, and an element containing at least one selected from trivalent metal elements other than Al, Ge, and Sn A represents an alkali metal element.
A to e are respectively
1.9 ≦ a ≦ 2.2
3.8 ≦ b ≦ 4.3
0.001 ≦ c ≦ 0.1
0.49c ^-0.35 ≦ d / c ≦ 15
0 ≦ e ≦ 0.1
Represents a number that satisfies ) The phosphor according to any one of claims 1 to 3, which has a peak top at 60 to 75 ppm when a solid ²⁷ Al-MAS-NMR spectrum is measured after the moisture absorption treatment. 2. The integrated intensity area of the signal intensity of 0 to 60 ppm is 300% or less with respect to the integrated intensity area of the signal intensity of 60 to 75 ppm when the solid ²⁷ Al-MAS-NMR spectrum is measured after the moisture absorption treatment. The phosphor according to any one of claims 1 to 4.   In the X-ray diffraction pattern, the black angle is 15.72-15.90, 20.50-20.70, 23.16-23.36, 29.50-29.78, 32.38-32.64, 32. The phosphor according to any one of claims 1 to 5, which has peaks in the ranges of .70-32.86, 35.56-35.76, and 47.36-47.76, respectively. A light emitting device having a first light emitter (excitation light source) and a second light emitter capable of emitting visible light by converting light from the first light emitter,
The light emitting device, wherein the second light emitter contains at least one of the phosphors according to any one of claims 1 to 6 as a first phosphor.

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