JP6036055B2 - Phosphor and light emitting device using the same - Google Patents

Description

  The present invention relates to a phosphor and a light emitting device using the same, and more particularly to a nitride phosphor and a light emitting device using the same.

  By combining the light emitted from the light source and the phosphor that can be excited by this light and emit light of a different hue from the light from the light source, light of various wavelengths can be obtained using the principle of color mixing of light. A light-emitting device capable of emitting light has been developed.

  As such a light-emitting device, a light-emitting element that emits light in the near-ultraviolet wavelength region is used as an excitation light source, and phosphors that emit blue, green, and red light are excited by light from the light-emitting element. There is also a method of obtaining white light by light emission.

  As phosphors that can be used in such light emitting devices, phosphors that perform wavelength conversion of light in the near-ultraviolet wavelength region and emit light in the visible wavelength region are being actively developed.

JP 2003-321675 A

  However, at present, a high-brightness nitride phosphor that emits light when excited by light including ultraviolet rays has not yet been obtained.

  Therefore, the present invention provides a high-luminance nitride phosphor that emits light when excited by light including ultraviolet rays, and a light-emitting device using the same.

In order to achieve the above object, the phosphor according to the present invention has a general formula of M _x Si _y N _{((2/3) x + (4/3) y)} : Eu (where M is Ca, Sr, And one or more alkaline earth metal elements selected from Ba, wherein x and y are 0.5 ≦ x ≦ 1.5 and 6.5 ≦ y ≦ 7.5. And 2θ is 30 when the intensity of a diffraction peak in the range of 29.3 ° to 29.9 ° is 2% in an X-ray diffraction pattern by CuKα rays. The relative intensity of the diffraction peak in the range of .6 ° to 31.2 ° is 410% to 650%, and the relative intensity of the diffraction peak in which 2θ is in the range of 55.8 ° to 56.4 ° is 90% to 160%, and the relative intensity of the diffraction peak with 2θ in the range of 66.1 ° to 66.7 ° is The phase is a 0% to 105%, characterized by containing the main and the production phase.

In the above general formula, it is preferable that M contains at least Sr. Similarly, the general formula, SrSi ₇ N _10: is preferably represented by Eu. The general formula is Sr _1-a Ca _a Si ₇ N ₁₀ : Eu (where 0 ≦ a ≦ 0.1), or Sr _1-b Ba _b Si ₇ N ₁₀ : Eu (where 0 ≦ b ≦ 0. It is preferable to be represented by 5).

  The light-emitting device according to the present invention is a light-emitting device that includes an excitation light source that emits light including at least ultraviolet light, and the phosphor that emits light by absorbing part of the light from the excitation light source.

  According to the phosphor of the present invention and a light-emitting device using the same, a high-luminance phosphor that emits light when excited by light including ultraviolet light can be obtained. In a light emitting device using this phosphor, white light can also be obtained by mixing the phosphor with other light emission having a different hue.

FIG. 1 shows measurement results of X-ray diffraction patterns of phosphors according to Examples 1 to 4 of the present invention. FIG. 2 shows an excitation spectrum of the phosphor according to Example 1 of the present invention. FIG. 3 shows the reflection spectrum of the phosphor according to Example 1 of the present invention. FIG. 4 shows an emission spectrum of the phosphor according to Example 1 of the present invention. FIG. 5 shows an SEM image of the phosphor according to Example 1 of the present invention. FIG. 6 shows the measurement results of the X-ray diffraction patterns of the phosphors according to Examples 5 to 9 of the present invention. FIG. 7 shows the measurement results of the X-ray diffraction patterns of the phosphors according to Examples 10 and 11 and Comparative Examples 1 to 3 of the present invention. FIG. 8 shows the measurement results of the X-ray diffraction patterns of the phosphors according to Examples 12 to 14 and Comparative Examples 4 and 5 of the present invention. FIG. 9 is a schematic cross-sectional view of the light emitting device according to the embodiment of the invention.

  The best mode for carrying out the present invention will be described below with reference to the drawings. However, the form shown below exemplifies a phosphor for embodying the technical idea of the present invention and a light emitting device using the phosphor, and the present invention provides a phosphor and a light emitting device using the phosphor. It is not limited to the following.

  The relationship between the color name and chromaticity coordinates, the relationship between the wavelength range of light and the color name of monochromatic light, and the like comply with JIS Z8110. Specifically, 380 nm to 455 nm is blue purple, 455 nm to 485 nm is blue, 485 nm to 495 nm is blue green, 495 nm to 548 nm is green, 548 nm to 573 nm is yellow green, 573 nm to 584 nm is yellow, 584 nm to 610 nm is yellow red , 610 nm to 780 nm is red.

  The phosphor according to the present embodiment is represented by the following general formula.

M _x Si _y N _{((2/3) x + (4/3) y)} : Eu (where M is one or more alkaline earth metal elements selected from Ca, Sr, Ba, and x, y is 0.5 ≦ x ≦ 1.5 and 6.5 ≦ y ≦ 7.5.)
Further, this phosphor has a property of having an emission peak wavelength at 440 to 470 nm when excited by a light source of 400 nm.

  The phosphor according to the present embodiment is a phosphor that contains at least one alkaline earth metal element M selected from Ca, Sr, and Ba, Si, and N, and is activated by Eu. Si is silicon, N is nitrogen, and Eu is europium. This phosphor contains a product phase having a crystal structure defined by an X-ray diffraction pattern described later. The phosphor according to the present embodiment absorbs light in the ultraviolet short wavelength region and emits blue light. Here, in the present specification, the short wavelength region from near ultraviolet to visible light is not particularly limited, but is preferably 250 nm to 520 nm.

  An X-ray diffraction pattern exhibited by the phosphor according to the present embodiment will be described with reference to FIG. FIG. 1 is a diagram showing an X-ray diffraction pattern by CuKα rays for phosphors of Examples 1 to 4 described later as examples of the phosphor according to the present embodiment.

  As shown in the respective X-ray diffraction patterns according to Examples 1 to 4, the phosphor according to the present embodiment has 2θ of 29.3 ° to 29.9 °, 30.6 ° to 31.2. It has main diffraction peaks in the range of °, 55.8 ° to 56.4 °, and 66.1 ° to 66.7 °.

  Here, in the present invention, as shown in each X-ray diffraction pattern according to Examples 1 to 4, the intensity of a diffraction peak having 2θ in the range of 29.3 ° to 29.9 ° is set to 100%. , The relative intensity of the diffraction peak with 2θ in the range of 30.6 ° to 31.2 ° is 410% to 650%. Similarly, the relative intensity of a diffraction peak having 2θ in the range of 55.8 ° to 56.4 ° is 90% to 160%. Similarly, the relative intensity of a diffraction peak having 2θ in the range of 66.1 ° to 66.7 ° is 60% to 105%.

  Here, a method for measuring the X-ray diffraction pattern of the phosphor according to the present embodiment will be described. The XRD apparatus and its measurement conditions are shown below.

XRD device: MiniFlex, manufactured by Rigaku Corporation
X-ray tube: CuKα
Tube voltage: 30 kV
Tube current: 15 mA
Scanning method: 2θ / θ
Scan speed: 4 ° / min
Sampling interval: 0.02 °
In addition, the diffraction peak position may shift due to changes in element ratio, solid solution with other elements, or when the sample surface irradiated with X-rays is not flat or due to differences in measurement conditions of the XRD apparatus. . Therefore, it is allowed that the 2θ range of the diffraction peak is slightly shifted.

  The phosphor according to the present embodiment shows an excitation spectrum that is efficiently excited over a wavelength region around 370 nm. The phosphor according to the present embodiment has an intensity of 50% or more when excited with light having an excitation wavelength of 270 nm to 420 nm, assuming that the maximum emission intensity when excited with light in this wavelength region is 100%. Can emit light.

  The phosphor according to the present embodiment has a peak wavelength in the wavelength region of 440 nm to 470 nm and emits blue light. Furthermore, the half width of the emission spectrum of the phosphor according to the present embodiment can be 39 nm. By having an emission spectrum with a narrow half-value width in this way, color can be reproduced with little color shift.

  Further, based on Examples 1 to 4, the molar ratio of the elements constituting the phosphor according to the present embodiment is M + Eu: Si: N = 1: 6 to 7: 8, where M is an alkaline earth metal element. It is preferable that it is .67-10. More preferably, it is M + Eu: Si: N = 1: 7: 10. By containing each element in such a molar ratio, the phosphor according to the present embodiment can emit high-luminance blue light.

  Further, based on Examples 5 to 9, the Eu concentration is preferably M + Eu: Eu = 1: 0.04 to 0.08, where M is an alkaline earth metal element. More preferably, M + Eu: Eu = 1: 0.06. By containing each element in such a molar ratio, the phosphor according to the present embodiment can emit high-luminance blue light.

  Moreover, it is preferable that the 1 or more types of alkaline-earth metal element M selected from Ca, Sr, Ba of the fluorescent substance which concerns on this Embodiment is Sr. A part of Sr may be substituted with Ca and Ba. Based on Examples 10 to 11 and Comparative Examples 1 to 3, when a part of Sr is replaced with Ca, the Ca concentration relative to Sr is preferably within 10%. Further, based on Examples 12 to 14 and Comparative Examples 4 to 5, when a part of Sr is replaced with Ba, the Ba concentration relative to Sr is preferably within 50%. Thus, about the alkaline-earth metal element M, the peak wavelength of fluorescent substance can be adjusted suitably by adjusting the compounding ratio of Ca, Sr, and Ba.

  Moreover, the phosphor according to the present embodiment uses Eu, which is a rare earth, as an activator. The concentration of the activator is preferably 0.001% to 20%, more preferably 4% to 8%, with respect to the alkaline earth metal element M. However, the activator is not limited to Eu, and a part of Eu may be Sc, Y, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, etc. Substitution with rare earth metals or alkaline earth metals is also possible. Thereby, the substituted element and Eu are co-activated, and the light emission characteristics can be adjusted, for example, by changing the color tone of the phosphor.

  The phosphor according to the present embodiment contains at least one element selected from the group consisting of Li, Na, K, Rb, Cs, Mn, Re, Cu, Ag, and Au in the composition. You may do it. Furthermore, other elements may be mixed to such an extent that the characteristics of the phosphor are not impaired.

  Further, the phosphor according to the present embodiment has a unit cell of crystals belonging to the orthorhombic system when the crystal structure is analyzed from an X-ray diffraction pattern described later. Moreover, it is preferable that most of the phosphor has crystals. Specifically, it is preferable that at least 50% by weight or more, more preferably 80% by weight or more have crystals. This is because the ratio of the crystal phase having a light-emitting property is shown, and if it has a crystal phase of 50% by weight or more, light emission that can withstand practical use can be obtained. Further, such powder is easy to manufacture and process. For example, since the glass body (amorphous) has a loose structure, the ratio of components in the phosphor is not constant, and there is a risk of causing chromaticity unevenness. Therefore, in order to avoid this, it is necessary to control the reaction conditions in the production process to be strictly uniform.

In consideration of mounting the phosphor according to the present embodiment in a light emitting device, the average particle diameter of the phosphor is preferably in the range of 1 μm to 100 μm, more preferably 2 μm to 50 μm. It is preferable that the phosphor having this average particle diameter value is contained with high frequency. Furthermore, the particle size distribution is preferably distributed in a narrow range because color unevenness can be suppressed. The average particle size is F.D. S. S. S. No. (Fisher Sub Sieve Sizer's No). Specifically, in an environment with an air temperature of 25 ° C. and a humidity of 70%, a sample of 1 cm ³ minutes is measured, packed in a special tubular container, then dried air of a constant pressure is flown, and the specific surface area is read from the differential pressure and averaged. Convert to particle size.

(Production method)
Below, the manufacturing method of the fluorescent substance which concerns on this Embodiment is demonstrated. This phosphor is weighed so as to use a simple substance of an element contained in the composition, an oxide, a carbonate or a nitride as a raw material, and each raw material to have a predetermined charged composition ratio. The “charge composition ratio” indicates the molar ratio of each element in the raw material containing the constituent elements of the phosphor in the mixture of the respective raw materials.

  The charging composition ratio of the phosphor according to the present embodiment is M + Eu: Si: N = 1: 5 to 8: 7.33 to 11.33, where M is an alkaline earth metal element, and preferably M + Eu: Si: N = 1: 6-7: 8.67-10. Each raw material is weighed so as to satisfy this relationship. Further, an additive material such as a flux can be appropriately added to these raw materials. Furthermore, boron can be contained as required.

  These raw materials are mixed so as to be uniform by a wet or dry method using a mixer. As the mixer, besides a ball mill which is usually used industrially, a grinder such as a vibration mill, a roll mill and a jet mill can be used. Moreover, in order to keep the specific surface area of the powder within a certain range, classification is performed using a wet type separator such as a sedimentation tank, a hydrocyclone, and a centrifugal separator, and a dry classifier such as a cyclone and an air separator. You can also

  The mixture is placed in a crucible made of a material such as SiC, quartz, alumina, boron nitride, or a plate-like boat, and then fired. For firing, a tubular furnace, a small furnace, a high-frequency furnace, a metal furnace, or the like can be used.

  Further, the firing is preferably performed in a circulating reducing atmosphere. Specifically, firing is preferably performed in a nitrogen atmosphere, a mixed atmosphere of nitrogen and hydrogen, an ammonia atmosphere, or a mixed atmosphere thereof.

  The firing temperature is preferably 1500 ° C. to 2100 ° C., more preferably 1900 ° C. to 2000 ° C. The firing time is preferably 2 hours to 20 hours, more preferably 5 hours to 10 hours.

  After firing, the fired product is pulverized, dispersed, filtered, etc. to obtain the desired phosphor powder. Solid-liquid separation can be performed by industrially used methods such as filtration, suction filtration, pressure filtration, centrifugation, and decantation. Drying can be achieved by industrially used apparatuses and methods such as a vacuum dryer, a hot air heating dryer, a conical dryer, and a rotary evaporator.

Here, a specific phosphor material will be described. The raw materials of Ca, Sr, and Ba constituting the element M with the charged composition ratio can use elements alone, as well as various salts such as metals, oxides, imides, amides, nitrides, carbonates, phosphates, and silicates. Etc. can be used. Specifically, SrCO ₃ , Sr ₃ N ₂ , CaCO ₃ or the like can be used.

In addition, for Si having a charged composition ratio, compounds such as metals, oxides, imides, amides, nitrides, and various salts can be used in addition to the elements alone. Moreover, you may use what mixed element M and Si previously. Specifically, Si ₃ N ₄ , SiO ₄ or the like can be used. Further, for example, in a compound containing Si, the purity of Si as a raw material is preferably 2N or more, but different elements such as Li, Na, K, B, and Cu may be contained. Furthermore, in order to substitute a part of Si with Al, Ga, In, Ge, Sn, Ti, Zr, and Hf, compounds containing these elements can also be used.

Further, Eu as the activator is preferably used alone, but halogen salts, oxides, carbonates, phosphates, silicates and the like can be used. Specifically, Eu ₂ O ₃ or the like can be used. When a part of Eu is replaced with another element, a compound containing other rare earth elements or the like can be mixed with a compound containing Eu.

  Furthermore, elements to be added as necessary are usually added as oxides or hydroxides, but are not limited thereto, and may be metals, nitrides, imides, amides, or other inorganic salts, , It may be contained in other raw materials in advance. Each raw material has an average particle diameter of about 0.1 μm to 15 μm, more preferably about 0.1 μm to 10 μm. This is preferable from the viewpoint of reactivity with other raw materials, particle size control at the time of baking and after baking, and when the particle size is more than the above range, it is pulverized in a glove box in an argon atmosphere or a nitrogen atmosphere. Can be achieved.

  Hereinafter, an example of a light-emitting device equipped with the phosphor according to the present embodiment is shown. Examples of the light emitting device include a lighting device such as a fluorescent lamp, a display device such as a display and a radar, a backlight for liquid crystal, and the like. The excitation light source is preferably a light-emitting element that emits light in the short wavelength region from near ultraviolet to visible light. In particular, the semiconductor light emitting element emits light of a bright color with a small size and high power efficiency. As another excitation light source, a mercury lamp used for an existing fluorescent lamp can be appropriately used.

  There are various types of light-emitting devices equipped with light-emitting elements, such as a so-called bullet type and surface mount type. In this embodiment mode, a surface-mounted light-emitting device will be described as an example with reference to FIG.

  FIG. 9 is a schematic diagram of the light emitting device 100 according to the present embodiment. The light emitting device 100 according to this embodiment includes a package 110 having a recess, a light emitting element 101, and a sealing member 103 that covers the light emitting element 101. The light emitting element 101 is disposed on a bottom surface 112 of a recess formed in the package 110 and is electrically connected to a pair of positive and negative lead electrodes 111 disposed on the package 110 by a conductive wire 104. The sealing member 103 is filled in the recess and is formed of a resin containing the phosphor 102. Further, the pair of positive and negative lead electrodes 111 has one end protruding on the outer surface of the package 110 and bent so as to follow the outer shape of the package 110. The light emitting device 100 emits light when externally supplied with electric power through these lead electrodes 111. Below, the member which comprises the light-emitting device which concerns on this Embodiment is demonstrated.

(Light emitting element 101)
The light emitting element 101 can emit light from the ultraviolet region to the visible light region. The light emitting device 101 may be, for example, a nitride semiconductor device _{(In X Al Y Ga 1-} X-Y N, 0 ≦ X, 0 ≦ Y, X + Y ≦ 1).

(Phosphor 102)
The phosphor 102 according to the present embodiment is blended so as to settle down due to its own weight below the sealing member 103. By arranging the phosphor close to the light emitting element 101 in this way, the wavelength of light from the light emitting element 101 can be efficiently converted, and a light emitting device with excellent light emission efficiency can be obtained. Further, by mixing the phosphors 102 in the sealing member 103 at a substantially uniform ratio, it is possible to obtain light without color unevenness.

In addition to the phosphor according to the present invention, two or more kinds of phosphors may be used as the phosphor 102. For example, in the light emitting device 100 according to the present embodiment, a color rendering property is obtained by using a light emitting element 101 that emits blue light, a phosphor that emits green light when excited, and a phosphor that emits red light. Excellent white light can be obtained. As phosphors emitting red light, (Ca _1-x Sr _x ) AlSiN ₃ : Eu (0 ≦ x ≦ 1.0, 0 ≦ y ≦ 0.5), (Ca _1-Z Sr _Z ) ₂ Si ₅ A phosphor such as N ₈ : Eu (0 ≦ z ≦ 1.0) or K ₂ SiF ₆ : Mn can be used in combination with the phosphor according to the present embodiment. By using these phosphors that emit red light in combination, the full width at half maximum of the component light corresponding to the three primary colors can be widened, so that white light richer in warm colors can be obtained.

Other examples of phosphors that can be used in combination include phosphors emitting red light, such as (La, Y) ₂ O ₂ S: Eu, Eu-activated oxysulfide phosphors, (Ca, Sr) S: Eu. Eu-activated sulfide phosphors such as (Y, Tb, Gd) ₃ Al ₅ O ₁₂ : Ce-activated aluminate phosphors such as Ce, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu, Mn activated halophosphate phosphors such as Eu and Mn, Lu ₂ CaMg ₂ (Si, Ge) ₃ O ₁₂ : Ce activated oxide phosphors such as Ce, Eu attached such as α-sialon An active oxynitride phosphor can be used.

As the phosphor emitting green _{light, (Ca, Sr, Ba)} 2 SiO 4: Eu, Ca 3 Sc 2 Si 3 O 12: silicate phosphor such as _{Ce, Ca 8 MgSi 4 O 16} Cl 2 _-Δ : _{Chlorosilicate} phosphor such as Eu, Mn, (Ca, Sr, Ba) ₃ Si ₆ O ₉ N ₄ : Eu, (Ca, Sr, Ba) ₃ Si ₆ O ₁₂ N ₂ : Eu, (Ca, Sr, Ba) Si ₂ O ₂ N ₂ : Eu, CaSc ₂ O 4: Ce, oxynitride phosphors such as β-type sialon, and Ce activated aluminate phosphors such as Y ₃ (Al, Ga) ₅ O ₁₂ : Ce Eu-activated sulfide phosphors such as SrGa ₂ S ₄ : Eu can be used.

As phosphors emitting blue light, (Sr, Ca, Ba) Al ₂ O ₄ : Eu, (Sr, Ca, Ba) ₄ Al ₁₄ O ₂₅ : Eu, (Ba, Sr, Ca) MgAl ₁₀ O ₁₇ : Eu, BaMgAl ₁₄ O ₂₅ : Eu-activated aluminate phosphor such as Eu, Tb, Sm, (Ba, Sr, Ca) MgAl ₁₀ O ₁₇ : Eu, Mn-activated aluminate such as Eu, Mn Phosphor, Ce-activated thiogallate phosphor such as SrGa ₂ S ₄ : Ce, CaGa ₂ S ₄ : Ce, Eu-activated halolin such as (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu An acid salt phosphor can be used.

(Sealing member 103)
The sealing member 103 is formed by being filled with a translucent resin so as to cover the light emitting element 101 disposed on the bottom surface 112 of the recess of the light emitting device 100. The translucent resin is preferably a silicone resin composition, but an insulating resin composition such as an epoxy resin composition or an acrylic resin composition can also be used. Moreover, although the phosphor 102 is contained in the sealing member 103, an additive member can be further contained as appropriate. For example, by including a light diffusing material, the directivity from the light emitting element can be relaxed and the viewing angle can be increased.

  Examples according to the present invention will be described in detail below. However, these examples illustrate phosphors for embodying the technical idea of the present invention and methods for producing the same, and the phosphors according to the present invention and methods for producing the same are not specified as follows.

Hereinafter, Examples 1 to 14 of the phosphor according to the present invention and Comparative Examples 1 to 5 will be described. In Examples 1 to 14 and Comparative Examples 1 to 5, the raw materials are strontium nitride (Sr ₃ N ₂ ), calcium nitride (Ca ₃ N ₂ ), barium nitride (Ba ₃ N ₂ ), silicon nitride (Si ₃ N _4). ) And europium oxide (Eu ₂ O ₃ ) were commonly used, and these raw materials were weighed so as to have the following charged composition ratios to obtain phosphors.

(Examples 1-4)
The composition ratio of the phosphor according to Example 1 is SrSi ₇ N ₁₀ : Eu _0.04 . Specifically, powders of Sr ₃ N ₂ , Si ₃ N ₄ , and Eu ₂ O ₃ are used as raw materials, and Sr ₃ N ₂ : Si ₃ N ₄ : Eu ₂ O ₃ = 0.32: 2.33 in molar ratio. : Each raw material was weighed so as to be 0.02. Specifically, each raw material was weighed to the mass shown below. However, the purity of each phosphor material is assumed to be 100%.
Sr ₃ N ₂ ... 10.89 g
Si ₃ N ₄ ···· 38.29g
Eu ₂ O ₃ ... 0.82 g
In a glove box purged with nitrogen, the raw materials weighed as described above are thoroughly mixed by a mortar in a dry manner, and then the mixture is placed in a furnace and baked at about 2000 ° C. for about 5 hours in a nitrogen atmosphere. Went. Thereby, a phosphor having a charged composition ratio of SrSi ₇ N ₁₀ : Eu _0.04 was obtained. An example of a reaction formula for producing the phosphor of Example 1 is shown in [Chemical Formula 1] below.

  However, the above chemical formula is a theoretically assumed reaction formula in which the elements contained in the raw material are reacted without being lost. The phosphor according to the present embodiment has a composition different from the composition of the product shown in the above reaction formula because a part of the element is lost during firing.

  The phosphors of Examples 2 to 4 were obtained by performing the same operations as in Example 1 except for changing the charged composition.

  Table 1 shows the results of measuring the charged composition ratio, the firing time, the chromaticity coordinates of the emission color, the luminance, and the peak wavelength of the emission spectrum for the phosphors of Examples 1 to 4. The luminances in Table 1 are relative luminances when the luminance of Example 1 is 100%.

  Unless otherwise specified, the phosphors according to the following examples emit light using 400 nm excitation light.

  From this result, the molar ratio of the elements constituting the phosphor according to the present embodiment is M + Eu: Si: N = 1: 6 to 7: 8.67-10, where M is an alkaline earth metal element. Is preferred.

  FIG. 1 shows X-ray diffraction patterns of the phosphors of Examples 1 to 4. Table 2 shows the values of the intensity of diffraction peaks in each 2θ range in the X-ray diffraction of the phosphors of Examples 1 to 4. The intensity of this diffraction peak indicates the relative intensity of other diffraction peaks, with the intensity of the diffraction peak having 2θ in the range of 29.3 ° to 29.9 ° being 100%.

  From this result, it can be seen that the peak intensity ratio in each 2θ range varies depending on the element ratio of preparation.

  FIG. 2 shows an excitation spectrum of the phosphor of Example 1. FIG. 3 shows the reflection spectrum of the phosphor of Example 1. FIG. 4 shows an emission spectrum when the phosphor in Example 1 is excited at 400 nm. FIG. 5 shows an SEM image of the phosphor according to Example 1.

  From this result, it can be seen that the phosphor of Example 1 emits blue light having a peak wavelength at 456 nm when excited with light having a peak wavelength at 300 to 400 nm.

(Examples 5 to 9)
The phosphors of Examples 5 to 9 were obtained by performing the same operation as in Example 1 except that the raw materials were weighed so that the Eu concentration relative to Sr was a predetermined concentration.

  Table 3 shows the results of measuring the charged composition ratio, the chromaticity coordinates of the emission color, the luminance, and the peak wavelength of the emission spectrum for the phosphors of Examples 5 to 9. Here, the luminance is relative luminance when the luminance of Example 7 is set to 100%.

  From these results, the phosphors of Examples 5 to 9 emitted blue light having a peak wavelength of 455 nm to 457 nm when excited with light having a peak wavelength of 400 nm. As the Eu concentration is increased, the peak wavelength can be made longer, although slightly. Further, although the luminance is improved up to 6% Eu concentration, it is considered that the concentration is extinguished and the luminance is lowered when the Eu concentration is exceeded.

  FIG. 6 shows X-ray diffraction patterns of the phosphors in Examples 5 to 9. Table 4 shows the values of the intensity of diffraction peaks in the respective 2θ ranges in the X-ray diffraction of the phosphors according to Examples 5 to 9. The intensity of this diffraction peak indicates the relative intensity of other diffraction peaks, with the intensity of the diffraction peak having 2θ in the range of 29.3 ° to 29.9 ° being 100%.

From this result, the peak intensity ratio in each 2θ range also changes depending on the Eu concentration with respect to Sr, but all satisfy the intensity range in each 2θ range described above.

(Examples 10-11, Comparative Examples 1-3)
Phosphor of Example 11 and Comparative Examples 1 to 3, to replace a part of Sr with Ca, the other were weighed and mixed by replacing a part of _Sr 3 _{N 2} in _Ca 3 _{N 2} is Example 1 was obtained by performing the same operation as in 1.

  Table 5 shows the measurement results of the charged composition ratio, the chromaticity coordinates of the emission color, the luminance, and the peak wavelength of the emission spectrum for the phosphors of Examples 10 to 11 and Comparative Examples 1 to 3. Here, the luminance is a relative luminance when the luminance of Example 10 without Ca substitution is 100%.

  From this result, the emission luminance can be maintained at about 80% with 10% substitution of Sr by Ca in Example 11; however, the emission luminance was greatly reduced with 30% or more substitution in Comparative Examples 1 to 3. Moreover, the main peak wavelength also changed in the substitution of 50% or more in Comparative Examples 2 to 3.

  FIG. 7 shows the X-ray diffraction patterns of the phosphors of Examples 10-11 and Comparative Examples 1-3. Table 6 shows the intensity values of diffraction peaks in each 2θ range in the X-ray diffraction of the phosphors of Examples 10 to 11 and Comparative Examples 1 to 3. The intensity of this diffraction peak indicates the relative intensity of other diffraction peaks, with the intensity of the diffraction peak having 2θ in the range of 29.3 ° to 29.9 ° being 100%.

  This result indicates that the substitution of Sr with Ca causes the peak intensity ratio in each 2θ range to change greatly, particularly at about 30% or more, resulting in an XRD pattern different from the phosphor of the present invention. From this, it is considered that when Sr is replaced with Ca, another composition is generated particularly at about 30% or more, and thus the emission luminance is greatly reduced.

(Examples 12-14, Comparative Examples 4-5)
The phosphors of Examples 12-14 and Comparative Examples 4-5 were weighed and mixed by substituting Ba ₃ N ₂ for part of Sr ₃ N ₂ in order to replace part of Sr with Ba. Obtained by carrying out the same operation as in Example 1.

  Table 7 shows the results of measuring the charged composition ratio, the chromaticity coordinates of the emission color, the luminance, and the peak wavelength of the emission spectrum for the phosphors of Examples 12 to 14 and Comparative Examples 4 to 5. Here, the luminance is a relative luminance when the luminance of Example 12 is 100% without Ba substitution.

  From this result, the emission luminance can be maintained at 90% or more with about 10 to 50% substitution of Sr of Ba in Examples 12 to 14, but the emission luminance is lower than 80% with about 70% substitution in Comparative Example 4. Moreover, the peak wavelength hardly changes regardless of the substitution amount.

  FIG. 8 shows the X-ray diffraction patterns of the phosphors of Examples 12 to 14 and Comparative Examples 4 to 5. Table 8 shows the intensity values of diffraction peaks in each 2θ range in the X-ray diffraction of Examples 12 to 14 and Comparative Examples 4 to 5. The intensity of this diffraction peak indicates the relative intensity of other diffraction peaks, with the intensity of the diffraction peak having 2θ in the range of 29.3 ° to 29.9 ° being 100%.

  This result shows that the substitution of Sr with Ba does not significantly change the peak intensity ratio in each 2θ range up to 50% substitution compared to the substitution with Ca. Further, in the replacement of Sr with Ba, a shift to the low angle side is observed as the replacement amount increases. This indicates that Sr is replaced with Ba while maintaining the original crystal structure, and the lattice constant is increased. From this, in the case of substitution of Sr with Ba, unlike the substitution with Ca, the substitution can be performed while maintaining the original structure in general, so that it is presumed that the emission luminance does not rapidly decrease.

  The phosphor of the present invention and a light-emitting device using the phosphor are extremely excellent in light emission characteristics using a fluorescent light-emitting diode, a display, a PDP, a CRT, a FL, a FED, a projection tube, etc., particularly a blue light-emitting diode or an ultraviolet light-emitting diode as a light source. It can be suitably used for illumination light sources, backlight light sources, and the like that emit warm white light.

DESCRIPTION OF SYMBOLS 100 ... Light emitting device, 101 ... Light emitting element, 102 ... Phosphor, 103 ... Sealing member, 104 ... Conductive wire, 110 ... Package, 111 ... Lead electrode, 112... Concave bottom surface.

Claims (2)

The general formula is Sr _1-a Ca _a Si ₇ N ₁₀ : Eu (where 0 <a ≦ 0.1) or Sr _1-b Ba _b Si ₇ N ₁₀ : Eu (where 0 <b <0 .5), a phosphor that emits light when excited by ultraviolet rays,
In the X-ray diffraction pattern by CuKα rays, when the intensity of a diffraction peak in the range of 2θ in the range of 29.3 ° to 29.9 ° is 100%,
The relative intensity of the diffraction peak with 2θ in the range of 30.6 ° to 31.2 ° is 410% to 650%,
The relative intensity of the diffraction peak with 2θ in the range of 55.8 ° to 56.4 ° is 90% to 160%,
A phosphor characterized in that it contains a product phase mainly composed of a phase having a relative intensity of a diffraction peak having 2θ in the range of 66.1 ° to 66.7 ° of 60% to 105%. A light-emitting device having an excitation light source that emits light including at least ultraviolet light, and a phosphor that emits light by absorbing a part of the light from the excitation light source,
The light emitting device according to claim 1, wherein the phosphor is the phosphor according to claim 1.