JP2663306B2 - Aluminate phosphor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminate-based phosphor which emits green light.

[0002]

2. Description of the Related Art As a green light-emitting phosphor, a divalent manganese-activated silicate-based phosphor (Zn ₂ SiO ₄ ; M
n ²⁺ ) are known. This silicate-based phosphor has a peak wavelength of 525 nm, has a relatively narrow half-value width, and is used in a wide range of fields such as lamps, copying light sources, and neon signs.

[0003] As aluminate-based green light-emitting phosphors, there are cerium-magnesium-aluminate phosphor (hereinafter referred to as CAT phosphor) activated by television, CAT-Mn phosphor co-activated with manganese, europium. There are barium / magnesium / aluminate phosphors (hereinafter referred to as BMA phosphors) co-activated with manganese, which are used for lamps, copying light sources, and the like, respectively.

[0004]

However, the conventionally used silicate-based phosphors have a disadvantage that they undergo large changes with time and deterioration. For CAT phosphors and BMA phosphors, for example, the color tone is displayed. There is a problem that it is not suitable as a green color for use.

[0005] At present, as a high efficiency fluorescent lamp, 3
Although a wavelength range light emitting lamp is commercially available, this high efficiency fluorescent lamp has three wavelengths, blue (peak position 450n).
m), yellow-green (peak position 550 nm), and red (peak position 611 nm) are combined to form a white lamp close to a natural color (a so-called Ra-improved type). The green color of the mercury lamp is hardly produced by using a phosphor emitting green light.

However, in the case of this kind of intermediate color, there is no phosphor having a high emission intensity, and there is a europium-activated strontium aluminate phosphor (hereinafter, referred to as SAE, peak wavelength 493 nm) as a relatively efficient phosphor. . However, this SAE phosphor does not emit blue-green light of a sufficiently satisfactory intensity, and there is a need to develop a phosphor instead of the SAE phosphor.

[0007] The present invention has been made in view of the above points, and conventionally used silicate-based phosphors and SAs.
It is an object of the present invention to provide an aluminate-based green light-emitting phosphor having emission characteristics superior to those of the E phosphor.

[0008]

The aluminate-based phosphor according to claim 1 has a general formula: (However, 1.0 ≧ z ≧ 0.80 , 0.5>m> 0, 0.
2>r> 0.05, and M ²⁺ is Ba, Sr, Ca,
It is selected from the group consisting of Zn. ) Is a green light-emitting phosphor (manganese, divalent metal-substituted cerium-magnesium-aluminate phosphor).

The aluminate phosphor of claim 2 has the general formula: (However, 0.5>b> 0.1, 0.5>m> 0, 0.2
>R> 0.05, and M ² + is Ba, Sr, Ca, Z
M ³⁺ is selected from the group consisting of La, Gd, Y, and In from the group consisting of n. ) Is a green light-emitting phosphor (manganese, divalent, trivalent metal-substituted cerium-magnesium-aluminate phosphor).

[0010] aluminate-based phosphor of claim 3, the general _{formula, (Ba p · Ca q ·} Mn r) O (p + q + r) · 6Al
₂ O _3;. Ce _z (where, 1.024 ≧ p ≧ 0 7, 0.
5>q> 0.05 , 0.22 ≧ r ≧ 0.13 , 1.28
≧ p + q + r ≧ 0.956), 0 . 2>z> 0.1) (manganese-substituted barium / calcium / aluminate phosphor).

[0011]

When divalent manganese is used as an activator in an aluminate-based phosphor having a spinel crystal structure and magnetoplumbite (included in β ″ alumina), ultraviolet excitation (mainly (254 nm), it is necessary to use energy transfer such as trivalent cerium and divalent europium, etc. When manganese is not activated, the cerium emission is in the near ultraviolet region (357 nm). the obtaining light emission of a strong peak at 517nm in the visible range when added. Further, only when co-activated with europium (divalent) in place of cerium, light emission can be obtained by the excitation of 254nm and 365 nm.

The present inventors have firstly developed a cerium-magnesium-aluminate phosphor (hereinafter referred to as a CMM phosphor).
And Ce emission (357 nm in the near ultraviolet region) and 517
The inventors have found that light emission due to Mn ²⁺ having a sharp peak in the green region of nm can be obtained, and the present inventors have made further studies to accomplish the present invention.

The green emission spectrum of this CMM phosphor shows a sharp emission at 517 nm, and the emission range is 480 nm.
580 nm, which is relatively short. Conventional silicate phosphor Z
When compared with n ₂ SiO ₄ ; Mn ²⁺ , the peak wavelength is slightly shifted to the shorter wavelength side, and the color tone is Zn ₂ SiO ₄ ;
₄ ; Mn ²⁺ chromaticity coordinates (x, y) = (0.2278,
0.7015), the color temperature CCT = 6993K,
_{e O 1.5 · (Mg 0.82 ·} Mn 0.18) O · 6A
Chromaticity coordinates (x, y) of l ₂ O ₃ = (0.1701, 0.
7126), color temperature CCT = 7874K,
The aluminate has a lower x-value, a slightly higher y-value, and a fairly high color temperature.

Now, conditions for improving the emission intensity of the CMM phosphor will be described. (1) In the CMM phosphor, the main peak of the phosphor does not shift from the Ce peak to the Mn peak unless the amount of Mn exceeds 0.05 mol, preferably not less than 0.1 mol. Therefore, in order to obtain intense green light emission, the amount of Mn should be set to 0.1.
It must be greater than 05 mole. Further, when the amount of Mn is 0.20 mol or more, the light emission intensity sharply decreases.
Therefore, the amount of Mn needs to be less than 0.20 (manganese, divalent metal substitution type CMM phosphor).

(2) The amount of Mn ²⁺ to be substituted for Mg varies as appropriate (greater than 0.05 mol and smaller than 0.2 mol). As a whole of the divalent metal, 6Al ₂ O ₃
Is always 1 mol. Further, when a part of Ce is replaced with a trivalent metal, 6Al ₂ O
It is best to always use 1 mole per ₃ (manganese, divalent, trivalent metal substituted CMM phosphor). That is, [M ³⁺ (whole trivalent metal)]: [M ²⁺ (whole divalent metal)]: Al ₂ O ₃ = 1: 1: 6 is the best.

(3) After satisfying the conditions of (2), a part of Mg among the divalent metals is further replaced with another metal (for example, Ba).
And the emission intensity is further improved. In this case, β "
It can be considered that the divalent metal contained in the conductor in contact with the alumina spinel block has a mirror effect on Mn. When the same molar substitution is performed with one kind of divalent metal, the emission intensity becomes Ba>Sr>Ca> Zn. Further, even when a part of the trivalent Ce is replaced by another metal (In ₂ O ₃ , Gd ₂ O ₃ , La ₂ O ₃ ), the above-described case is more than the case where the divalent metal is only Mg and Mn. The emission intensity is improved by adding another divalent metal.

The phosphor satisfying the above conditions includes E
When u ²⁺ is co-activated (at the position of manganese), blue-green emission can be obtained.

Next, the barium / calcium / aluminate phosphor will be described. CMM phosphor, Mn
As described above, relatively good green light emission can be obtained by ^2+. However, the present inventors have found that when manganese is further activated in a barium / calcium / aluminate phosphor (hereinafter referred to as a BCM phosphor). And found that the green emission intensity was very high.

The peak wavelength of this BCM phosphor shifts to a shorter wavelength side by about 9 nm than that of a conventional divalent manganese-activated silicate phosphor, and shows a sharp green emission with a half width of about 27 nm. In the BCM phosphor, the amount of Ce may be almost the same as or slightly lower than the amount of Mn.
The amount of e decreases. This is because the way of capturing divalent ions in the BCM phosphor greatly depends on the alkaline earth metal,
Cerium plays an auxiliary role in manganese emission.

The BCM phosphor for (divalent manganese, coactivated a trivalent cerium), when varying the divalent metal amount (prototype 1.28M _O · _6Al 2 O ₃ Ca as a reference, The amount of M is varied by changing Ba while keeping Mn and Ce constant ) , and the concentration range of the divalent metal (M ²⁺ ) is set to 0.1.
Good green light emission was obtained in the range of 956 to 1.28 mol. However, if it was less than 0.956 mol , the Al concentration tended to be high, and vacancy might occur. The best Ba concentration is 77.7% of the total amount of metals (not including trivalent metals).

Regarding the color tone, if the metal concentration with respect to Al increases, the x value of the chromaticity coordinate becomes 0.1414 (M = 0.414).
956) to 0.1567 (M = 1.28), but the y value hardly changes to the extent that the third digit below the decimal point fluctuates. The color temperature (K) is 8300 (M = 0.
956) to 7903 (M = 1.28), which decreases as the metal concentration increases and changes by about 400K.

The appropriate amount of Ca is 0.05 to 0.5 mol, but if it exceeds 43% of the total amount of metals (not including trivalent metals), the luminescence decreases. Regarding the color tone, neither the x value nor the y value changes. Although the color temperature slightly decreases as the Ca amount increases, there is no particular correlation.

Each of the above-mentioned phosphors has Ce emission (357 nm) in the near ultraviolet region . However, Eu may be added when Ce emission causes some hindrance depending on the application.

The phosphor materials preferably used in the present invention include aluminum oxide, cerium carbonate, manganese carbonate, and lanthanum oxide, yttrium oxide, indium oxide, gadolinium oxide as trivalent metals and strontium carbonate as divalent metals. , Barium carbonate, basic magnesium carbonate, zinc carbonate, calcium carbonate, and other carbonates which easily become oxides when heated.

[0025]

EXAMPLES Example 1 (Manganese-Substituted CMM Phosphor) Table 1 shows the results of examining the improvement of the emission intensity of the CMM phosphor by varying the Mn content and the CeO ₂ content.

[0026]

[Table 1]

As shown in Table 1, the amount of Mn was 0.01
Up to 0.05 mol, the Ce peak is stronger and the visible emission is lower. When the amount of Mn is 0.1 mol or more, Mn ²⁺
Becomes the peak of the phosphor as it is. The maximum emission intensity is obtained when the amount of Mn is 0.17 to 0.18 mol. When the amount of Mn is increased, the peak wavelength of Mn becomes 1 nm.
Although it is closer to the longer wavelength side, there is no significant change in both green light emission and color tone.

Further, when the Mn concentration is increased to 0.20 mol or more, the luminescence intensity sharply decreases. In the spectrum diagram, the energy does not disperse, but the Ce peak and the Mn peak both fall. This is Mn excess
It can be said that the state is the concentration quenching due to

Example: 2 (manganese, divalent metal (Ba)
²⁺ ) Substitution CMM Phosphor) Next, an example in which CMX (X = Ba, Ca, Sr) in which a part of Mg of the CMM phosphor is substituted with another divalent metal will be described. Cerium carbonate 35.63 g Manganese carbonate 2.17 g Basic magnesium carbonate 4.85 g Barium carbonate 5.92 g Alumina oxide 60.44 g Aluminum fluoride 1.50 g

The above-mentioned raw materials were accurately measured, mixed in a blender mill, and reduced and fired in the range of 1000 to 1500 ° C. to produce a CMX phosphor (X = Ba, hereinafter referred to as CMB phosphor). The composition of the obtained phosphor is Ce ·
_{(Mg 0.52 Ba 0.3 Mn 0.18)} · Al 12 O
_20.5 . The emission intensity of this phosphor was Ce · (Mg), which showed the highest emission intensity among CMM phosphors.
_The emission intensity was improved by 46% as compared with the emission intensity of _0.82 · Mn _0.18 ) · Al ₁₂ O _20.5 .

FIG. 1 is a graph showing a comparison between the emission spectrum of the CMB phosphor and the emission spectrum of the CMM phosphor. As can be seen from the figure, the emission intensity at 517 nm of the CMB phosphor is remarkably higher,
The peak around nm is low. Further, the half width of the peak (517 nm) of the CMB phosphor is narrower and sharper than that of the CMM phosphor. In FIG. 1,
The specific composition of the phosphor used is such that CMB-4 is (Ce ·
(Mn _0.18 Mg _0.52 Ba _0.30 ) · Al ₁₂
O _20.5 ) and CMB-5 are (Ce · (Mn _0.18
Mg _0.72 Ba _0.10 ) · Al ₁₂ ·
O _20.5 ) and CMB-11 are (Ce · (Mn _0.18
Mg _0.82) is a _· Al _{12 · O 20.5).}

Example: 3 (manganese, divalent metal (Sr
²⁺ ) Substitution type CMM phosphor) 35.63 g cerium carbonate 2.17 g manganese carbonate 4.85 g strontium carbonate 4.43 g aluminum oxide 60.44 g aluminum fluoride 1.50 g

The above raw materials were accurately measured, mixed in a blender mill, and then reduced and fired in the range of 1000 to 1500 ° C. to produce a CMX (X = Sr) phosphor. The composition of the obtained phosphor is Ce · (Mg _0.52 Sr _0.3
Mn _0.18 ) .Al ₁₂ O _20.5 . The emission intensity of this phosphor was Ce · (Mg _0.82 · Mn _0.18 ) · which showed the highest emission intensity among the CMM phosphors.
The emission intensity was improved by 15% as compared with the emission intensity of Al ₁₂ O _20.5 .

Example 4 (Manganese, divalent, trivalent metal-substituted CMM phosphor) Next, a part of Mg in the CMM phosphor is replaced with another divalent metal, and a part of Ce is substituted. An example in which a phosphor substituted with another trivalent metal is manufactured will be described. Cerium carbonate 32.10 g lanthanum oxide 1.63 g manganese carbonate 2.17 g basic magnesium carbonate 4.85 g barium carbonate 5.92 g aluminum oxide 60.44 g aluminum fluoride 1.50 g

The above-mentioned raw materials were accurately measured, mixed with a blender mill, and then reduced and fired in the range of 1000 to 1500 ° C. to produce a phosphor. The composition of the obtained phosphor is (Ce _0.9 La _0.1 ) · (Ba _0.3 Mg )
It was _{0.52 Mn 0.18) · Al 12 O} 20.5. The emission intensity of this phosphor was Ce · (Mg _0.82 · Mn) , which showed the highest emission intensity among the CMM phosphors.
_0.18 ) . The emission intensity was improved by 41% as compared with the emission intensity of Al ₁₂ O _20.5 .

Example: 5 (Comparison of trivalent metal-substituted CMM phosphors) With respect to the CMB phosphor, the trivalent metal that partially replaces Ce is changed to (1) In, (2) Y, and 3) St (Star)
FIG. 2 shows the result of examining the emission spectrum in comparison with (Dand) . As shown in the figure, the green emission intensity is In
>Y> St. The firefly used in FIG.
The specific composition of the phosphor is as follows: (1) The phosphor used in In is
“(Ce _0.9 In _0.1 ) · (Mn _0.18 Mg
_{0.52 Ba 0.30) · Al 12 ·} O 20.5 ",
(2) The phosphor used in Y is “(Ce _0.9 Y _0.1 ) ·
(Mn _0.18 Mg _0.52 Ba _0.30 ) · Al ₁₂
O _20.5 ”, which was compared with (3) St (Standard)
) Is CMB-11 (Ce · (Mn _0.18 M
_{g 0.82) · Al 12 · O} 20.5) is a fluorescent substance.

Example 6 (Manganese-Substituted BCM Phosphor 1) Next, FIG. 3 shows the result of examining the relationship between the amount of Ba and the emission intensity of the BCM phosphor. That is, the amount of Ba was changed.
BCM phosphor _{[(Ba p · Ca 0.102 ·} M n 0.
_{177) O (p + 0.279)} · 6Al 2 O 3; Ce
_0.13 ] and its emission intensity was determined. As shown in the figure, the emission intensity becomes maximum when the amount of Ba is about 0.89.

FIG. 4 shows the result of examining the relationship between the Mn amount and the luminescence intensity while fixing the composition other than Mn of the BCM phosphor. That is, a BCM phosphor [(Ba
_0.896 · Ca _0.102 · Mn _r ) O
_{(R + 0.998)} · 6Al ₂ O ₃ ; Ce _0.13 ]
It was fabricated and its emission intensity was determined. From the figure, it can be seen that the amount of Mn is 0.
It can be seen that the emission intensity becomes maximum around 18.

Further, the emission intensity of the Mn content was set to 100.0.
Emission intensity and peak energy of each phosphor when
Table 2 shows the results. Mn amount from the results shown in Table 2 is 0.179
It can be seen that the light emission intensity becomes the most at the time of.

[0040]

[Table 2]

FIG. 5 is a graph showing the result of examining the relationship between the amount of Mn and the color temperature CCT (K). That is, in FIG.
Check the color temperature CCT (K) of each phosphor
Was. As shown in FIG. 5 , the color temperature changes around the Mn amount of about 0.17 mol, and the color temperature changes to about 80 mol at about 0.16 mol or less.
0K, whereas about 0.18 mol or more is 780
The temperature is as low as ~ 785K.

Example: 7 (Manganese-Substituted BCM Phosphor 2) An example in which a BCM phosphor was manufactured will be described below. Barium carbonate 17.68 g Calcium carbonate 1.02 g Manganese carbonate 1.86 g Cerium carbonate 4.63 g Aluminum oxide 60.44 g Aluminum fluoride 1.50 g

The above-mentioned raw materials were accurately measured, mixed with a blender mill, and then reduced and fired in the range of 1000 to 1500 ° C. to produce a phosphor. The composition of the obtained phosphor was 1.15 (Ba _0.779 · Ca _0.089 · Mn
Was _{Ce 0.13; 0.154) O · 6Al} 2 O 3. The emission intensity of this phosphor was 1.28 (Ba _0.80 · Ca _0.08 · M), a standard BCM phosphor.
The emission intensity of n _0.12 ) O.6Al ₂ O ₃ ; Ce _0.13 was 107.8%, assuming 100%, indicating an improvement of about 8%.

Example 8 (Manganese-substituted BCM phosphor 3) Barium carbonate 13.77 g Calcium carbonate 3.00 g Manganese carbonate 2.16 g Cerium carbonate 4.63 g Aluminum oxide 60.44 g Aluminum fluoride 1.50 g

The above-mentioned raw materials were accurately measured, mixed with a blender mill, and then reduced and fired in the range of 1000 to 1500 ° C. to produce a phosphor. The composition of the obtained phosphor was 1.15 (Ba _0.78 · Ca _0.088 · Mn
Was _{Ce 0.13; 0.1336) O · 6Al} 2 O 3. The emission intensity of this phosphor was 1.28 (Ba _0.80 · Ca _0.08 · M), a standard BCM phosphor.
n _0.12 ) 0.6Al ₂ O ₃ ; 126% and 26% improvement compared to Ce _0.13 .

Example 9 9 (Manganese-substituted BCM phosphor 4) Barium carbonate 17.68 g Calcium carbonate 1.02 g Manganese carbonate 2.16 g Cerium carbonate 4.63 g Aluminum oxide 60.44 g Aluminum fluoride 1.50 g

The above-mentioned raw materials were accurately measured, mixed with a blender mill, and then reduced and fired in the range of 1000 to 1500 ° C. to produce a phosphor. The composition of the obtained phosphor was 1.18 (Ba _0.761 · Ca _0.087 · Mn
Was _{Ce 0.13; 0.152) O · 6Al} 2 O 3. The emission intensity of this phosphor was 1.28 (Ba _0.80 · Ca _0.08 · M), a standard BCM phosphor.
n _0.12 ) O.6Al ₂ O ₃ ; showed an improvement of 116.5% and 16.5% as compared with Ce _0.13 .

The BCM phosphors shown in the above examples, conventional _Zn z _SiO 4: Compared with ^{Mn 2+} phosphor, but is slightly shorter wavelength close, and high emission intensity by about 20%, It can be said that it has practically equivalent or better characteristics than the conventional silicate green phosphor.

In the case of a BCM phosphor, the Ce
Is about the amount of an activator, so that it can be manufactured at a relatively low cost.

Example: 10 (Comparison with conventional green light emitting phosphor) Table 3 and FIG. 6 show the results of examining the light emitting characteristics of a phosphor obtained by activating divalent manganese in a cerium / magnesium / aluminate salt. , Phosphoric acid, zinc and manganese activated phosphors. As shown in the table and figure, the cerium / magnesium / aluminate salt phosphor is more
High emission intensity of far green emission as compared to the manganese activated phosphor, which is considerably smaller for half width. Further, among the cerium-magnesium-aluminate salt-based phosphors, among the CBM phosphor and the BCM phosphor, the BCM type has a higher Y value.

[0051]

[Table 3]

Example: 11 (Comparison of blue-green light-emitting phosphors) The result of examining the light emission characteristics when europium was added to each of the CMM, CMB, and BCM phosphors in comparison with a strontium-aluminate salt-based phosphor Are shown in Table 4 and FIG. In this example, europium was co-activated by substituting a part of the divalent metal or substituting a part of the activator.

[0053] In FIG. 7, CMM phosphor CMM -11 is obtained by adding only ^{_{Mn 2+ (Ce · (Mn 0.18}} Mg
_{0.82) · Al 12 · O 20.5} ), CMME the Eu
CMM phosphor to which ²⁺ and Mn ²⁺ are added (Ce _0.82 ·
_{Eu 0.01 · Mn 0.17 · Mg 1.00} · Al 12
· _O x), CMBE is ^Eu 2+, it was added to the ^{Mn 2+} CM
B phosphor ((Ce _0.90 .Eu _0.10 ). (Mn
_0.15 · Mg _0.55 · Ba _0.30 ) · Al ₁₂ ·
O _x ) and SAE are Sr ₄ .Al ₁₄ O ₂₅ ; Eu ²⁺ . The method of manufacturing each phosphor is based on the method of the above-described embodiment.

[0054]

[Table 4]

As can be seen from Table 4 and FIG. 7, even with the same blue-green color, each cerium-aluminate salt-based phosphor has a higher emission intensity than the strontium-aluminate salt-based phosphor. In the case of the CMBE phosphor, a sub-peak appears at 450 nm, and the Ce peak almost disappears. Further, the FWHM of the blue-green peak is considerably narrower in each of the cerium / aluminate salt-based phosphors than in the strontium / aluminate salt-based phosphor.

[0056]

As described above, the aluminate-based phosphor of the present invention can emit green light with a much higher emission intensity and a narrower half-value width than conventional silicate-based phosphors. , For high efficiency fluorescent lamps and the like. Also, BCM
Since the phosphor requires a small amount of Ce, there is also an advantage that the phosphor can be manufactured relatively inexpensively.

[Brief description of the drawings]

FIG. 1 is a graph showing light emission of a CMM phosphor and a CMB phosphor.

FIG. 2 is a CMB in which a part of Ce is substituted by another trivalent metal.
It is a graph which shows the emission spectrum of a fluorescent substance.

FIG. 3 is a graph showing the results of examining the relationship between the amount of Ba and the emission intensity of a BCM phosphor.

FIG. 4 is a graph showing the result of examining the relationship between the amount of Mn and the emission intensity for a BCM phosphor.

FIG. 5 is a graph showing the result of examining the relationship between the amount of Mn and the color temperature of a BCM phosphor.

FIG. 6 is a graph showing emission characteristics of an aluminate-based phosphor according to the present invention and a conventional silicate-based phosphor.

FIG. 7 is a graph showing emission characteristics of an aluminate-based phosphor to which Eu ²⁺ is added and a conventional SAE phosphor.

Claims (3)

(57) [Claims] (1) a general formula, (However, 1.0 ≧ z ≧ 0.80 , 0.5>m> 0, 0.
2>r> 0.05, and M ²⁺ is Ba, Sr, Ca,
It is selected from the group consisting of Zn. The aluminate-based phosphor represented by). 2. The general formula: (However, 0.5>b> 0.1, 0.5>m> 0, 0.2
>R> 0.05, and M ²⁺ is Ba, Sr, Ca, Z
M ³⁺ is selected from the group consisting of La, Gd, Y, and In from the group consisting of n. The aluminate-based phosphor represented by). 3. A general _{formula, (Ba p -Ca q · Mn} r) O (p + q + r) · 6Al
₂ O _3; Ce _z (where, 1.024 ≧ p ≧ 0.7, 0 .
5>q> 0.05 , 0.22 ≧ r ≧ 0.13 , 1.28
≧ p + q + r ≧ 0.956), and an aluminate phosphor represented by the formula: 0.2>z> 0.1).