JP3445473B2 - Phosphor and phosphor film - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a phosphor and a phosphor film , and more particularly to a spherical rare earth phosphor and a fluorescence containing the same.
Regarding the membrane .

[0002]

2. Description of the Related Art Phosphors used in displays such as cathode ray tubes and plasma displays, or fluorescent lamps emit light when excited by electron beams or ultraviolet rays, and particularly have high luminous efficiency when the particle size is about several μm. Is said to be obtained. A phosphor having such a particle size is usually manufactured by using a solid phase reaction using a flux. However, the shape is a polyhedral shape having low symmetry, reflecting the shape of the raw material particles and the crystal structure of the phosphor particles.

Therefore, when such a polyhedral phosphor is used to form a phosphor film of a cathode ray tube, for example, many voids exist between phosphor particles, and a high packing density cannot be obtained. . Further, since the smoothness of the surface of the fluorescent film is deteriorated, the smoothness of the aluminum back which is the light reflecting film is also deteriorated. Therefore, when the fluorescent film of the cathode ray tube is formed by using a polyhedral fluorescent material, diffuse reflection of emitted light occurs, resulting in a decrease in output light intensity and an increase in spot diameter.

Even in the case of a plasma display panel, since a thin fluorescent film cannot be obtained, the discharge space is narrowed and the luminous efficiency is reduced.

Such a phenomenon also applies to fluorescent lamps. Therefore, it is desired that a fluorescent film can be formed with a high packing density in a phosphor used in a display such as a cathode ray tube or a plasma display, or a fluorescent lamp.

In response to the above demand, Japanese Patent Laid-Open No. 20198/1990
No. 9 (Japanese Patent Publication No. 7-45655) describes heating a phosphor material in high-frequency thermal plasma to obtain a spherical phosphor. Since the phosphor formed by this method has a spherical shape, it is possible to form a phosphor film having a high packing density. Therefore, when the fluorescent film of the projection tube is formed using this spherical phosphor,
The fluorescent film can be thinned, and the spot diameter of the emitted light can be reduced to some extent as compared with the case where a polyhedral fluorescent material is used.

However, since the phosphor particles have extremely low light-scattering properties, the components of the emitted light in the in-plane direction of the phosphor film are hardly scattered and proceed. As a result, in the case of the projection tube, the spot diameter cannot be sufficiently reduced, and the resolution cannot be significantly increased. In the case of a plasma display, when the phosphor particles having a small specific surface area are used, the absorption efficiency of vacuum ultraviolet rays is small and the light emission efficiency is lowered.

Other spherical phosphors include:
It is known that tens of thousands of primary particles are spherically aggregated by a wet method. However, such a phosphor has a large number of primary particle-particle interfaces in the phosphor particles, and therefore the luminous efficiency is extremely low. Further, when heat treatment is performed to improve this, the aggregated primary particles are separated from each other, so that the shape of the phosphor particles cannot be kept spherical. Therefore, with such a phosphor in which primary particles are aggregated, the packing density of the phosphor film cannot be increased, and a phosphor film having sufficient emission efficiency of emission and capable of reducing the spot diameter is provided. It cannot be formed.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a fluorescent film having a sufficient emission efficiency and a small spot diameter, and a fluorescent film formed therewith . It is an object of the present invention to provide a phosphor that can be manufactured.

[0010]

The present invention provides 10,000
The unevenness that can be observed in the SEM photograph taken at double magnification is displayed.
The spherical surface has a spherical shape with a ratio of major axis to minor axis in the range of 1 to 1.3, and is 1.01 to 1.5 times the surface area of a sphere having the same volume. It is composed of particles having a surface area and has a composition formula Ln ₃ M ₅ O ₁₂ : R or Ln ₂
Provided is a phosphor having a chemical composition represented by SiO ₅ : R. (In the formula, Ln is Sc, Y, Gd,
At least one element selected from La and Lu, M
Is at least one element selected from Al and Ga, R
Indicates at least one element selected from Cr, Ti, Fe, and elements of the lanthanide group. ) The present invention is
The unevenness is formed, and the ratio of the major axis to the minor axis is 1 to 1.3.
A table of spheres that have a spherical shape in the range and have the same volume.
Has a surface area of 1.01 to 1.5 times the area
Of the composition formula Ln ₃ M ₅ O ₁₂ : R or Ln
₂ SiO ₅ : R having the chemical composition shown in R and having the concave and convex portions.
The maximum depth of the particles is 10 nm or more, and the particles are
Is less than 20% of the diameter of the sphere circumscribing to
To provide a phosphor. (In the formula, Ln is Sc, Y, Gd,
At least one element selected from La and Lu, M
Is at least one element selected from Al and Ga, R
Is selected from Cr, Ti, Fe, and lanthanide elements
At least one element is shown. ) The present invention is
It has a spherical shape with irregularities and has the same volume
1.01 to 1.5 times the surface area of the sphere
And has a composition formula Ln ₃ M ₅ O ₁₂ : R
Has the chemical composition shown in Ln ₂ SiO ₅ : R,
The maximum value of the depth of the concave portion is 10 nm or more, and
The diameter is 20% or less of the sphere circumscribing the particles.
Provide a fluorescent substance as a characteristic. (In the formula, Ln is Sc, Y,
At least one element selected from Gd, La, and Lu
Element, M is at least one element selected from Al and Ga
Elementary, R is Cr, Ti, Fe, or lanthanide element
At least one element selected from the following is shown. )

The present invention provides the phosphor described above, wherein 0.11
It 0 cm ² / mg free and having a light scattering coefficient of 0.180 cm ² / mg. The present invention also provides the above firefly.
Provided is a phosphor film including a light body.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail below.

The phosphor of the present invention has the composition formula Ln ₃ M
_It has a chemical composition of ₅ O ₁₂ : R or Ln ₂ SiO ₅ : R. In these composition formulas, Ln is Sc, Y,
At least one element selected from Gd, La, and Lu is shown, and M is at least 1 selected from Al and Ga.
The elements of the species are shown. Therefore, Ln and M may each be a single element or may contain a plurality of types of elements.

In the above composition formula, R is Cr, T
i, Fe, and at least one element selected from lanthanide group elements. R may be a single element or may include a plurality of types of elements. Also, R is
Usually, the phosphor particles contain 0.1% by weight to 10% by weight.

In the phosphor of the present invention composed of the above-mentioned elements, the combination of these elements is not particularly limited, but R, Ce, Pr, Nd, Sm, Eu, Tb,
When elements such as Dy, Ho, Er, Tm, and Yb are used, high brightness can be obtained, and in particular, the composition formula Y ₂ Si is used.
When the chemical composition is O ₅ : Tb, Y ₃ (Al, Ga) ₅ O ₁₂ : Tb, etc., the highest brightness can be obtained in a projection tube, for example.

The shape of the phosphor of the present invention will be described below.

The phosphor of the present invention is 0.2 μm to 10 μm.
Have an average particle size within the range of. Average particle size 0.2μ
If it is less than m, sufficient powder brightness cannot be obtained and 1
If it exceeds 0 μm, fine display cannot be performed.

Further, the phosphor of the present invention has a spherical shape in which irregularities are formed on the surface and the ratio of the major axis to the minor axis is in the range of 1 to 1.3. The concavo-convex here is a groove-shaped, crater-shaped, well-shaped recessed portion, or a terrace-shaped, hill-shaped, mountain-shaped protruding portion, or the like. That is, those that reduce the packing density of the phosphor film, such as columnar, granular, or protrusions such as edge portions that significantly reduce the spherical property of the phosphor particles, are excluded. Therefore, the phosphor of the present invention is
It is possible to form a fluorescent film with a high packing density.
Since the surface of the phosphor particle is provided with irregularities and the specific surface area is large, the surface of the phosphor particle has a high light scattering property.

It is preferable that the irregularities are provided such that the surface area of the phosphor particles is 1.01 to 1.5 times the surface area of a sphere having the same volume.
More preferably, it is provided to be 1 to 1.3 times. If this ratio is less than the lower limit value, the surface area of the phosphor particles cannot be sufficiently increased. Further, if the upper limit is exceeded, not only can the phosphor film having a high packing density be formed because the spherical property of the phosphor particles is reduced, but also the light scattering property will be excessively increased, so that when used as the phosphor film. Moreover, the light absorption in the aluminum reflection film and the fluorescent film increases, and the output light from the fluorescent film decreases.

The ratio of the major axis to the minor axis in the range of 1 to 1.3 means that the length of the longest axis obtained when the projection of each phosphor particle is observed in all directions. And the length of the shortest axis are in the range of 1 to 1.3, and the ratio is more preferably 1 to 1.1. If this ratio exceeds the upper limit value, it is not possible to form a phosphor film with a high packing density, and further, the dispersibility of the phosphor particles in the slurry used when forming the phosphor film is reduced, so that it is dense. Fluorescent film cannot be formed.

Next, the shape of the phosphor of the present invention will be described in more detail with reference to FIG. As shown in FIG. 1A, the phosphor particle 1 of the present invention is composed of a plurality of single crystals 2, and the surface of the phosphor particle 1 is indicated by a broken line due to the interface of these single crystals 2. The groove-shaped recess 4 is formed. In this figure, the broken line indicated by reference numeral 5 indicates a sphere circumscribing the phosphor particle 1.

FIG. 1B shows a part 7 of the phosphor particle 1 in an enlarged manner. In this figure, reference numeral 6 indicates the distance from the circumscribing sphere 5 to the recess 4. In the phosphor particle 1 of the present invention, the distance 6 is usually 50 nm to
It is about 0.2 μm. However, this distance 6 is
It can be controlled by the manufacturing conditions of the phosphor particles 1. The distance 6 is preferably 10 nm or more and 20% or less of the diameter of the smallest sphere 5 described above.
It is more preferably 0 nm or more and 5% or less. If the distance 6 is less than the lower limit value, the surface area of the phosphor particles 1 cannot be sufficiently increased. On the other hand, when the upper limit is exceeded, light may be scattered in the recesses 4 and the emitted light may be confined, so that the output light from the fluorescent film decreases.

It is considered that the unevenness is caused by the interface between the plurality of single crystals 2 constituting the phosphor 1. That is,
The interfaces and crystal planes of the plurality of single crystals 2 form the above-mentioned unevenness. Therefore, it is possible to control the number and size of the irregularities by changing the number of single crystals 2 constituting the phosphor 1. The number of single crystals 2 is
It is preferable that the number is about 2 to 100. Phosphor 1 is 1
When it is composed of one single crystal, sufficient unevenness cannot be formed, and when it is composed of more than 100 single crystals, the number of grain boundaries inside the phosphor particles is increased, and the luminous efficiency of the entire particle is increased. Is reduced. For this reason, the light scattering on the surface becomes excessive, and it is not possible to form a fluorescent film having high luminous efficiency.

In the phosphor of the present invention, as described above, the surface of spherical phosphor particles is provided with irregularities in order to obtain an appropriate light scattering property. Although the light scattering coefficient of the phosphor of the present invention varies depending on the material used and the particle size of the phosphor, it is generally 0.
It is preferably ^{110cm 2 /mg~0.180cm 2 / mg, 0.120cm} 2 /mg~0.170c
More preferably, it is m ² / mg. As will be described later, when the light scattering coefficient is less than the lower limit value, the emission light is not sufficiently scattered in the fluorescent film, and the spot diameter cannot be reduced sufficiently. On the other hand, when the value exceeds the upper limit, light scattering of emitted light in the fluorescent film becomes excessive, the spot diameter increases, and the intensity of output light decreases.

The method for producing the phosphor of the present invention will be described below.

In producing the phosphor of the present invention, first, the raw material phosphor powder is melt-processed in a high-frequency thermal plasma by the high-frequency thermal plasma processing method disclosed in JP-A-8-059156, and this is processed. A spherical intermediate phosphor is formed by rapid cooling. At this time, the power of the high-frequency thermal plasma and the supply amount of the raw material phosphor powder are controlled so that the surface of the particles is completely melted without evaporating the entire raw material phosphor powder.

The intermediate phosphor obtained as described above is
Although it has a spherical shape, at this stage, it is a polycrystalline particle containing many defects such as twins, and ultrafine particles adhere to the surface.

Next, this intermediate phosphor is heat-treated at a temperature of about 80% of its melting point (absolute temperature). By this heat treatment, the polycrystalline nuclei in the intermediate phosphor grow by diffusion to form a single crystal, and the ultrafine particles adhering to the surface of the intermediate phosphor melt to form wavy unevenness on the surface of the phosphor. . Therefore, the finally obtained phosphor of the present invention has a structure in which single crystals are densely bonded, that is, a structure separated by boundaries as seen in a sintered body such as ceramics, and adheres. Due to the amount of the ultrafine particles, the surface has irregularities.

The above-mentioned heat treatment depends on the composition of the intermediate phosphor and the average particle size, but is usually from 1300 ° C to 1700 ° C.
It is performed at 10 ° C. for 10 minutes to 10 hours. Heat treatment temperature is 1300
When the temperature is lower than 0 ° C. or the heat treatment time is shorter than 10 minutes, the above-mentioned single crystal cannot be formed in the phosphor particles and sufficient unevenness cannot be formed on the surface of the phosphor particles. Further, when the heat treatment temperature exceeds 1700 ° C. or the heat treatment time exceeds 10 hours, the phosphor particles are sintered with each other, and a well-dispersed phosphor cannot be obtained.

Since the phosphor of the present invention described above is heat-treated at a high temperature, it has good crystallinity and high luminous efficiency. Furthermore, since the bonds between the single crystals in the phosphor particles are strong, the phosphor particles will not be broken by the ball mill performed to improve the dispersibility.

Hereinafter, a phosphor film using the phosphor of the present invention will be described.

FIG. 2 shows a cross-sectional view of the fluorescent film of the projection tube using the phosphor of the present invention and the conventional phosphor. The phosphor film 21 shown in FIG. 2A is formed of the phosphor of the present invention,
The fluorescent film 21 is formed on a glass panel (not shown). An aluminum reflection film (not shown) is formed on the fluorescent film 21. The display on such a projection tube is performed by irradiating the fluorescent film 21 with an electron beam 25 having a predetermined diameter from the aluminum reflective film side to cause the fluorescent material in the fluorescent film 21 to emit light and output light with a spot diameter L ₁ . Is emitted.

FIGS. 2B and 2C show a fluorescent film using a conventional spherical fluorescent material and a conventional fluorescent film using a polyhedral fluorescent material, respectively. These Figure 2
Comparing the spot diameters L ₁ , L ₂ , and L ₃ of the phosphor films shown in (a), (b), and (c), respectively,
₁ is smaller than L ₂ and L ₃ . That is, by forming a phosphor film using the phosphor of the present invention, a finer display can be performed as compared with the case of using the conventional phosphor.

The reason why the spot diameter of the fluorescent film of the projection tube can be reduced by using the phosphor of the present invention will be described below with reference to FIG.

In the phosphor film 23 shown in FIG. 3C, a polyhedral phosphor is used. Since the phosphor film 23 formed of such a polyhedral phosphor has a low packing density, a thick film is formed in order to obtain sufficient luminous efficiency.
Therefore, the emitted light 26 traveling obliquely with respect to the fluorescent film 23 is diffused and output from the light emitting position 27 to a position separated by the distance L ₆ in the in-plane direction of the fluorescent film 23. Also,
The conventional polyhedral phosphor has an excessive light scattering property. Therefore, the emitted light 26 is scattered and absorbed by the surface of many phosphor particles and the aluminum reflection film before being output from the fluorescent film 23, so that not only the distance L ₆ is increased but also the intensity of the output light is increased. Will fall.

In the phosphor film 22 shown in FIG. 3B, a conventional spherical phosphor having no unevenness on its surface is used. When such a spherical phosphor is used, the packing density of the fluorescent film 22 is increased, so that the fluorescent film 22 can be made thin. Therefore, in the fluorescent film 22, FIG.
The degree of diffusion is lower than that of the fluorescent film 23 shown in (1), and the light is emitted from a position away from the light emitting position 27 in the in-plane direction of the fluorescent film 22 by a distance L ₅ .

However, the fluorescent film 2 shown in FIG.
Since the phosphor used in No. 2 has extremely low scattering property, scattering on the surface of the phosphor particles is unlikely to occur. That is, the fluorescent film 2
The emitted light 26 traveling in an oblique direction with respect to 2 has a very small number of scatterings on the surface of the phosphor and has a high straight traveling property, so that the distance L ₅ is not reduced so much as compared with the distance L ₆ .

On the other hand, the fluorescent film 21 shown in FIG.
The phosphor of the present invention used in 1. has a spherical shape and is provided with irregularities on the surface. Therefore, when such a phosphor is used, the packing density of the fluorescent film 21 is increased, so that the fluorescent film can be formed thin. Further, the phosphor of the present invention used in the phosphor film 21 shown in FIG.
The light scattering property is higher than that of the phosphor used in the phosphor film 22 shown in (b), and the light scattering property is lower than that of the phosphor used in the phosphor film 23 shown in FIG. Therefore, the fluorescent film 2
The emitted light 26 traveling in an oblique direction with respect to 1 is appropriately scattered on the phosphor surface, and the distance L ₄ is further reduced as compared with the distance L ₅ .

Next, the reason why the light extraction efficiency of the plasma display panel can be improved by using the phosphor of the present invention will be described.

When the phosphor of the present invention is used, since a thin phosphor film can be formed, not only the discharge efficiency is increased and the light emission efficiency is improved, but also the following two advantages are provided. First, because of its large specific surface area, it absorbs more vacuum ultraviolet light than conventional spherical phosphors and improves the luminous efficiency. Secondly, since light scattering increases in proportion to the specific surface area, the emitted light can be efficiently extracted.

As described above, the phosphor of the present invention has an appropriate light scattering property and can form a film with a high packing density, so that it has sufficient emission efficiency of emitted light and a small spot diameter. It is possible to form a fluorescent film that can be formed.

[0042]

EXAMPLES Examples of the present invention will be described below.

Example 1 Y ₂ O ₃ and Tb ₄ O ₇ were dissolved in a nitric acid aqueous solution, and an oxalate aqueous solution was added to this solution to prepare a coprecipitated oxalate. Flux was added to this oxalate salt and baked at a temperature of 1000 ° C. in the atmosphere to prepare an oxide. Silica is mixed with this oxide,
Further firing is performed to obtain a composition formula (Y _0.93 Tb _0.07 ) ₂ Si
A conventional polyhedral phosphor (Sample 1) having a composition shown by O ₅ was manufactured.

Next, this polyhedron-shaped phosphor was subjected to high-frequency thermal plasma treatment in an Ar atmosphere to manufacture a conventional spherical phosphor (Sample 2) having no irregularities formed on its surface.

Further, the spherical phosphor is added to the phosphor at 1300 ° C.
Heat treatment for 2 hours in the reducing atmosphere (N ₂ / H ₂ ) of
A spherical phosphor (Sample 3) having irregularities formed on the surface was obtained.

FIGS. 4 to 6 show the SE of Samples 1 to 3 above.
M photographs are shown respectively. As is clear from these SEM images, Sample 1 is a polyhedron in which primary particles are aggregated,
Sample 2 is a sphere with a smooth surface, although ultra-fine particles adhere to the surface. On the other hand, sample 3 has a large number of irregularities formed on the surface while maintaining a spherical shape.
The average depth of these concave and convex portions is 0.2 μm.
Met.

Various powder characteristics of these samples were measured. The results are shown in Table 1 below.

[0048]

[Table 1] In Table 1 above, the average particle size is a value obtained by the Blaine method, and the specific surface area and the light scattering coefficient are described in terms of actual measurement values and relative values with respect to Sample 2.
The major axis / minor axis indicates the ratio of the major axis to the minor axis of the phosphor particles, and the surface area ratio indicates the ratio of the surface area of the phosphor particles to the surface area of spheres having the same volume, and the depth of the recess is , The maximum value of the distance from the sphere circumscribing the phosphor particles to the surface of the phosphor particles, and the ratio of the distance to the diameter of the sphere. The major axis / minor axis, the surface area ratio, and the depth of the recesses were obtained from the contours of the plurality of phosphor particles in the SEM photograph, and the values were averaged for estimation. The specific surface area was calculated using the Blaine diameter, and the light scattering coefficient was measured according to the Kubelka-Munk theory.

Next, using these samples 1 to 3, a 7-inch projection tube was prepared by a usual method, and the film thickness of the fluorescent film and the brightness and resolution (spot diameter) at 32 kV and 1 mA were measured. The results are shown in Table 2.

[0050]

[Table 2] In Table 2 above, the relative brightness, the spot diameter, and the film thickness of the fluorescent film are shown as relative values with respect to the values in the projection tube manufactured using Sample 1, respectively. Furthermore, the actual measured value is shown. The spot diameter is the diameter of an area having a strength of 5% with respect to the maximum brightness.

As shown in Table 2 above, in the projection tube manufactured using the phosphor of Sample 3, the thickness of the phosphor film was 20%.
Despite being thin as described above, almost the same brightness as the projection tube manufactured using the phosphor of Sample 1 was obtained. Moreover, in the projection tube manufactured using the phosphor of Sample 3,
The projection tube using the phosphor of Sample 2 and the fluorescent film have almost the same film thickness, but a brightness higher than that of Sample 1 by about 10% is obtained. Therefore, by using the phosphor of Sample 3, it is possible to form a phosphor film having a relatively high brightness and a higher packing density.

Further, comparing the spot diameters of these projection tubes, the smallest spot diameter is obtained in the projection tube manufactured using the phosphor of Sample 3. Therefore, by using the phosphor of Sample 3, it is possible to form a phosphor film having relatively high brightness and capable of fine display.

(Example 2) In the same manner as in Example 1, coprecipitation, mixing, and firing were carried out to obtain a compositional formula (Y _0.95 Tb _0.05 ).
A polyhedral phosphor (Sample 4) represented by ₃ (Al, Ga) ₅ O ₁₂ was prepared.

Next, this polyhedron-shaped phosphor was subjected to high-frequency thermal plasma treatment in an Ar atmosphere to produce a spherical phosphor having no irregularities on its surface. Further, this spherical phosphor was heat-treated in an air atmosphere at 1450 ° C. for 2 hours to obtain a spherical phosphor (Sample 5) having irregularities formed on its surface.

FIG. 7 shows an SEM photograph of Sample 5 above. As is clear from this SEM image, Sample 5 has
It is a spherical body with many irregularities formed on the surface. The average depth of the concave and convex portions was 0.1 μm.

Various powder characteristics of these samples were measured, and further, a 7-inch projection tube was produced using these samples to measure the spot diameter. The results are shown in Table 3 below.
Shown in.

[0057]

[Table 3] As shown in Table 3 above, in the projection tube manufactured using the phosphor of sample 5, the projection tube manufactured using the phosphor of sample 4 despite the thickness of the phosphor film being 20% or more thin. Brightness almost equal to is obtained. Therefore, by using the phosphor of Sample 5, it is possible to form a phosphor film having a relatively high brightness and a higher packing density.

Further, comparing the spot diameters of these projection tubes, a spot diameter as small as about 15% is obtained in the projection tube manufactured using the phosphor of Sample 5. Therefore, by using the phosphor of Sample 5, it is possible to form a phosphor film having relatively high brightness and capable of fine display.

[0059]

According to the present invention, the composition formula Ln ₃ M ₅ O ₁₂ :
R ₁ or Ln ₂ SiO ₅ : R ₂ having a chemical composition shown in a spherical shape and forming irregularities on the surface of the particle imparts appropriate light-scattering property to increase the packing density, so that it is sufficient. Provided are a phosphor film having a high emission efficiency and a small spot diameter, and a phosphor capable of forming the same.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of a phosphor of the present invention.

FIG. 2 is a cross-sectional view showing a phosphor film using a phosphor of the present invention and a conventional phosphor.

FIG. 3 is a cross-sectional view showing a phosphor film using a phosphor of the present invention and a conventional phosphor.

FIG. 4 is an SEM photograph of a conventional phosphor.

FIG. 5 is an SEM photograph of a conventional phosphor.

FIG. 6 is an SEM photograph of a phosphor according to an example of the present invention.

FIG. 7 is an SEM photograph of a phosphor according to an example of the present invention.

[Explanation of symbols]

1 ... Phosphor particles 2 ... Single crystal 4 ... Recess 5 ... Sphere 6 ... distance 7 ... Part of phosphor particles 21-23 ... Fluorescent film 25 ... Electron beam 26 ... Emitted light 27 ... Light emitting position

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Naoshi Matsuda, Komukai Toshiba Town, Komukai-shi, Kawasaki-shi, Kanagawa 1st, Toshiba Research and Development Center (72) Inventor Shinichi Nakamura Toshiba, Komukai-shi, Kawasaki-shi, Kanagawa Machi No. 1 within Toshiba Research and Development Center (56) References JP-A-8-109375 (JP, A) JP-A-62-201989 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C09K 11/00-11/89

Claims (5)

(57) [Claims] 1. An SEM photographed at a magnification of 10,000 times.
Asperities that can be observed in the photograph are formed on the surface and have a spherical shape in which the ratio of the major axis to the minor axis is in the range of 1 to 1.3. A phosphor comprising particles having a surface area of double to 1.5 times, and having a chemical composition represented by a composition formula Ln ₃ M ₅ O ₁₂ : R or Ln ₂ SiO ₅ : R. (In the formula,
Ln is at least one element selected from Sc, Y, Gd, La, and Lu, M is at least one element selected from Al and Ga, and R is selected from Cr, Ti, Fe, and lanthanide group elements. At least one element is shown. ) 2. A spherical surface having irregularities formed therein and having a ratio of major axis to minor axis in the range of 1 to 1.3 and having a surface area of 1.01 with respect to the surface area of a sphere having the same volume. times to be particles having a surface area of 1.5 times, composition formula Ln ₃ M ₅ O _12: R or Ln ₂ SiO _5: comprising a chemical composition shown in R, the maximum value of the depth of the concave portion of the irregularities 10 nm or more
And 20% or less of the diameter of the sphere circumscribing the particles.
Phosphor, characterized in that that. (In the formula, Ln is Sc, Y,
At least one element selected from Gd, La, and Lu, M is at least one element selected from Al and Ga, R is at least one element selected from Cr, Ti, Fe, and lanthanide group elements Indicates. ) 3. A spherical shape having irregularities formed on its surface.
However, it is composed of particles having a surface area of 1.01 to 1.5 times the surface area of a sphere having the same volume, and has the chemical formula Ln ₃ M ₅ O ₁₂ : R or Ln ₂ SiO ₅ : R. comprising a composition, the maximum value of the depth of the concave portion of the irregularities, der least 10nm
And 20% or less of the diameter of the sphere circumscribing the particles.
Phosphor, characterized in that that. (In the formula, Ln is Sc, Y,
At least one element selected from Gd, La, and Lu, M is at least one element selected from Al and Ga, R is at least one element selected from Cr, Ti, Fe, and lanthanide group elements Indicates. ) 4. 0.110 cm ² / mg to 0.18
The phosphor according to any one of claims 1 to 3, which has a light scattering coefficient of 0 cm ² / mg. 5. The method according to any one of claims 1 to 4.
A phosphor film containing a phosphor.