JP2014189592A - Phosphor and phosphor-containing composition, light-emitting device, image display device and lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a phosphor which is a red phosphor having a peak emission wavelength in a comparatively long wavelength region, can be efficiently excited by light in a wavelength range of 390-460 nm, emits light with high brightness, and is easily produced, and to provide a phosphor-containing composition, a light emitting device, an image display device, and a lighting device.SOLUTION: A phosphor has a crystal phase containing at least one alkaline earth metal element, Al element, Ga element or Ti element, and oxygen element, and is activated at least by Mn, and when the phosphor is excited by light in a wavelength range of 300-500 nm, the maximum peak wavelength of the emission spectrum exists in a wavelength range of 610-700 nm. In the excitation spectrum, a value of a ratio E/Eof an excitation intensity Eat a wavelength of 400 nm to the maximum excitation intensity value Ein a wavelength range of 250-600 nm is 0.56 to 1.0.

Description

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

Light-emitting devices that emit white light by using a phosphor together with an excitation light source that emits light in the near-ultraviolet or short-wavelength visible range, such as LEDs or LDs, have become commonplace and have been put to practical use in image display devices and lighting devices. . In particular, a phosphor that emits red fluorescence (hereinafter referred to as “red phosphor” as appropriate) is used in a light-emitting device for an image display device or a lighting device, and its light emission characteristics are variously improved. Among these, in order to improve the color rendering properties, in recent years, the value of the special color rendering index R9 that represents the appearance of the red region has been regarded as important. For example, in Patent Document 1, as a method for obtaining a highly efficient light source having a desired color rendering index, in addition to a red phosphor having a peak emission wavelength in a short wavelength region, a red fluorescence having a peak emission wavelength in a long wavelength region. The use of a combination of bodies is disclosed.

Thus, the relatively long wavelength range as a red phosphor having a peak emission wavelength, for example, such as Mn ⁴⁺ -activated fluoride complex phosphor, such as fluoro germanate Nate phosphor and KSF of Mn ⁴⁺ -activated, with a Mn ⁴⁺ A phosphor that is an active element is known. However, these phosphors have problems that the raw materials are expensive, that it is difficult to produce them stably, and that the properties such as water resistance are poor.

On the other hand, CaO.6Al ₂ O ₃ : Mn ⁴⁺ described in Patent Document 2 is known as an oxide phosphor that is relatively inexpensive and easy to manufacture, and Non-Patent Document 1 describes a part of Ca. the _Ca was replaced with _{Mg 1-x Mg x Al 12} O 19: yMn 4+ (x = 0,0.2,0.4,0.5,0.6,0.8,1 and y = 0.0001 Experimental examples are shown (˜1.5%). Non-Patent Document 2 exemplifies a SrAl ₁₂ O ₁₉ : Mn ⁴⁺ phosphor.

JP 2012-124356 A JP 2004-111344 A

Y.X.Pan, G.K.Liu, `` Influence of Mg2 + on luminescence efficiency and charge compensating mechanism in phosphor CaAl12O19: Mn4 + ”, Journal of Luminescence 131 (2011) 465-468 Bergstein.A., "Manganese-Activated Luminescence in SrAl12O19and CaAl12O19", J. Electrochem.Soc.:Solid State Science, Vol 118, No 7, p1166-11

However, the phosphor disclosed in Patent Document 2 is only specifically disclosed as a phosphor that emits light by ultraviolet excitation of less than 390 nm, and the LD and the like exhibiting emission wavelengths near 400 nm and 450 nm, which are currently mainstream. It is not suitable for use in combination with light emitting elements such as LEDs.
Further, although the phosphors described in Non-Patent Documents 1 and 2 can be excited at 390 to 460 nm, an LD, an LED, or the like that exhibits an emission wavelength near 400 nm or 450 nm, which is currently mainstream from the shape of the excitation spectrum. When combined with this light emitting element, there is a problem that the excitation efficiency is extremely low.
A phosphor activated with Mn ⁴⁺ has a possibility of overcoming the above problem as a red phosphor having a peak emission wavelength in a relatively long wavelength region, but a method for increasing excitation efficiency because of low excitation efficiency Was desired.

  The present invention was devised in view of the above problems, and is a red light having a peak emission wavelength in a relatively long wavelength region that is efficiently excited by light having a wavelength of around 400 nm and around 450 nm among wavelengths of 390 nm to 460 nm. An object of the present invention is to provide a phosphor that emits light with high brightness and can be easily manufactured as a phosphor, and a phosphor-containing composition, a light-emitting device, an image display device, and an illumination device.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have improved the excitation efficiency in the desired excitation band by replacing the Al site in the crystal structure with Ga or Ti, and the red fluorescence excellent in emission characteristics. The present invention was completed by finding that a body can be provided.
That is, the gist of the present invention resides in the following (1) to (10).
(1) at least one alkaline earth metal element;
Al element,
Ga element or Ti element;
Having a crystal phase containing oxygen element;
^Activated with at least Mn ⁴⁺ ,
When excited with light having a wavelength in the range of 300 nm to 500 nm, the maximum peak wavelength in the emission spectrum is in the range of 610 nm to 700 nm,
In the excitation spectrum, the ratio E ₄₀₀ / E _250-600 max between the excitation intensity E ₄₀₀ at a wavelength of 400 nm and the maximum excitation intensity E _250-600 max in the wavelength range of 250 nm to 600 nm is 0.56 or more, 1.0 A phosphor characterized by the following:
(2) In the excitation spectrum, excitation intensity E ₄₅₅ at wavelength ₄₅₅ nm and wavelength 25
The phosphor according to (1), wherein the ratio E ₄₅₅ / E _{250-600max to} the maximum value of excitation intensity E _{250-600max in} the range of 0 nm to 600 nm is 0.22 or more and 1.0 or less.
(3) The phosphor according to (1) or (2), which has a peak wavelength in the excitation spectrum in a wavelength range of 395 nm to 460 nm.
(4) The ratio (N2 / N1) of the number of elements (N2) of Ga element or Ti element contained in the phosphor to the number of elements (N1) of Al element contained in the phosphor is 0.12- The phosphor according to any one of (1) to (3), which is 5.0.
(5) The phosphor according to any one of (1) to (4), wherein the crystal phase further contains Mg. (6) The phosphor according to any one of (1) to (5), which contains a crystal phase having a chemical composition represented by the following formula [1].
_{M 1 Al 12-x-y} -z (Ga, Ti) z Mg y O 19: Mn 4+ x [1]
However, in the above formula [1], M represents one or more alkaline earth metals,
x, y, and z represent numbers satisfying 0 <x ≦ 0.4, 0 ≦ y ≦ 1, and 1.2 <z ≦ 10, respectively.
(7) A phosphor-containing composition comprising the phosphor according to any one of (1) to (6) and a liquid medium.
(8) a first light emitter, and a second light emitter that emits visible light by irradiation of light from the first light emitter,
The light-emitting device in which this 2nd light-emitting body contains 1 or more types of fluorescent substance as described in any one of (1)-(6) as 1st fluorescent substance.
(9) An image display device comprising the light emitting device of (8) as a light source.
(10) An illumination device comprising the light-emitting device according to (8) as a light source.

  According to the present invention, a phosphor that is efficiently excited by light having a wavelength of 390 nm to 460 nm, has a peak emission wavelength in a relatively long wavelength region, emits light with high brightness, and can be easily manufactured. And a phosphor-containing composition, a light emitting device, an image display device, and a lighting device.

It is an XRD pattern of the phosphors of Examples 1 to 5 and Comparative Examples 1 and 2. It is a graph which shows the change of the lattice constant a of the fluorescent substance of Examples 1-5 and Comparative Examples 1 and 2. FIG. It is a graph which shows the change of the lattice constant c of the fluorescent substance of Examples 1-5 and Comparative Examples 1 and 2. FIG. It is an excitation spectrum of the phosphors of Examples 1 to 5 and Comparative Example 1. It is an excitation spectrum of the phosphors of Comparative Examples 1 and 2. It is a graph which shows the change of the peak top wavelength between the wavelengths of 390 nm to 460 nm of the excitation spectrum of the phosphors of Examples 1 to 5 and Comparative Examples 1 and 2. Example 1-5 is a graph showing changes in phosphor excitation intensity ratios of Comparative Examples _{1,2 (E 400 / E 250-600max)} . Example 1-5 is a graph showing changes in phosphor excitation intensity ratios of Comparative Examples _{1,2 (E 455 / E 250-600max)} . It is an emission spectrum of the phosphors of Examples 1 to 5 and Comparative Example 1. 3 is an emission spectrum of the phosphor of Comparative Example 2. It is a graph which shows the change of the normalization light emission peak intensity | strength of the fluorescent substance of Examples 1-5 and Comparative Examples 1 and 2. FIG. It is a graph which shows the change of another normalized light emission peak intensity of the fluorescent substance of Examples 1-5 and Comparative Examples 1 and 2. FIG. It is an XRD pattern of the phosphors of Examples 2, 6, and 7. It is an XRD pattern of the phosphors of Examples 5, 8, and 9. It is an XRD pattern of the phosphors of Comparative Examples 2 and 3.

Hereinafter, the present invention will be described with reference to embodiments and examples, but the present invention is not limited to the following embodiments and examples, and may be arbitrarily modified without departing from the gist of the present invention. Can be implemented.
In the composition formula of the phosphors 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 of “(Ca, Sr, Ba) Al ₂ O ₄ : Eu” is “CaAl ₂ O ₄ : Eu”, “SrAl ₂ O ₄ : Eu”, and “BaAl ₂ O ₄ : Eu”. “Ca _1-x S
r _x Al ₂ O ₄ : Eu ”,“ Sr _1−x Ba _x Al ₂ O ₄ : Eu ”, and“ Ca _1−x Ba _x Al ₂ O _{4 ”.}
: A Eu "," _{Ca 1-xy Sr x Ba y} Al 2 O 4: Eu "and all assumed to generically indicated (in the above formula, 0 <x <1,0 <y < 1, 0 <x + y <1).

[1. Phosphor]
Light having a crystal phase containing at least one alkaline earth metal element, Al element, Ga element or Ti element, and oxygen element, activated by at least Mn ⁴⁺ and having a wavelength in the range of 300 nm to 500 nm When excited with a phosphor, the peak wavelength in the emission spectrum is in the range of 610 nm to 700 nm. In the excitation spectrum, the phosphor of the present invention has a ratio of E ₄₀₀ / E _250-600 max between the excitation intensity E ₄₀₀ at a wavelength of 400 nm and the maximum excitation intensity E _250-600 max in the wavelength range of 250 nm to 600 nm. It is 0.56 or more and 1.0 or less.

[1-1. Composition of phosphor]
The phosphor of the present invention has a crystal phase containing at least one alkaline earth metal element, Al element, Ga element or Ti element, and oxygen element, and is activated with at least Mn ^4+. is there.
Here, the alkaline earth metal element means Mg, Ca, Sr, Ba, or Ra. One of these alkali metal elements may be contained alone, or two or more thereof may be contained in any ratio. As at least one alkaline earth metal element, Mg, Ca, Sr, or Ba is preferably included, and at least Ca, Sr, or Ba is more preferably included. These elements are preferable because various kinds of raw materials with high purity are supplied stably at low cost, and a desired phosphor can be produced as appropriate.

  The Al element contained in the phosphor of the present invention is preferably present as a trivalent cation having a coordination number of 6 in the crystal phase. The amount of Al element contained in the phosphor is not particularly limited, but the ratio of the number of Al elements contained in the phosphor (N1) to the total number of elements (N3) contained in the phosphor (N1 / N3) ) Is preferably 0.04 or more, more preferably 0.045 or more, still more preferably 0.05 or more, preferably 0.30 or less, more preferably 0.27 or less, more preferably 0.20. Hereinafter, it is more preferably 0.14 or less. By making it into the above range, the effects of the present invention can be remarkably exhibited, which is preferable.

The phosphor of the present invention contains Ga element or Ti element. A Ga element or a Ti element is an element that is present in a crystal structure by being substituted with an Al element. Therefore, Ga is preferably present as a trivalent cation having a coordination number of 6, and Ti may be present as a tetravalent cation having a coordination number of 6, so that Al can be substituted in the crystal phase. preferable.
It is considered that the lattice constant of the crystal phase changes slightly by substituting part of Al with Ga or Ti in the crystal phase. This is because the effective ion radius of Al is 0.535, whereas the effective ion radius of Ga is 0.620, and the effective ion radius of Ti is 0.605, which is slightly larger than Al. Therefore, by substituting Al with Ga or Ti and changing the microscopic crystal structure, it is considered that the peripheral structure of the Mn ⁴⁺ ion, which is the activating element, in particular changes, and the excitation spectrum can be adjusted. .

In addition, the value of each effective ion radius is a reference: RD Shannon, Acta Crystallogr.,
Sect. A, 32, 751 (1976).
The ratio (N2 / N1) of the number of elements (N2) of Ga element or Ti element contained in the phosphor to the number of elements (N1) of Al element contained in the phosphor of the present invention is 0.12 or more. It is preferably 0.13 or more, more preferably 0.14 or more, and preferably 5.0 or less, more preferably 2.5 or less, still more preferably 1.2. Hereinafter, it is preferably 0.60 or less. By setting N2 / N1 to be equal to or higher than the lower limit, it becomes possible to make the excitation band longer, and it is possible to efficiently excite light with wavelengths near 400 nm and 450 nm. Particularly preferred as a body. Moreover, it is preferable to make it below the upper limit value because a crystal phase maintaining a stable crystal structure can be obtained.

The phosphor of the present invention is an oxide-based phosphor containing oxygen. Here, the oxide-based phosphor is a concept including an oxyfluoride phosphor containing fluorine and an oxynitride phosphor containing nitrogen in addition to oxygen.
In the phosphor of the present invention, the above-mentioned alkaline earth metal element, Al element, Ga element or Ti element, and an oxygen element constitute a base crystal, and this base crystal is activated with an activator element. It has a structure. The crystal phase of the host crystal may contain elements other than the above-mentioned specific elements. For example, rare earth such as Y, or Mg ²⁺ that is likely to exist stably as divalent and relatively close to the ion size of Al ^3+. And Zn ²⁺ . Here, Mg or Zn effective ionic radii are 0.720 nm and 0.740 nm, respectively.

The phosphor of the present invention contains at least Mn ⁴⁺ as an activator element. An activator element (co-activator element) other than Mn ⁴⁺ may be used in combination, and examples thereof include Eu ²⁺ and Ce ³⁺ .
In addition, the fluorescent substance of this invention may contain only 1 type of activation elements, and may contain 2 or more types by arbitrary combinations and ratios. However, the phosphor of the present invention is preferably activated only by Mn ⁴⁺ from the viewpoint of keeping the emission wavelength in a narrow range.

The activating element usually activates the phosphor of the present invention by substituting Al, Ga or Ti sites in the above-mentioned host crystal. The degree of activation is not limited as long as the advantages of the present invention are not significantly impaired. However, in the phosphor of the present invention, Al, Ga, with respect to the total amount of Ti and ^{Mn 4+,} the proportion of ^{Mn 4+} is usually 0.04 mol% or more, preferably 0.06 mol% or more, more preferably It is 0.08 mol% or more, and is usually less than 100 mol%, preferably 80 mol% or less, more preferably 70 mol% or less. When the content of Mn ⁴⁺ falls within the above range, concentration quenching can be suppressed.

When the activation element Mn ⁴⁺ is substituted with an Al or Ga site in the host crystal, the tetravalent activation element enters the trivalent site, so that the charge balance of the entire host crystal is adjusted. There is a need. For this reason, it is preferable to substitute a divalent cation such as Mg on the Al or Ga site in an amount equal to or more than the amount of Mn ⁴⁺ substituted on the Al or Ga site. Therefore, the phosphor of the present invention preferably contains Mg in the crystal phase.

Preferable examples of the composition of the phosphor of the present invention include SrAl ₁₂ O ₁₉ , Y ₃ Al ₅ O ₁₂ , MgAl ₂ O ₄ , Mg ₂ TiO _{4 and the} like having a crystal structure in which Al and Ti are six-coordinated. Based on this crystal structure, a substance in which Ga and Al are substituted is preferable. As described above, Al, Ga, and Ti may be appropriately replaced in order to obtain desired characteristics.
Furthermore, the phosphor of the present invention may contain a flux component element as necessary. The flux component elements are usually those in which the constituent elements of the flux used during production remain in the phosphor, but not all of them may be derived from the flux, for example, those contained in the raw material, and heating It also includes elements mixed in phosphor manufacturing processes such as processing, cleaning, and surface treatment. Examples of flux component elements include Li, Na, K, Rb, Cs, P, Cl, F, Br, I, Zn, Ga, Ge, In, Sn, Ag, Au, Pb, Cd, and Bi. Can be mentioned. In addition, the fluorescent substance of this invention may contain only 1 type of flux component elements, and may contain 2 or more types by arbitrary combinations and ratios.

The flux component element may be present either inside or outside the crystal phase (crystal lattice) of the phosphor of the present invention, but is usually contained by being contained in the crystal phase of the phosphor.
When the phosphor of the present invention contains a flux component element, the concentration range is not limited, but is usually 1 ppm or more, preferably 3 ppm or more, more preferably 10 ppm or more, and usually 5000 ppm or less, preferably 1000 ppm or less, more Preferably it is 100 ppm or less. By including the flux component element in the above concentration range, the particle size and shape of the phosphor particles of the present invention are preferable. Moreover, when there are too many flux component elements, there exists a possibility of affecting the characteristic of the fluorescent substance of this invention. When the flux component element is present outside the crystal phase of the phosphor, the concentration range of the flux component element is not particularly limited as long as the effects of the present invention are not impaired.

The concentration of the flux component in the phosphor can be measured as follows.
First, the phosphor is crushed. The degree of crushing is such that the weight-average median diameter D ₅₀ of the phosphor falls within the range described later. Thereafter, the phosphor is washed with an acid such as hydrochloric acid or nitric acid, and then washed with water to remove soluble parts such as unreacted substances during production. The degree of washing with water is such that the electrical conductivity of the supernatant after dispersion and sedimentation of the washed phosphor in 10 times weight of water is 5 mS / m or less. Then, elemental analysis of the phosphor satisfying this condition is performed, and the concentration of the flux component element in the crystal phase is measured. Elemental analysis is performed using a glow discharge mass spectrometer (GD-MS) in which a solid sample is used as a cathode, the surface of the sample is sputtered using glow discharge, and the emitted neutral particles are ionized by collision with Ar or electrons in the plasma. Can be quantified. In addition, the said crushing and water washing are unnecessary when the fluorescent substance which is a measuring object satisfy | fills the said conditions, without performing crushing and water washing.

The crystal phase contained in the phosphor of the present invention is preferably a crystal phase having a chemical composition represented by the following formula [1].
_{M 1 Al 12-x-y} -z (Ga, Ti) z Mg y O 19: Mn 4+ x [1]
However, in the above formula [1], M represents one or more alkaline earth metals,
x, y, and z represent numbers satisfying 0 <x ≦ 0.4, 0 ≦ y ≦ 1, and 1.2 <z ≦ 10, respectively.

  In the above formula [1], M represents at least one divalent element selected from alkaline earth metal elements. Here, the alkaline earth metal element means Mg, Ca, Sr, Ba, or Ra. M element may contain individually 1 type in these alkali metal elements, and may have 2 or more types together in arbitrary ratios. The M element preferably includes at least Mg, Ca, Sr, or Ba, and more preferably includes at least Ca, Sr, or Ba.

In said Formula [1], "x" shows the molar ratio of ^{Mn4 +} which is an activation element. “X” is a number satisfying 0 <x ≦ 0.4, preferably 0.001 or more, more preferably 0.005 or more, and preferably 0.04 or less, more preferably 0.03. It is as follows.
In said Formula [1], "y" shows the molar ratio of Mg. “Y” is a number satisfying 0 ≦ y ≦ 1, preferably 0.001 or more, more preferably 0.005 or more, and preferably 0.1 or less, more preferably 0.08 or less. is there. It is preferable that y is in the above range since Mn can be stably substituted as tetravalent.

  In the formula [1], “z” represents a molar ratio of Ga and / or Ti. “Z” is a number satisfying 1.2 <z ≦ 10, preferably 1.3 or more, more preferably 1.5 or more, and preferably 8.5 or less, more preferably 6.5. Below, more preferably 4.5 or less. It is preferable to set z in the above range because the phosphor can be efficiently excited and can emit light with high efficiency by the wavelength (for example, around 400 nm or around 450 nm) of industrially used LEDs.

[1-2. Crystal phase]
When the coordination environment of Mn ⁴⁺ has octahedral symmetry (Oh symmetry), it is well known that the transition of Mn ⁴⁺ is forbidden and the transition probability is low. On the other hand, when a certain strain is introduced into the regular octahedron around Mn ⁴⁺ and the symmetry is lowered, the forbidden state is relaxed and the transition probability may be improved.

Therefore, the crystalline phase activated with Mn ^4+, when an element replacing Mn ⁴⁺ also with atoms and six-coordinate of the first coordinate, the Mn ⁴⁺ is activated, substantially regular octahedron symmetry It is preferable to have a structural unit that is distorted from the nature. For example, the environment of the site where Mn ⁴⁺ is substituted may have both a distorted octahedron and a regular octahedron, such as a magnetoplumbite crystal phase, and a garnet crystal phase. Like the spinel type crystal phase, the host alone has only an octahedron, but it may be one in which minute strains can be introduced by substitution of Mn ⁴⁺ or other elements.

[1-3. Emission spectrum]
-Emission wavelength The phosphor of the present invention is a phosphor that emits red fluorescence, and is usually 570 nm or more, preferably 580 nm or more, more preferably 585 nm or more, and usually 780 nm or less, preferably 700 nm or less, more preferably 680 nm or less. It emits fluorescence in the wavelength range.

  In addition, when the phosphor of the present invention is excited with light having a wavelength in the range of 300 nm to 500 nm, the wavelength of the emission peak having the maximum intensity among the emission peaks in the emission spectrum (hereinafter referred to as the maximum peak wavelength), The wavelength is usually 610 nm or more and usually 700 nm or less. Preferably it is 615 nm or more, More preferably, it is 620 nm or more, Preferably it is 690 nm or less, More preferably, it is 680 nm or less.

-Half-width The phosphor of the present invention has one of the advantages that the emission peak is sharp. Specifically, the half width of the maximum emission peak is usually 40 nm or less, preferably 30 nm or less, and more preferably 20 nm or less. By having such a sharp emission peak, the phosphor of the present invention can be used favorably for the light source application of an image display device. In addition, although there is no restriction | limiting in the minimum of the said half value width, Usually, it is 1 nm or more.

-Measurement method of emission spectrum The emission spectrum of the phosphor of the present invention, and the emission peak wavelength, half-value width, and emission peak intensity are measured at room temperature, for example, 25 ° C. For example, a fluorescence measuring apparatus using an F-4500 type spectrofluorometer manufactured by Hitachi, Ltd. or using 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. (Manufactured by JASCO Corporation) can be used for measurement.

[1-4. Excitation spectrum]
Excitation wavelength Although there is no limitation on the excitation spectrum of the phosphor of the present invention, for example, the excitation spectrum at an emission wavelength of 660 nm is usually 250 nm or more, preferably 300 nm or more and usually 550 nm or less, preferably 500 nm or less. Visible light is emitted when excited by light.

In the phosphor of the present invention, in the excitation spectrum, the excitation intensity E ₄₀₀ at a wavelength of ₄₀₀ nm is set, and the maximum excitation intensity E _250-60 in the wavelength range of 250 nm to 600 nm.
When the _0max, characterized in that _E 400 _{/ E} value of _250-600max 0.56 or more is these ratios is 1.0 or less. The value of E ₄₀₀ / E _250-600max is preferably 0.58 or more, more preferably 0.60 or more, and may be 0.83 or less. This is preferable because the effects of the invention can be achieved. It is preferable to be in the above-mentioned range because it becomes a phosphor that can emit light efficiently, particularly in a light emitting device using a light emitting element of near ultraviolet light as a light source.

The phosphor of the present invention further has an excitation intensity E ₄₅₅ at a wavelength of 455 nm in the excitation spectrum, and a maximum excitation intensity E ₂₅ in the wavelength range of 250 nm to 600 nm.
When the _{0-600max, E} 455 _{/ E} value of _250-600max 0.22 or more is these ratios is preferably 1.0 or less. The value of E ₄₅₅ / E _250-600max is preferably 0.23 or more, more preferably 0.24 or more, may be 0.59 or less, and may be 0.46 or less. This is preferable because the effects of the invention can be achieved. By being in the above range, a phosphor that can emit light efficiently can be obtained even in a light-emitting device that uses a blue light-emitting element as a light source.

As described above, in the phosphor of the present invention, the excitation spectrum can be adjusted to the above range by replacing the Al site in the host crystal with Ga or Ti. It is considered that a part of Al in the crystal phase is substituted with Ga or Ti, thereby changing the coordination environment of Mn ⁴⁺ ions that are activators. For example, when Ga is substituted at the Al site, it is considered that the lattice constant increases and the distance between the Mn ⁴⁺ ions and the surrounding oxygen octahedron continuously increases from the results of the study by the present inventors. As a result, the excitation band can be made longer by replacing Ga. Further, when the coordination number is 6, an element such as Ti having an effective ion radius similar to Ga is considered to exhibit the same effect as Ga substitution.

  In the excitation spectrum, the peak wavelength is preferably 393 nm or more, more preferably 394 nm or more, further preferably 395 nm or more, preferably 470 nm or less, more preferably 465 nm or less, Preferably it is 460 nm or less. In addition, an excitation spectrum means the excitation spectrum in the maximum peak wavelength of light emission.

Since the phosphor of the present invention can efficiently absorb light in a wide wavelength range as described above, it is presumed that the phosphor of the present invention can emit light with higher luminance than the conventional phosphor.
Measurement of excitation spectrum The excitation spectrum and absorption peak wavelength of the phosphor of the present invention are measured at room temperature, for example, 25 ° C. For example, it can be measured using the same measuring apparatus as mentioned in the section of the method for measuring the emission spectrum. In the measurement, the red emission peak near the wavelength of 660 nm is monitored, and the excitation spectrum in the wavelength range of 250 nm to 600 nm is measured.

[1-5. Other characteristics]
・ Weight median diameter D ₅₀
Phosphor of the present invention, the weight-average median diameter _{D 50} is usually 0.1μm or more and preferably 1μm or more, and usually 50μm or less, and preferably among them 30μm or less. When the weight-average median diameter D ₅₀ is too small, and if the luminance is lowered, there is a case where phosphor particles tend to aggregate. On the other hand, when the weight-average median diameter D ₅₀ is too large, there is a tendency for blockage, such as uneven coating or a dispenser.
The weight-average median diameter D ₅₀ of the phosphor in the present invention, for example, can be measured using a device such as a laser diffraction / scattering particle size distribution measuring apparatus.

The specific surface area of the phosphor-specific surface area present invention, usually 1.3 m ² / g or less, preferably 1.1 m ² / g or less, particularly preferably at 1.0 m ² / g or less, typically 0.05 m ² / g or more, preferably 0.1 m ² / g or more. If the specific surface area of the phosphor is too small, the phosphor particles are large, which tends to cause coating unevenness and clogging of the dispenser, etc. If too large, the phosphor particles are small, so the contact area with the outside increases and durability It becomes inferior.
In addition, the specific surface area of the phosphor in the present invention is measured by a BET one-point method, for example, using a fully automatic specific surface area measuring device (flow method) (AMS1000A) manufactured by Okura Riken.

・ Particle size distribution
The phosphor of the present invention preferably has one peak value in the particle size distribution.
A peak value of 2 or more indicates that there are a peak value due to single particles and a peak value due to aggregates thereof. Therefore, a peak value of 2 or more means that single particles are very small.

Therefore, a phosphor having a single particle size distribution peak value has large single particles and very few aggregates. As a result, the luminance is improved, and the specific surface area is reduced due to the large growth of single particles, thereby improving the durability.
The particle size distribution of the phosphor can be measured by, for example, a laser diffraction / scattering particle size distribution measuring device (LA-300) manufactured by Horiba, Ltd. In the measurement, ethanol was used as a dispersion solvent, the phosphor was dispersed, the initial transmittance on the optical axis was adjusted to around 90%, and the influence of aggregation was minimized while stirring the dispersion solvent with a magnet rotor. It is preferable to perform measurement while suppressing the pressure to a minimum.

[2. Method for producing phosphor]
There is no restriction | limiting in the manufacturing method of the fluorescent substance of this invention, As long as the fluorescent substance of this invention mentioned above is obtained, arbitrary methods are employable. However, from the viewpoint of industrial production, it is preferable that the powdery raw material compound is mixed and then heated and manufactured without a pellet forming step. For example, the raw material compound is mixed with a mixer (eg, ribbon blender, V-type blender, Henschel mixer, etc.), or the raw material compound is pulverized with a dry pulverizer (eg, hammer mill, roll mill, ball mill, jet mill, etc.). Then, using the above-mentioned mixer, or after mixing these raw material compounds, the dry method of pulverizing using a dry pulverizer; or adding these raw material compounds into a medium such as water, A slurry prepared by pulverizing and mixing using a wet pulverizer such as a stirring pulverizer, or by pulverizing these raw material compounds with a dry pulverizer and then adding and mixing them in a medium such as water, It is preferable to prepare a pulverized mixture by a wet method of drying by spray drying, etc., and heat-treat and fire the obtained pulverized mixture. .
Specifically, it is preferable to manufacture by the manufacturing method described below (hereinafter referred to as “the manufacturing method of the present invention” as appropriate).

[2-1. Raw material compound]
As the raw material compound, a compound containing an element constituting the phosphor of the present invention (hereinafter appropriately referred to as “phosphor constituent element”) can be used. Examples thereof include oxides, hydroxides, carbonates, nitrates, sulfates, oxalates, carboxylates and halides containing phosphor constituent elements. Therefore, as raw material compounds, alkaline earth metals, Al, Ga, Ti, and Mn, which are phosphor constituent elements, oxides, hydroxides, carbonates, nitrates, sulfates, oxalates, carboxyls of each element of each element Acid salts, halides, and the like can be used. Among these, since the phosphor of the present invention is an oxide-based phosphor, a raw material compound that becomes an oxide by firing, such as an oxide, a hydroxide, and a carbonate, is particularly preferable. Further, when selecting the raw material compound, it is preferable to select in consideration of reactivity to the obtained composite oxide (that is, phosphor) and non-generation of NOx, SOx, etc. during firing. Furthermore, corresponding to each element constituting the phosphor of the present invention, the raw material compounds may be used alone or in combination of two or more in any combination and ratio.

Among the raw material compounds, compounds containing alkaline earth metal elements will be described with specific examples.
Specific examples of the compound containing Ba (hereinafter referred to as “Ba source” as appropriate) include BaO, Ba (OH) ₂ .8H ₂ O, BaCO ₃ , Ba (NO ₃ ) ₂ , BaSO ₄ , Ba (OCO) _{2. · H 2 O, Ba (OCOCH} 3) 2, BaCl 2, Ba 3 N 2, BaNH and the like. Of these, carbonates, oxides and the like can be preferably used. However, carbonates are more preferable from the viewpoint of handling because oxides easily react with moisture in the air. Of these, BaCO ₃ is preferable. This is because the stability in the air is good, and it is easily decomposed by heating, so that undesired elements hardly remain and it is easy to obtain high-purity raw materials. When carbonate is used as a raw material, the carbonate may be pre-baked and used as a raw material.
Specific examples of the compound containing Sr (hereinafter referred to as “Sr source” as appropriate) include SrO, Sr
(OH) ₂ · 8H ₂ O, SrCO ₃ , Sr (NO ₃ ) ₂ · 4H ₂ O, SrSO ₄ , Sr (OCO) ₂ · H ₂ O, 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. Among these, SrCO ₃ is preferable. This is because the stability in the air is good, it is easily decomposed by heating, it is difficult for undesired elements to remain, and it is easy to obtain high-purity raw materials. When carbonate is used as a raw material, the carbonate may be pre-baked and used as a raw material.

As specific examples of the compound containing Ca (hereinafter referred to as “Ca source” as appropriate), CaO, Ca (OH) ₂ , CaCO ₃ , Ca (NO ₃ ) ₂ .4H ₂ O, CaSO ₄ .2H ₂ O, Ca
(OCO) ₂ · H ₂ O, Ca (OCOCH ₃ ) ₂ · H ₂ O, CaCl ₂ , Ca ₃ N ₂ , CaNH and the like can be mentioned. Of these, CaCO ₃ , CaCl _{2 and the} like are preferable. When carbonate is used as a raw material, the carbonate may be pre-baked and used as a raw material.

Specific examples of the compound containing Mg (hereinafter referred to as “Mg source” as appropriate) include MgO, Mg (OH) ₂ , basic magnesium carbonate (mMgCO ₃ .Mg (OH) ₂ .nH ₂ O), Mg ( NO ₃ ) ₂ · 6H ₂ O, MgSO ₄ , Mg (OCO) ₂ · H ₂ O, Mg (OCOCH ₃ ) ₂ · 4H ₂ O, MgCl ₂ , Mg ₃ N ₂ , MgNH, and the like. Of these, MgO and basic magnesium carbonate are preferred. When carbonate is used as a raw material, the carbonate may be pre-baked and used as a raw material.
Among the raw material compounds, specific examples of the compound containing Al (hereinafter referred to as “Al source” as appropriate) include α-Al ₂ O ₃ , γ-Al ₂ O ₃ , Al (OH) _{3 and the} like. Of these, α-Al ₂ O ₃ is preferable.

Specific examples of the compound containing Ga (hereinafter referred to as “Ga source” as appropriate) among the raw material compounds include Ga ₂ O, Ga ₂ O ₃ , Ga (OH) _{3 and the} like. Of these, Ga ₂ O ₃ is preferable.
Among the raw material compounds, examples of the compound containing Ti (Ti source) include TiO ₂ , H ₄ TiO ₄ , and Ti (OCOCH ₃ ) ₄ .

Specific examples of the raw material of Mn (hereinafter referred to as “Mn source” as appropriate) include MnO ₂ , Mn ₂ O ₃ , Mn ₃ O ₄ , MnO, Mn (OH) ₂ , MnCO ₃ , Mn (NO ₃ ) ₂ , Mn (OCOCH ₃ ) ₂ .2H ₂ O, Mn (OCOCH ₃ ) ₃ .nH ₂ O, MnCl ₂ .4H ₂ O and the like can be mentioned. Of these, carbonates, oxides and the like can be preferably used. However, carbonates are more preferable from the viewpoint of handling because oxides easily react with moisture in the air. Among these, MnCO ₃ is preferable. This is because the stability in the air is good, and it is easily decomposed by heating, so that undesired elements hardly remain and it is easy to obtain high-purity raw materials. When carbonate is used as a raw material, the carbonate may be pre-baked and used as a raw material.

When the phosphor of the present invention contains Zn, specific examples of the compound containing Zn (hereinafter referred to as “Zn source” as appropriate) include ZnO, ZnF ₂ , ZnCl ₂ , Zn (OH) ₂ , and Zn ₃ N _2. ,
Examples thereof include zinc compounds such as ZnNH, Zn (OCO) ₂ and ZnSO ₄ (but may be hydrates). Of these, ZnF ₂ .4H ₂ O (however, it may be an anhydride) is preferable from the viewpoint that the effect of promoting particle growth is high. When carbonate is used as a raw material, the carbonate may be pre-baked and used as a raw material.
Further, the oxygen element in the composition of the phosphor of the present invention is usually supplied at the time of phosphor production as an anion component of a raw material compound of each of the above constituent elements or as a component contained in a firing atmosphere.

[2-2. Mixing process]
The phosphor of the present invention can be obtained by weighing the raw material compounds so as to obtain the target composition, mixing them, preparing a raw material mixture, and firing the raw material mixture in a predetermined temperature and atmosphere. In this case, it is preferable that the mixing is sufficiently performed using a ball mill or the like.
Although it does not specifically limit as said mixing method, Specifically, the well-known method which was mentioned as following (A) and (B) can be used arbitrarily. As for these various conditions, for example, known conditions such as mixing and using two kinds of balls having different particle diameters in a ball mill can be appropriately selected.

  (A) Dry pulverizer such as hammer mill, roll mill, ball mill, jet mill, etc., or pulverization using mortar and pestle, and mixer such as ribbon blender, V-type blender, Henschel mixer, or mortar and pestle A dry mixing method in which the above raw material compounds are pulverized and mixed in combination with mixing.

(B) A solvent or dispersion medium selected from water or ethanol-based solvents such as ethanol is added to the above-described raw material compound, and mixed using, for example, a pulverizer, a mortar and pestle, or an evaporating dish and stirring rod, Alternatively, a wet mixing method in which the slurry is dried and then dried by spray drying, heat drying, natural drying, or the like.
Further, the raw material compound may be sieved as necessary during the mixing and pulverization. In this case, various types of commercially available sieves can be used, but it is preferable to use a resin mesh such as a nylon mesh rather than a metal mesh in terms of preventing impurities from being mixed.

  It is preferable that the raw material mixture obtained as described above is subjected to a firing step in a powder state without being compressed into a pellet. Usually, the raw material compound to be used is in powder form, and the raw material compound which was not initially in powder form is crushed by the mixing operation in the mixing step to become powder form. If this is formed into a pellet, a step of compressing and molding the raw material mixture and a step of crushing the obtained phosphor must be performed, which is impractical for industrial production. On the other hand, since the phosphor of the present invention can be produced without making the raw material mixture into a pellet form, it is advantageous over the prior art from the viewpoint of its production method.

[2-3. Firing step]
The phosphor of the present invention is obtained by firing the obtained raw material mixture. This firing is preferably performed by filling a raw material compound in a container such as a crucible and firing at a predetermined temperature and atmosphere.
As the container, it is preferable to use a heat-resistant container such as a crucible or a tray made of a material having low reactivity with each raw material compound. Examples of the material of the heat-resistant container used at the time of firing include ceramics such as alumina, quartz, boron nitride, silicon nitride, silicon carbide, magnesium, mullite, platinum, molybdenum, tungsten, tantalum, niobium, iridium, rhodium, and the like. Examples thereof include metals, alloys containing them as main components, and carbon (graphite). Here, the heat-resistant container made of quartz can be used for heat treatment at a relatively low temperature, that is, 1200 ° C. or less.

Examples of such heat-resistant containers are preferably made of boron nitride, alumina, silicon nitride,
Examples thereof include heat-resistant containers made of silicon carbide, platinum, molybdenum, tungsten, and tantalum.
As the firing temperature for producing the phosphor of the present invention, if the firing temperature is too low, the crystal does not grow sufficiently and the particle size may be reduced, while the firing temperature is too high. In such a case, there is a possibility that the emission intensity may be lowered, so that it may be set arbitrarily according to the target phosphor in consideration of these viewpoints. The specific firing temperature is usually 1000 ° C. or higher, preferably 1100 ° C. or higher, more preferably 1300 ° C. or higher, and usually 1800 ° C. or lower, preferably 1700 ° C. or lower, more preferably 1600 ° C. or lower. It is.

Although it does not restrict | limit especially as a baking atmosphere, Usually, it carries out by atmospheric pressure and atmospheric pressure.
Moreover, although baking time changes also with the temperature, pressure, etc. at the time of baking, it is 1 hour or more normally, Preferably it is 3 hours or more, More preferably, it is 6 hours or more. The firing time is preferably longer, but is usually 100 hours or shorter, preferably 24 hours or shorter, more preferably 18 hours or shorter, and further preferably 12 hours or shorter. If necessary, the fired product may be taken out from the furnace after the primary firing and pulverized, followed by further secondary firing.

[2-5. Other processes]
In the production method of the present invention, steps other than those described above may be performed as long as the effects of the present invention are not significantly impaired. For example, after the heat treatment in the above baking step, a post-treatment step such as pulverization, washing, drying, and classification treatment may be performed as necessary.
The pulverization treatment is performed on the fired product when, for example, the obtained phosphor does not have a desired particle size. The pulverization method is not particularly limited, and for example, the dry pulverization method and the wet pulverization method described in the description of the mixing step of the raw material compounds can be used.

  The cleaning treatment can be performed, for example, with water such as deionized water, an organic solvent such as ethanol, or an alkaline aqueous solution such as ammonia water. In addition, for the purpose of removing the impurity phase adhering to the phosphor surface such as the flux used and improving the light emission characteristics, for example, an inorganic acid such as hydrochloric acid, nitric acid, sulfuric acid; or an organic acid such as acetic acid. An aqueous solution of can also be used. In this case, it is preferable to further wash with water after washing in an acidic aqueous solution.

  The classification treatment can be performed, for example, by performing a water sieving or water tank treatment, or by using various classifiers such as various air classifiers or vibrating sieves. In particular, when dry classification using a nylon mesh is used, a phosphor with good dispersibility having a weight median diameter of about 20 μm can be obtained.

[3. Use of phosphor]
The phosphor of the present invention can be used for any application that uses the phosphor. In particular, taking advantage of the fact that it can be excited by blue light or near-ultraviolet light, various light emitting devices (see “ The light-emitting device of the invention ") can be suitably used. Further, by adjusting the types and usage ratios of the phosphors to be combined, light emitting devices having various emission colors can be manufactured, and a high performance white light emitting device can also be realized. 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. Among these, it is suitable for use in an image display device by utilizing the point where the emission wavelength is in a narrow range.

[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.

[4-1. 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 from what was mentioned above. Moreover, the fluorescent substance of this invention contained in the fluorescent substance containing composition of this invention may be only 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
Further, the phosphor-containing composition of the present invention 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.

[4-2. Liquid medium]
The liquid medium used in the phosphor-containing composition of the present invention is not particularly limited as long as the performance of the phosphor is not impaired within the intended range. As an example of the liquid medium, any inorganic material and / or any inorganic material may be used as long as it exhibits liquid properties under desired use conditions, suitably disperses the phosphor of the present invention, and does not cause an undesirable reaction. Alternatively, an organic material can be used.

Examples of the inorganic material include a solution obtained by hydrolyzing a solution containing a metal alkoxide, a ceramic precursor polymer, or a metal alkoxide by a sol-gel method (for example, an inorganic material having a siloxane bond). it can.
Examples of organic materials include thermoplastic resins, thermosetting resins, and photocurable resins. Specifically, for example, methacrylic resin such as polymethylmethacrylate; styrene resin such as polystyrene and styrene-acrylonitrile copolymer; polycarbonate resin; polyester resin; phenoxy resin; butyral resin; polyvinyl alcohol; Cellulose resins such as cellulose acetate butyrate; epoxy resins; phenol resins; silicone resins.

Among these, in particular, when a phosphor is used for a high-power light-emitting device such as illumination, it is preferable to use a silicon-containing compound as a liquid medium for the purpose of heat resistance and light resistance.
The silicon-containing compound refers to a compound having a silicon atom in the molecule, for example, an organic material (silicone material) such as polyorganosiloxane, an inorganic material such as silicon oxide, silicon nitride, silicon oxynitride, and borosilicate. And glass materials such as phosphosilicate and alkali silicate. Among these, silicone materials are preferable from the viewpoint of ease of handling.

The content of the liquid medium is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 50% by weight or more, preferably 75% by weight or more, based on the entire phosphor-containing composition of the present invention. It is 99 weight% or less, Preferably it is 95 weight% 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, if there is too little liquid medium, there is a possibility that it will be difficult to handle due to lack of fluidity.
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.

[4-3. Other ingredients]
The phosphor-containing composition of the present invention may contain other components in addition to the phosphor and the liquid medium as long as the effects of the present invention are not significantly impaired. Moreover, 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]
The light-emitting device of the present invention (hereinafter referred to as “light-emitting device” as appropriate) includes a first light-emitting body (excitation light source), and a second light-emitting body that emits visible light when irradiated with light from the first light-emitting body. A light-emitting device comprising: one or more of the phosphors of the present invention as the second phosphor, as the first phosphor.

The phosphor of the present invention is usually a red phosphor that emits fluorescence in the red region under irradiation of light from an excitation light source. Any one of the phosphors of the present invention may be used alone, or two or more thereof may be used in any combination and ratio.
Specifically, the light-emitting device of the present invention uses an excitation light source as will be described later as the first light emitter, adjusts the type and proportion of the phosphor used as the second light emitter, and is a known device configuration By arbitrarily taking, a light emitting device that emits light in any color can be manufactured.

  For example, a white light emitting device is manufactured by combining an excitation light source that emits blue light, a phosphor that emits green fluorescence (green phosphor), and a phosphor that emits orange or red fluorescence (orange or red phosphor). be able to. The emission color in this case can be changed to a desired emission color by adjusting the emission wavelength of the phosphor to be used. For example, a so-called pseudo white color (for example, a blue light emitting diode (hereinafter referred to as a light emitting diode as appropriate) It is also possible to obtain an emission spectrum similar to the emission spectrum of a light emitting device combining a “LED” and a yellow phosphor. Further, by combining a red phosphor with this white light emitting device, it is possible to realize a light emitting device that is extremely excellent in red color rendering and a light emitting device that emits light of a light bulb color (warm white). Also, a white light emitting device can be manufactured by combining an excitation light source that emits near-ultraviolet light with a phosphor that emits blue fluorescence (blue phosphor), a green phosphor, and a red phosphor.

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.
Furthermore, if necessary, yellow phosphors (phosphors that emit yellow fluorescence), blue phosphors, orange to red phosphors, other types of green phosphors, etc. It is also possible to manufacture a light emitting device that adjusts and emits light in an arbitrary color.

[5-4. Application of light emitting device]
The application of the light-emitting device of the present invention is not particularly limited and can be used in various fields where ordinary light-emitting devices are used. However, since the color reproduction range is wide and the color rendering property is high, illumination is particularly important. It is particularly preferably used as a light source for a device or an image display device.
[5-4-1. 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.

[5-4-2. 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.
[Measurement method of physical properties]
The physical property values of the phosphors obtained in Examples and Comparative Examples described later were measured and calculated by the following methods.

{Luminescent characteristics}
<Emission spectrum>
The emission spectrum was measured at room temperature (25 ° C.) using a 150 W xenon lamp as an excitation light source and a fluorescence measuring apparatus (manufactured by JASCO Corporation) equipped with a multi-channel CCD detector C7041 (manufactured by Hamamatsu Photonics) as a spectrum measuring apparatus. did. More specifically, an emission spectrum in the wavelength range of 300 nm to 800 nm was obtained by irradiating with 400 nm excitation light. The emission peak wavelength (hereinafter sometimes referred to as “peak wavelength”) was read from the obtained emission spectrum.

<Excitation spectrum>
The excitation spectrum was measured at room temperature (25 ° C.) using a fluorescence spectrophotometer F-4500 type (manufactured by Hitachi, Ltd.). More specifically, the red emission peak near 660 nm was monitored to obtain an excitation spectrum in the wavelength range of 600 nm to 750 nm.
{Powder X-ray diffraction measurement for general identification}
Powder X-ray diffraction was precisely measured with a powder X-ray diffractometer X′Pert (manufactured by PANalytical). The measurement conditions are as follows. The measurement data was compiled using data processing software X'Pert High Score (manufactured by PANalytical).

Using CuKα tube X-ray output = 45 kV, 40 mA
Divergence slit = automatic, irradiation width 10mm x 10mm
Detector = Semiconductor array detector X'Celerator used, Ni filter used Scanning range 2θ = 10 to 65 degrees Reading width = 0.0170 degrees Counting time = 10 seconds <Lattice constant refinement>
The lattice constant should be refined using the data processing software X'Pert Plus (manufactured by PANalytical) by selecting the peak due to the crystal structure of the sample from the powder X-ray diffraction measurement data of each example and comparative example. Determined by

[Example 1]
_{SrAl 12-x-y-z} Ga z Mg y O 19: in the composition notation ^{_{Mn x 4+, x = 0.02,}} y = 0.04, so that z = 1.99, SrCO ₃ (Rare Metallic Made)
17.48 wt%, _Al 2 _{O 3} (manufactured by Sumitomo Chemical) 60.07 wt%, _Ga 2 _{O 3} (manufactured by High Purity Chemical) 22.09 wt%, MnO (Wako Pure Chemical Industries, Ltd.) 0.17 wt%, MgO (made by Wako Pure Chemical Industries) 0.19 mass% was weighed. Mixing was performed until the weighed raw materials were sufficiently uniform to obtain a phosphor raw material mixed powder.

The obtained phosphor raw material mixed powder was placed in a crucible having an inner wall made of Pt. The crucible in which the phosphor raw material mixed powder was placed was calcined by holding at 1200 ° C. for 4 hours in the air, and then crushed in a mortar to obtain a phosphor raw material calcined powder.
The obtained phosphor raw material calcined powder, placed in a crucible whose inner wall is made of Pt, main-baked by holding at 1500 ° C. for 12 hours, and then crushed in a mortar to obtain the phosphor of Example 1 It was.

[Example 2]
_{SrAl 12-x-y-z} Ga z Mg y O 19: in the composition notation ^{_{Mn x 4+, x = 0.02,}} y = 0.04, except that materials were weighed such that z = 3.98 is In the same manner as in Example 1, the phosphor of Example 2 was obtained.
[Example 3]
_{SrAl 12-x-y-z} Ga z Mg y O 19: in the composition notation ^{_{Mn x 4+, x = 0.02,}} y = 0.04, except that materials were weighed such that z = 5.97 is In the same manner as in Example 1, the phosphor of Example 3 was obtained.

[Example 4]
_{SrAl 12-x-y-z} Ga z Mg y O 19: in the composition notation ^{_{Mn x 4+, x = 0.02,}} y = 0.04, except that materials were weighed such that z = 7.96 is In the same manner as in Example 1, the phosphor of Example 4 was obtained.
[Example 5]
_{SrAl 12-x-y-z} Ga z Mg y O 19: in the composition notation ^{_{Mn x 4+, x = 0.02,}} y = 0.04, and it was weighed raw materials such that z = 9.95 The phosphor of Example 5 was obtained in the same manner as in Example 1 except that the main-baking temperature was 1400 ° C.

[Comparative Example 1]
_{SrAl 12-x-y-z} Ga z Mg y O 19: in the composition notation _Mn ^{x 4+,} except that materials were weighed so that x = 0.02, y = 0.04, z = 0 is performed The phosphor of Comparative Example 1 was obtained in the same manner as Example 1.
[Comparative Example 2]
_{SrAl 12-x-y-z} Ga z Mg y O 19: in the composition notation _{Mn x, x = 0.02, y} = 0.04, the same raw materials as in Example 1 so that z = 11.94 Was weighed. The weighed raw materials were mixed so that they were sufficiently uniform to obtain a phosphor raw material mixed powder.

The obtained phosphor raw material mixed powder was put in a folder with an inner diameter of 20 mmφ, and a pressure of 100 kg / cm ² was applied to produce a pellet.
The prepared pellet was placed in a crucible whose inner wall was made of Pt. The crucible in which the sample was installed was fired by holding it in the atmosphere at 1300 ° C. for 6 hours. The obtained fired body was crushed in a mortar to obtain the phosphor of Comparative Example 2.

<Powder X-ray diffraction>
The result of having performed the powder X-ray-diffraction measurement of the fluorescent substance of Examples 1-5 and Comparative Examples 1 and 2 using the CuK (alpha) X-ray source is shown in FIG. From FIG. 1, the main phases of Examples 1 and 2 and Comparative Examples 1, 2, 3, 4, and 5 were all Sr (Al 2 _, Ga, Mg) ₁₂ O ₁₉ phases.
<Lattice constant refinement>
The lattice constant a of Sr (Al 2 _, Ga, Mg) ₁₂ O ₁₉ of Examples 1 to 5 and Comparative Examples 1 and 2 is shown in FIG. 2, and the lattice constant c is shown in FIG. 2 and 3, it was confirmed that the lattice constant changed linearly. Therefore, it can be said that Al and Ga are completely dissolved.

<Excitation spectrum measurement>
FIG. 4 shows normalized excitation spectra obtained by normalizing the excitation spectra of the phosphors of Examples 1 to 3 and Comparative Example 1 so that the maximum value at a wavelength of 250 to 600 nm is 1.
FIG. 5 shows normalized excitation spectra obtained by normalizing the excitation spectra of the phosphors of Comparative Examples 1 and 2 and Examples 4 and 5 so that the maximum value at a wavelength of 250 to 600 nm is 1. Here, since the phosphor of Comparative Example 2 was not excited at room temperature, the excitation spectrum was measured at a low temperature of liquid nitrogen.

SrAl _11.94-z Ga _z Mg _0.04 O ₁₂ : Fluorescence of Examples 1 to 5 and Comparative Examples 1 and 2 with increasing z (change in Ga substitution amount) when Mn ⁴⁺ _0.04 The peak top wavelength between wavelengths of 390 nm to 460 nm of the excitation spectrum of the body is shown in FIG. It can be seen that the excitation peak wavelength changes substantially continuously due to the solid solution of Al and Ga.

In the case of Al alone (z = 0), no clear peak is observed in the spectrum between 395 nm and 460 nm, but the excitation of Mn ⁴⁺ between 395 nm and 460 nm is increased as the amount of substitution of Ga increases. It can be seen that peaks develop in the spectral shape. However, since the excitation spectrum of the phosphor of Comparative Example 2 is measured at a low temperature, it is slightly different from the tendency of Examples 1 to 5 and Comparative Example 1.

SrAl _11.94-z Ga _z Mg _0.04 O ₁₂ : Fluorescence of Examples 1 to 5 and Comparative Examples 1 and 2 with increasing z (change in Ga substitution amount) when Mn ⁴⁺ _0.04 FIG. 7 shows the excitation intensity ratio ( _E400 / _E250-600max ) at ₄₀₀ nm when the maximum value between wavelengths of 250 nm to 600 nm is set to 1 for the body. From FIG. 7, it can be seen that the relative excitation intensity at 400 nm almost continuously increased to near z = 5.97 with the development of the excitation peak between 395 nm and 460 nm due to Ga substitution. Further, it was found that sufficient strength was obtained at z = 7.96 and 9.95.

SrAl _11.94-z Ga _z Mg _0.04 O ₁₂ : Fluorescence of Examples 1 to 5 and Comparative Examples 1 and 2 with increasing z (change in Ga substitution amount) when Mn ⁴⁺ _0.04 FIG. 8 shows the excitation intensity ratio (E ₄₅₅ / E _{250 -600 max} ) at ₄₅₅ nm when the maximum value between wavelengths of 250 nm to 600 nm is set to 1 for the body. From FIG. 8, it can be seen that the relative excitation intensity at 455 nm increases substantially continuously to near z = 9.95 with the development of the excitation peak between 395 nm and 460 nm due to Ga substitution.

[Reason for excitation spectrum change]
From the above results, it was found that an excitation peak between 395 nm and 460 nm was developed by Ga substitution, and as a result, E ₄₀₀ / E _250-600max and E ₄₅₅ / E _250-600max could be adjusted to a suitable range. The reason why the excitation spectrum changes depending on the Ga substitution amount can be interpreted as follows.

When Mn ⁴⁺ ions are arranged in an octahedral crystal field, the change in the excitation wavelength of the Mn ⁴⁺ phosphor is qualitatively explained by the Tanabe-Ogino diagram. According to the Tabe-Ogino diagram, the energy required to excite Mn ⁴⁺ ions decreases as the energy level splitting width due to the crystal field decreases. In other words, in the oxide, when the distance between the Mn ⁴⁺ ions and the surrounding oxygen octahedron becomes longer, the excitation wavelength becomes longer. However, the Tabe-Ogino diagram generally gives only a qualitative understanding.

On the other hand, in the present invention, it is shown that the excitation wavelength becomes longer when the Ga substitution amount is increased. This is because the lattice constant is linearly increased by Ga substitution in FIGS. 2 and 3, so that the distance between the Mn ⁴⁺ ions and the surrounding oxygen octahedron is also continuously increased. This is because it is considered. In other words, in the present invention, the Al site in the crystal is replaced with Ga having an appropriate effective ionic radius, and the bond distance between the activating element Mn ⁴⁺ ions and O ²⁻ ions is adjusted, thereby changing the excitation band. It is shown that can be controlled quantitatively. In addition, an unexpected effect indicates that the change in excitation band shape can be adjusted to a shape suitable for industrially used LEDs.
As a result, it has been found that the phosphor of the present invention has an excitation band suitable for use in a white light emitting device that uses visible light from short ultraviolet to short wavelength.

<Measurement of emission spectrum>
FIG. 9 shows a standard emission spectrum in which the phosphors of Examples 1 to 5 and Comparative Example 1 were excited at 400 nm and normalized with the emission peak intensity = 1.
The phosphor of Comparative Example 2 did not emit light at room temperature. Therefore, FIG. 10 shows a standard emission spectrum in which the phosphor of Comparative Example 2 was excited at 400 nm at a low liquid nitrogen temperature and normalized with emission peak intensity = 1.
From FIGS. 9 and 10, it can be seen that the shape of the emission spectrum changes depending on the substitution amount of Al and Ga.

SrAl _11.94-z Ga _z Mg _0.04 O ₁₂ : Fluorescence of Examples 1 to 5 and Comparative Examples 1 and 2 with increasing z (change in Ga substitution amount) when Mn ⁴⁺ _0.04 FIG. 11 shows the normalized emission peak intensity obtained by standardizing the emission intensity when excited at 400 nm with Comparative Example 1 as 100%. FIG. 11 shows the emission intensity when excited at 455 nm as 100%. The normalized normalized emission peak intensity is shown in FIG. However, in Comparative Example 5, no light emission was observed at room temperature, so the light emission intensity was set to zero.

  From FIG. 11, when excited at 400 nm, the emission peak intensity ratio is the maximum (about 109%) in Example 1 (z = 1.99) and about 81 in Example 2 (z = 3.98). %. In Example 3 (z = 5.97), Example 4 (z = 7.96), and Example 5 (z = 9.95), which had a larger Ga content than Example 2, the emission peak intensity decreased. Furthermore, in Comparative Example 2 (z = 11.94), no light emission at room temperature was observed.

  From FIG. 12, when excited at 455 nm, the emission peak intensity ratio is maximum (about 128%) in Example 1 (z = 1.99) and about 104 in Example 2 (z = 3.98). % Improved. In Example 3 (z = 5.97), Example 4 (z = 7.96), and Example 5 (z = 9.95), the emission peak intensity decreased. Further, in Comparative Example 2 (z = 11.94), no light emission at room temperature was observed.

Ga substitution amount of Examples 1 to 5 and Comparative Examples 1 and 2, normalized emission peak intensity when excited at 400 nm (ex. 400 nm), normalized emission peak intensity when excited at 455 nm (ex. 455 nm), Further, the excitation intensity ratio at 400 nm (E ₄₀₀ / E _250-600max ) when the maximum value between wavelengths of 250 nm to 600 nm is 1, and the excitation intensity at 455 nm when the maximum value between wavelengths of 250 nm to 600 nm is 1. the characteristic list of specific _{(E 455 /} E _250-600max) shown in Table 1.
From Table 1, the range of Ga substitution amount that is particularly preferable as the phosphor of the present invention is 1.2 <z ≦ 6.5, and the more preferable range is 1.5 ≦ z ≦ 4.5.

[Example 6]
The phosphor of Example 6 was obtained in the same manner as Example 2 except that the temperature for the main firing was 1400 ° C.
[Example 7]
The phosphor of Example 7 was obtained in the same manner as Example 2 except that the temperature for the main firing was 1300 ° C.

[Example 8]
The phosphor of Example 8 was obtained in the same manner as in Example 5 except that the main baking temperature was 1500 ° C.
[Example 9]
The phosphor of Example 9 was obtained in the same manner as Example 5 except that the temperature for the main firing was 1300 ° C.
[Comparative Example 3]
A phosphor of Comparative Example 3 was obtained in the same manner as in Comparative Example 2 except that the main-baking temperature was 1500 ° C.

<Powder X-ray diffraction>
FIG. 13 shows the results of the powder X-ray diffraction measurement of the phosphors of Examples 2, 6, and 7 using a CuKα X-ray source. FIG. 13 shows that the half width is narrower in the order of Example 2, Example 6, and Example 7, and the crystallinity is higher in the order of Example 2, Example 6, and Example 7.

FIG. 14 shows the results of powder X-ray diffraction measurement of the phosphors of Examples 5, 8, and 9 using a CuKα X-ray source. FIG. 14 shows that Example 5 is a single phase of SrGa ₁₂ O ₁₉ , but Examples 8 and 9 have different phases.
FIG. 15 shows the result of the powder X-ray diffraction measurement of the phosphors of Comparative Examples 2 and 3 using a CuKα X-ray source. FIG. 15 shows that Comparative Example 2 is a single phase of SrGa ₁₂ O ₁₉ , but Comparative Example 3 has a different phase.

  From the above, it can be seen that when only Ga is used instead of Al, a single phase can be obtained by firing at less than 1500 ° C. When both Al and Ga are included, a higher quality crystal can be obtained with a higher firing temperature as the Al ratio increases. In the case of Ga substitution amount x = 3.98, it can be seen that a phosphor with high crystallinity can be obtained when the firing temperature is 1400 ° C. or higher.

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

Claims (10)

At least one alkaline earth metal element;
Al element,
Ga element or Ti element;
Having a crystal phase containing oxygen element;
When activated with at least Mn ⁴⁺ and excited with light in the wavelength range of 300 nm to 500 nm, the maximum peak wavelength in the emission spectrum is in the range of 610 nm to 700 nm,
In the excitation spectrum, the ratio E ₄₀₀ / E _250-600 max between the excitation intensity E ₄₀₀ at a wavelength of 400 nm and the maximum excitation intensity E _250-600 max in the wavelength range of 250 nm to 600 nm is 0.56 or more, 1.0 A phosphor characterized by the following: In the excitation spectrum, the excitation intensity E ₄₅₅ at a wavelength of 455 nm and a wavelength of 250 n
2. The phosphor according to claim 1, wherein a value of a ratio E ₄₅₅ / E _{250 -600} max to a maximum value E _{250 -600} max of excitation intensity in the range of m to 600 nm is 0.22 or more and 1.0 or less.   The phosphor according to claim 1, which has a peak wavelength in the excitation spectrum in a wavelength range of 395 nm to 460 nm.   The ratio (N2 / N1) of the number of elements (N2) of Ga element or Ti element contained in the phosphor to the number of elements (N1) of Al element contained in the phosphor is 0.12-5.0. The phosphor according to any one of claims 1 to 3, wherein   The phosphor according to claim 1, wherein the crystal phase further contains Mg. The phosphor according to any one of claims 1 to 5, comprising a crystal phase having a chemical composition represented by the following formula [1].
_{M 1 Al 12-x-y} -z (Ga, Ti) z Mg y O 19: Mn 4+ x [1]
However, in the above formula [1], M represents one or more alkaline earth metals,
x, y, and z represent numbers satisfying 0 <x ≦ 0.4, 0 ≦ y ≦ 1, and 1.2 <z ≦ 10, respectively.   A phosphor-containing composition comprising the phosphor according to any one of claims 1 to 6 and a liquid medium. A first light emitter, and a second light emitter that emits visible light by irradiation of light from the first light emitter,
The light-emitting device in which this 2nd light-emitting body contains 1 or more types of fluorescent substance as described in any one of Claims 1-6 as a 1st fluorescent substance.   An image display device comprising the light-emitting device according to claim 8 as a light source.   An illumination device comprising the light-emitting device according to claim 8 as a light source.

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