JP2016204432A - Phosphor, light-emitting device, illumination device and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a KSF phosphor that has a narrow half-value width of an emission spectrum and is excellent in durability, to provide a light-emitting device that has high efficiency and high color rendering properties and hardly changes luminous efficiency and a luminescent color with the lapse of time, and to provide a high-quality illumination device and a high-quality image display device each including the light-emitting device.SOLUTION: The phosphor includes a crystal phase having a composition represented by formula [1] as given below and satisfies formula [2] as given below. The light-emitting device uses the phosphor. The illumination device and the image display device each include the light-emitting device. Formula [1]: MnKSiF(m, a, b and c each independently represent 0<m≤0.2, 1.6≤a≤2.4, m+b=1, 4.8≤c≤7.2) and formula [2]: 1.4≤A1/A2<9.95 (A1 represents an area of spectrum in the range of 637 to less than 645 eV, as determined by XPS measurement; and A2 represents an area of spectrum in the range of 645 to 651 eV, as determined by XPS measurement).SELECTED DRAWING: None

Description

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

  A light-emitting device that emits white light (hereinafter referred to as “LED” as appropriate) by using a phosphor together with an excitation light source that emits light in the near-ultraviolet or short-wavelength visible range has become common and has been put to practical use in image display devices and illumination devices. ing. 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 achieve both efficiency and color rendering properties, development of a phosphor having a narrow half-value width in a specific wavelength band is regarded as important.

In order to achieve both high efficiency and color rendering of the image display device and the lighting device, for example, the emission peak wavelength of the emission spectrum is 590 nm or more and less than 780 nm, and the half width of the emission spectrum is 1 nm or more and 130 nm or less. It is effective to use a certain red phosphor. For this reason, conventionally, red phosphors having the above-mentioned light emission characteristics have been developed.
As such a phosphor, for example, Patent Document 1 discloses a fluorogermanate phosphor and a Mn ⁴⁺ activated fluoride phosphor such as K ₂ SiF ₆ : Mn ⁴⁺ (KSF).

  In particular, KSF has been developed. For example, Patent Document 2 discloses KSF having a surface region in which the Mn concentration is lower than the internal region.

US Pat. No. 3,576,756 Japanese Patent Laying-Open No. 2015-28148

However, the phosphors described in Patent Documents 1 and 2 sometimes have durability problems. If the durability of the phosphor is not sufficient, when used as a light emitting device, the light emission efficiency and the light emission color may change over time.
With respect to the durability of the phosphor, studies have been made by subjecting the phosphor to surface treatment or devising the structure of the light-emitting device, but a light-emitting device with sufficient performance has not been obtained.

Therefore, a red phosphor having a narrow emission spectrum half-width and excellent water resistance has been desired.
In view of the above problems, the present invention provides a KSF phosphor that has a narrow half-value width of an emission spectrum and is excellent in durability.
In addition, the present invention provides a light-emitting device that is highly efficient and has high color rendering properties, and whose light emission efficiency and light emission color are unlikely to change with time. Furthermore, a high quality lighting device and an image display device including the light emitting device are provided.

As a result of intensive studies to solve the above problems, the present inventors have presumed as follows why the durability in the LED may be a problem.
In order to improve the durability of KSF, it is important that Mn ⁴⁺ is stably present in the phosphor matrix. In particular, on the surface of KSF, Mn ⁴⁺ bonded to fluorine exists, but this state is an unstable state in which it reacts with oxygen and water in the atmosphere.

For this reason, in order to make Mn ⁴⁺ more stable on the KSF surface, the inventors found that the above problem can be solved by increasing the proportion of Mn ⁴⁺ bonded to oxygen instead of fluorine, and reached the present invention. .
That is, the present invention provides a phosphor, a light emitting device, a lighting device, and an image display device characterized by including a crystal phase having a composition represented by the following formula [1] and further satisfying the following formula [2]. Exist.
Mn _m K _a Si _b F _c [1]
(In the above formula [1], m, a, b and c are values satisfying the following formula independently.
0 <m ≦ 0.2
1.6 ≦ a ≦ 2.4
m + b = 1
4.8 ≦ c ≦ 7.2)
1.4 ≦ A1 / A2 <9.95 [2]

(In the above formula [2]),
A1 represents the area of the spectrum in the range of 637 eV or more and less than 645 eV in the XPS measurement,
A2 represents the area of the spectrum in the range of 645 eV or more and 651 eV or less in the XPS measurement. )

According to the present invention, it is possible to provide a KSF phosphor excellent in durability.
In addition, the present invention can provide a light-emitting device that has high efficiency and high color rendering properties, and whose light emission efficiency and light emission color are unlikely to change with time. Furthermore, it is possible to provide a high-quality lighting device and image display device including the light-emitting device.

(A) is a signal diagram of the X-ray photoelectron spectroscopy measurement of the phosphors obtained in Examples 1 to 4. FIG. (B) is a signal diagram of X-ray photoelectron spectroscopy measurement of K ₂ MnF ₆ and MnO ₂ . It is a figure which shows the result of the LED durability test of the fluorescent substance obtained in Examples 1-4 and the comparative example 1. FIG. In (a), the horizontal axis represents time (h), and the vertical axis represents the maintenance ratio (%) from the initial value of chromaticity x. In (b), the horizontal axis represents A1 / A2, and the vertical axis represents the maintenance ratio (%) from the initial value of chromaticity x.

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.
In the composition formulas 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 “(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 " and all assumed to generically indicated (in the above formula, 0 <x <1,0 <y <1,0 <X + y <1).
In the present specification, “Mn ⁴⁺ ” and “tetravalent manganese” are synonymous.

{About phosphor}
[Regarding Formula [1]]
The phosphor of the present invention includes a crystal phase having a composition represented by the following formula [1].
Mn _m K _a Si _b F _c [1]
(In the above formula [1], m, a, b and c are values satisfying the following formula independently.

0 <m ≦ 0.2
1.6 ≦ a ≦ 2.4
m + b = 1
4.8 ≦ c ≦ 7.2)

  In formula [1], Mn represents manganese. As long as the effects of the present invention are not impaired, Mn is another activator element, for example, europium (Eu), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), terbium (Tb), It may be partially substituted with one or more of dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm) and ytterbium (Yb).

In the formula [1], K represents potassium. K is partially substituted with other elements of Group 1 of the periodic table, for example, alkali metals such as lithium (Li), sodium (Na), rubidium (Rb), cesium (Cs), and francium (Fr). May be.
In formula [1], Si represents silicon. Si may be partially substituted with other tetravalent elements such as germanium (Ge), tin (Sn), titanium (Ti), and zirconium (Zr).

In formula [1], F represents fluorine. F may be partially substituted with other halogen elements such as Cl (chlorine), Br (bromine), I (iodine), and oxygen.
m represents the content of Mn, the range is usually 0 <m ≦ 0.2, the lower limit is preferably 0.01, more preferably 0.02, and the upper limit is preferably 0. .15, more preferably 0.1.

Within the above range, concentration quenching is unlikely to occur, and a different phase showing a chemical composition other than the phosphor of the present invention is unlikely to occur.
a represents the content of K, the range is usually 1.6 ≦ a ≦ 2.4, the lower limit is preferably 1.8, more preferably 1.85, and the upper limit is preferably Is 2.2, more preferably 2.15.

b represents the silicon content.
The relationship between m and b is usually
m + b = 1
Satisfied.
c represents the content of fluorine, the range is usually 4.8 ≦ c ≦ 7.2, the lower limit is preferably 5.2, more preferably 5.6, and the upper limit is preferably Is 6.8, more preferably 6.4.

[Regarding Formula [2]]
The phosphor of the present invention satisfies the following formula [2].
1.4 ≦ A1 / A2 <9.95 [2]
(In the above formula [2]),
A1 represents the area of the spectrum in the range of 637 eV or more and less than 645 eV in the XPS measurement,
A2 represents the area of the spectrum in the range of 645 eV or more and 651 eV or less in the XPS measurement. )
A1 in the formula [2] corresponds to the amount of Mn ⁴⁺ bonded to oxygen. A2 in the formula [2] corresponds to the amount of Mn ⁴⁺ bonded to fluorine. Therefore, the ratio between A1 and A2 corresponds to the amount ratio of Mn ⁴⁺ bonded to oxygen and Mn ⁴⁺ bonded to fluorine.

A1 / A2 is usually 1.4 ≦ A1 / A2 <9.95, and the lower limit is preferably 1.51, more preferably 1.62, and the upper limit is preferably 6.44, more preferably. Is 4.68, more preferably 2.72.
The upper limit of 9.95 is a value when XPS measurement is performed on MnO ₂ . Moreover, the preferable value in said lower limit and upper limit contains its own number.

[XPS measurement]
In XPS measurement (X-ray photoelectron spectroscopy measurement), Quantum 2000 (manufactured by PHI) was used. The measurement conditions are as follows.
-X-ray source: Monochromatic Al-Kα, output 16kV-34W (X-ray generation area 170umφ)
・ Spectroscopic system: Path energy
187.85eV@wide spectrum
58.70eV@Narrow spectrum (O1s)
29.35eV@Narrow spectrum (C1s (K2p), F1s, Si2p, Mn2p3 / 2)
・ Measurement area: 170umφspot (<340umφ)
・ Pickup angle: 45 ° (from surface)
A1 / A2 is calculated by the following procedure.

Calculation procedure 1. Average the signal intensity of 1.637 ± 0.25 eV to obtain the signal intensity of 637 eV.
Calculation procedure 2. The signal intensity of 651 ± 0.25 eV is averaged to obtain the signal intensity of 651 eV.
Calculation procedure: A straight line is drawn between 3.637 eV and 651 eV to make the background.

Calculation procedure: 4. Subtract background between 637 and 651 eV.
Calculation Procedure Calculate the spectrum area (A1) in the range of 5.637 eV or more and less than 645 eV.
Calculation procedure: The spectrum area (A2) in the range of 6.645 to 651 eV is calculated.
Calculation procedure7. Divide A1 by A2 to calculate the area ratio (A1 / A2).

[Characteristics of phosphor]
(Emission spectrum)
The phosphor of the present invention preferably has the following characteristics when the emission spectrum is measured by excitation with light having a peak wavelength of 455 nm.
The peak wavelength λp (nm) in the above emission spectrum is usually larger than 600 nm, preferably 610 nm or more, more preferably 620 nm or more, and usually 650 nm or less.

Within the above range, it is preferable in that it has a suitable orange or red light emission.
In the phosphor of the present invention, the half width of the emission peak in the above-mentioned emission spectrum is usually less than 50 nm, particularly 40 nm or less, more preferably 20 nm or less, particularly 10 nm or less, usually 1 nm or more. If this half width is too wide, the color purity may decrease, and if it is too narrow, the emission intensity may decrease.

  For example, a xenon light source can be used to excite the phosphor with light having a peak wavelength. The emission spectrum of the phosphor of the present invention can be measured using, for example, a fluorescence spectrophotometer F-4500 (manufactured by Hitachi, Ltd.). The emission peak wavelength and the half width of the emission peak can be calculated from the obtained emission spectrum.

{Phosphor production method}
Although there is no restriction | limiting in particular in the method to manufacture the fluorescent substance of this invention, For example, the following methods (1) or (2) are mentioned.
(1) Method of putting phosphor in crucible and heating in atmosphere containing oxygen (2) Method of heating while floating phosphor in gas containing oxygen

[Phosphor production conditions]
When the target phosphor can be synthesized by the method (1), the phosphor is weighed and then put into a crucible and heated using an electric furnace or the like.
The crucible to be used is preferably selected from a material that does not deform at the heating temperature and hardly reacts with the contents. As the crucible material, alumina, zirconia, boron nitride or the like can be used.

When a large amount of phosphor is continuously produced, the method (2) may be adopted.
In the methods (1) and (2) above, the heating temperature varies depending on other conditions such as pressure, but it is usually preferably in a temperature range of 130 ° C. or higher and 600 ° C. or lower, more preferably 150 ° C. or higher. 450 ° C. or lower, particularly preferably 200 ° C. or higher and 350 ° C. or lower. If the heating temperature is too high, the base crystal tends to decompose. When the heating temperature is too low, the progress of bonding between the phosphor surface and oxygen tends to be slow.

Although there is no special restriction | limiting about the pressure at the time of a synthesis | combination, The process under high pressure is also employable as needed.
Although the heating time varies depending on the heating temperature and atmosphere, it is usually 5 minutes or longer, preferably 15 minutes or longer, and usually 48 hours or shorter, preferably 24 hours or shorter.
The atmosphere for the treatment is not particularly specified as long as oxygen is contained even if it is an inert gas such as Ar or N ₂ , but is preferably air for practical use, and more preferably air at 85 ° C. and a humidity of 85% or less. Is preferred.

<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 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. Furthermore, you may make the fluorescent substance containing composition of this invention contain fluorescent substances other than the fluorescent substance of this invention, unless the effect of this embodiment is impaired remarkably.

[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. For example, any inorganic material and / or organic material may be used as long as it exhibits liquid properties under the desired use conditions, suitably disperses the phosphor of the present invention, and does not cause an undesirable reaction. Examples thereof include silicone resin, epoxy resin, and polyimide silicone resin.

[Content of liquid medium and phosphor]
The content of the phosphor and 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, but the liquid medium is included in the entire phosphor-containing composition of the present embodiment. On the other hand, it is usually 50% by weight or more, preferably 75% by weight or more, and usually 99% by weight or less, preferably 95% by weight or less.

[Other ingredients]
In addition, you may make the fluorescent substance containing composition of this invention contain other components other than a fluorescent substance and a liquid medium, unless the effect of this embodiment is impaired remarkably. 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.

{Light emitting device}
A light-emitting device of the present invention is a light-emitting device that 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. 2 contains the phosphor of the present invention. Here, 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.

  As the phosphor included in the light emitting device of the present invention, for example, a phosphor that emits fluorescence in a yellow region or a red region under irradiation of light from an excitation light source is used. Specifically, when constituting a light emitting device, the green or yellow phosphor preferably has an emission peak in the wavelength range of 520 nm to 600 nm, and the orange or red phosphor has a wavelength range of 600 to 650 nm, Particularly preferably, it has an emission peak in the wavelength range of 610 nm to 700 nm.

An excitation source having an emission peak in a wavelength range of less than 460 nm may be used.
Hereinafter, a light-emitting device in which the phosphor of the present invention has a light emission peak in a wavelength range of 600 nm to 650 nm and a first light emitter has a light emission peak in a wavelength range of 350 nm to 500 nm. However, the present embodiment is not limited to these.

In the above case, the light-emitting device of this embodiment can be set to the following embodiment (A) or (B), for example.
(A) As a 1st light-emitting body, what has a light emission peak in the wavelength range of 420 nm or more and 500 nm or less is used, and a light emission peak is used in the wavelength range of 560 nm or more and less than 600 nm as a 2nd fluorescent substance of a 2nd light-emitting body. An embodiment using at least one phosphor (yellow phosphor) having the phosphor according to the present invention.
(B) A first phosphor having a light emission peak in a wavelength range of 420 nm to 500 nm is used, and a light emission peak in a wavelength range of 500 nm to less than 560 nm is used as the second phosphor of the second light emitter. An embodiment using at least one phosphor (green phosphor) having the phosphor of the present invention.

(Yellow phosphor)
As the yellow phosphor in the embodiment (A), for example, the following phosphors are preferably used.
Examples of the garnet phosphor include (Y, Gd, Lu, Tb, La) ₃ (Al, Ga) ₅ O ₁₂ : (Ce, Eu, Nd),
Examples of the orthosilicate include (Ba, Sr, Ca, Mg) ₂ SiO ₄ : (Eu, Ce),
Examples of (acid) nitride phosphors include (Ba, Ca, Mg) Si ₂ O ₂ N ₂ : Eu (SION phosphor), (Li, Ca) ₂ (Si, Al) ₁₂ (O, N ₁₆ : (Ce, Eu) (α-sialon phosphor), (Ca, Sr) AlSi ₄ (O, N) ₇ : (Ce, Eu) (1147 phosphor)
Etc.

The phosphor is preferably a garnet phosphor, and most preferably a YAG phosphor represented by Y ₃ Al ₅ O ₁₂ : Ce.

(Green phosphor)
As the green phosphor in the aspect (B), for example, the following phosphors are preferably used.
Examples of the garnet phosphor include (Y, Gd, Lu, Tb, La) ₃ (Al, Ga) ₅ O ₁₂ : (Ce, Eu, Nd), Ca ₃ (Sc, Mg) ₂ Si ₃ O _12. : (Ce, Eu) (CSMS),
Examples of the silicate phosphor include (Ba, Sr, Ca, Mg) ₃ SiO ₁₀ : (Eu, Ce), (Ba, Sr, Ca, Mg) ₂ SiO ₄ : (Ce, Eu) (BSS phosphor). ),
As the oxide phosphor, for example, (Ca, Sr, Ba, Mg) (Sc, Zn) ₂ O ₄ : (Ce, Eu) (CASO phosphor),
Examples of (acid) nitride phosphors include (Ba, Sr, Ca, Mg) Si ₂ O ₂ N ₂ : (Eu, Ce), Si _6-z Al _z O _z N _8−z : (Eu, Ce) (β-sialon phosphor) (0 <z ≦ 1), (Ba, Sr, Ca, Mg, La) ₃ (Si, Al) ₆ O ₁₂ N ₂ : (Eu, Ce) (BSON phosphor)
As the aluminate phosphor, for example, (Ba, Sr, Ca, Mg) ₂ Al ₁₀ O ₁₇ : (Eu, Mn) (GBAM phosphor)
Etc.

(Red phosphor)
In the light emitting device of the present invention, other red phosphors may be used in combination with the phosphor of the present invention. As other red phosphors, for example, the following phosphors are preferably used.
Examples of sulfide phosphors include (Sr, Ca) S: Eu (CAS phosphor), La ₂ O ₂ S: Eu (LOS phosphor),
Examples of the garnet phosphor include (Y, Lu, Gd, Tb) ₃ Mg ₂ AlSi ₂ O ₁₂ : Ce,
Examples of nanoparticles include CdSe,
Examples of the nitride or oxynitride phosphor include (Sr, Ca) AlSiN ₃ : Eu (S / CASN phosphor), (CaAlSiN ₃ ) _1-x · (SiO ₂ N ₂ ) _x : Eu (CASON fluorescence). Body), (La, Ca) ₃ (Al, Si) ₆ N ₁₁ : Eu (LSN phosphor), (Ca, Sr, Ba) ₂ Si ₅ (N, O) ₈ : Eu (258 phosphor), ( _{Sr, Ca) Al 1 + x} Si 4-x O x N 7-x: Eu (1147 _{phosphors), M x (Si, Al} ) 12 (O, N) 16: Eu (M is, Ca, Sr, etc.) ( α sialon phosphor), Li (Sr, Ba) Al ₃ N ₄ : Eu (wherein x is 0 <x <1).

[Configuration of light emitting device]
The light emitting device of this embodiment has a first light emitter (excitation light source) and uses at least the phosphor according to the first embodiment of the present invention as the second light emitter, The configuration is not limited, and a known device configuration can be arbitrarily employed.
Examples of the device configuration and the light emitting device include those described in Japanese Patent Application Laid-Open No. 2007-291352.
In addition, examples of the form of the light emitting device include a shell type, a cup type, a chip on board, a remote phosphor, and the like.

{Use 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.

[Lighting device]
The illumination device of the present invention includes the light emitting device of the present invention as a light source.
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, a surface emitting illumination device in which a large number of light emitting devices are arranged on the bottom surface of the holding case can be used.

[Image display device]
The image display device of the present invention includes the light emitting device of the present invention as a light source.
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, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples without departing from the gist thereof.

{Measuring method}
[XPS measurement method]
In XPS measurement (X-ray photoelectron spectroscopy measurement), Quantum 2000 (manufactured by PHI) was used. The measurement conditions are shown below.
・ X-ray source: Monochromatic Al-K, output 16kV-34W (X-ray generation area 170umφ)
・ Spectroscopic system: Path energy ・ 187.85eV@Wide spectrum ・ 58.70eV@Narrow spectrum (O1s)
・ 29.35eV@Narrow spectrum (C1s (K2p), F1s, Si2p, Mn2p3 / 2)
・ Measurement area: 170umφspot (<340umφ)
・ Pickup angle: 45 ° (from surface)

[Luminescent characteristics]
In order to excite the phosphor with light having a peak wavelength of 455 nm, for example, a xenon light source can be used. The emission spectrum of the phosphor of the present invention can be measured by, for example, 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. ) Or the like. The emission peak wavelength and the half width of the emission peak can be calculated from the obtained emission spectrum.

{Synthesis of phosphor}
(Comparative Example 1)
KHF ₂ , H ₂ SiF ₆ , and K ₂ MnF ₆ weighed so that the molar ratio of K: Si: Mn was 2: 0.94: 0.06 were mixed in HF, and K ₂ SiF ₆ : Mn ⁴⁺ A phosphor-containing slurry containing was obtained. The phosphor-containing slurry was filtered, washed with ethanol, and dried at 100 ° C. for 15 hours to obtain the phosphor of Comparative Example 1.
Moreover, the peak wavelength of the emission peak of the obtained phosphor was 631 nm, and the half width of the main emission peak was 6 nm.

Example 1
The phosphor of Comparative Example 1 was heated in vacuum at 250 ° C. for 4 hours to obtain the phosphor of Example 1.
Moreover, the peak wavelength of the emission peak of the obtained phosphor was 631 nm, and the half width of the main emission peak was 6 nm.

(Example 2)
The phosphor of Comparative Example 1 was heated in argon at 250 ° C. for 4 hours to obtain the phosphor of Example 2.
Moreover, the peak wavelength of the emission peak of the obtained phosphor was 631 nm, and the half width of the main emission peak was 6 nm.

Example 3
The phosphor of Comparative Example 1 was heated in a dry air at 250 ° C. for 4 hours to obtain the phosphor of Example 3.
Moreover, the peak wavelength of the emission peak of the obtained phosphor was 631 nm, and the half width of the main emission peak was 6 nm.

Example 4
The phosphor of Comparative Example 1 was heated at 85 ° C. in a humid air of 85% humidity at 250 ° C. for 4 hours to obtain the phosphor of Example 4.
Moreover, the peak wavelength of the emission peak of the obtained phosphor was 631 nm, and the half width of the main emission peak was 6 nm.

{Luminescent characteristics}
For the phosphors obtained in Comparative Example 1 and Examples 1 to 4, the emission spectra when excited at 455 nm were measured. All the phosphors had an emission peak wavelength of 631 nm and a half width of 6 nm.

{XPS measurement}
The XPS spectra of the phosphor of Comparative Example 1, the phosphors of Examples 1 to 4, and K ₂ MnF ₆ and Mn2p2 / 3 of MnO ₂ are shown in FIG. The XPS spectrum of FIG. 1 is normalized so that the background is subtracted from the measurement data and the maximum value is 1.
The XPS signals of the phosphor of Comparative Example 1 and the phosphors of Examples 1 to 4 are a signal showing a peak top around 637 to 645 eV (spectrum area is A1) and a signal showing a peak top around 645 to 651 eV ( The spectrum area was A2. From the XPS measurement result of MnO ₂ , the former (A1) indicates Mn bonded to oxygen. From the XPS measurement result of K ₂ MnF ₆ , the latter (A2) indicates Mn bonded to fluorine.
Table 1 shows the area ratio (A1 / A2) of Comparative Example 1 and Examples 1 to 4 and MnO ₂ and K ₂ MnF ₆ .

As shown in Table 1, the phosphors of Examples 1 to 4 have a larger area ratio (A1 / A2) than the phosphor of Comparative Example 1. Therefore, it can be seen that the phosphor of the present invention has an increased proportion of Mn bonded to oxygen.
{LED durability test}
Table 2 shows the results of the durability test of the phosphors of Comparative Example 1 and Examples 1-4.

As shown in Tables 1 and 2, when the A1 / A2 value is within the range of the present invention, it can be seen that the maintenance ratio of the LED chromaticity x is high.
That is, on the surface, the ratio of Mn bonded to oxygen to Mn bonded to fluorine increases, so that deterioration of the phosphor during the LED test is suppressed, and the durability of the obtained LED is improved. Inferred.

Claims (5)

Including a crystal phase having a composition represented by the following formula [1],
Furthermore, the phosphor satisfying the following formula [2].
Mn _m K _a Si _b F _c [1]
(In the above formula [1], m, a, b and c are values satisfying the following formula independently.
0 <m ≦ 0.2
1.6 ≦ a ≦ 2.4
m + b = 1
4.8 ≦ c ≦ 7.2)
1.4 ≦ A1 / A2 <9.95 [2]
(In the above formula [2]),
A1 represents the area of the spectrum in the range of 637 eV or more and less than 645 eV in the XPS measurement,
A2 represents the area of the spectrum in the range of 645 eV or more and 651 eV or less in the XPS measurement. )   2. The phosphor according to claim 1, wherein the phosphor has an emission peak wavelength in a range of 600 nm to 650 nm by irradiating excitation light having a wavelength of 350 nm to 460 nm.   A first illuminant and a second illuminant that emits visible light when irradiated with light from the first illuminant, wherein the second illuminant comprises the phosphor according to claim 1 or 2. A light-emitting device comprising:   An illumination device comprising the light-emitting device according to claim 3 as a light source.   An image display device comprising the light-emitting device according to claim 3 as a light source.

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