JPWO2015099145A1 - Phosphor and method for producing phosphor - Google Patents

Abstract

An object of the present invention is to provide a phosphor excellent in long afterglow characteristics by ultraviolet excitation and excellent in long afterglow characteristics by blue light excitation, and a method for producing the same. The present invention provides the following composition formula (1): A3B2C3O12 (1) (wherein A is at least one selected from the group consisting of (i) Mg, Ca, Sr, La, Gd, Tb, Lu, and Y) And (ii) Ce, B is at least one element selected from the group consisting of Al, Ga, Sc, In, Mg, Lu, and Y, and C is Si, Ge, And at least one element selected from the group consisting of Al and Ga), Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Hf, Si, Yb Further, the present invention relates to a phosphor that is doped with at least one metal element selected from the group consisting of Eu, Pr, and Tb.

Description

  The present invention relates to a phosphor and a method for producing the phosphor.

  Phosphorescent long afterglow phosphors temporarily trap electrons, holes, and other carriers generated by external energy (eg, ultraviolet light, purple light, etc.) into defects in the crystal, and the trapped carriers The light is gradually released by the thermal energy of the air temperature, and recombines at the emission center to show long-lasting emission. This long afterglow phosphor stores sunlight energy during the day, light energy from room lighting, etc., and shines at night or after extinguishing the light, so that it can be used as a visible nocturnal paint. Therefore, the long afterglow phosphor is used for safety signs and evacuation guidance systems.

Long-afterglow phosphors reported to date (eg, SrAl ₂ O ₄ : Eu ²⁺ -Dy ³⁺ etc.) are generally excited by short-wavelength light such as ultraviolet light (ultraviolet light) and purple light. High efficiency. When such a long afterglow phosphor is used under sunlight or a fluorescent lamp, since the light from the sunlight or the fluorescent lamp contains ultraviolet rays or the like, the long afterglow phosphor can be used without any problem. Can be used.

  However, in recent years, white LEDs (Light Emitting Diodes) having characteristics such as long-term stability, energy saving, and high emission quantum efficiency have been frequently used as solid-state lighting devices in place of the fluorescent lamps. White LEDs that are commonly used are composed of a combination of a blue LED and a yellow phosphor, or a combination of a blue LED, a red phosphor, and a green phosphor. That is, the light from the white LED includes only blue light as light having the shortest wavelength, and does not include ultraviolet rays. Therefore, due to the shift of indoor lighting to white LEDs in recent years, it is possible to store light not only from fluorescent lamps but also from white LEDs as a characteristic required for long afterglow phosphors ( In other words, there is a demand for whether or not light storage by blue light as well as light storage by ultraviolet rays or the like is possible.

As a phosphor that absorbs light in the blue region, a Ce ^{3 +} -added A ₃ B ₂ C ₃ O ₁₂ garnet phosphor (for example, Ce ³⁺ : Y ₃ Al ₂ Al ₃ O ₁₂ , hereinafter referred to as Ce ³⁺ : YAG phosphor). Is known). The Ce ³⁺ : YAG phosphor absorbs light in the blue region and exhibits yellow light emission with high quantum efficiency. Therefore, the phosphor constituting the white LED (that is, the yellow phosphor used in combination with the blue LED) ). However, Ce ³⁺ : YAG does not exhibit afterglow characteristics due to blue light excitation.

Further, as the ^{Ce 3+} added garnet phosphors of another composition that absorbs light in the blue region, ^{Ce 3+} added _{Y 3 Al 5-x Ga x} O 12 ( ^hereinafter, Ce 3+: YAGG also called) (x = 3, 3.5) is known (Non-Patent Document 1). This non-patent document 1 describes that Ce ³⁺ : YAGG (x = 3, 3.5) exhibits afterglow in ultraviolet light excitation.

J. W. W. Holloway, and M. Kestigian, “Optical Properties of Cerium-Activated Garnet Crystals,” J. Opt. Soc. Am. 59, 60-63 (1969).

However, there are few reports on the long afterglow characteristics of the Ce ³⁺ : YAGG due to blue light excitation.

Therefore, the present inventors examined the long afterglow characteristics of Ce ³⁺ : YAGG by blue light excitation. As a result, Ce ³⁺ : YAGG was found to have a very low afterglow intensity (afterglow luminance) although it exhibited afterglow characteristics when the blue light was blocked after being excited with blue light.

  Accordingly, an object of the present invention is to provide a phosphor excellent in long afterglow characteristics by ultraviolet excitation and excellent in long afterglow characteristics by blue light excitation, and a method for producing the same.

  As a result of intensive studies, the present inventors have found that the above object can be achieved by a phosphor represented by a specific composition, and have completed the present invention.

That is, the present invention relates to the following phosphor (garnet crystal phosphor) and a method for producing the same. 1. The following composition formula (1):
A ₃ B ₂ C ₃ O ₁₂ (1)
(Where
A is (i) at least one element selected from the group consisting of Mg, Ca, Sr, La, Gd, Tb, Lu, and Y, and (ii) Ce.
B is at least one element selected from the group consisting of Al, Ga, Sc, In, Mg, Lu, and Y;
C is at least one element selected from the group consisting of Si, Ge, Al, and Ga).
At least one metal element selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Hf, Si, Yb, Eu, Pr, and Tb is doped. A phosphor characterized by.
2. Item 2. The phosphor according to Item 1, wherein a doping amount of the metal element is 0.001 to 5 mol% with respect to the compound represented by the formula (1).
3. Item 3. The phosphor according to Item 1 or 2, wherein a molar ratio of the element (i) to the (ii) Ce is 0.9999: 0.0001 to 0.95: 0.05.
4). Item 4. The phosphor according to any one of Items 1 to 3, which is used for a phosphorescent phosphor, white LED, phosphorescent ceramics, phosphorescent resin, phosphorescent paint, phosphorescent evacuation guidance system, or bioimaging marker.
5. The following composition formula (1):
A ₃ B ₂ C ₃ O ₁₂ (1)
(Where
A is (i) at least one element selected from the group consisting of Mg, Ca, Sr, La, Gd, Tb, Lu, and Y, and (ii) Ce.
B is at least one element selected from the group consisting of Al, Ga, Sc, In, Mg, Lu, and Y;
C is at least one element selected from the group consisting of Si, Ge, Al, and Ga).
Fluorescence doped with at least one metal element selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Hf, Si, Yb, Eu, Pr, and Tb A method for manufacturing a body,
(1) Step 1 of preparing a composition containing the element-containing compound (i), B-element-containing compound, C-element-containing compound, Ce-containing compound, and the metal-element-containing compound;
(2) Step 2 of heating the composition at 1200 to 1800 ° C
In order.

Explanation of Terms In this specification, “long afterglow” refers to a long period of time (eg, several) even if the excitation light (eg, ultraviolet light, violet light, blue light, etc.) is irradiated and then the excitation light is cut off (stopped). (Minutes to several tens of hours or more) means to continue to emit light, and can be clearly distinguished from the time scale (ns to ms) of light emission indicated by the electronic transition of atoms. In the present specification, the phosphor having the long afterglow function is also referred to as “long afterglow phosphor”, and the phosphor of the present invention is a long afterglow phosphor. The center wavelength (emission peak) of afterglow in the present invention is about 480 to 700 nm (green to red).

  In this specification, “light storage” means that carriers such as electrons and holes are stored (stored or trapped) so as to store (collect) light. Here, the carrier is generated by external energy such as ultraviolet light, purple light, and blue light, is captured by the trap, and emits light by being released by the thermal energy of the outside air.

  In this specification, “blue light” refers to visible light having a wavelength of 400 to 460 nm unless otherwise specified.

  In this specification, “ultraviolet light (ultraviolet light)” means ultraviolet light having a wavelength of 200 to 380 nm unless otherwise specified.

  In this specification, “room temperature” means that the air temperature is 10 to 30 ° C. unless otherwise specified.

<< 1. Phosphor of the present invention >>
The phosphor of the present invention has the following composition formula (1):
A ₃ B ₂ C ₃ O ₁₂ (1)
(Where
A is (i) at least one element selected from the group consisting of Mg, Ca, Sr, La, Gd, Tb, Lu, and Y, and (ii) Ce.
B is at least one element selected from the group consisting of Al, Ga, Sc, In, Mg, Lu, and Y;
C is at least one element selected from the group consisting of Si, Ge, Al, and Ga).
At least one metal element selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Hf, Si, Yb, Eu, Pr, and Tb is doped. It is characterized by.

  The phosphor of the present invention having the above-described characteristics can be obtained by, in particular, ultraviolet excitation by doping a specific garnet crystal phosphor containing a Ce element with a specific metal element (the specific metal element is also referred to as an M element). Excellent long afterglow characteristics and excellent long afterglow characteristics by blue light excitation. The phosphor of the present invention is also excellent in water resistance.

The phosphor of the present invention is also referred to as Ce and a specific metal element co-added garnet crystal phosphor. Here, a schematic diagram of the garnet crystal structure and occupied cations is shown in FIG. A composition of a general garnet crystal structure (garnet structure) is represented by the composition formula (1): A ₃ B ₂ C ₃ O ₁₂ . The cation of the element (A element) represented by A in the above formula (1) occupies a dodecahedron site, and the cation of the element (B element) represented by B in the above formula (1) occupies an octahedral site. The cation of the element (C element) represented by C in the above formula (1) occupies a tetrahedral site. The phosphor of the present invention is a phosphor obtained by co-adding Ce and M elements in the garnet crystal as a base crystal. Here, (ii) Ce of A in the above formula (1) means that it contains Ce ³⁺ as the emission center, and this Ce ³⁺ occupies a dodecahedron site. The cations of the M element mainly occupy octahedral sites in many cases.

  The garnet-type structure in the phosphor of the present invention may have a solid solution region. In this case, lattice defects and antisite defects occur in the crystal, and a slight composition ratio deviation may occur with respect to the above formula (1) (that is, the phosphor of the present invention has the above formula (1)). In contrast, the present invention may have a non-stoichiometric composition (which may have a non-stoichiometric (non-chemical) stoichiometric composition).

  The crystal structure of the phosphor of the present invention can be confirmed by an X-ray diffraction method or the like.

The element A is (i) at least one element selected from the group consisting of Mg, Ca, Sr, La, Gd, Tb, Lu, and Y, and (ii) Ce. The cation of A (the cation of the element (i) and the cation of (ii) Ce) is in the 8-coordinate position and occupies a dodecahedron site (the site is also referred to as A site).

<Elements represented by (i)>
The element represented by the above (i) in A (at least one selected from the group consisting of Mg, Ca, Sr, La, Gd, Tb, Lu and Y) is one or more elements Can be used. When using at least one element selected from the group consisting of Mg, Ca and Sr as the element represented by (i) (the cation of the element is a divalent cation), From this point of view, it is necessary to use an element which becomes a tetravalent cation as C.

  Among the above elements (i), at least one element selected from the group consisting of Lu, Gd and Y is preferable, and Y is more preferable.

<(Ii) Ce element>
The cation Ce ³⁺ of Ce is an emission center and occupies the A site (decahedral site).

Ce ³⁺ has strong and broad absorption due to 4f-5d allowable transition and high luminous efficiency. Further, the Ce ³⁺ 5d level is reduced in energy by a centroid shift due to the electron cloud expansion effect, and is split into a plurality of levels in the host structure due to the influence of the crystal field. Here, FIG. 2 shows changes in the band structure depending on the composition of the garnet crystal structure. Since the phosphor of the present invention uses a garnet crystal structure as a host, the 5d orbit of Ce ³⁺ is split into five, and the split width depends on the garnet crystal composition. Therefore, as described above, it is possible to change the optical characteristics (light emission color) of Ce ³⁺ by changing the garnet crystal composition.

Among the above A, the ratio (molar ratio) between the element (i) and (ii) Ce element is as follows: (i) element: (ii) Ce element = 0.999: 0.0001-0.95: 0.05 (99.99: 0.01-95 : 5 (molar ratio (%))), preferably 0.995: 0.0005 to 0.99: 0.01 (99.95: 0.05 to 99: 1 (molar ratio (%))). Due to the fact that the molar ratio of the element (i) to the element (ii) Ce is within the above range, there is a disadvantage of concentration quenching caused by a decrease in the absorption intensity of excitation light due to a decrease in concentration or a concentration increase. Without generation, it is further excellent in long afterglow characteristics by ultraviolet excitation and blue light excitation. Note that the center wavelength of afterglow originating from Ce ³⁺ varies depending on the garnet crystal composition and is mainly in the range of 500 nm to 550 nm.

The B element B is at least one element selected from the group consisting of Al, Ga, Sc, In, Mg, Lu, and Y. The cation of B occupies a hexacoordinate octahedral site (the site is also referred to as B site). B can use 1 type, or 2 or more types of elements.

  Among B, at least one element selected from the group consisting of Al and Ga is preferable.

The C element C is at least one element selected from the group consisting of Si, Ge, Al, and Ga. The C cation is in a tetracoordinate position and occupies a tetrahedral site (the site is also referred to as a C site). C can use 1 type, or 2 or more types of elements. In the case of using at least one element selected from the group consisting of Si and Ge as C (the cation of the element is a tetravalent cation), from the viewpoint of electrical neutrality, It is necessary to use an element that becomes a divalent cation as the element to be represented.

  Among C, at least one element selected from the group consisting of Al and Ga is preferable, and Ga is more preferable.

Here, when both B and C are at least one element selected from the group consisting of Al and Ga (that is, the phosphor of the present invention has the following composition formula (2):
A ₃ (Al, Ga) ₂ (Al, Ga) ₃ O ₁₂ (2)
[A is the same as above. ]
The relationship between the number of moles of Ga / (total number of moles of B and C) and the afterglow characteristics due to blue light excitation in the case where the compound represented by the above formula is a phosphor in which the M element is doped) will be described. . When the phosphor of the present invention is irradiated with excitation light, Ce ³⁺ as an emission center is excited to an excitation level, and the excited electron returns to a level lower than the excitation level. A phenomenon in which energy is emitted as light when the excited electrons return to the level is light emission. On the other hand, after the electrons of Ce ³⁺ are trapped in an electron trap (where electrons can be temporarily stored), the electrons receive thermal energy of the temperature, and then jump out of the electron trap to return to the original Ce. ^The phenomenon of light emission when returning to ³⁺ is afterglow. Therefore, efficiently transporting the electrons of Ce ³⁺ to the electron trap leads to long-time persistence characteristics.

Therefore, (a) when the composition ratio (abundance ratio) of Ga in B and C is increased, the energy difference between the excited 3d level of Ce ³⁺ and the conduction band of the garnet base crystal is reduced, so that the above can be achieved more efficiently. Electrons can be transported to the electron trap. On the other hand, when the composition ratio of (b) Ga is reduced, the energy difference between the electron trap and the conduction band is increased, and the temperature exhibiting the strongest afterglow characteristic is shifted to the high temperature side. Therefore, considering the above (a) and (b), the Ga composition ratio in the phosphor of the present invention is set so that the number of moles of Ga / (total number of moles of B and C) is 0.5 to 0.8. It is preferable. When the number of moles of Ga / (total number of moles of B and C) is 0.6, Al occupies the B site (octahedral site) and Ga occupies the C site (tetrahedral site). When the number of moles of Ga / (total number of moles of B and C) is less than 0.6, the B site is occupied by Al and the C site is occupied by Ga and Al. When the number of moles of Ga / (total number of moles of B and C) exceeds 0.6, Ga and Al occupy the B site, and Ga occupies the C site.

Metal element M
The phosphor of the present invention is at least one metal selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Hf, Si, Yb, Eu, Pr and Tb. The element is doped. The metal element M newly forms the above-described electron trap as a co-doped ion. The said M element can use 1 type, or 2 or more types of the said metal element.

  Among the M elements, at least one selected from the group consisting of Cr, Ni, Fe, V, Yb and Si is preferable, and at least one selected from the group consisting of Cr, Ni, Yb and Si is more preferable, At least one selected from the group consisting of Cr and Yb is more preferable, and Cr is particularly preferable.

  The doping amount of the M element is preferably 0.001 to 5 mol%, more preferably 0.01 to 1 mol%, and further preferably 0.05 to 0.5 mol% with respect to the compound represented by the above formula (1). When the doping amount of the M element is within the above range, the afterglow intensity does not decrease, and the long afterglow characteristics due to ultraviolet excitation and blue light excitation are further improved.

Here, the example of the preferable aspect of the fluorescent substance of this invention is described. When using the phosphor of the present invention at room temperature,
Composition formula (1): A ₃ B ₂ C ₃ O ₁₂ (1)
[Wherein A is Y and Ce (molar ratio of Y and Ce is Y: Ce = 0.999: 0.0001 to 0.95: 0.05), B is at least one element selected from the group consisting of Al and Ga, C Is at least one element selected from the group consisting of Al and Ga, the number of moles of Ga / (total number of moles of B and C) is 0.5 to 0.8]
A phosphor in which 0.001 to 5 mol% of Cr is doped with respect to the compound (also referred to as a Cr co-doped phosphor) is preferable. The center wavelength of afterglow in this Cr co-doped phosphor is 510 nm corresponding to the center wavelength of afterglow originating from Ce ³⁺ from the garnet crystal composition of the phosphor and is easily visible to the human eye. Further, since Cr ³⁺ persists even in the vicinity of 700 nm, it is also useful as an afterglow phosphor for bioimaging.

When the phosphor of the present invention is used at a high temperature (eg, 50 to 80 ° C.)
Composition formula (1): A ₃ B ₂ C ₃ O ₁₂ (1)
[Wherein A is Y and Ce (molar ratio of Y and Ce is Y: Ce = 0.999: 0.0001 to 0.95: 0.05), B is at least one element selected from the group consisting of Al and Ga, C Is at least one element selected from the group consisting of Al and Ga, the number of moles of Ga / (total number of moles of B and C) is 0.5 to 0.8]
A phosphor in which 0.001 to 5 mol% of Ni is doped with respect to the compound (also referred to as Ni co-doped phosphor) is preferable. The center wavelength of afterglow in this Ni co-doped phosphor is 510 nm corresponding to the center wavelength of afterglow originating from Ce ³⁺ from the garnet crystal composition of the phosphor and is easily visible to the human eye.

When the phosphor of the present invention is used at a low temperature (eg, −60 to −30 ° C.),
Composition formula (1): A ₃ B ₂ C ₃ O ₁₂ (1)
[Wherein A is Y and Ce (molar ratio of Y and Ce is Y: Ce = 0.999: 0.0001 to 0.95: 0.05), B is at least one element selected from the group consisting of Al and Ga, C Is at least one element selected from the group consisting of Al and Ga, the number of moles of Ga / (total number of moles of B and C) is 0.5 to 0.8]
A phosphor in which 0.001 to 5 mol% Fe is doped with respect to the compound (also referred to as Fe co-doped phosphor) is preferable. The center wavelength of afterglow in this Fe co-doped phosphor is 510 nm corresponding to the center wavelength of afterglow originating from Ce ³⁺ from the garnet crystal composition of the phosphor, and is easily visible to the human eye.

In the present invention,
Composition formula (1): A ₃ B ₂ C ₃ O ₁₂ (1)
[Wherein A is Y and Ce (molar ratio of Y and Ce is Y: Ce = 0.999: 0.0001 to 0.95: 0.05), B is at least one element selected from the group consisting of Al and Ga, C Is at least one element selected from the group consisting of Al and Ga, the number of moles of Ga / (total number of moles of B and C) is 0.5 to 0.8]
A phosphor in which 0.001 to 5 mol% of Mn is doped with respect to the compound (also referred to as a Mn co-doped phosphor) is preferable. Since this Mn co-doped phosphor has an afterglow center wavelength originating from Mn ions at 700 nm, it is effective for application to bioimaging described later.

Material Form The state, shape, size and the like of the phosphor of the present invention are not particularly limited, and may be appropriately set according to the purpose of use. For example, the state includes single crystal, polycrystal (translucent ceramic), and the shape includes powder, pellets, and the like.

  When the phosphor of the present invention is a powder, the average particle size of the powder is preferably about 0.5 to 50 μm. As a method for measuring the average particle diameter, a known method may be adopted, and for example, a measuring method using an apparatus using a light scattering method may be mentioned.

  As described above, the crystal structure of the phosphor of the present invention may be either single crystal or polycrystal.

≪2. Method for producing phosphor of the present invention >>
The method for producing the phosphor of the present invention is not particularly limited. For example,
The following composition formula (1):
A ₃ B ₂ C ₃ O ₁₂ (1)
(Where
A is (i) at least one element selected from the group consisting of Mg, Ca, Sr, La, Gd, Tb, Lu, and Y, and (ii) Ce.
B is at least one element selected from the group consisting of Al, Ga, Sc, In, Mg, Lu, and Y;
C is at least one element selected from the group consisting of Si, Ge, Al, and Ga).
Fluorescence doped with at least one metal element selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Hf, Si, Yb, Eu, Pr, and Tb A method for manufacturing a body,
(1) Step 1 of preparing a composition containing the element-containing compound (i), B-element-containing compound, C-element-containing compound, Ce-containing compound, and the metal-element-containing compound;
(2) Step 2 of heating the composition at 1200 to 1800 ° C
Manufacturing method including, in order,
Is mentioned.

  Hereafter, each process of the said manufacturing method is demonstrated in detail.

Process 1
In step 1, as a raw material of the phosphor of the present invention, a composition comprising the element-containing compound (i), a B element-containing compound, a C element-containing compound, a Ce-containing compound and the metal element (M element) -containing compound ( Compound-containing composition) is prepared. Examples of the compound include oxides, hydroxides, halides (chlorides, fluorides, etc.), nitrates, oxalates, carbonates, sulfates, and the like. What is necessary is just to determine suitably the usage-amount of each compound other than the M element containing compound in the said composition so that the composition of the fluorescent substance finally obtained may satisfy the said composition formula (1). The amount of the M element-containing compound used may be appropriately determined according to the intended use or the like (Note that the amount of the M element-containing compound used is a compound in which the doping amount of the M element is represented by the above formula (1)). It is preferably used in an amount of 0.001 to 5 mol%, more preferably 0.01 to 1 mol%, still more preferably 0.05 to 0.5 mol%.

Specifically, in order to obtain a phosphor having a garnet structure of the present invention in which the compound represented by A ₃ B ₂ C ₃ O ₁₂ (1) is doped with M element, the compound represented by the above formula (1) is used. Determine the amount of the element-containing compound, B element-containing compound, C element-containing compound and Ce-containing compound of (i) so as to have a stoichiometric composition (according to the stoichiometric composition represented by the above formula (1)). Furthermore, the usage amount of the M element-containing compound is determined. After preparing the composition containing the said each compound, the fluorescent substance of this invention is obtained by heating (baking) the said composition at the following process 2. FIG. The obtained garnet structure in the phosphor of the present invention may have a solid solution region. In this case, lattice defects and antisite defects occur in the crystal, and a slight composition ratio deviation may occur with respect to the above formula (1) (that is, the phosphor of the present invention has the above formula (1)). On the other hand, it may have a non-stoichiometric composition), but a case having the non-stoichiometric composition is also within the scope of the present invention.

  Examples of the element-containing compound (i) include oxides, hydroxides, halides, nitrates, oxalates, carbonates and sulfates containing the element (i). The element-containing compound (i) can be used alone or in combination of two or more.

Examples of the oxide containing the element (i) include MgO, CaO, SrO, La ₂ O ₃ , Gd ₂ O ₃ , Tb ₄ O ₇ , Lu ₂ O ₃ , Y ₂ O _3, etc. The hydrate can also be used.

Examples of the hydroxide containing the element (i) include Mg (OH) ₂ , Ca (OH) ₂ , Sr (OH) ₂ , La (OH) ₃ , Gd (OH) ₃ , and Tb (OH) _3. , Lu (OH) ₃ , Y (OH) _{3 and the} like, and hydrates thereof can also be used.

Among the halides containing the element (i), examples of the chloride include MgCl ₂ , CaCl ₂ , SrCl ₂ , LaCl ₃ , GdCl ₃ , TbCl ₃ , LuCl ₃ , YCl _{3 and the} like. Japanese products can also be used.

Examples of the nitrate containing the element (i) include Mg (NO ₃ ) ₂ , Ca (NO ₃ ) ₂ , Sr (NO ₃ ) ₂ , La (NO ₃ ) ₃ , Gd (NO ₃ ) ₃ , Tb ( NO ₃ ) ₃ , Lu (NO ₃ ) ₃ , Y (NO ₃ ) _{3 and the} like, and hydrates thereof can also be used.

As the oxalate containing an element of _{(i), MgC 2 O 4} , CaC 2 O 4, SrC 2 O 4, La 2 (C 2 O 4) 3, Gd 2 (C 2 O 4) 3, _{Tb 2 (C 2 O 4)} 3, Lu 2 (C 2 O 4) 3, Y 2 (C 2 O 4) 3 and the like, it can also be used these hydrates.

Examples of the carbonate containing the element (i) include MgCO ₃ , CaCO ₃ , SrCO ₃ , La ₂ (CO ₃ ) ₃ , Gd ₂ (CO ₃ ) ₃ , Tb ₂ (CO ₃ ) ₃ , Lu ₂ ( _{CO 3) 3, Y 2 (} CO 3) 3 and the like, can also be used these hydrates. In addition, the carbonate includes a bicarbonate such as Ca (HCO ₃ ) ₂ .

Examples of the sulfate containing the element (i) include MgSO ₄ , CaSO ₄ , SrSO ₄ , La ₂ (SO ₄ ) ₃ , Gd ₂ (SO ₄ ) ₃ , Tb ₂ (SO ₄ ) ₃ , Lu ₂ ( _{SO 4) 3, Y 2 (} SO 4) 3 and the like, it can also be used these hydrates.

  Examples of the B element-containing compound include oxides, hydroxides, halides, nitrates, oxalates, carbonates and sulfates containing B element. The B element-containing compound can be used alone or in combination of two or more.

Examples of the oxide containing B element include Al ₂ O ₃ , Ga ₂ O ₃ , Sc ₂ O ₃ , In ₂ O ₃ , MgO, Lu ₂ O ₃ , Y ₂ O _{3, and the} like. Things can also be used.

As the hydroxide containing B element, Al (OH) ₃ , Ga (OH) ₃ , Sc (OH) ₃ , In (OH) ₃ , Mg (OH) ₂ , Lu (OH) ₃ , Y (OH) ₃ ), etc., and these hydrates can also be used.

Among the halides containing B element, examples of the chloride include AlCl ₃ , GaCl ₃ , ScCl ₃ , InCl ₃ , MgCl ₂ , LuCl ₃ , YCl _3, etc., and these hydrates may also be used. it can.

The nitrate containing B element includes Al (NO ₃ ) ₃ , Ga (NO ₃ ) ₃ , Sc (NO ₃ ) ₃ , In (NO ₃ ) ₃ , Mg (NO ₃ ) ₂ , and Lu (NO ₃ ) _3. , Y (NO ₃ ) _{3 and the} like, and these hydrates can also be used.

As the oxalate containing B element, Al ₂ (C ₂ O ₄ ) ₃ , Ga ₂ (C ₂ O ₄ ) ₃ , Sc ₂ (C ₂ O ₄ ) ₃ , In ₂ (C ₂ O ₄ ) ₃ MgC ₂ O ₄ , Lu ₂ (C ₂ O ₄ ) ₃ , Y ₂ (C ₂ O ₄ ) _{3 and the} like, and hydrates thereof can also be used.

Examples of the carbonate containing B element include Al ₂ (CO ₃ ) ₃ , Ga ₂ (CO ₃ ) ₃ , Sc ₂ (CO ₃ ) ₃ , In ₂ (CO ₃ ) ₃ , MgCO ₃ , Lu ₂ (CO ₃ ) ₃ , Y ₂ (CO ₃ ) _{3 and the} like, and hydrates thereof can also be used.

The sulfate containing B element includes Al ₂ (SO ₄ ) ₃ , Ga ₂ (SO ₄ ) ₃ , Sc ₂ (SO ₄ ) ₃ , In ₂ (SO ₄ ) ₃ , MgSO ₄ , Lu ₂ (SO ₄ ) ₃ , Y ₂ (SO ₄ ) _{3 and the} like, and these hydrates can also be used.

  Examples of the C element-containing compound include oxides, hydroxides, halides (chlorides, fluorides, etc.), nitrates, oxalates, carbonates, sulfates and the like containing C elements. The C element-containing compound can be used alone or in combination of two or more.

Examples of the oxide containing C element include SiO ₂ , GeO ₂ , Al ₂ O ₃ , and Ga ₂ O ₃ , and these hydrates can also be used.

Examples of the hydroxide containing C element include Si (OH) ₄ , Ge (OH) ₄ , Al (OH) ₃ , Ga (OH) _{3, and the} like, and these hydrates can also be used. .

Among the halides containing the C element, examples of the chloride include SiCl ₄ , GeCl ₄ , AlCl ₃ , GaCl _3, etc., and hydrates thereof can also be used.

Examples of nitrates containing C element include Si (NO ₃ ) ₄ , Ge (NO ₃ ) ₄ , Al (NO ₃ ) ₃ , Ga (NO ₃ ) ₃ , and the use of these hydrates. Can do.

Examples of the oxalate containing the C element include Si (C ₂ O ₄ ) ₂ , Ge (C ₂ O ₄ ) ₂ , Al ₂ (C ₂ O ₄ ) ₃ , Ga ₂ (C ₂ O ₄ ) _{3 and the} like. These hydrates can also be used.

Examples of the Ce-containing compound include Ce-containing oxides, hydroxides, halides (chlorides, fluorides, etc.), nitrates, oxalates, carbonates, sulfates, and the like. Specifically, CeO ₂ , Ce ₂ O ₃ , Ce (OH) ₃ , CeCl ₃ , Ce (NO ₃ ) ₃ , Ce ₂ (C ₂ O ₄ ) ₃ , Ce ₂ (CO ₃ ) ₃ , Ce ₂ ( SO ₄ ) ₃ , Ce (SO ₄ ) _{2 and the} like, and hydrates of these can also be used. The Ce-containing compound can be used alone or in combination of two or more.

  Examples of the metal element (M element) -containing compound include M as a metal component, such as a metal oxide, a metal hydroxide, a metal halide, a metal nitrate, a metal oxalate, a metal carbonate, and a metal sulfate. Compounds. A metal element containing compound (M element containing compound) can be used by 1 type or in combination of 2 or more types.

As the metal _{oxide, TiO 2, VO, V 2} O 3, VO 2, V 2 O 5, CrO, Cr 2 O 3, CrO 3, MnO, M 3 O 4, MnO 2, FeO, Fe 2 O 3 , Fe ₃ O ₄ , CoO, Co ₂ O ₃ , Co ₃ O ₄ , NiO, CuO, Cu ₂ O, ZnO, ZrO ₂ , HfO ₂ , SiO ₂ , Yb ₂ O ₃ , Eu ₂ O ₃ , Pr ₆ O ₁₁ , Tb ₂ O _{3 and the} like, and these hydrates can also be used.

As the metal hydroxide, TiO (OH) ₂ , V (OH) ₂ , Cr (OH) ₂ , Cr (OH) ₃ , Mn (OH) ₂ , Fe (OH) ₂ , FeO (OH) ₂ , Co (OH) ₂ , Ni (OH) ₂ , Cu (OH), Cu (OH) ₂ , Zn (OH) ₂ , Zr (OH) ₂ , Zr (OH) ₄ , Hf (OH) ₄ , Si (OH) ₄ , Yb (OH) ₃ , Eu (OH) ₂ , Eu (OH) ₃ , Pr (OH) ₃ , Tb (OH) _{3 and the} like, and these hydrates can also be used.

Examples of metal halides include TiCl ₃ , TiCl ₄ , VCl ₂ , VCl ₃ , VCl ₄ , VCl ₅ , CrCl ₂ , CrCl ₃ , MnCl ₂ , FeCl ₂ , FeCl ₃ , CoCl ₂ , NiCl ₂ , CuCl, CuCl ₂ , _{ZnCl 2, ZrCl 2, ZrCl 4} , HfCl 4, SiCl 3, Si 3 Cl 8, Si 4 Cl 10, Si 5 Cl 12, Si 6 Cl 12, YbCl 3, EuCl 3, PrCl 3, TbCl 3 , etc. of a metal chloride _{things; TiF 3, TiF 4, VF} 3, VF 4, VF 5, CrF 2, CrF 3, MnF 2, MnF 3, FeF 2, FeF 3, CoF 2, CoF 3, NiF 2, CuF, CuF 2, ZnF ₂ , ZrF ₄ , HfF ₄ , SiF ₄ , YbF ₃ , EuF ₃ , PrF ₃ , metal fluorides such as TbF ₃ ; and the like, and hydrates thereof can also be used.

Metal nitrates include Ti (NO ₃ ) ₄ , V (NO ₃ ) ₅ , Cr (NO ₃ ) ₃ , Mn (NO ₃ ) ₂ , Fe (NO ₃ ) ₂ , Fe (NO ₃ ) ₃ , Co (NO ₃ ) ₂ , Ni (NO ₃ ) ₂ , Cu (NO ₃ ) ₂ , Zn (NO ₃ ) ₂ , Zr (NO ₃ ) ₂ , Zr (NO ₃ ) ₄ , Hf (NO ₃ ) ₄ , Yb (NO ₃₎ ) ₃ , Eu (NO ₃ ) ₃ , Pr (NO ₃ ) ₃ , Tb (NO ₃ ) _{3 and the} like, and these hydrates can also be used.

As the metal oxalate, Ti (C ₂ O ₄ ) ₂ , V ₂ (C ₂ O ₄ ) ₅ , Cr ₂ (C ₂ O ₄ ) ₃ , Mn (C ₂ O ₄ ), Fe (C ₂ O ₄₎ ), Fe ₂ (C ₂ O ₄ ) ₃ , Fe ₃ (C ₂ O ₄ ) ₄ , Co (C ₂ O ₄ ), Co ₂ (C ₂ O ₄ ) ₃ , Co ₃ (C ₂ O ₄ ) ₄ , Ni (C ₂ O ₄ ), Cu (C ₂ O ₄ ), Cu ₂ (C ₂ O ₄ ), Zn (C ₂ O ₄ ), Zr (C ₂ O ₄ ) ₂ , Hf (C ₂ O ₄ ) ₂ Yb ₂ (C ₂ O ₄ ) ₃ , Eu ₂ (C ₂ O ₄ ) ₃ , Pr ₂ (C ₂ O ₄ ) ₃ , Tb ₂ (C ₂ O ₄ ) _{3 and the} like, and hydrates thereof Can also be used.

Examples of the metal carbonate include CrCO ₃ , MnCO ₃ , FeCO ₃ , CoCO ₃ , NiCO ₃ , Cu ₂ CO ₃ , ZnCO ₃ , ZrCO ₃ , Yb ₂ (CO ₃ ) ₃ , Eu ₂ (CO ₃ ) ₃ , Pr _{2. (CO 3) 3, Tb 2} (CO 3) 3 and the like, it can also be used these hydrates.

Metal _{sulfates, Ti (SO 4) 2,} V 2 (SO 4) 5, CrSO 4, MnSO 4, FeSO 4, CoSO 4, NiSO 4, CuSO 4, ZnSO 4, ZrSO 4, Zr (SO 4) ₂ , Yb ₂ (SO ₄ ) ₃ , Eu ₂ (SO ₄ ) ₃ , Pr ₂ (SO ₄ ) ₃ , Tb ₂ (SO ₄ ) _{3 and the} like, and these hydrates can also be used.

  You may grind | pulverize a compound containing composition as needed. Examples of the pulverization method include wet pulverization methods such as a medium stirring mill, colloid mill, and wet ball mill; dry pulverization methods such as a jet mill, a dry ball mill, and a roll crusher. In the wet pulverization method, water, an organic solvent (for example, methanol, ethanol, etc.) and the like are mixed with the compound-containing composition, and then each compound in the compound-containing composition can be pulverized. As the pulverization method, a plurality of pulverization methods may be used in combination.

  In addition, the compound-containing composition may be subjected to classification, chemical treatment, drying or the like as necessary.

  The compound-containing composition may contain a sintering aid. Examples of the sintering aid include boric acid, boron oxide, colloidal silica, and TEOS (tetraethyl orthosilicate).

Process 2
In step 2, the compound-containing composition prepared in step 1 is heated (baked) at 1200 to 1800 ° C.

In the calcination in step 2, the compound-containing composition is put into a crucible such as aluminum oxide or magnesium oxide and heated. The heating temperature is preferably 1500 to 1600 ° C. The heating time is preferably 3 hours to 24 hours. The atmosphere for heating may be any of an air atmosphere, a reducing atmosphere, and a vacuum atmosphere, but heating is preferably performed in a vacuum atmosphere. By heating the compound-containing composition in a vacuum atmosphere, Ce ⁴⁺ is easily reduced to Ce ³⁺ , oxygen defects are generated, and as a result, a phosphor with particularly excellent long afterglow characteristics is obtained.

  Before performing the heating in the step 2, if necessary, temporary baking may be performed. By performing the preliminary firing, evaporation of Ga can be prevented. As for the temperature at the time of temporary baking, 1000-1400 degreeC is preferable.

Other Steps In the present invention, after step 2, single crystallization, pulverization, water resistance treatment, etc. may be performed by the floating zone method.

  In the floating zone method, a polycrystalline sample rod is used as a raw material. In the floating zone method, a part of the sample rod is heated to create a melted portion between the lower single crystal that becomes the seed crystal and the sample rod, and the melt portion (in the melted portion) is subjected to surface tension. This is a method of cooling the melt part by moving the whole downward while supporting the melt. The heating method is not particularly limited, and examples include heating with a halogen lamp.

  As the pulverization, the same method as the pulverization method in the above step 1 may be mentioned.

  Examples of the water resistance treatment include a method of surface coating with an organic material or an inorganic material.

≪3. Application of phosphor of the present invention >>
The phosphor of the present invention can be applied to phosphorescent phosphors, white LEDs, phosphorescent ceramics, phosphorescent resins, phosphorescent paints, phosphorescent evacuation guidance systems, bioimaging and the like.

  As an application to a phosphorescent phosphor, it can be used as a green afterglow phosphor, a yellow afterglow phosphor, or the like under white LED illumination. Specifically, there are warning lights; clock dials; lighting for evacuation guidance when facilities lighting, guide lights, etc. cannot be used due to a power failure or the like.

  As an application to a white LED, the phosphor of the present invention is mounted on a white LED device to obtain a lighting device that shines faintly even after the light is turned off.

  As an application to the phosphorescent paint, it can be used as a visible luminous paint for a dial or an escape sign.

In application to bioimaging, the metal M ion (Cr ³⁺ , Mn ²⁺ , Mn ^4+, etc.) in the phosphor of the present invention is appropriately selected to show afterglow in the near infrared, and as a fluorescent marker A near infrared long afterglow phosphor is obtained. The near-infrared long afterglow phosphor has a wavelength that is well transmitted by cells of the human body, and furthermore, the excitation light for the image can be irradiated before the human body injection, thus preventing autofluorescence and scattering of the excitation light, As a result, an imaging image with less noise can be obtained.

  The phosphor of the present invention is excellent in long afterglow characteristics by ultraviolet excitation and long afterglow characteristics by blue light excitation because a specific metal element is doped in a specific garnet crystal phosphor containing Ce element. Excellent. In addition, the phosphor of the present invention emits green to red light (center wavelength is about 480 to 700 nm) by excitation by irradiation with excitation light such as ultraviolet rays and blue light, and particularly green to yellow (center wavelength is 480). (Approx. ~ 560nm) is prominent and is easily visible to the human eye. Therefore, the phosphor of the present invention can be applied to various uses (phosphorescent phosphor, white LED, phosphorescent ceramics, phosphorescent resin, phosphorescent paint, phosphorescent evacuation guidance system, bioimaging, etc.).

Composition formula (1) showing a garnet crystal structure: In A ₃ B ₂ C ₃ O ₁₂ , the above structure and occupied cations when A = Y, B = Al, and C = Ga are shown. A compositional formula (1) indicating a garnet crystal structure: In A ₃ B ₂ C ₃ O ₁₂ , a band structure change depending on a composition when A = Y, B = Al, and C = Ga is shown. 2 shows X-ray diffraction patterns (using CuKα rays) in the phosphors of Examples 2 and 3. FIG. Further, an X-ray diffraction pattern (using CuKα rays) of (Y _0.995 Ce _0.005 ) ₃ Al ₂ Ga ₃ O ₁₂ of Comparative Example 1 is shown. In addition, ▼ is literature data of Y ₃ Al ₂ Ga ₃ O ₁₂ . 2 shows a fluorescence excitation spectrum in Example 1. The excitation spectrum was measured using a fluorescence spectrophotometer (RF5300) manufactured by Shimadzu Corporation. The upper spectrum is an excitation spectrum obtained by monitoring Ce ³⁺ emission at 520 nm, and the lower spectrum is an excitation spectrum obtained by monitoring emission of Cr ³⁺ at 690 nm. It can be seen that both Ce ³⁺ emission and Cr ³⁺ emission can be efficiently excited by ultraviolet and blue light. The fluorescence spectrum and afterglow spectrum (after 5 minutes) in Example 1 are shown. This spectrum was measured by using a luminance measurement system manufactured by Konica Minolta Co., Ltd., using 460 nm obtained by spectrally separating a xenon lamp light source (MAX302) manufactured by Asahi Spectroscopy Co., Ltd. with a bandpass filter. Strong emission of Ce ³⁺ (520 nm) and Cr ³⁺ (700 nm) was observed in both emission and afterglow spectra. FIG. 10 shows an afterglow spectrum by ultraviolet storage in Example 17. FIG. Almost no afterglow of Ce ³⁺ was observed, and only 700m strong afterglow of Mn ions was observed. 2 shows a fluorescence excitation spectrum (λ _em = 505 nm) and an emission spectrum (λ _ex = 350 nm) of the phosphor of Comparative Example 1. In Comparative Example 1, only emission from 500 nm Ce ³⁺ was observed. The results of thermoluminescence measurements on the phosphors of Examples 1, 4, and 5 and Comparative Example 1 are shown. The thermoluminescence measurement result in the fluorescent substance of Example 1 and 3 is shown. For the phosphors of Examples 6 to 16, (a) under white LED illumination, (b) afterglow characteristics immediately after the UV lamp was interrupted (room temperature), (c) afterglow characteristics immediately after the white LED illumination was interrupted (room temperature), and ( d) A photograph showing the afterglow characteristics immediately after the white LED lighting is turned off (150 ° C). All the phosphors of Examples 6 to 16 exhibit afterglow after ultraviolet excitation and after blue light excitation by LED illumination. The thermoluminescence measurement result in the fluorescent substance of Example 18 is shown.

  The present invention will be specifically described below with reference to examples and comparative examples. However, the present invention is not limited to the examples.

Example 1
The following raw material powders and 30 ml of ethanol were mixed using a ball mill (product name premium line P-7, manufactured by Fritsch, manufactured by Fritsch Japan Ltd.) to obtain a mixture. Next, the mixture was calcined at 1200 ° C. for 6 hours using an electric furnace (product name KBF314N1, manufactured by Koyo Thermo System Co., Ltd.), and then further using an electric furnace (product name KBF314N1, manufactured by Koyo Thermo System Co., Ltd.). The main calcination was performed at 1600 ° C. for 24 hours. In addition, this baking was performed in the atmospheric condition. This makes the composition
(Y _0.995 Ce _0.005 ) ₃ Al ₂ Ga ₃ O ₁₂
[In the above formula (1), A is Y and Ce (molar ratio of Y and Ce is Y: Ce = 0.95: 0.005), B is Al, C is Ga, and the number of moles of Ga / (B (Al) The phosphor of Example 1 was obtained in which Cr was doped into the compound represented by 0.6]. The doping amount of Cr was 0.1 mol% with respect to the compound.
<Each raw material powder used>
-CeO ₂ (Furuuchi Chemical Co., Ltd.): 0.0357g
・ Y ₂ O ₃ (Mitsuwa Chemical Co., Ltd.): 4.6633g
・ Al ₂ O ₃ (Mitsuwa Chemical Co., Ltd.): 1.4107g
・ Ga ₂ O ₃ (Mitsuwa Chemical Co., Ltd.): 3.8902g
_{· Cr (NO 3) 3 ·} 9H 2 O ( manufactured by STREM CHEMICALS): 0.0028g.

The excitation spectrum of the phosphor of Example 1 was measured using a fluorescence spectrophotometer (RF5300) manufactured by Shimadzu Corporation. FIG. 4 shows the fluorescence excitation spectrum in Example 1. FIG. 4 shows that both Ce ³⁺ emission and Cr ³⁺ emission can be efficiently excited by ultraviolet and blue light.

Further, the fluorescence spectrum and afterglow spectrum of the phosphor of Example 1 were measured. 460 nm obtained by spectrally separating a xenon lamp light source (MAX302) manufactured by Asahi Spectroscopic Co., Ltd. with a bandpass filter was used as an excitation light source, and emission and afterglow spectra were measured using a luminance measurement system manufactured by Konica Minolta. FIG. 5 shows the fluorescence spectrum and afterglow spectrum (after 5 minutes) in Example 1. Strong emission of Ce ³⁺ (520 nm) and Cr ³⁺ (700 nm) was observed in both emission and afterglow spectra.

Example 2
Except for performing the main baking in a vacuum atmosphere using a vacuum electric furnace (product name VF-1800, manufactured by Crystal Systems Co., Ltd.), the composition is as follows:
(Y _0.995 Ce _0.005 ) ₃ Al ₂ Ga ₃ O ₁₂
[In the above formula (1), A is Y and Ce (molar ratio of Y and Ce is Y: Ce = 0.95: 0.005), B is Al, C is Ga, and the number of moles of Ga / (B (Al) A phosphor of Example 2 was obtained in which Cr was doped into a compound represented by 0.6].

  An X-ray diffraction pattern (using CuKα rays) in the phosphor of Example 2 is shown in FIG.

Example 3
The following raw material powders and 30 ml of ethanol were mixed using a ball mill (product name premium line P-7, manufactured by Fritsch, manufactured by Fritsch Japan Ltd.) to obtain a mixture. Next, the mixture was calcined at 1200 ° C. for 6 hours using an electric furnace (product name KBF314N1, manufactured by Koyo Thermo Systems Co., Ltd.), and then a vacuum tubular electric furnace (product name VF-1800, manufactured by Crystal Systems Co., Ltd.). ) And then calcined at 1600 ° C. for 24 hours. The main firing was performed in a vacuum atmosphere. This makes the composition
(Y _0.995 Ce _0.005 ) ₃ Al ₂ (Al _1/6 Ga _5/6 ) ₃ O ₁₂
[In the above formula (1), A is Y and Ce (molar ratio of Y and Ce is Y: Ce = 0.95: 0.005), B is Al, C is Al and Ga (molar ratio of Al and Ga is , Al: Ga = (1/6) :( 5/6)], a phosphor of Example 3 was obtained in which Cr was doped with Cr. The phosphor had a composition of 0.1 mol%.
(Y _0.995 Ce _0.005 ) ₃ Al _2.5 Ga _2.5 O ₁₂
[Number of moles of Ga / (total number of moles of B (Al) and C (Al and Ga)) is 0.5]
It can also be said that the compound represented by is a phosphor in which Cr is doped by 0.1 mol%.
<Each raw material powder used>
・ CeO ₂ (Furuuchi Chemical Co., Ltd.): 0.0368g
・ Y ₂ O ₃ (Mitsuwa Chemical Co., Ltd.): 4.8054 g
・ Al ₂ O ₃ (Mitsuwa Chemical Co., Ltd.): 1.8172g
・ Ga ₂ O ₃ (Mitsuwa Chemical Co., Ltd.): 3.3406g
_{· Cr (NO 3) 3 ·} 9H 2 O ( Mizuno made sum Pure Chemicals Co., Ltd.): 0.0055g.

  The X-ray diffraction pattern (using CuKα rays) in the phosphor of Example 3 is shown in FIG.

Example 4
Using the following raw material powders, the composition is the same as in Example 1 except that the main baking is performed at 1600 ° C. for 12 hours.
(Y _0.995 Ce _0.005 ) ₃ Al ₂ Ga ₃ O ₁₂
[In the above formula (1), A is Y and Ce (molar ratio of Y and Ce is Y: Ce = 0.95: 0.005), B is Al, C is Ga, and the number of moles of Ga / (B (Al) The phosphor of Example 4 was obtained by doping Ni into a compound having a total number of moles of C and Ga (Ga) of 0.6]. The doping amount of Ni was 0.3 mol% with respect to the compound.
<Each raw material powder used>
・ CeO ₂ (Furuuchi Chemical Co., Ltd.): 0.03572g
・ Y ₂ O ₃ (Mitsuwa Chemical Co., Ltd.): 4.6633g
・ Al ₂ O ₃ (Mitsuwa Chemical Co., Ltd.): 1.4107g
・ Ga ₂ O ₃ (Mitsuwa Chemical Co., Ltd.): 3.8902g
_{· Ni (NO 3) 2 ·} 6H 2 O ( manufactured by Wako Pure Chemical Industries, Ltd.): 0.0121g.

Example 5
Except for using the following raw material powder, in the same manner as in Example 4, the composition is
(Y _0.995 Ce _0.005 ) ₃ Al ₂ Ga ₃ O ₁₂
[In the above formula (1), A is Y and Ce (molar ratio of Y and Ce is Y: Ce = 0.95: 0.005), B is Al, C is Ga, and the number of moles of Ga / (B (Al) The phosphor of Example 5 was obtained by doping Fe into a compound having a total number of moles of C and Ga (Ga) of 0.6]. The amount of Fe doped was 0.3 mol% with respect to the compound.
<Each raw material powder used>
・ CeO ₂ (Furuuchi Chemical Co., Ltd.): 0.03572g
・ Y ₂ O ₃ (Mitsuwa Chemical Co., Ltd.): 4.6633g
・ Al ₂ O ₃ (Mitsuwa Chemical Co., Ltd.): 1.4107g
・ Ga ₂ O ₃ (Mitsuwa Chemical Co., Ltd.): 3.8902g
_{· Fe 2 (SO 4) 3} · nH 2 O (n = 6~9) ( manufactured by Wako Pure Chemical Industries, Ltd.): 0.0113g.

Examples 6-16
Using the following raw material powders, the composition is the same as in Example 1 except that the main baking is performed at 1600 ° C. for 6 hours.
(Y _0.995 Ce _0.005 ) ₃ Al ₂ Ga ₃ O ₁₂
[In the above formula (1), A is Y and Ce (molar ratio of Y and Ce is Y: Ce = 0.95: 0.005), B is Al, C is Ga, and the number of moles of Ga / (B (Al) Example 6 in which Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, or Hf was doped as a metal element M to a compound having a total number of moles of C and Ga (Ga) of 0.6] ˜16 phosphors were obtained. In addition, the dope amount of each metal element M in Examples 6-16 was 0.1 mol% with respect to the said compound.
<Each raw material powder used>
・ CeO ₂ (Furuuchi Chemical Co., Ltd.): 0.03572g
・ Y ₂ O ₃ (Mitsuwa Chemical Co., Ltd.): 4.6633g
・ Al ₂ O ₃ (Mitsuwa Chemical Co., Ltd.): 1.4107g
・ Ga ₂ O ₃ (Mitsuwa Chemical Co., Ltd.): 3.8902g
TiCl ₃ (manufactured by Wako Pure Chemical Industries, Ltd.): 0.0021 g (used in Example 6).
V ₂ O ₅ (manufactured by Aldrich): 0.0010 g (used in Example 7).
_{· Cr (NO 3) 3 ·} 9H 2 O ( manufactured by STREM CHEMICALS, Ltd.): 0.0055 g (used in Example 8).
· MnCO ₃ (manufactured by Wako Pure Chemical Industries, Ltd.): 0.0016g (used in Example 9).
_{· Fe 2 (SO 4) 3} · nH 2 O (n = 6~9) ( manufactured by Wako Pure Chemical Industries, Ltd.): 0.0038 g (used in Example 10).
CoCl ₂ (Mitsuwa Chemical Co., Ltd.): 0.0018 g (used in Example 11).
_{· Ni (NO 3) 2 ·} 6H 2 O ( Wako Pure Chemical Industries, Ltd.): 0.0040 g (used in Example 12).
CuCl ₂ (Mitsuwa Chemical Co., Ltd.): 0.0035 g (used in Example 13).
_{· Zn (NO 3) 2 ·} 6H 2 O ( Wako Pure Chemical Industries, Ltd.): 0.0050 g (used in Example 14).
ZrF ₄ (manufactured by Aldrich): 0.0023 g (used in Example 15).
HfCl ₄ (Wako Pure Chemical Industries, Ltd.): 0.0044 g (used in Example 16).

Example 17
The following raw material powders and 30 ml of ethanol were mixed using a ball mill (product name premium line P-7, manufactured by Fritsch, manufactured by Fritsch Japan Ltd.) to obtain a mixture. The mixture was then fired for 24 hours in a tubular electric furnace (product name VF-1800, manufactured by Crystal Systems Co., Ltd.) in an N2-H2 (5%) atmosphere. This makes the composition
(Y _0.995 Ce _0.005 ) ₃ Sc ₂ Ga ₃ O ₁₂
[In the above formula (1), A is Y and Ce (molar ratio of Y and Ce is Y: Ce = 0.95: 0.005), B is Sc, C is Ga, and the number of moles of Ga / (B (Sc) A phosphor of Example 17 was obtained in which Mn was doped into the compound represented by the formula [No. The doping amount of Mn was 0.5 mol% with respect to the compound.
<Each raw material powder used>
・ CeO ₂ (Furuuchi Chemical Co., Ltd.): 0.0340g
・ Y ₂ O ₃ (Mitsuwa Chemical Co., Ltd.): 4.4422g
・ Sc ₂ O ₃ (Mitsuwa Chemical Co., Ltd.): 1.8177g
・ Ga ₂ O ₃ (Mitsuwa Chemical Co., Ltd.): 3.7059g
· MnCO ₃ (manufactured by Wako Pure Chemical Industries, Ltd.): 0.0080g.

FIG. 6 shows an afterglow spectrum by ultraviolet storage in Example 17. Almost no afterglow of Ce ³⁺ was observed, and only 700m strong afterglow of Mn ions was observed.

Example 18
The following raw material powders and 30 ml of ethanol were mixed using a ball mill (product name premium line P-7, manufactured by Fritsch, manufactured by Fritsch Japan Ltd.) to obtain a mixture. Subsequently, the mixture was fired at 1600 ° C. for 12 hours using an electric furnace (product name KBF314N1, manufactured by Koyo Thermo System Co., Ltd.). The firing was performed in a vacuum atmosphere. This makes the composition
(Y _0.995 Ce _0.005 ) ₃ (Al _3/4 Ga _1/4 ) ₂ Ga ₃ O ₁₂
[In the above formula (1), A is Y and Ce (Y: Ce molar ratio is Y: Ce = 0.95: 0.005), B is Al and Ga (Al: Ga molar ratio is Al: Ga = (3/4) :( 1/4)), the phosphor of Example 18 was obtained by doping Yb with the compound represented by C = Ga]. The doping amount of Yb was 0.15 mol% with respect to the compound. The phosphor has a composition of
(Y _0.995 Ce _0.005 ) ₃ Al _1.5 Ga _3.5 O ₁₂
[Number of moles of Ga / (total number of moles of B (Al and Ga) and C (Ga)) is 0.7]
It can also be said that the compound represented by the formula is a phosphor in which 0.15 mol% of Yb is doped.
<Each raw material powder used>
・ CeO ₂ (Furuuchi Chemical Co., Ltd.): 0.035g
・ Y ₂ O ₃ (Mitsuwa Chemical Co., Ltd.): 4.5294g
・ Al ₂ O ₃ (Mitsuwa Chemical Co., Ltd.): 1.0277g
・ Ga ₂ O ₃ (Mitsuwa Chemical Co., Ltd.): 4.4082 g
· _Yb 2 _{O 3} (manufactured by Mitsuwa Chemicals Co., Ltd.): 0.004g.

Comparative Example 1
Except for using the following raw material powders, the composition is the same as in Example 1,
(Y _0.995 Ce _0.005 ) ₃ Al ₂ Ga ₃ O ₁₂
[In the above formula (1), A is Y and Ce (molar ratio of Y and Ce is Y: Ce = 0.95: 0.005), B is Al, C is Ga, and the number of moles of Ga / (B (Al) A phosphor of Comparative Example 1 having a total number of moles of C and Ga (Ga) of 0.6] was obtained.
<Each raw material powder used>
・ CeO ₂ (Furuuchi Chemical Co., Ltd.): 0.03572g
・ Y ₂ O ₃ (Mitsuwa Chemical Co., Ltd.): 4.6633g
・ Al ₂ O ₃ (Mitsuwa Chemical Co., Ltd.): 1.4107g
· _Ga 2 _{O 3} (manufactured by Mitsuwa Chemicals Co., Ltd.): 3.8902g.

  The X-ray diffraction pattern (using CuKα rays) in the phosphor of Comparative Example 1 is shown in FIG.

Further, the fluorescence excitation spectrum (λ _em = 505 nm) and the emission spectrum (λ _ex = 350 nm) in the phosphor of Comparative Example 1 are shown in FIG. In Comparative Example 1, only emission from 500 nm Ce ³⁺ was observed.

Reference example 1
A phosphor of SrAl ₂ O ₄ : Eu ²⁺ -Dy ³⁺ (GLL-300FFS, manufactured by Nemoto Special Chemical Co., Ltd.) was prepared.

Test example 1 (Thermoluminescence measurement)
The phosphors obtained in Examples 1, 3 to 5 and 18, and Comparative Example 1 were formed into pellets. Specifically, the above phosphors were compression molded at 50 MPa using a pellet molding machine (product name NT-50H, manufactured by Sansho Industry Co., Ltd.) to form pellets having a diameter of 10 mm and a thickness of 2 mm. .

Next, thermoluminescence measurement was performed on each phosphor. Specifically, each sample was irradiated with excitation light (ultraviolet light of 250 nm to 400 nm), and after the irradiation was cut off, the emission luminance was measured while raising the temperature of each sample from 100K. This measurement makes it possible to observe at which temperature each sample has the best afterglow characteristics.
<Each condition of Test Example 1>
・ Cryostat: Product name: Helitran, Advanced Research Systems Co., Ltd. ・ Excitation light source: Product name: MAX302 Asahi Spectrometer Co., Ltd. ・ PMT detector: Product name: R3896, Hamamatsu Photonics Co., Ltd. ・ Excitation light irradiation time: 10 minutes Temperature rate: 10 ℃ / min
The results are shown in FIGS. 8, 9 and 11 below.

(Discussion)
As is clear from FIG. 8, a large peak was observed around 300K in the phosphor of Example 1 (doped M element: Cr). Further, in the phosphor of Example 4 (doped M element: Ni), a broad peak was observed in the range of 300 to 450K. Further, in the phosphor of Example 5 (doped M element: Fe), peaks were observed in the vicinity of 200K and 300K. As is clear from FIG. 11, a large peak was observed around 300K in the phosphor of Example 18 (doped M element: Yb). Therefore, all of Examples 1, 4, 5, and 18 have an electron trap that can be released near 300 K (that is, near room temperature), and it has been clarified that it works advantageously on long afterglow characteristics.

  As is apparent from FIG. 9, the phosphor of Example 1 (doped M element: Cr, B in the above formula (1) is Al, C in the above formula (1) is Ga, and the moles of Ga. Number / (total number of moles of B and C) is 0.6), whereas a large peak was observed around 300K, whereas the phosphor of Example 3 (doped M element: Cr, the above formula (1)) A large peak was observed in the vicinity of 330K, with B in Al and C in the above formula (1) being Al and Ga, the number of moles of Ga / (total number of moles of B and C) being 0.5). Therefore, by reducing the number of moles of Ga / (the total number of moles of B and C) (the mole ratio of Ga to the total number of moles of B and C), the glow peak can be shifted to the high temperature side. It was revealed that the initial intensity and afterglow duration at room temperature can be set as appropriate. 9, the electron trap depth of the phosphor of Example 1 was estimated to be 0.59 eV, and the electron trap depth of the phosphor of Example 3 was estimated to be 0.65 eV.

Test example 2 (Measurement of afterglow luminance after ultraviolet light irradiation)
The phosphors obtained in Examples 1 to 3, Comparative Example 1 and Reference Example 1 were formed into pellets having a diameter of 10 mm and a thickness of 2 mm by the same method as in Test Example 1. Next, excitation light (ultraviolet light 360 nm) was irradiated to each of the above-mentioned pellet-shaped phosphors, and afterglow luminance was measured 5 minutes, 20 minutes, and 1 hour after the irradiation was cut off. In addition, a shutter was placed in front of the detector for baseline measurement, and the shutter was closed after 120 minutes.
<Each condition of Test Example 2>
・ Excitation light source: Product name MAX302 Asahi Spectroscopic Co., Ltd. + 360nm bandpass filter ・ Afterglow luminance measuring device: Product name Luminance measurement system, manufactured by Konica Minolta ・ Excitation light irradiation time: 5 minutes ・ Baseline measurement: 120 minutes Rear, temperature: 25 ℃

Test example 3 (Measurement of afterglow luminance after blue light irradiation)
Except for irradiating blue light (460 nm) instead of ultraviolet light (360 nm) as excitation light, the afterglow luminance of each of the above-mentioned pellet-shaped phosphors (blocking blue light irradiation was interrupted) in the same manner as in Test Example 2. The afterglow brightness after 5 minutes, 20 minutes and 1 hour was measured.

  The results of Test Examples 2 and 3 are shown in Table 1 below.

(Discussion)
As is clear from the above results, the phosphors of Examples 1 to 3 are excellent in long afterglow characteristics due to ultraviolet light excitation and also excellent in long afterglow characteristics due to blue light excitation. In particular, it can be seen that the phosphors of Examples 1 to 3 have a very high afterglow luminance after one hour after blocking the excitation by blue light as compared with Reference Example 1. This is due to the generation of electron traps by co-doped ions (M) and the translucency of the sample. Blue light (460 nm) is an emission wavelength of a general-purpose InGaN blue LED, and is generally used for a white LED realized by a blue LED + yellow phosphor, and is therefore optimal as an excitation wavelength of blue light.

Test Example 4 (Afterglow decay curve evaluation after blue light irradiation)
The phosphors obtained in Examples 1 to 3 were pelletized by the same method as in Test Example 1. Next, each pellet-like phosphor was irradiated with excitation light (blue light 460 nm), and afterglow decay curves of each pellet-like phosphor after the irradiation was cut off were measured. From the afterglow decay curve, a time (afterglow time) when the afterglow luminance was less than 2 mcd / m ² was obtained.
<Each condition of Test Example 4>
Excitation light source: Product name MAX302 Asahi Spectral Co., Ltd. + 460nm bandpass filter ・ Afterglow luminance measurement device: Product name Luminance measurement system, manufactured by Konica Minolta Co., Ltd. ・ Excitation light irradiation time: 5 minutes ・ Baseline measurement: 120 minutes Rear, temperature: 25 ℃
As a result, the afterglow time in Example 1 was 265 minutes, the afterglow time in Example 2 was 485 minutes, and the afterglow time in Example 3 was 792 minutes, both of which have excellent long afterglow characteristics due to blue light excitation. It was shown that

Test Example 5 (Afterglow characteristics evaluation after ultraviolet light irradiation)
The phosphors obtained in Examples 6 to 16 and Comparative Example 1 were formed into pellets having a diameter of 10 mm and a thickness of 2 mm by the same method as in Test Example 1. Next, excitation light (ultraviolet light 360 nm) was irradiated to each of the above-mentioned pellet-shaped phosphors, and afterglow characteristics (light storage characteristics) of each phosphor immediately after the irradiation was cut off were visually evaluated. The evaluation criteria are as follows. The afterglow characteristics due to ultraviolet excitation of the phosphors obtained in Examples 6 to 16 are shown in FIG. 10 below.
<Evaluation criteria>
A: Excellent afterglow brightness as compared with the phosphor of Comparative Example 1.
○: The afterglow brightness is superior to the phosphor of Comparative Example 1.
Δ: Afterglow luminance is equivalent to that of the phosphor of Comparative Example 1.
X: The afterglow brightness is inferior to the phosphor of Comparative Example 1.
<Each condition of Test Example 5>
・ Ultraviolet light irradiation device (ultraviolet lamp): Product name FL10BLB manufactured by Toshiba ・ Excitation light irradiation time: 5 minutes ・ Air temperature: Room temperature (25 ℃)
From FIG. 10, it can be seen that the phosphors of Examples 6 to 16 exhibit afterglow after ultraviolet excitation and after blue light excitation by LED illumination.

Test Example 6 (Evaluation of afterglow characteristics after blue light irradiation)
The afterglow characteristics (phosphorescence characteristics) of each of the above-mentioned pellet-shaped phosphors are the same as in Test Example 5, except that a white LED containing blue light (460 nm) is used instead of ultraviolet light (360 nm) as excitation light. Was visually evaluated. The evaluation criteria are the same as in Test Example 5.

The results of Test Examples 5 and 6 are shown in Table 2 below.
<Each condition of Test Example 6>
・ Excitation light irradiation time: 5 minutes ・ Air temperature: Room temperature (25 ℃) and 150 ℃

(Discussion)
As is clear from the above results, the phosphors of Examples 6 to 16 are excellent in long afterglow characteristics due to ultraviolet light excitation and also excellent in long afterglow characteristics due to blue light excitation.

Claims (5)

The following composition formula (1):
A ₃ B ₂ C ₃ O ₁₂ (1)
(Where
A is (i) at least one element selected from the group consisting of Mg, Ca, Sr, La, Gd, Tb, Lu, and Y, and (ii) Ce.
B is at least one element selected from the group consisting of Al, Ga, Sc, In, Mg, Lu, and Y;
C is at least one element selected from the group consisting of Si, Ge, Al, and Ga).
At least one metal element selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Hf, Si, Yb, Eu, Pr, and Tb is doped. A phosphor characterized by.   The phosphor according to claim 1, wherein a doping amount of the metal element is 0.001 to 5 mol% with respect to the compound represented by the formula (1).   The phosphor according to claim 1 or 2, wherein a molar ratio of the element (i) to the (ii) Ce is 0.9999: 0.0001 to 0.95: 0.05.   The phosphor according to any one of claims 1 to 3, which is used for a phosphorescent phosphor, a white LED, a phosphorescent ceramic, a phosphorescent resin, a phosphorescent paint, a phosphorescent evacuation guidance system, or a bioimaging marker. The following composition formula (1):
A ₃ B ₂ C ₃ O ₁₂ (1)
(Where
A is (i) at least one element selected from the group consisting of Mg, Ca, Sr, La, Gd, Tb, Lu, and Y, and (ii) Ce.
B is at least one element selected from the group consisting of Al, Ga, Sc, In, Mg, Lu, and Y;
C is at least one element selected from the group consisting of Si, Ge, Al, and Ga).
Fluorescence doped with at least one metal element selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Hf, Si, Yb, Eu, Pr, and Tb A method for manufacturing a body,
(1) Step 1 of preparing a composition containing the element-containing compound (i), B-element-containing compound, C-element-containing compound, Ce-containing compound, and the metal-element-containing compound;
(2) Step 2 of heating the composition at 1200 to 1800 ° C
In order.

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