JP6700630B2 - Phosphor, manufacturing method thereof, light emitting device, image display device, pigment and ultraviolet absorber - Google Patents

Description

In the present invention, an inorganic crystal represented by M _n X _n+1 containing at least a metal element M and a non-metal element X, an inorganic crystal having the same crystal structure as the inorganic crystal, or an inorganic crystal which is a solid solution thereof is used as a host crystal. TECHNICAL FIELD The present invention relates to a phosphor, a method for producing the same, and an application thereof.

  The fluorescent substance is a fluorescent display tube (VFD (Vacuum-Fluorescent Display)), a field emission display (FED (Field Emission Display) or SED (Surface-Condition Electron Display) (PD), plasma display. ), a cathode ray tube (CRT (Cathode-Ray Tube)), a liquid crystal display backlight (Liquid-Crystal Display Backlight), a white light emitting diode (LED (Light-Emitting Diode)), and the like. In any of these applications, in order to cause the phosphor to emit light, it is necessary to supply energy to the phosphor for exciting the phosphor, and the phosphor is a vacuum ultraviolet ray, an ultraviolet ray, an electron beam, a blue light, or the like. When excited by an excitation source having high energy, it emits visible light such as blue light, green light, yellow light, orange light, and red light. However, as a result of the phosphor being exposed to the excitation source as described above, the brightness of the phosphor is likely to decrease, and there is a demand for a phosphor that does not exhibit a decrease in brightness. Therefore, instead of conventional phosphors such as silicate phosphors, phosphate phosphors, aluminate phosphors, and sulfide phosphors, sialon phosphors are used as phosphors with little brightness reduction even at high energy excitation. , Oxynitride phosphors, nitride phosphors, and the like, have been proposed that use an inorganic crystal having a crystal structure containing nitrogen as a matrix.

An example of this sialon phosphor is manufactured by a manufacturing process as outlined below. First, silicon nitride (Si ₃ N ₄ ), aluminum nitride (AlN), and europium oxide (Eu ₂ O ₃ ) are mixed in a predetermined molar ratio, and the mixture is mixed in nitrogen at 1 atm (0.1 MPa) at a temperature of 1700° C. It is manufactured by holding for 1 hour and firing by a hot pressing method (see, for example, Patent Document 1). It has been reported that the Eu ²⁺ ion-activated α-sialon obtained by this process becomes a phosphor that emits yellow light of 550 to 600 nm when excited with blue light of 450 to 500 nm. It is also known that the emission wavelength is changed by changing the ratio of Si and Al or the ratio of oxygen and nitrogen while maintaining the crystal structure of α-sialon (see, for example, Patent Document 2 and Patent Document 3). ).

As another example of the sialon phosphor, a green phosphor in which β 2 -sialon is activated with Eu ²⁺ is known (see Patent Document 4). In this phosphor, it is known that the emission wavelength changes to a short wavelength by changing the oxygen content while maintaining the crystal structure (for example, see Patent Document 5). Further, it is known that when Ce ³⁺ is activated, it becomes a blue phosphor (see, for example, Patent Document 6).

An example of an oxynitride phosphor, JEM phase _{(LaAl (Si 6-z Al} z) N 10-z O z) blue phosphor were activated with Ce as host crystals (see Patent Document 7) are known ing. It is known that in this phosphor, by exchanging a part of La with Ca while maintaining the crystal structure, the excitation wavelength becomes longer and the emission wavelength becomes longer.

As another example of the oxynitride phosphor, blue phosphor and La-N-crystal _La 3 _Si 8 _N 11 _{O 4} was activated with Ce as host crystals (see Patent Document 8) have been known.

As an example of the nitride phosphor, a red phosphor in which CaAlSiN ₃ is used as a host crystal and Eu ²⁺ is activated (see Patent Document 9) is known. The use of this phosphor has the effect of improving the color rendering of the white LED. The phosphor to which Ce is added as an optically active element is reported to be an orange phosphor.

  As described above, the emission color of the phosphor is determined by the combination of the base crystal and the metal ions (activating ions) that form a solid solution with the crystal. Furthermore, the combination of the host crystal and the activating ion determines emission characteristics such as emission spectrum and excitation spectrum, and chemical stability and thermal stability. Therefore, when the host crystal is different or when the activating ion is different, Considered different phosphors. Materials having the same chemical composition but different crystal structures have different emission characteristics and stability due to different host crystals, and are therefore regarded as different phosphors.

Furthermore, in many phosphors, it is possible to substitute the types of constituent elements while maintaining the crystal structure of the host crystal, thereby changing the emission color. For example, a phosphor in which Ce is added to YAG emits green light, but a phosphor in which a part of Y in the YAG crystal is replaced with Gd and a part of Al is replaced with Ga emits yellow light. Furthermore, it is known that in the phosphor obtained by adding Eu to CaAlSiN ₃ , the composition changes while maintaining the crystal structure by substituting a part of Ca with Sr, and the emission wavelength is shortened. As described above, the phosphors in which the element substitution is performed while maintaining the crystal structure are regarded as the same group of materials.

  From these facts, it is important to find a host crystal having a novel crystal structure in the development of a new phosphor, and to activate the metal ion responsible for light emission in such a host crystal so as to develop the fluorescent property. Thereby, a novel phosphor can be proposed.

Patent No. 3668770 Japanese Patent No. 3837551 Patent No. 4524368 Japanese Patent No. 3921545 International Publication No. 2007/066733 International Publication No. 2006/101096 International Publication No. 2005/019376 JP, 2005-112922, A Japanese Patent No. 3837588

  The present invention is intended to meet such a demand, and one of the objects is an LED having emission characteristics (emission color, excitation characteristic, emission spectrum) different from those of conventional phosphors and having a wavelength of 470 nm or less. It is intended to provide a chemically and thermally stable inorganic phosphor which has a high emission intensity even when combined with. Another object of the present invention is to provide a light emitting device using such a phosphor and having excellent durability, and an image display device having excellent durability. A further object of the present invention is to provide a pigment and an ultraviolet absorber using such a phosphor.

Under such circumstances, the present inventors have conducted detailed research on new crystals containing nitrogen and phosphors having a crystal in which a metal element or N in this crystal structure is replaced with another element as a matrix, and at least An inorganic crystal represented by M _n X _n+1 containing a metal element M and a non-metal element X (where n is a numerical value in the range of 3≦n≦52), an inorganic crystal having the same crystal structure, or It has been found that an inorganic compound in which luminescent ions are solid-dissolved in an inorganic crystal having an inorganic crystal that is a solid solution as a matrix becomes a novel phosphor. In particular, an inorganic crystal represented by Si _x Al _13-x O _3-x N _11+x (0<x≦3), an inorganic crystal having the same crystal structure as that of the inorganic crystal, or a fluorescence having a solid solution of the inorganic crystal as a matrix. We found that the body fluoresces with high brightness. It was also found that a specific composition emits blue to green light.

  Furthermore, by using this phosphor, it was found that a white light emitting diode (light emitting device) having high luminous efficiency and small temperature fluctuation, a lighting fixture using the same, and an image display device with vivid color can be obtained. It was

  As a result of earnest studies in view of the above-mentioned circumstances, the present inventor succeeded in providing a phosphor exhibiting a high-luminance light emission phenomenon in a specific wavelength region by implementing the configuration described below. In addition, we succeeded in producing a phosphor with excellent emission characteristics using the following method. Furthermore, by using this phosphor, by succeeding in providing a light-emitting device, a lighting fixture, an image display device, a pigment, an ultraviolet absorber having excellent characteristics by taking the configuration described below. The configuration is as described below.

The phosphor according to the present invention is an inorganic crystal represented by M _n X _n+1 containing at least a metal element M and a non-metal element X (where n is a numerical value in the range of 3≦n≦52, and the metal element M is At least Al (aluminum), Si (silicon), and optionally an L element (L element is a metal element other than Al and Si), the non-metal element X is at least N (nitrogen) And optionally O (oxygen) and optionally Z element (Z element is a non-metal element other than N and O), an inorganic crystal having the same crystal structure, or these Inorganic compound which is a solid solution of A element (where A is one or more elements selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy and Yb) as a solid solution And the inorganic crystal represented by M _n X _n+1 is an inorganic crystal represented by Si _x Al _13-x O _3-x N _11+x (provided that 0<x≦3), thereby solving the above problems. To do.
The inorganic crystal having the same crystal structure may be an inorganic crystal represented by (Si,Al) ₁₃ (O,N) ₁₄ .
The inorganic crystal represented by the Si _x Al _13-x O _3-x N _11+x , the inorganic crystal having the same crystal structure as the inorganic crystal, or the inorganic crystal which is a solid solution thereof is a orthorhombic crystal. And has the symmetry of the space group Cmcm, and the lattice constants a, b, and c are
a = 0.30749±0.05 nm
b=1.87065±0.05 nm
c=3.8432±0.05 nm
May be a value in the range.
The x value may be 1.5≦x≦3.
The x value may be 2≦x≦2.9.
The element A may be Eu.
The inorganic compound has a composition formula Si _a Al _b O _c N _d A _e Q _f (where a+b+c+d+e+f=1, where A is Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Yb. 1 or 2 or more elements selected from, Q is one or two or more elements selected from elements other than Al, Si, O, N, A), and parameters a, b, c, d, e, f are
0.014 ≤ a ≤ 0.111
0.369 ≤ b <0.48
0 ≤ c <0.111
0.406 <d <0.517
0.0001 ≤ e ≤ 0.03
0 ≤ f ≤ 0.3
It may be a value in a range that satisfies all of the above conditions.
The parameters a, b, c, d, e, f are
0.0185 ≤ a ≤ 0.1107
0.369 ≤ b ≤ 0.4613
0 ≤ c ≤ 0.0923
0.4244 ≤ d ≤ 0.5166
0.0001 ≤ e ≤ 0.0196
0 ≤ f ≤ 0.0233
It may be a value in a range that satisfies all of the above conditions.
The parameters a, b, c, d, e, f are
0.0738 ≤ a ≤ 0.1107
0.369 ≤ b ≤ 0.4059
0 ≤ c ≤ 0.0369
0.4797 ≤ d ≤ 0.5166
0.0004 ≤ e ≤ 0.0196
0 ≤ f ≤ 0.0233
It may be a value in a range that satisfies all of the above conditions.
The inorganic compound may be single crystal particles having an average particle size of 0.1 μm or more and 40 μm or less or an aggregate of single crystals.
The phosphor may be composed of a mixture of the above-mentioned phosphor made of an inorganic compound and another crystal phase or an amorphous phase, and the content of the phosphor may be 20% by mass or more.
By irradiating an excitation source, fluorescence having a peak in the wavelength range of 460 nm to 500 nm may be emitted.
The excitation source may be vacuum ultraviolet light having a wavelength of 100 nm or more and 420 nm or less, ultraviolet light or visible light, electron beam or X-ray.
In the method for producing a phosphor according to the present invention, a raw material mixture that is a mixture of metal compounds and that can form the phosphor described above is burned at 1200° C. or higher and 2200° C. in an inert atmosphere containing nitrogen. The firing is performed in the following temperature range to solve the above problems.
The mixture of the metal compounds is AlN and/or Al ₂ O ₃ , Si ₃ N _4, and an oxide or nitride of A (where A is Mn, Ce, Pr, Nd, Sm, Eu, Tb, And one or more elements selected from Dy and Yb).
The metal compound in the form of powder or agglomerate may be baked after being filled in a container in a state where the filling rate is 40% or less in bulk density.
The light emitting device according to the present invention is composed of at least a light emitting body and a phosphor, and the phosphor uses the above-mentioned phosphor, thereby solving the above problems.
The light emitting body may be a light emitting diode (LED), a laser diode (LD), a semiconductor laser, or an organic EL light emitting body (OLED) that emits light having a wavelength of 330 to 500 nm.
The light emitting device may be a white light emitting diode, a lighting fixture including a plurality of the white light emitting diodes, or a liquid crystal panel backlight.
The luminescent material emits ultraviolet or visible light having a peak wavelength of 300 to 450 nm, and white light or white light is obtained by mixing blue or green light emitted by the above-mentioned phosphor and light having a wavelength of 450 nm or more emitted by another phosphor. Light other than white light may be emitted.
The image display device according to the present invention comprises an excitation source and a phosphor, and the phosphor contains the above-mentioned phosphor, thereby solving the above problems.
The image display device may be a fluorescent display tube (VFD), a field emission display (FED), a plasma display panel (PDP), a cathode ray tube (CRT), or a liquid crystal display (LCD).
The pigment according to the present invention comprises the above-mentioned phosphor, which solves the above-mentioned problems.
The ultraviolet absorbent according to the present invention is composed of the above-mentioned phosphor, thereby solving the above-mentioned problems.

The phosphor of the present invention has a multi-element nitride containing Si and Al, or a multi-element oxynitride, among them, an inorganic crystal represented by M _n X _n+1 (3≦n≦52), which has the same crystal structure. Inorganic crystals or inorganic crystals which are solid solutions of these are contained as host crystals. More _preferably, represented by M _{n X n +} as an inorganic crystal (3 ≦ n ≦ 52) as indicated by _1, is _{n = 13 Si x Al 13-} x O 3-x N 11 + x (0 <x ≦ 3) Inorganic Conventionally, by containing a crystal, an inorganic crystal having the same crystal structure as the inorganic crystal represented by Si _x Al _13-x O _3-x N _11+x , or an inorganic crystal which is a solid solution thereof as a main component, It emits light with higher brightness than the oxide phosphor and the oxynitride phosphor, and is excellent as a blue to green phosphor with a specific composition. The brightness of this phosphor does not decrease even when exposed to an excitation source, so it is suitable for use in light-emitting devices such as white light-emitting diodes, lighting fixtures, backlight sources for liquid crystals, VFDs, FEDs, PDPs and CRTs. The present invention provides a useful phosphor. Further, since this phosphor absorbs ultraviolet rays, it is suitable for pigments and ultraviolet absorbers.

_{Si x Al 13-x O 3} -x N 11 + x (0 <x ≦ 3) illustrates the crystal structure of the crystal. _{Si x Al 13-x O 3} -x N 11 + x (0 <x ≦ 3) shows a powder X-ray diffraction using a CuKα ray calculated from the crystal structure of the crystal. The figure which shows the powder X-ray-diffraction result of the fluorescent substance synthesize|combined in Example 51. FIG. 16 shows the excitation spectrum and emission spectrum of the phosphor synthesized in Example 51. FIG. 3 is a schematic diagram showing a lighting device (bullet-type LED lighting device) according to the present invention. Schematic which shows the lighting fixture (board-mounted LED lighting fixture) by this invention. 1 is a schematic view showing an image display device (plasma display panel) according to the present invention. 1 is a schematic view showing an image display device (field emission display panel) according to the present invention.

Hereinafter, the phosphor of the present invention will be described in detail with reference to the drawings.
The phosphor of the present invention is an inorganic crystal represented by M _n X _n+1 containing at least a metal element M and a non-metal element X (where n is a numerical value in the range of 3≦n≦52) and has the same crystal structure. Inorganic crystal having, or an inorganic crystal which is a solid solution thereof, and A element (where A is one or more elements selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Yb). ) Contains an inorganic compound as a solid solution as a main component, and exhibits high brightness. However, the metal element M contains at least Al (aluminum), Si (silicon), and optionally an L element (L element is a metal element other than Al and Si), and the non-metal element X is It contains at least N (nitrogen), O (oxygen) as necessary, and Z element (Z element is a non-metal element other than N and O) as necessary.

Among them, the inorganic crystal represented by M _n X _n+1 is a general crystal of Si _x Al _m+2-x O _3-x N _m+x (where m=n−2, 0<x≦3, and 1≦m≦50). The phosphor having an inorganic crystal represented by the formula as a matrix is a phosphor having a high emission intensity and capable of controlling a change in color tone by changing the composition.

Further, the inorganic crystal represented by M _n X _n+1 has a homologous structure. As the number of n increases, the longest lattice axis (c-axis in general notation) extends. The remaining two axes (a axis and b axis) have almost the same values.

  Preferably, the phosphor having the value of x of 1.5≦x≦2.9 has high emission intensity. More preferably, the phosphor with the value of x satisfying 2≦x≦2.9 has particularly high emission intensity.

  Further, the phosphor having a value of m of 5≦m≦20 has particularly high emission intensity.

  Further, the value of n is represented by an integer value.

  Further, the phosphor having the value of n of 9≦n≦15 has particularly high emission intensity.

An inorganic crystal represented by M _n X _n+1 , an inorganic crystal having the same crystal structure as M _n X _n+1 , or an inorganic crystal that is a solid solution of these is a tetragonal (orthorhombic) crystal and is stable. The phosphor used as the host crystal has high emission intensity. It should be noted that in the present specification, based on the resolution of the General Meeting of the Crystallographic Society of Japan held in 2014, "Orthorhombic" is used as a term intended to be "Orthorhombic system (orthorhombic system)" (for example, Japan. Crystallographic Society of Japan, 57, 131-133 (2015)).

An inorganic crystal represented by M _n X _n+1 , an inorganic crystal having the same crystal structure as that of the inorganic crystal, or an inorganic crystal that is a solid solution thereof is a orthorhombic (orthorhombic) crystal and is expressed by a space group Cmcm. The obtained crystals are particularly stable, and the phosphor having these as a host crystal has high emission intensity.

An inorganic crystal represented by M _n X _n+1 , an inorganic crystal having the same crystal structure as that of the inorganic crystal, or an inorganic crystal that is a solid solution thereof is a orthorhombic (orthorhombic) crystal and has a symmetry of the space group Cmcm And the lattice constants a, b and c are
a=0.31±0.05 nm
b=1.87±0.2 nm
c=0.275×(n+1)±0.1 nm (3≦n≦52)
When the value is in the range of 1, the crystal is particularly stable, and the phosphor having these as a host crystal has high emission intensity. If it is out of this range, the crystal becomes unstable and the emission intensity may decrease.

An inorganic crystal represented by M _n X _n+1 , an inorganic crystal having the same crystal structure as that of the inorganic crystal, or an inorganic crystal that is a solid solution thereof is a orthorhombic (orthorhombic) crystal and has a symmetry of the space group Cmcm And the lattice constants a, b and c are
a=0.31±0.05 nm
b=1.87±0.2 nm
c=0.275×(n+1)±0.1 nm (3≦n≦52)
Is a value in the range
(1) When n is an even number,
The atomic coordinates Mi of the M element contained in the unit cell are
(0, (4+6i-3n)/16±0.05, (1/4+(i-1)/(2n))±0.05), where 1≦i≦n+1 (n+1 in total) ,
The atomic coordinate Xi of the X element is
(0, (4+6i-3n)/16±0.05, (1/4+(i-1)/(2n+1))±0.05), where 1≦i≦n+2 (n+2 in total) ,
(2) When n is an odd number,
The atomic coordinates Mj of the M element contained in the unit cell are
(0, (8+6j-3n)/16±0.05, (1/4+(j-1)/(2n))±0.05), where 1≦j≦n+1 (n+1 pieces in total) ,
The atomic coordinate Xj of the X element is
(0, (4+6j-3n)/16±0.05, (1/4+(j-1)/(2n+1))±0.05), where 1≦j≦n+2 (n+2 in total). The crystals of these are particularly stable, and the phosphors having these as host crystals have high emission intensity.

Such an inorganic compound has a composition formula Si _a Al _b O _c N _d A _e Q _f (where a+b+c+d+e+f=1, where A is Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy. , Yb, one or more elements selected from Yb, and Q is one or more elements selected from elements other than Al, Si, O, N, and A), and parameters a, b, c, d, e, f are
0.0117 ≤ a ≤ 0.3472
0.0694 ≤ b ≤ 0.4812
0 ≤ c ≤ 0.2283
0.3261 ≤ d ≤ 0.53
0.0001 ≤ e ≤ 0.03
0 ≤ f ≤ 0.3 (however, when there are multiple Q elements, f is the sum of the parameters of each element)
The phosphor represented by the composition satisfying all the above conditions has particularly high emission intensity.

  The parameter a is a parameter representing the composition of the Si element, and if it is less than 0.0117 or higher than 0.3472, the crystal structure becomes unstable and the emission intensity decreases. The parameter b is a parameter representing the composition of the Al element, and if it is less than 0.0694 or higher than 0.4812, the crystal structure becomes unstable and the emission intensity decreases. The parameter c is a parameter representing the composition of O element, and if it is higher than 0.2283, the crystal structure becomes unstable and the emission intensity decreases. Further, considering the impurity oxygen contained in the powder raw material, there is no problem even if oxygen is contained in a range not exceeding 0.2283 (for example, c is more than 0, more preferably 0.001 or more), The emission intensity can be improved. The parameter d is a parameter representing the composition of the N element, and if it is less than 0.3261 or higher than 0.53, the crystal structure becomes unstable and the emission intensity decreases. The parameter e is the addition amount of the activator element A, and if it is less than 0.0001, the amount of luminescent ions is insufficient and the brightness is reduced. If it is more than 0.03, the emission intensity may decrease due to concentration quenching due to the interaction between the luminescent ions. The parameter f is a parameter representing the composition of the Q element other than the Al, Si, O, N, and A elements, and if it is higher than 0.3, the crystal structure becomes unstable and the emission intensity decreases. The composition of the parameters of each element is determined so that the neutral charges of the cations Al, Si, and A elements and the anions O, N, and Q elements are maintained.

Preferably, the parameters a, b, c, d, e, f are
0.0199 ≤ a ≤ 0.2747
0.1648 ≤ b ≤ 0.4642
0 ≤ c ≤ 0.0996
0.4183 ≤ d ≤ 0.5213
0.0004 ≤ e ≤ 0.0196
0 ≤ f ≤ 0.0233
The crystal having a value in the range satisfying all of the above conditions has a stable crystal structure and particularly has high emission intensity.

The inorganic crystal represented by M _n X _n+1 is the inorganic crystal represented by Si _x Al _m+2-x O _3-x N _m+x (m=n-2, 0<x≦3, and 1≦m≦50). Among the phosphors used as the matrix, inorganic crystals (simply Si _x Al _13-x ) represented by Si _x Al _13-x O _3-x N _11+x (0<x≦3) with m=11 (n=13). O _3−x N _11+x crystal), Si _x Al _13−x O _3−x N _11+x (0<x≦3), which has the same crystal structure as the inorganic crystal, or a solid solution thereof. An inorganic compound in which an A element (where A is one or more elements selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, and Yb) in a certain inorganic crystal is particularly high Indicates brightness.

The inorganic crystal represented by Si _x Al _13-x O _3-x N _11+x (0<x≦3) was newly synthesized by the present inventor and confirmed to be a novel crystal by crystal structure analysis. It has not been reported before.

FIG. 1 is a diagram showing a crystal structure of a Si _x Al _13-x O _3-x N _11+x (x≈2.2) crystal.

According to the present inventors have synthesized _{Si x Al 13-x O 3} -x N 11 + x single crystal structure analysis was performed on the _{crystal, Si x Al 13-x O} 3-x N 11 + x crystals rectangular tetragonal (rhombic It belongs to the Cmcm space group (the 63rd space group of International Tables for Crystallography) and occupies the crystal parameters and atomic coordinate positions shown in Table 1.

  In Table 1, the lattice constants a, b, and c indicate the lengths of the unit lattice axes, and α, β, and γ indicate the angles between the unit lattice axes. Atomic coordinates indicate the position of each atom in the unit cell with a value between 0 and 1 in units of the unit cell. In this crystal, each atom of Si, Al, O, and N exists, and Si and Al do not distinguish their seats, and SiAl(1) to SiAl(10), SiAl(11A) to SiAl(14A), And the analysis result which exists in 18 kinds of seats of SiAl(11B) to SiAl(14B) was obtained. Furthermore, O and N obtained the analysis result that 15 kinds of seats from ON (1) to ON (15) exist in the same seat.

As a result of the analysis using the data in Table 1, the Si _x Al _13-x O _3-x N _11+x crystal has the structure shown in FIG. 1, and is a tetrahedron composed of a bond of Si or Al and O or N. It was found to have a skeletal structure in which In the crystal, the element A, which becomes an activating ion such as Eu, is incorporated into the crystal in the form of locally substituting one O or N and four Si or Al bonded to the O or N. It is estimated to be.

As a crystal having the same crystal structure as the synthesized and structurally analyzed Si _x Al _13-x O _3-x N _11+x crystal, there is a (Si,Al) ₁₃ (O,N) ₁₄ crystal. In the (Si,Al) ₁₃ (O,N) ₁₄ crystal, in the Si _x Al _13-x O ₃ -xN _11+x crystal, Si and Al enter into the seats where Si and Al enter without distinguishing from each other. , O and N can enter the seats where O and N enter, without distinguishing each other. Thereby, while maintaining the crystal structure, the ratio of the total number of Si and Al elements is 13, and the total number of O and N is 14 atoms. However, it is desirable that the Si/Al ratio and the O/N ratio satisfy the condition that the electrical neutrality in the crystal is maintained.

In the following, for _simplicity, an inorganic crystal having a _{Si x Al 13-x O 3} -x N 11 + inorganic crystals represented by _{x, Si x Al 13-x} O 3-x N 11 + x crystal and the same crystal structure, these Inorganic crystals that are solid solutions are collectively referred to as Si _x Al _13-x O _3-x N _11+x based crystals.

The Si _x Al _13-x O _3-x N _11+x system crystal of the present invention can be identified by X-ray diffraction or neutron diffraction. As the substance having an _{Si x Al 13-x O 3} -x N 11 + x X -ray diffraction results same diffraction and crystals in this _invention, the _{Si x Al 13-x O 3} -x N 11 + x crystal and the same crystal structure It is a crystal that has, for example, an inorganic crystal represented by (Si,Al) ₁₃ (O,N) ₁₄ . Further, there is a crystal in which the lattice constant and the atomic position are changed by replacing the constituent element with another element in the Si _x Al _13-x O _3-x N _11+x crystal. Here, the constituent element being replaced by another element means that, for example, a part of Si or a part of Al in the Si _x Al _13-x O _3-x N _11+x crystal is replaced by L other than Si and Al. Some of them are replaced by elements (however, L is a metal element other than Si and Al). Further, there is one in which a part or all of O in the crystal or a part of N is replaced with a Z element other than O and N (where Z is a non-metal element other than O and N). These substitutions are performed so that the entire charge in the crystal becomes neutral. Those that do not change in crystal structure as a result of these element substitutions are Si _x Al _13-x O _3-x N _11+x based crystals. The substitution of elements changes the emission characteristics, chemical stability, and thermal stability of the phosphor, so it is advisable to place the element in a range where the crystal structure is maintained and select it according to the application.

The Si _x Al _13-x O _3-x N _11+x- based crystal has a lattice constant that is changed by substituting its constituents with other elements or forming a solid solution with an activating element such as Eu. The atomic positions given by the structure and the sites occupied by the atoms and their coordinates do not change so much that the chemical bonds between the skeletal atoms are broken. In the present invention, the results of X-ray diffraction and neutron diffraction are Al-N, Al-O, Si-N, and Si calculated from the lattice constants and atomic coordinates obtained by Rietveld analysis in the Cmcm space group space group. The length of the chemical bond of -O (distance between adjacent atoms) was calculated from the lattice constant and atomic coordinates of the Si _x Al _13-x O _3-x N _11+x (x≈2.2) crystal shown in Table 1. When it is within ±5% of the length of the chemical bond, it is defined as the same crystal structure and it is determined whether or not it is a Si _x Al _13-x O _3-x N _11+x system crystal. According to experiments, this criterion is that, in the Si _x Al _13-x O _3-x N _11+x type crystal, if the chemical bond length changes by more than ±5%, the chemical bond is broken and another crystal is formed. This is because it was confirmed.

Further, when the amount of solid solution is small, there is the following method as a simple determination method for the Si _x Al _13-x O _3-x N _11+x type crystal. When the lattice constant calculated from the X-ray diffraction results measured for a new substance and the diffraction peak position (2θ) calculated using the crystal structure data of Table 1 match for the main peak, the crystal structure is identified as the same. can do.

FIG. 2 is a diagram showing powder X-ray diffraction using CuKα rays calculated from the crystal structure of a Si _x Al _13-x O _3-x N _11+x crystal.

By comparing the substance to be compared with FIG. 2, it is possible to easily determine whether the crystal is a Si _x Al _13-x O _3-x N _11+x system crystal. As the main peak of the Si _x Al _13-x O _3-x N _11+x type crystal, it is preferable to determine about 10 peaks having high diffraction intensity. In that sense, Table 1 is important because it serves as a reference for specifying the Si _x Al _13-x O _3-x N _11+x system crystal. Further, the crystal structure of the Si _x Al _13-x O _3-x N _11+x system crystal can be defined by using another crystal system of the orthorhombic system (orthorhombic system), and in that case, it is different. Although the space group, the lattice constant, and the plane index are used, the X-ray diffraction result (eg, FIG. 2) and the crystal structure (eg, FIG. 1) are the same, and the identification method and the identification result using the same are the same. It becomes the thing of. Therefore, in the present invention, X-ray diffraction analysis is performed as a orthorhombic system (orthorhombic system). The method of identifying a substance based on Table 1 will be specifically described in Examples described later, and only a brief description will be given here.

The Si _x Al _13-x O _3-x N _11+x system crystal is provided with one or more elements selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, and Yb as the A element. When activated, a phosphor is obtained. Since the emission characteristics such as the excitation wavelength, the emission wavelength, and the emission intensity change depending on the composition of the Si _x Al _13-x O _3-x N _11+x- based crystal and the type and amount of the activating element, it may be selected according to the application. ..

Inorganic crystals represented by _{Si x Al 13-x O 3} -x N 11 + x, inorganic crystals having a _{Si x Al 13-x O 3} -x N same crystal structure as the inorganic crystal represented by _{11 + x,} or solid solutions thereof Is an orthorhombic (orthorhombic) crystal, has a symmetry of space group Cmcm, and lattice constants a, b, and c are
a = 0.30749±0.05 nm
b=1.87065±0.05 nm
c=3.8432±0.05 nm
When the value is in the range of 1, the crystal is particularly stable, and the phosphor having these as a host crystal has high emission intensity. If it is out of this range, the crystal becomes unstable and the emission intensity may decrease.

  Preferably, the phosphor with 1.5≦x≦3 has high emission intensity. More preferably, the fluorescent intensity of 1.8≦x≦3 is even higher, and the fluorescent intensity of 2≦x≦3 is particularly high. Considering the impurity oxygen in the raw material, it is preferable to set the upper limit of x to 2.9 or less because a phosphor with high emission intensity can be obtained without performing highly accurate control during production.

  The activator element A contains at least Eu. As a result, a phosphor having particularly high emission intensity can be obtained.

Preferably, the composition formula Si _a Al _b O _c N _d A _e Q _f (where a+b+c+d+e+f=1 in the formula, A is selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy and Yb). 1 or 2 or more elements, Q is one or two or more elements selected from elements other than Al, Si, O, N, and A), and parameters a, b, c, d, e and f are
0.014 ≤ a ≤ 0.111
0.369 ≤ b <0.48
0 ≤ c <0.111
0.406 <d <0.517
0.0001 ≤ e ≤ 0.03
0 ≤ f ≤ 0.3 (however, when there are multiple Q elements, f is the sum of the parameters of each element)
The phosphor represented by the composition satisfying all the above conditions has particularly high emission intensity.

  The parameter a is a parameter representing the composition of the Si element, and if it is less than 0.014 or higher than 0.111, the crystal structure becomes unstable and the emission intensity decreases. The parameter b is a parameter representing the composition of the Al element, and if it is less than 0.369 or 0.48 or more, the crystal structure becomes unstable and the emission intensity decreases. The parameter c is a parameter representing the composition of O element, and if it is 0.111 or more, the crystal structure becomes unstable and the emission intensity decreases. Further, in consideration of impurity oxygen contained in the powder raw material, there is no problem even if oxygen is contained in a range not exceeding 0.111 (for example, c is more than 0, more preferably 0.001 or more), The emission intensity can be improved. The parameter d is a parameter representing the composition of the N element, and if it is 0.406 or less or 0.517 or more, the crystal structure becomes unstable and the emission intensity decreases. The parameter e is the addition amount of the activator element A, and if it is less than 0.0001, the amount of luminescent ions is insufficient and the brightness is reduced. If it is more than 0.03, the emission intensity may decrease due to concentration quenching due to the interaction between the luminescent ions. The parameter f is a parameter representing the composition of the Q element other than the Al, Si, O, N, and A elements, and if it is higher than 0.3, the crystal structure becomes unstable and the emission intensity decreases. The composition of the parameters of each element is determined so that the neutral charges of the cations Al, Si, and A elements and the anions O, N, and Q elements are maintained.

More preferably, the parameters a, b, c, d, e, f are
0.0185 ≤ a ≤ 0.1107
0.369 ≤ b ≤ 0.4613
0 ≤ c ≤ 0.0923
0.4244 ≤ d ≤ 0.5166
0.0001 ≤ e ≤ 0.0196
0 ≤ f ≤ 0.0233
The crystal having a value in the range satisfying all of the above conditions has a stable crystal structure and particularly has high emission intensity.

More preferably, the parameters a, b, c, d, e, f are
0.05 ≤ a ≤ 0.1107
0.369 ≤ b ≤ 0.43
0 ≤ c ≤ 0.056
0.45 ≤ d ≤ 0.5166
0.0001 ≤ e ≤ 0.0196
0 ≤ f ≤ 0.0233
The crystal having a value in the range satisfying all of the above conditions has a stable crystal structure and particularly has high emission intensity.

It is preferable that the parameters a, b, c, d, e and f are
0.0738 ≤ a ≤ 0.1107
0.369 ≤ b ≤ 0.4059
0 ≤ c ≤ 0.0369
0.4797 ≤ d ≤ 0.5166
0.0004 ≤ e ≤ 0.0196
0 ≤ f ≤ 0.0233
The crystal having a value in the range satisfying all of the above conditions has a stable crystal structure and particularly has high emission intensity.

  A phosphor in which an inorganic compound is a single crystal particle having an average particle size of 0.1 μm or more and 40 μm or less or an aggregate of single crystals has high emission efficiency and has good operability when mounted on an LED, and thus the particle size in this range It is better to control to.

  The Fe, Co, and Ni impurity elements contained in the inorganic compound may reduce the emission intensity. When the total amount of these elements in the phosphor is 500 ppm or less, the effect of lowering the emission intensity is reduced.

As one of the embodiments of the present invention, an inorganic crystal represented by M _n X _n+1 containing at least a metal element M and a non-metal element X (where n is a numerical value in the range of 3≦n≦52) and the same Inorganic crystal having a crystal structure, or, as a matrix, an inorganic crystal that is a solid solution thereof, a phosphor composed of an inorganic compound in which luminescent ions are solid-solved, and composed of a mixture of another crystal phase or an amorphous phase, There is a phosphor having a phosphor content of 20% by mass or more. When the inorganic crystal represented by M _n X _n+1 , the inorganic crystal having the same crystal structure as that of the inorganic crystal, or the single substance of the inorganic compound having the inorganic crystal that is a solid solution thereof as a matrix cannot obtain the desired characteristics, This embodiment may be used when a function such as conductivity is added. The content of the inorganic crystal represented by M _n X _n+1 , the inorganic crystal having the same crystal structure as that of the inorganic crystal, or the content of the phosphor composed of the inorganic compound having the inorganic crystal, which is a solid solution thereof as a matrix, is adjusted according to the desired characteristics. However, if the content is less than 20% by mass, the emission intensity may be low. Therefore, the amount of the main component is 20% by mass or more.

  When the phosphor is required to have conductivity such as for electron beam excitation, an inorganic substance having conductivity as another crystal phase or amorphous phase may be added.

  Examples of the inorganic substance having conductivity include oxides, oxynitrides or nitrides containing one or more elements selected from Zn, Al, Ga, In and Sn, or a mixture thereof. Examples thereof include zinc oxide, aluminum nitride, indium nitride, tin oxide, and the like.

One of the embodiments of the present invention is a phosphor having a peak in a wavelength range of 460 nm to 500 nm when irradiated with an excitation source. For example, an inorganic crystal represented by M _n X _n+1 activated with Eu, an inorganic crystal having the same crystal structure as that of the phosphor, or a phosphor having an inorganic crystal, which is a solid solution thereof, as a host material has a composition within this range. Has an emission peak.

  As one of the embodiments of the present invention, there is a phosphor whose excitation source emits a vacuum ultraviolet ray having a wavelength of 100 nm or more and 420 nm or less, an ultraviolet ray or visible light, an electron beam or an X-ray. Efficient light emission can be achieved by using these excitation sources.

  As described above, the phosphor of the present invention has a wider excitation range from electron rays, X-rays, and ultraviolet rays to visible light, and emits blue to green light, as compared with ordinary oxide phosphors and existing sialon phosphors. In particular, a specific composition exhibits a blue to green color of 460 nm to 500 nm, and the emission wavelength and emission peak width are adjustable. Due to such a light emitting property, the phosphor of the present invention is suitable for lighting equipment, image display devices, pigments, and ultraviolet absorbers. The phosphor of the present invention is also excellent in heat resistance because it does not deteriorate even when exposed to high temperatures, and has the advantage that it is also excellent in long-term stability in an oxidizing atmosphere and a moisture environment, and is durable. A product with excellent properties can be provided.

The method for producing the phosphor of the present invention is not particularly limited, but for example, it is a mixture of metal compounds, and by firing, an inorganic crystal represented by at least M _n X _n+1 and having the same crystal structure as that of the inorganic crystal. A raw material mixture that can form a phosphor composed of an inorganic crystal or an inorganic compound having an inorganic crystal that is a solid solution of these as a matrix is fired in a temperature range of 1200° C. or more and 2200° C. or less in an inert atmosphere containing nitrogen. Can be obtained by The main crystal of the present invention belongs to the space group Cmcm in the orthorhombic system, but crystals having a different crystal system or space group may be mixed depending on the synthesis conditions such as the firing temperature. Even in this case, since the change in the light emission characteristic is slight, it can be used as a high-luminance phosphor.

As the starting material, for example, a mixture of metal compounds may be AlN and/or Al ₂ O ₃ , Si ₃ N _4, and an oxide or nitride of A (where A is Mn, Ce, Pr, Nd, One or more elements selected from Sm, Eu, Tb, Dy and Yb) are preferably used. These mixtures are preferable because the raw materials are easily available and excellent in stability. It is also preferable because the reaction easily proceeds during firing. When the phosphor of the present invention contains Ca as the L element, F (fluorine) as the Y element, or the F (fluorine) as the Z element, the mixture of the metal compounds further contains a fluoride of the L element (eg, calcium fluoride) or an oxidation of the L element. (For example, calcium oxide, yttrium oxide) may be included. Such a starting material may be an inorganic compound that forms a liquid phase at a temperature equal to or lower than the firing temperature described below.

  Since the furnace used for firing has a high firing temperature and the firing atmosphere is an inert atmosphere containing nitrogen, carbon is used as the material for the high temperature part of the furnace by the metal resistance heating method or the graphite resistance heating method. An electric furnace that has been used is suitable. A nitrogen-containing inert atmosphere in a pressure range of 0.1 MPa or more and 100 MPa or less is preferable because thermal decomposition of a starting material or a product such as a nitride or an oxynitride can be suppressed. The oxygen partial pressure in the firing atmosphere is preferably 0.0001% or less in order to suppress the oxidation reaction of the starting materials and products such as nitrides and oxynitrides.

  The firing time varies depending on the firing temperature, but is usually about 1 to 10 hours.

  In order to manufacture the phosphor in the form of powder or aggregate, it is advisable to employ a method in which the raw material is filled in a container in a state where the filling rate is 40% or less in bulk density and then baked. By setting the bulk density to be 40% or less, it is possible to prevent strong adhesion between particles. Here, the relative bulk density is a ratio of a value (bulk density) obtained by dividing the mass of the powder filled in the container by the volume of the container and the true density of the substance of the powder.

  Although various heat-resistant materials can be used as a container for holding the raw material compound when firing the raw material mixture, the adverse effect of the material deterioration on the metal nitride used in the present invention is low, and thus the journal of the Journal of the A container coated with boron nitride as shown in the graphite crucible coated with boron nitride used in the synthesis of α-sialon, as described in American Ceramic Society 2002 Volume 85, No. 5, pp. 1229 to 1234, or boron nitride. A sintered body is suitable. When the firing is performed under such conditions, the boron or boron nitride component is mixed into the product from the container, but if the amount is small, the light emitting property is not deteriorated, so that there is little influence. The addition of a small amount of boron nitride may improve the durability of the product, which is preferable in some cases.

  In order to produce the phosphor in the form of powder or aggregate, it is preferable that the raw material powder particles or aggregate have an average particle size of 500 μm or less, because the reactivity and operability are excellent.

  As a method for controlling the particle size of the particles or aggregates to 500 μm or less, it is preferable to use spray dryer, sieving, or air classification because the work efficiency and operability are excellent.

  The firing method is not hot pressing, but is a method of obtaining a powder or agglomerate product, such as atmospheric pressure sintering method or gas pressure sintering method, which does not apply mechanical pressure from the outside. preferable.

  The average particle size of the phosphor powder is preferably 50 nm or more and 200 μm or less in terms of volume-based median diameter (d50) because the emission intensity is high. The volume-based average particle diameter can be measured by, for example, Microtrac or a laser scattering method. The average particle size of the phosphor powder synthesized by firing may be adjusted to 50 nm or more and 200 μm or less by using one or more methods selected from crushing, classification, and acid treatment.

  The phosphor powder after firing, the phosphor powder after pulverization treatment, or the phosphor powder after particle size adjustment is heat-treated at a temperature of 1000° C. or higher and a firing temperature or lower, so that defects contained in the powder or damage due to pulverization are included. May recover. Defects or damage may cause a decrease in emission intensity, and in this case, heat treatment restores the emission intensity.

  At the time of firing for synthesizing the phosphor, by adding an inorganic compound that forms a liquid phase at a temperature below the firing temperature and firing, it acts as a flux, reaction and grain growth are promoted and stable crystals are obtained. In some cases, this may improve the emission intensity.

  As an inorganic compound that forms a liquid phase at a temperature equal to or lower than the firing temperature, a fluoride, chloride, iodide, or bromide of one or more elements selected from Li, Na, K, Mg, Ca, Sr, and Ba Alternatively, one or a mixture of two or more phosphates may be mentioned. Since these inorganic compounds have different melting points, it is preferable to use them properly depending on the synthesis temperature.

  Further, by washing with a solvent after firing, the emission intensity of the phosphor may be increased by reducing the content of the inorganic compound that forms a liquid phase at a temperature equal to or lower than the firing temperature.

  When the phosphor of the present invention is used for a light emitting device or the like, it is preferable to use the phosphor dispersed in a liquid medium. It can also be used as a phosphor mixture containing the phosphor of the present invention. A dispersion containing the phosphor of the present invention in a liquid medium is referred to as a phosphor-containing composition.

  The liquid medium that can be used in the phosphor-containing composition of the present invention exhibits a liquid property under desired use conditions, and preferably does not cause an undesired reaction or the like while appropriately dispersing the phosphor of the present invention. If so, it is possible to select an arbitrary one according to the purpose. Examples of the liquid medium include addition reaction type silicone resin before condensation, condensation reaction type silicone resin, modified silicone resin, epoxy resin, polyvinyl resin, polyethylene resin, polypropylene resin, polyester resin and the like. One of these liquid media may be used alone, or two or more thereof may be used in any combination and ratio.

  The amount of the liquid medium used may be appropriately adjusted depending on the application etc., but generally, the weight ratio of the liquid medium to the phosphor of the present invention is usually 3% by weight or more, preferably 5% by weight or more, Further, it is usually 30% by weight or less, preferably 15% by weight or less.

  In addition to the phosphor of the present invention and the liquid medium, the phosphor-containing composition of the present invention may contain any other component depending on its application. Examples of other components include a diffusing agent, a thickening agent, a bulking agent, and an interfering agent. Specifically, silica-based fine powder such as Aerosil, alumina and the like can be mentioned.

  The light emitting device of the present invention comprises at least a light emitting body or a light emitting source and the phosphor of the present invention.

  Examples of the light emitter or light source include an LED light emitting device, a laser diode light emitting device, an EL light emitting device, and a fluorescent lamp. The LED light-emitting device can be manufactured using the phosphor of the present invention by a known method as described in JP-A-5-152609, JP-A-7-99345, JP-A-2927279 and the like. In this case, the light emitting body or the light emitting source preferably emits light having a wavelength of 330 to 500 nm, and among them, an ultraviolet (or purple) LED light emitting element of 330 to 420 nm or a blue LED light emitting element of 420 to 500 nm is preferable. Some of these LED light emitting elements are made of a nitride semiconductor such as GaN or InGaN, and can be a light emitting light source that emits light of a predetermined wavelength by adjusting the composition.

  Examples of the light emitting device of the present invention include a white light emitting diode containing the phosphor of the present invention, a lighting fixture including a plurality of white light emitting diodes, a backlight for a liquid crystal panel, and the like.

In such a light emitting device, in addition to the phosphor of the present invention, Eu-activated β-sialon green phosphor, Eu-activated α-sialon yellow phosphor, and Eu-activated Sr ₂ Si ₅ N ₈ orange The phosphor may further include one or more kinds of phosphors selected from Eu-activated (Ca,Sr)AlSiN ₃ orange phosphor and Eu-activated CaAlSiN ₃ red phosphor. As the yellow phosphor other than the above, for example, YAG:Ce, (Ca,Sr,Ba)Si ₂ O ₂ N ₂ :Eu, etc. may be used.

  As one mode of the light-emitting device of the present invention, a light-emitting body or a light-emitting source emits ultraviolet or visible light having a peak wavelength of 300 to 450 nm, and the phosphor of the present invention emits blue to green light and other phosphors of the present invention. There is a light emitting device that emits white light or light other than white light by mixing emitted light having a wavelength of 450 nm or more.

As one mode of the light emitting device of the present invention, in addition to the phosphor of the present invention, a blue phosphor that emits light having a peak wavelength of 420 nm to 500 nm or less by the light emitter or a light emitting source can be further included. Such as the blue _{phosphor, AlN: (Eu, Si)} , BaMgAl 10 O 17: Eu, SrSi 9 Al 19 ON 31: Eu, LaSi 9 Al 19 N 32: Eu, α- sialon: Ce, JEM : Ce, etc.

As one mode of the light emitting device of the present invention, in addition to the phosphor of the present invention, a green phosphor that emits light having a peak wavelength of 500 nm or more and 550 nm or less by the light emitter or a light emitting source can be further included. Examples of such green phosphors include β-sialon:Eu, (Ba,Sr,Ca,Mg) ₂ SiO ₄ :Eu, (Ca,Sr,Ba)Si ₂ O ₂ N ₂ :Eu. is there.

As one mode of the light emitting device of the present invention, in addition to the phosphor of the present invention, a yellow phosphor that emits light having a peak wavelength of 550 nm or more and 600 nm or less by the light emitter or a light emitting source can be further included. Examples of such a yellow phosphor include YAG:Ce, α-sialon:Eu, CaAlSiN ₃ :Ce, and La ₃ Si ₆ N ₁₁ :Ce.

As one mode of the light emitting device of the present invention, in addition to the phosphor of the present invention, a red phosphor that emits light having a peak wavelength of 600 nm or more and 700 nm or less by the light emitter or a light emitting source can be further included. Examples of such red phosphors include CaAlSiN ₃ :Eu, (Ca,Sr)AlSiN ₃ :Eu, Ca ₂ Si ₅ N ₈ :Eu, and Sr ₂ Si ₅ N ₈ :Eu.

  The image display device of the present invention comprises at least an excitation source and the phosphor of the present invention, and includes a fluorescent display tube (VFD), a field emission display (FED), a plasma display panel (PDP), a cathode ray tube (CRT) and the like. is there. It has been confirmed that the phosphor of the present invention emits light when excited by vacuum ultraviolet rays of 100 to 190 nm, ultraviolet rays of 190 to 380 nm, an electron beam or the like, and in combination of these excitation sources and the phosphor of the present invention, The image display device as described above can be configured.

  The phosphor of the present invention comprising an inorganic compound crystal phase having a specific chemical composition has a white object color, and thus can be used as a pigment or a fluorescent pigment. That is, when the phosphor of the present invention is irradiated with illumination such as sunlight or a fluorescent lamp, a white object color is observed, but the color development is good, and it does not deteriorate for a long period of time. Is suitable for inorganic pigments. Therefore, when it is used in paints, inks, paints, glazes, colorants added to plastic products, and the like, good color development can be maintained high for a long period of time.

  The nitride phosphor of the present invention absorbs ultraviolet rays and is therefore suitable as an ultraviolet absorber. Therefore, when used as a paint, applied to the surface of a plastic product, or kneaded into a plastic product, the effect of blocking ultraviolet rays is high and the product can be effectively protected from deterioration by ultraviolet rays.

  The present invention will be described in more detail with reference to the following examples, but this is merely disclosed as an aid for easily understanding the present invention, and the present invention is not limited to these examples. Absent.

[Raw materials used for synthesis]
The raw material powder used for the synthesis is a silicon nitride powder having a specific surface area of 11.2 m ² /g and an oxygen content of 1.29% by weight and an α-type content of 95% (SN-E10 manufactured by Ube Industries, Ltd.). Grade), an aluminum nitride powder having an oxygen content of 0.82% by weight (E grade manufactured by Tokuyama Corp.) having a specific surface area of 3.3 m ² /g, and a specific surface area of 13.2 m ² /g. Aluminum oxide powder (Taimicron manufactured by Daimei Chemical Co., Ltd.), europium oxide (Eu ₂ O ₃ ; purity 99.9% manufactured by Shin-Etsu Chemical Co., Ltd.), and cerium oxide (CeO ₂ ; purity 99.9%, Shin-Etsu) Chemical Industry Co., Ltd.), europium nitride (EuN; metal europium obtained by nitriding metal by heating at 800° C. for 10 hours in an ammonia stream), and terbium oxide (Tb ₄ O ₇ ; Purity 99.9% manufactured by Shin-Etsu Chemical Co., Ltd.), ytterbium oxide (Yb ₂ O ₃ ; purity 99.9% manufactured by Shin-Etsu Chemical Co., Ltd.), and manganese carbonate (MnCO ₃ ; purity 99.9% ( Manufactured by Kojundo Chemical Research Institute Co., Ltd.) and calcium fluoride (CaF ₂ ; purity 99.9% manufactured by Kojundo Chemical Research Institute Co., Ltd.).

[Phosphor Example: Examples 1 to 36]
According to the design composition shown in Table 2 and Table 3, the raw materials were weighed so as to have the mixed composition (mass ratio) in Table 4. The design parameters were in the range of m=2 to 40 (n=4 to 42) and x=1 to 3. Depending on the type of raw material used, the composition may differ between the design composition of Tables 2 and 3 and the mixed composition of Table 4, and in this case, the mixed composition was determined so that the amounts of metal ions would match. The component having the compositional deviation is mixed in the product as the second phase, but the amount thereof is small, so that the influence on the performance is small. The weighed raw material powders were mixed for 5 minutes using a silicon nitride sintered body pestle and a mortar. Then, the mixed powder was put into a crucible made of a boron nitride sintered body. The bulk density of the powder was about 20% to 30%.

The crucible containing the mixed powder was set in a graphite resistance heating type electric furnace. In the firing operation, the firing atmosphere was first evacuated to a vacuum with a pressure of 1×10 ⁻¹ Pa or less and heated from room temperature to 800° C. at a rate of 500° C./hour to obtain a purity of 99.999% by volume at 800° C. Nitrogen was introduced to adjust the pressure in the furnace to 1 MPa, the temperature was raised to the set temperature shown in Table 5 at 500° C./hour, and the temperature was maintained for 2 hours.

Next, the synthesized compound was crushed using an agate mortar, and powder X-ray diffraction measurement was performed using K _α rays of Cu. As a result, an inorganic crystal represented by M _n X _n+1 , that is, a crystal represented by a general formula of Si _x Al _m+2-x O _3-x N _m+x (m=n−2, 0<x≦3, m: integer). It was confirmed that the phase was the main productive phase. Moreover, it was confirmed from the measurement of EDS that the compound contained Eu, Si, Al, N, and O. That is, it was confirmed that the compound was an inorganic compound in which Eu, which is a luminescent ion, was solid-dissolved in a Si _x Al _m+2-x O _3-x N _m+x (0<x≦3, m: integer) crystal.

  After firing, the obtained fired body was roughly pulverized, then manually pulverized using a crucible and a mortar made of a silicon nitride sintered body, and passed through a 30 μm mesh sieve. When the particle size distribution was measured, the average particle size was 3 to 8 μm.

  As a result of irradiating these powders with a lamp that emits light having a wavelength of 365 nm, it was confirmed that light was emitted from blue to green. The emission spectrum and excitation spectrum of this powder were measured using a fluorescence spectrophotometer. Table 6 shows the peak wavelength of the excitation spectrum and the peak wavelength of the emission spectrum. It was confirmed that these inorganic compounds are phosphors that can be excited by ultraviolet rays of 300 nm to 380 nm, violet of 380 nm to 450 nm or blue light, and emit blue to green light.

  It should be noted that a portion where the mixed raw material composition and the chemical composition of the synthetic product are different from each other is considered to be present in a small amount as a second phase of impurities in the synthetic product.

[Phosphor Example: Example 37]
According to the design composition shown in Table 7 and Table 8, the raw materials were weighed so as to have the mixed composition (mass ratio) in Table 9. The design parameters are m=10 and x=2.5, and what is different from Examples 1 to 36 is that calcium fluoride (CaF ₂ ) is added as a flux. Flux is an inorganic compound that forms a liquid phase at a temperature lower than the firing temperature during firing for synthesizing a phosphor, and when added and fired, the reaction and grain growth are promoted and stable crystals are obtained. In some cases, this may improve the emission intensity. The flux, an alkali metal compound (LiCl, NaC1, KCl, LiF , NaF, KF , etc.) it is or alkaline earth metal compound _{(CaF 2, SrF 2, BaF} 2, CaC1 2, SrCl 2, BaCl 2 , etc.) In Example 37, calcium fluoride (CaF ₂ ) was used.

  The weighed raw material powders were mixed for 5 minutes using a pestle made of a silicon nitride sintered body and a mortar in the same manner as in Examples 1 to 36. Then, the mixed powder was put into a crucible made of a boron nitride sintered body. The bulk density of the powder was in the range of about 20% to 30%.

The crucible containing the mixed powder was set in a graphite resistance heating type electric furnace. In the firing operation, the firing atmosphere was first evacuated to a vacuum with a pressure of 1×10 ⁻¹ Pa or less and heated from room temperature to 800° C. at a rate of 500° C./hr. Nitrogen was introduced to bring the pressure in the furnace to 1 MPa, the temperature was raised to a preset temperature of 2000° C. at 500° C./hour, and the temperature was maintained for 2 hours.

Next, the synthesized compound was crushed using an agate mortar, and powder X-ray diffraction measurement was performed using K _α rays of Cu. As a result, an inorganic crystal represented by M _n X _n+1 , that is, a crystal represented by a general formula of Si _x Al _m+2-x O _3-x N _m+x (m=n−2, 0<x≦3, m: integer). It was confirmed that the phase was the main productive phase. Moreover, it was confirmed from the measurement of EDS that the compound contained Eu, Si, Al, N, O, Ca, and F. That is, the compound is an inorganic compound in which Eu, which is a light emitting ion, and Ca and F are solid-dissolved in a Si _x Al _m+2-x O _3-x N _m+x (0<x≦3, m: integer) crystal. confirmed.

  After firing, the obtained fired body was roughly pulverized, then manually pulverized using a crucible and a mortar made of a silicon nitride sintered body, and passed through a 30 μm mesh sieve. When the particle size distribution was measured, the average particle size was within the range of 3 to 8 μm.

  As a result of irradiating this powder with a lamp that emits light having a wavelength of 365 nm, it was confirmed that light was emitted from blue to green. The emission spectrum and excitation spectrum of this powder were measured using a fluorescence spectrophotometer. Table 10 shows the peak wavelength of the excitation spectrum and the peak wavelength of the emission spectrum. It was confirmed that this inorganic compound is a phosphor that can be excited by ultraviolet rays of 300 nm to 380 nm, violet of 380 nm to 450 nm or blue light, and emits blue to green light.

[Phosphor Examples; Examples 38 to 43]
According to the design composition shown in Table 11 and Table 12, the raw materials were weighed so as to have the mixed composition (mass ratio) in Table 13. Different from Examples 1 to 36, the activator element to be the luminescent ion was an element other than Eu. Depending on the type of raw material used, the composition may differ between the design composition of Tables 11 and 12 and the mixed composition of Table 13, and in this case, the mixed composition was determined so that the amounts of metal ions would match. The component having the compositional deviation is mixed in the product as the second phase, but the amount thereof is small, so that the influence on the performance is small. The weighed raw material powders were mixed for 5 minutes using a silicon nitride sintered body pestle and a mortar. Then, the mixed powder was put into a crucible made of a boron nitride sintered body. The bulk density of the powder was about 20% to 30%.

The crucible containing the mixed powder was set in a graphite resistance heating type electric furnace. In the firing operation, the firing atmosphere was first evacuated to a vacuum with a pressure of 1×10 ⁻¹ Pa or less and heated from room temperature to 800° C. at a rate of 500° C./hr. Nitrogen was introduced to bring the pressure in the furnace to 1 MPa, the temperature was raised to a preset temperature of 2000° C. at 500° C./hour, and the temperature was maintained for 2 hours.

Next, the synthesized compound was crushed using an agate mortar, and powder X-ray diffraction measurement was performed using K _α rays of Cu. As a result, an inorganic crystal represented by M _n X _n+1 , that is, a crystal represented by a general formula of Si _x Al _m+2-x O _3-x N _m+x (m=n−2, 0<x≦3, m: integer). It was confirmed that the phase was the main productive phase. Further, it was confirmed from the measurement of EDS that the compound contained Ce, Tb, Yb or Mn, Si, Al, N, and O. That is, it was confirmed that the compound was an inorganic compound in which the element A, which is a luminescent ion, was solid-dissolved in the Si _x Al _m+2-x O _3-x N _m+x (0<x≦3, m: integer) crystal.

  After firing, the obtained fired body was roughly pulverized, then manually pulverized using a crucible and a mortar made of a silicon nitride sintered body, and passed through a 30 μm mesh sieve. When the particle size distribution was measured, the average particle size was within the range of 3 to 8 μm.

  As a result of irradiating these powders with a lamp that emits light having a wavelength of 365 nm, it was confirmed that light was emitted from blue to green. Even if Ce, Tb, Yb, or Mn is used as an activating element, these inorganic compounds can be excited by ultraviolet rays of 300 nm to 380 nm, violet of 380 nm to 450 nm, or blue light, and emit blue to green light. It was confirmed to be a phosphor.

[Synthesis and Structural Analysis of Crystalline Si _x Al _13-x O _3-x N _11+x (x≈2.2)]
The present inventors have found that the inorganic crystals represented by M _n X _n+1 obtained in Examples 1 to 43 are Si _x Al _m+2-x O _3-x N _m+x (m=n-2, 0<x≦. Among the phosphors whose parent is the inorganic crystal represented by the general formula 3), the phosphor is represented by Si _x Al _13-x O _3-x N _11+x (0<x≦3) with m=11 (n=13). It has been found that the phosphor having an inorganic crystal as a base material exhibits particularly excellent light emitting characteristics. _{Hereinafter, Si x Al 13-x O} 3-x N 11 + x (0 <x ≦ 3) will be described in detail the synthesis and structural analysis of the crystals.

A mixed composition of silicon nitride (Si ₃ N ₄ ), aluminum nitride (AlN), and aluminum oxide (Al ₂ O ₃ ) was designed in such a ratio that the cation ratio became Si:Al=2.2:10.8. These raw material powders were weighed so as to have the above-mentioned mixed composition, and mixed for 5 minutes using a silicon nitride sintered body pestle and a mortar in a nitrogen atmosphere glove box having an oxygen content of 1 ppm. Next, the obtained mixed powder was put into a crucible made of a boron nitride sintered body. The bulk density of the mixed powder (powder) was about 30%.

The crucible containing the mixed powder was set in a graphite resistance heating type electric furnace. In the firing operation, the firing atmosphere was first evacuated to a vacuum with a pressure of 1×10 ⁻¹ Pa or less and heated from room temperature to 800° C. at a rate of 500° C./hr. Nitrogen was introduced to adjust the pressure in the furnace to 1 MPa, the temperature was raised from 500° C./hour to 2000° C., and the temperature was maintained for 2 hours.

  The synthesized product was observed with an optical microscope, and crystal particles having a size of 7 μm×26 μm×57 μm were collected from the synthesized product. Using a scanning electron microscope (SEM; SU1510 manufactured by Hitachi High-Technologies Corp.) equipped with an energy dispersive elemental analyzer (EDS; QUANTAX manufactured by Bruker AXS), the particles were analyzed for Analysis was carried out. As a result, the presence of Si, Al, O, and N elements was confirmed, and the ratio of the number of atoms contained in Si and Al was measured to be 2.2:10.8.

  Next, this crystal was fixed to the tip of the glass fiber with an organic adhesive. This was subjected to X-ray diffraction measurement under the condition that the output of the X-ray source was 50 kV 50 mA, using a single crystal X-ray diffractometer (SMART APEXII Ultra manufactured by Bruker AXS) with a rotating anticathode of MoKα ray. .. As a result, it was confirmed that the crystal grains were single crystals.

  Next, the crystal structure was determined from the X-ray diffraction measurement results using single crystal structure analysis software (APEX2 manufactured by Bruker AXS). The obtained crystal structure data is shown in Table 1, and the crystal structure diagram is shown in FIG. Table 1 describes the crystal system, space group, lattice constant, atom type and atom position, and this data can be used to determine the shape and size of the unit cell and the arrangement of atoms in it. .. It should be noted that Si and Al enter at the same atomic position, and oxygen and nitrogen enter at the same atomic position, and become the composition ratio of the crystal when averaged as a whole.

This crystal belongs to the orthorhombic system (orthorhombic system) (orthorhombic system), the space group Cmcm, (International Tables for Crystallography No. 63 space group), and the lattice constants a, b, and c are
a=0.30749 nm, b=1.87065 nm, c=3.85432 nm, angles α=90°, β=90°, γ=90°. The atomic positions were as shown in Table 1. In the table, Si and Al are present at the same atomic position in a certain ratio determined by the composition. Further, since Al has a valence of +3 and Si has a valence of +4, if the atomic position and the ratio of Al and Si are known, the ratio of O and N occupying the (O,N) position depends on the electrically neutral condition of the crystal. Desired. The composition of this crystal obtained from the Si:Al ratio of the measured value of EDS and the single crystal X-ray structural analysis was Si _x Al _13-x O _3-x N _11+x (x≈2.2). The starting material composition and the crystal composition may be different, but this is because a composition other than Si _x Al _13-x O _3-x N _11+x (x≈2.2) was generated as a small amount of the second phase. .. Even in that case, since the measurement uses a single crystal, the analysis result shows a pure Si _x Al _13-x O _3-x N _11+x (x≈2.2) structure.

When a similar composition was investigated, it was found that the Si _x Al _13-x O _3-x N _11+x (x≈2.2) crystal was partially replaced with Al while maintaining the crystal structure. Can be replaced with Si, a part or all of O can be replaced with N, and a part of N can be replaced with O, and these replaced crystals have Si _x Al _13-x O _3-x N _11+x (x≈ It was confirmed to be one composition of crystal groups having the same crystal structure as in 2.2). Further, it can be described as a composition represented by Si _x Al _13-x O _3-x N _11+x (0<x≦3) from the condition of electrical neutrality.

In addition, Si _x Al _13-x O _3-x N _11+x can also be described as a composition represented by Si _x Al _m+2-x O _3-x N _m+x (0<x≦3, m=11). These structures including the Si _x Al _13-x O _3-x N _11+x (0<x≦3) crystal in which m=11 are obtained by converting Al ₂ O ₃ (AlN) _m into SiAlON. , O→N substitution correspond to increase/decrease in valence of +1 and −1, respectively, so that both change amounts can be represented by the same variable. As the number of m increases, AlN-like phases increase, and the longest lattice axis (c-axis in general notation) extends. The remaining two axes (a-axis and b-axis) have almost the same values.

It was confirmed from the crystal structure data that this crystal was a novel substance that had not been reported until now. The powder X-ray diffraction pattern calculated from the crystal structure data is shown in FIG. In the future, powder X-ray diffraction measurement of the compound will be performed, and if the measured powder pattern is the same as in FIG. 2, it can be determined that the crystal Si _x Al _13-x O _3-x N _{11+x in} FIG. 1 is generated. .. Further, as the Si _x Al _13-x O _3-x N _11+x- based crystal in which the lattice constant and the like changed while maintaining the crystal structure, the values of the lattice constant obtained by the powder X-ray diffraction measurement and the crystal of Table 1 were used. Since the powder X-ray pattern can be calculated from the structural data by calculation, it can be determined by comparison with the calculated pattern that a Si _x Al _13-x O _3-x N _11+x- based crystal is generated.

[Phosphor Examples; Examples 44 to 53]
According to the design composition shown in Table 14 and Table 15, the raw materials were weighed so as to have the mixed composition (mass ratio) of Table 16. The design parameters were m=11 (n=13), and x was in the range of 0.5 to 3. Depending on the type of raw material used, the composition may differ between the design composition of Tables 14 and 15 and the mixed composition of Table 16, and in this case, the mixed composition was determined so that the amounts of metal ions would match. The component having the compositional deviation is mixed in the product as the second phase, but the amount thereof is small, so that the influence on the performance is small. The weighed raw material powders were mixed for 5 minutes using a silicon nitride sintered body pestle and a mortar. Then, the mixed powder was put into a crucible made of a boron nitride sintered body. The bulk density of the powder was about 20% to 30%.

The crucible containing the mixed powder was set in a graphite resistance heating type electric furnace. In the firing operation, the firing atmosphere was first evacuated to a vacuum with a pressure of 1×10 ⁻¹ Pa or less and heated from room temperature to 800° C. at a rate of 500° C./hour to obtain a purity of 99.999% by volume at 800° C. The pressure in the furnace was raised to 1 MPa by introducing nitrogen, the temperature was raised to the set temperature shown in Table 17 at 500° C./hour, and the temperature was maintained for 2 hours.

Next, the synthesized compound was crushed using an agate mortar, and powder X-ray diffraction measurement was performed using K _α rays of Cu. As a result, it was confirmed that a crystal phase having the same crystal structure as the crystal of Si _x Al _13-x O _3-x N _11+x (x≈2.2) was generated. Moreover, it was confirmed from the measurement of EDS that the compound contained Eu, Si, Al, N, and O. That is, it was confirmed that the compound was an inorganic compound in which Eu, which was a light emitting ion, was solid-dissolved in the Si _x Al _13-x O _3-x N _11+x system crystal.

  After firing, the obtained fired body was roughly pulverized, then manually pulverized using a crucible and a mortar made of a silicon nitride sintered body, and passed through a 30 μm mesh sieve. When the particle size distribution was measured, the average particle size was 3 to 8 μm.

  As a result of irradiating these powders with a lamp that emits light having a wavelength of 365 nm, it was confirmed that blue to yellow light was emitted, and that blue light was emitted from green light in a specific composition. The emission spectrum and excitation spectrum of this powder were measured using a fluorescence spectrophotometer. Table 18 shows the peak wavelength of the excitation spectrum and the peak wavelength of the emission spectrum. It was confirmed that these inorganic compounds are phosphors that can be excited by ultraviolet rays of 300 nm to 380 nm, violet of 380 nm to 450 nm or blue light, and emit blue to green light.

  It should be noted that a portion where the mixed raw material composition and the chemical composition of the synthetic product are different from each other is considered to be present in a small amount as a second phase of impurities in the synthetic product.

FIG. 3 is a diagram showing a powder X-ray diffraction result of the phosphor synthesized in Example 51.
FIG. 4 is a diagram showing an excitation spectrum and an emission spectrum of the phosphor synthesized in Example 51.

The powder X-ray diffraction result (FIG. 3) of the synthesized phosphor shows good agreement with the result of structural analysis (FIG. 2), and in Example 51, Si _x Al _13-x O _3-x N _11+x (x≈2. 2) It was confirmed that the X-ray diffraction pattern was the same as that of the crystal, and the crystal having the same crystal structure as the Si _x Al _13-x O _3-x N _11+x (x≈2.2) crystal was the main component. It was In Example 51, it was found that excitation was most efficient at 359 nm, and it was found that the emission spectrum when excited at 359 nm exhibits emission having a peak at 479 nm. Further, it was confirmed that the emission color of the phosphor of Example 51 was (0.169, 0.273) on the CIE1931 chromaticity coordinate.

[Examples of Light-Emitting Device and Image Display Device; Examples 54 to 57]
Next, a light emitting device using the phosphor of the present invention will be described.

Example 54
FIG. 5 is a schematic view showing a lighting device (bullet-type LED lighting device) according to the present invention.

  A so-called bullet type white light emitting diode lamp (1) shown in FIG. 5 was manufactured. There are two lead wires (2, 3), one of which (2) has a recess and an ultraviolet light emitting diode element (4) having an emission peak at 365 nm is mounted. The lower electrode of the ultraviolet light emitting diode element (4) and the bottom surface of the recess are electrically connected by a conductive paste, and the upper electrode and the other lead wire (3) are electrically connected by a thin gold wire (5). It is connected to the. The phosphor (7) is dispersed in resin and mounted in the vicinity of the ultraviolet light emitting diode element (4). The first resin (6) in which this phosphor is dispersed is transparent and covers the entire ultraviolet light emitting diode element (4). The tip portion of the lead wire including the concave portion, the ultraviolet light emitting diode element, and the first resin in which the phosphor is dispersed are sealed with a transparent second resin (8). The transparent second resin (8) has a substantially columnar shape as a whole, and the tip end portion thereof has a lens-shaped curved surface, which is commonly called a shell type.

In this example, the phosphor powder prepared by mixing the phosphor prepared in Example 51 and the CaAlSiN ₃ :Eu red phosphor at a mass ratio of 4:1 was mixed with an epoxy resin at a concentration of 25% by weight, and this was mixed with a dispenser. A proper amount of the mixture was dropped to form a first resin (6) in which a mixture of phosphors (7) was dispersed. The color of the obtained light emitting device was x=0.45 and y=0.39, and was a light bulb color.

  Further, when a bullet-shaped white light emitting diode lamp was produced in the same manner by using a purple light emitting diode element having an emission peak at 405 nm, almost the same result was obtained.

[Example 55]
FIG. 6 is a schematic view showing a lighting device (board-mounted LED lighting device) according to the present invention.

  A chip-type white light emitting diode lamp (11) for mounting on a substrate shown in FIG. 6 was manufactured. Two lead wires (12, 13) are fixed to a white alumina ceramics substrate (19) having a high visible light reflectance, one end of each of these wires is located in the substantially central part of the substrate, and the other end is external. It is an electrode that is soldered when mounted on an electric board. One of the lead wires (12) has a blue light emitting diode element (14) having an emission peak wavelength of 450 nm mounted and fixed at one end thereof so as to be in the central portion of the substrate. The lower electrode of the blue light emitting diode element (14) and the lower lead wire are electrically connected by a conductive paste, and the upper electrode and another lead wire (13) are electrically connected by a thin gold wire (15). Connected to each other.

  A mixture of the first resin (16), the α-SiAlON:Eu yellow phosphor, and the phosphor (17) obtained by mixing the phosphor prepared in Example 51 in a mass ratio of 7:3 was used in the vicinity of the light emitting diode element. It is implemented in. The first resin in which the phosphor is dispersed is transparent and covers the entire blue light emitting diode element (14). A wall surface member (20) having a hole at the center is fixed on the ceramic substrate. The central portion of the wall member (20) is a hole for the resin (16) in which the blue light emitting diode element (14) and the phosphor (17) are dispersed to be accommodated, and the portion facing the center is a slope. Is becoming This slope is a reflection surface for extracting light forward, and the curved shape of the slope is determined in consideration of the light reflection direction. Further, at least the surface forming the reflecting surface is white or has a metallic luster and has a high visible light reflectance. In this embodiment, the wall surface member (20) is made of white silicone resin. The hole in the center of the wall member forms a recess as the final shape of the chip type light emitting diode lamp, but here, the first resin (in which the blue light emitting diode element (14) and the phosphor (17) are dispersed ( A transparent second resin (18) is filled so as to seal all of 16). In this example, the same epoxy resin was used for the first resin (16) and the second resin (18). The addition ratio of the phosphor was almost the same as in Example 54, and the achieved chromaticity was x=0.33 and y=0.33, which was white.

  Next, a design example of an image display device using the phosphor of the present invention will be described.

[Example 56]
FIG. 7 is a schematic view showing an image display device (plasma display panel) according to the present invention.

The blue phosphor (31), the green phosphor (β-sialon:Eu ²⁺ )(32) and the red phosphor (CaAlSiN ₃ :Eu 2 ⁺ )(33) of Example 51 of the present invention were placed on the glass substrate (44). On the inner surfaces of the respective cells (34, 35, 36) arranged via electrodes (37, 38, 39) and a dielectric layer (41). When the electrodes (37, 38, 39, 40) are energized, vacuum ultraviolet rays are generated by Xe discharge in the cell, which excites the phosphors and emits red, green, and blue visible light, which is the protective layer. It is observed from the outside through (43), the dielectric layer (42), and the glass substrate (45), and functions as an image display device.

Example 57
FIG. 8 is a schematic view showing an image display device (field emission display panel) according to the present invention.

  The blue phosphor (56) of Example 51 of the present invention is applied to the inner surface of the anode (53). Electrons (57) are emitted from the emitter (55) by applying a voltage between the cathode (52) and the gate (54). The electrons are accelerated by the voltages of the anode (53) and the cathode, collide with the blue phosphor (56), and the phosphor emits light. The whole is protected by glass (51). The figure shows one light emitting cell consisting of one emitter and one phosphor, but in reality, in addition to blue, many red and green cells are arranged to form a display that emits various colors. It The phosphors used in the green and red cells are not particularly specified, but it is preferable to use a phosphor that emits high brightness with a low-speed electron beam.

  INDUSTRIAL APPLICABILITY The nitride phosphor of the present invention has emission characteristics (emission color, excitation characteristic, emission spectrum) different from those of conventional phosphors, has high emission intensity even when combined with an LED of 470 nm or less, and is chemically It is a nitride phosphor that is suitable for use in VFD, FED, PDP, CRT, white LED, etc., because it is thermally stable, and the brightness of the phosphor does not deteriorate much when exposed to an excitation source. . In the future, it can be expected that it will be greatly utilized in the material design of various display devices and contribute to the development of industry.

1. Cannonball type light emitting diode lamp.
2, 3. Lead wire.
4. Light emitting diode element.
5. Gold wire.
6,8. resin.
7. Phosphor.
11. Chip type white light emitting diode lamp for board mounting.
12, 13. Lead wire.
14. Light emitting diode element.
15. Gold wire.
16,18. resin.
17. Phosphor.
19. Alumina ceramic substrate.
20. Wall member.
31. Blue phosphor.
32. Green phosphor.
33. Red phosphor.
34, 35, 36. Ultraviolet light emitting cell.
37, 38, 39, 40. electrode.
41, 42. Dielectric layer.
43. Protective layer.
44, 45. Glass substrate.
51. Glass.
52. cathode.
53. anode.
54. Gate.
55. The emitter.
56. Phosphor.
57. Electronic.

Claims (24)

An inorganic crystal represented by M _n X _n+1 containing at least a metal element M and a non-metal element X (where n is a numerical value in the range of 3≦n≦52, and the metal element M is at least Al (aluminum)). , Si (silicon) and, if necessary, L element (where L element is a metal element other than Al and Si), the non-metal element X is at least N (nitrogen), and optionally O. (Oxygen) and, if necessary, Z element (Z element is a nonmetallic element other than N and O), an inorganic crystal having the same crystal structure, or an inorganic crystal which is a solid solution thereof. , A element (provided that A is one or more elements selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, and Yb) as a solid solution, and M _n X _The inorganic crystal represented by _n+1 is a phosphor that is an inorganic crystal represented by Si _x Al _13-x O _3-x N _11+x (provided that 0<x≦3). The phosphor according to claim 1, wherein the inorganic crystals having the same crystal structure are inorganic crystals represented by (Si,Al) ₁₃ (O,N) ₁₄ . The inorganic crystal represented by the Si _x Al _13-x O _3-x N _11+x , the inorganic crystal having the same crystal structure as the inorganic crystal, or the inorganic crystal which is a solid solution thereof is a orthorhombic crystal. And has the symmetry of the space group Cmcm, and the lattice constants a, b, and c are
a = 0.30749±0.05 nm
b=1.87065±0.05 nm
c=3.8432±0.05 nm
The phosphor according to claim 1, which has a value within the range.   The phosphor according to claim 1, wherein the x value is 1.5≦x≦3.   The phosphor according to claim 4, wherein the x value is 2≦x≦2.9.   The phosphor according to claim 1, wherein the A element is Eu. The inorganic compound has a composition formula Si _a Al _b O _c N _d A _e Q _f (where a+b+c+d+e+f=1, where A is Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Yb. 1 or 2 or more elements selected from, Q is one or two or more elements selected from elements other than Al, Si, O, N, A), and parameters a, b, c, d, e, f are
0.014 ≤ a ≤ 0.111
0.369 ≤ b <0.48
0 ≤ c <0.111
0.406 <d <0.517
0.0001 ≤ e ≤ 0.03
0 ≤ f ≤ 0.3
The phosphor according to claim 1, which has a value in a range that satisfies all of the conditions. The parameters a, b, c, d, e, f are
0.0185 ≤ a ≤ 0.1107
0.369 ≤ b ≤ 0.4613
0 ≤ c ≤ 0.0923
0.4244 ≤ d ≤ 0.5166
0.0001 ≤ e ≤ 0.0196
0 ≤ f ≤ 0.0233
The phosphor according to claim 7, which has a value in a range satisfying all of the conditions. The parameters a, b, c, d, e, f are
0.0738 ≤ a ≤ 0.1107
0.369 ≤ b ≤ 0.4059
0 ≤ c ≤ 0.0369
0.4797 ≤ d ≤ 0.5166
0.0004 ≤ e ≤ 0.0196
0 ≤ f ≤ 0.0233
The phosphor according to claim 8, which has a value in a range satisfying all of the conditions.   The phosphor according to claim 1, wherein the inorganic compound is a single crystal particle or an aggregate of single crystals having an average particle size of 0.1 μm or more and 40 μm or less.   The phosphor according to claim 1, which is composed of a mixture of the phosphor comprising the inorganic compound according to claim 1 and another crystalline phase or an amorphous phase, and the content of the phosphor is 20% by mass or more.   The phosphor according to claim 1, which emits fluorescence having a peak in a wavelength range of 460 nm to 500 nm when irradiated with an excitation source.   The phosphor according to claim 12, wherein the excitation source is vacuum ultraviolet light having a wavelength of 100 nm or more and 420 nm or less, ultraviolet light or visible light, electron beam or X-ray.   A raw material mixture, which is a mixture of metal compounds and can form the phosphor according to claim 1, is fired in a temperature range of 1200° C. or higher and 2200° C. or lower in an inert atmosphere containing nitrogen. The method for producing the phosphor according to claim 1. The mixture of the metal compounds is AlN and/or Al ₂ O ₃ , Si ₃ N _4, and an oxide or nitride of A (where A is Mn, Ce, Pr, Nd, Sm, Eu, Tb, 15. One or more elements selected from Dy and Yb)), The method for producing the phosphor according to claim 14.   The method for producing a phosphor according to claim 14, wherein the powdery or agglomerate-shaped metal compound is filled in a container in a state where the filling rate is 40% or less in bulk density and then baked.   A light emitting device comprising at least a light emitting body and a phosphor, wherein the phosphor uses at least the phosphor according to claim 1.   The light emitting device according to claim 17, wherein the light emitter is a light emitting diode (LED), a laser diode (LD), a semiconductor laser, or an organic EL light emitter (OLED) that emits light having a wavelength of 330 to 500 nm.   The light emitting device according to claim 17, wherein the light emitting device is a white light emitting diode, a lighting fixture including a plurality of the white light emitting diodes, or a liquid crystal panel backlight.   The phosphor emits ultraviolet or visible light having a peak wavelength of 300 to 450 nm, and mixes blue or green light emitted by the phosphor according to claim 1 with light having a wavelength of 450 nm or more emitted by another phosphor. The light emitting device according to claim 17, which emits white light or light other than white light.   An image display device comprising an excitation source and a phosphor, wherein the phosphor includes at least the phosphor according to claim 1.   The image display device is any one of a fluorescent display tube (VFD), a field emission display (FED), a plasma display panel (PDP), a cathode ray tube (CRT), and a liquid crystal display (LCD). The image display device described.   A pigment comprising the phosphor according to claim 1.   An ultraviolet absorber comprising the phosphor according to claim 1.