JP5100059B2 - Phosphor, method for producing the same, and light emitting device using the same - Google Patents

Description

  The present invention relates to a novel oxynitride phosphor, a method for producing the phosphor, and a light emitting device using the phosphor.

  Phosphors are widely used as wavelength conversion materials in light emitting devices such as LEDs and cold cathode fluorescent lamps (CCFL), and various phosphors such as YAG, BAM, and SiAlON have been developed. In general, in these light emitting devices, light emitted from a light emitting source such as an LED chip and extracted outside without being absorbed by the phosphor is synthesized with light emitted from the phosphor by absorbing light from the light emitting source. The light becomes light emitted from the light emitting device.

  For example, a well-known white LED absorbs light emitted from a blue light emitting LED chip having a monochromatic peak from 420 nm to 490 nm and a peak wavelength in the vicinity of 510 nm to 610 nm. White light is realized by combining with a cerium-activated garnet phosphor (YAG phosphor), which is a yellow light-emitting phosphor that emits light (Patent Document 1).

Further, Patent Document 2, the general _{formula: Me x Si 12- (m +} n) Al (m + n) O n N 16-n: Re1 y Re2 represented by _z alpha sialon oxynitride as a host A yellow light-emitting phosphor that can be excited by ultraviolet light to blue light has been proposed. This phosphor can obtain a white LED by combining with a blue LED having an emission peak of 450 to 500 nm.

On the other hand, the presence of MgA ₁₂ Si ₄ O ₆ N ₄ as a ceramic, not a phosphor, is known from Non-Patent Document 1. Non-Patent Document 1 describes a hot press method and a gas pressure sintering method as methods for producing MgA ₁₂ Si ₄ O ₆ N ₄ . In the hot press method, the material molded into pellets is baked at 1400 ° C. or 1550 ° C. for 1 hour while uniaxially pressing at 35 MPa in an N ₂ gas flow, and then the sample is annealed at 1300 ° C. for 20 hours. In the gas pressure sintering method, a material molded into a pellet is baked at 1640 ° C. for 2 hours in a nitrogen atmosphere pressurized to 1.5 MPa, and then the sample is annealed at 1300 ° C. for 20 hours.
Japanese Patent No. 3503139 JP 2002-363554 A “Formation of N-phase and Phase Relationshipsin MgO-Si2N2O-Al2O3 System” ZKHuang et al, J. Am. Ceram. Soc., 77 (12), 3251-54, (1994)

  A conventional white LED has a problem that chromaticity varies greatly between white LEDs because light transmitted from a blue light emitting LED chip is used as a white component. This problem is that the emission wavelength from the blue LED chip varies by about 10 nm between individuals, so the excitation efficiency is not constant when combined with phosphors with different excitation efficiency depending on the wavelength, and the phosphor coating around the chip If the situation is not strictly controlled, the optical path length of the light from the chip is not constant in each LED, and this is because the ratio of the transmitted light from the chip and the emission of the phosphor easily changes. This variation in chromaticity results in a large number of lot-out products, which is a major cause of a decrease in yield.

  The oxynitride phosphor described in Patent Document 2 has characteristics particularly suitable for phosphors for LEDs, such as an excitation wavelength ranging from near-ultraviolet (nUV) to visible light and an emission color in visible light. With the expansion, LED phosphors exhibiting various emission colors such as blue, green, and intermediate colors are desired.

  Of the two ceramic manufacturing methods described in Non-Patent Document 1, the gas pressure sintering method is considered to be applicable as a phosphor manufacturing method. However, in the method described in this document, firing is performed in a nitrogen-pressurized atmosphere of 1.5 MPa, and in such a pressurized atmosphere, the apparatus must be expensive to withstand high temperatures and pressures. Man-hours are also required for maintenance.

  One object of the present invention is to provide a novel phosphor that absorbs near-ultraviolet light and emits visible light, and in particular, to provide a phosphor that enables various light emission such as blue, green, and intermediate colors. It is in. Another object of the present invention is to provide a method for producing the novel phosphor of the present invention without using a high-pressure resistant apparatus, and to combine the novel phosphor of the present invention with a near-ultraviolet light source for fluorescence. An object of the present invention is to provide a light emitting device capable of obtaining white color only by light emission from the body.

In order to solve the above problems, the present invention provides a blue to green and white oxynitride phosphor having a novel composition ratio. That is, the phosphor of the present invention is a phosphor containing MgAl ₂ Si ₄ O ₆ N ₄ as a main phase and Eu as an activator (Re) (hereinafter referred to as MgSiAlON phosphor). The activator Re may contain Mn in addition to Eu.

  The element which becomes an activator can be substituted with a part of Mg, and can emit light in various colors from blue to white depending on the combination of elements. For example, when the activator is only Eu, it has a light emission peak between 450 and 520 nm, and its chromaticity is 0.15 ≦ x ≦ 0.28 and 0.25 ≦ y ≦ 0.48 on the CIExy chromaticity diagram. Become a body. When Mn is contained in addition to Eu, the emission peak is between 450 to 520 nm and 590 to 660 nm, and the chromaticity is 0.27 ≦ x ≦ 0.40, 0.28 ≦ y ≦ 0.40 on the CIExy chromaticity diagram. It becomes white fluorescent substance which shows. In addition to Eu and Mn, it is also possible to add rare earth elements such as Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu as the activator element.

The phosphor of the present invention has MgAl ₂ Si ₄ O ₆ N ₄ as a main phase, but may contain MgAl ₂ O ₄ and / or Si ₃ N ₄ as a subphase. That is, the composition of the phosphor of the present invention can be represented by the general formula Mg _1-x Al ₂ Si ₄ O ₆ N ₄ Re _x , but the phosphor of the present invention contains MgAl ₂ Si ₄ O ₆ N ₄ as the main phase. In this case, a composition slightly deviated from the composition represented by the general formula is included.

That is, the phosphor of the present invention can be produced even when the starting material is mixed at a ratio deviating from the stoichiometric ratio as the starting material. For example, when the starting material is an oxide of each element and silicon nitride, the mixing ratio (molar ratio) of MgO: Al ₂ O ₃ : SiO ₂ : Si ₃ N ₄ : Eu ₂ O ₃ : MnO (1-y / 2-z): When expressed as a: b: c: y: z, the ranges of 0.04 ≦ y ≦ 0.2, 0 ≦ z ≦ 0.1, 0.5 ≦ a ≦ 1, b = 1, 0.33 ≦ c ≦ 1 can do.
As the starting material of the phosphor of the present invention, it is preferable to use these oxides and silicon nitride. For Mg and Al, besides oxides, carbonates, oxalates, halides, hydroxides, and the like are also included. If the valence in this case is the same as that of the oxide, the mixing ratio (molar ratio) can be in the above range.

  The phosphor of the present invention can be produced by a general method for producing a ceramic material including mixing of raw material powders and a firing step, but the firing step is preferably performed in a nitrogen atmosphere. In particular, it is preferable to include a step of firing the mixed raw material compound in a nitrogen pressure atmosphere of 1 MPa or less, and a step of crushing the material after firing and annealing in a nitrogen atmospheric pressure atmosphere.

Hereinafter, an example of the procedure for producing the phosphor of the present invention will be described.
First, a material that becomes an oxide during high-temperature heating represented by nitrides, oxides, or carbonates is prepared as a material at a desired composition ratio, and sufficiently mixed with an alumina mortar and pestle. The mixed powder is put in a BN crucible and fired at 1600-1800 ° C., preferably 1650-1750 ° C. for about 2 hours in a nitrogen pressurized atmosphere of 0.9 MPa. At this time, the higher the firing temperature, the higher the emission intensity, but the fired product sticks to the crucible and is difficult to recover.

Subsequently, the fired product is taken out and sufficiently pulverized with an alumina mortar and pestle, and then again put in a BN crucible and annealed at about 1300 ° C. for about 10 hours in a nitrogen atmosphere. The desired phosphor powder is obtained by crushing the fired product.
It is preferable to perform all the mixing / pulverization of the materials and the charging operation into the crucible in a glove box in which the oxygen / water content is kept at 1 ppm or less and the atmosphere is nitrogen.
Compared to the conventional manufacturing method of MgAl ₂ Si ₄ O ₆ N ₄ as a ceramic, the manufacturing method described above is fired in a nitrogen-pressurized atmosphere of 0.9 MPa, so the equipment becomes inexpensive and the number of man-hours for equipment maintenance can be reduced. It becomes easy to secure safety.

  The light-emitting device of the present invention is a combination of the phosphor of the present invention described above and an excitation light source that emits ultraviolet to near-ultraviolet light having a wavelength of 140 nm to 420 mn. Examples of the excitation light source include a semiconductor light emitting element that emits ultraviolet light or near ultraviolet light, and a light source that generates ultraviolet light having a wavelength of 140 to 420 nm by exciting a gas such as mercury or xenon. Depending on the type of excitation light source, various forms of light emitting devices such as LEDs, a combination of a semiconductor light emitting element and a phosphor, a fluorescent lamp, and a cold cathode fluorescent lamp (CCFL) can be used.

  The light emitting device of the present invention uses a phosphor that emits light having an emission peak between 450 to 520 nm, or light having an emission peak between 450 to 520 nm and between 590 to 660 nm, as the phosphor. Therefore, by appropriately adjusting the composition of the phosphor according to the desired color tone, it is possible to realize a light emitting device that emits light of any color (for example, white) from blue to white with only one type of phosphor.

This light emitting device has the following advantages.
First, it is sufficient to use only one type of phosphor to obtain white, and it is not necessary to store and quality control a plurality of phosphors, so that the manufacturing cost can be reduced.
Next, since white is obtained with one phosphor, it is possible to suppress color misregistration due to variations in the phosphor mixture ratios in the plurality of phosphor wavelength conversion units.
When multiple phosphors are used to make white, the wavelength dependence of the excitation efficiency of the phosphors that make up the white color varies depending on the individual phosphors, so that the emission wavelength of the excitation light source varies with the ambient temperature and drive current. However, in the light emitting device of the present invention, white color is obtained with one kind of phosphor, so that there is little change in color tone due to ambient temperature and drive current.

  In addition, when compared with the light emitting device of the present invention and a conventional blue excited white LED, in the case of a blue excited white LED, the chromaticity coordinates of the excitation element (that is, the peak shape and peak wavelength), the concentration of the wavelength conversion unit, and the filling amount Since the color tone changes very sensitively, it is difficult to obtain an LED having the same color tone as a result, and it is difficult to obtain a high yield, whereas the light emitting device of the present invention has a little influence on the obtained white light. Since white light is obtained with one type of phosphor excited by an ultraviolet LED, even if the chromaticity coordinates of the excitation element vary, and the concentration and filling amount of the wavelength conversion section vary, there is little change in color tone. There is an advantage that it is easy to obtain a high yield.

  Next, the light emitting device of the present invention using the above phosphor will be described. The light emitting device of the present invention is the same as a known light emitting device except that the above MgSiAlON phosphor is used as the phosphor, and the structure and type are not particularly limited. FIG. 1 shows a typical light emitting device (LED) to which the present invention is applied as a first embodiment. The light-emitting device is provided on the base 7 so as to surround the semiconductor light-emitting element 1, the semiconductor light-emitting element 1 mounted on the base 7, the extraction electrode 6, the lead wire 2 connecting the extraction electrode 6 and the light-emitting element 1, and the semiconductor light-emitting element 1. And the sealing portion 4 that fills the recess 8. The phosphor is used as a wavelength conversion material 3 that emits light having a wavelength different from that of light emitted from the light emitting element 1, and is mixed in the sealing portion 4.

  As the semiconductor light emitting element 1, one having an emission peak wavelength range of 300 to 420 nm is used. Examples of the semiconductor light emitting device 1 that emits light within the above emission peak wavelength range include a group III-nitrogen compound (InGaAlN) semiconductor, a zinc oxide compound (ZnMgO) semiconductor, and a zinc selenide compound (ZnMgSeSTe) semiconductor. Typical examples include silicon carbide compound (SiGeC) semiconductors, but other compound semiconductors may be used as long as they emit light from ultraviolet light to near ultraviolet light. In the present invention, the semiconductor light emitting element 1 includes those fixed on the submount.

  The base body 7, the semiconductor light emitting element 1, and the lead electrode 6 can take various forms. The semiconductor light emitting element 1 is fixed on the base body 7, and each lead electrode 6 for the anode / cathode and the semiconductor light emitting element 1 are provided. It is only necessary that the anode / cathode electrode is electrically connected to each other. Typically, as shown in FIG. 1, an extraction electrode 6 for both anode and cathode is wired on a base 7 made of an insulating material such as glass fiber or epoxy resin. The semiconductor light emitting element 1 is fixed on the substrate 7 with an adhesive such as an epoxy resin, and the anode / cathode electrodes of the semiconductor light emitting element 1 are electrically joined by the corresponding lead electrode 6 and the conductive wire 2. Alternatively, although not shown in the drawing, the anode / cathode electrodes corresponding to the anode / cathode electrodes of the semiconductor light emitting device 1 are represented by eutectic materials such as Au—Sn, Au bumps, anisotropic conductive sheets, and Ag pastes. With such a conductive resin or the like, it is electrically joined and fixed to the base 7, and only one electrode of the semiconductor light emitting element 1 is electrically joined to the corresponding extraction electrode 6 with the material described above. The lead electrode 6 fixed to the base body 7 and corresponding to the other electrode can take a form of electrical connection with a conductive wire. Further, the base 7 may be made of a conductive material such as metal in order to improve the heat dissipation of the semiconductor light emitting device 1 and may also serve as the single electrode lead electrode 6.

  The substrate 7 is preferably provided with a recess 8 in which the semiconductor light emitting element 1 is fixed inside. The concave portion 8 can be formed by various methods such as a method of integrally molding with the base body 7 and a method of bonding to the base body 7 later, and any method may be used in the present invention. The surface of the recess 8 may be any material as long as the lead electrode 6 of each electrode of the anode / cathode is not electrically short-circuited. For example, the surface of the recess 8 may be coated, plated, or deposited on the inside of the recess 8. A high reflectivity material may be formed. The shape of the recess 8 is preferably a substantially truncated cone, but may be a substantially quadrangular pyramid. Although it is desirable that the side wall of the recess 8 is inclined, in the case of a light-emitting device in which a thin element is desired, such as a white LED for a backlight light source for a display unit of a mobile phone, the end face is almost vertical It may be.

  The material of the sealing part 4 filling the recess 8 may be any material that is transparent up to a wavelength region shorter than the emission peak wavelength from the semiconductor light emitting element 1 and can be mixed with the wavelength conversion material 3. Specifically, thermosetting resin, photocurable resin, low melting point glass, and the like can be given. Particularly preferred are thermosetting resins such as epoxy resins, silicone resins, polydimethylsiloxane derivatives having an epoxy group, oxetane resins, acrylic resins and cycloolefin resins. These resins can be used alone or in combination of two or more.

  The wavelength conversion material 3 needs to contain at least the MgSiAlON phosphor of the present invention. Further, the phosphor of the present invention can be combined with one or more other phosphors to form a color tone that cannot be achieved by the phosphor of the present invention alone. As another phosphor, a wavelength conversion material that absorbs near-ultraviolet light generated by the light-emitting element 1 or light emitted from the phosphor of the present invention and converts the wavelength to a longer wavelength than the absorbed light can be used.

Other phosphors include A ₃ B ₅ O ₁₂ : M (A is Y, Gd, Lu, Tb, B is Al, Ga, M is Ce ³⁺ , Tb ³⁺ , Eu ³⁺ , Cr ³⁺ , Nd ⁺ or Er ³⁺ ), rare earth and manganese doped barium-aluminum-magnesium compound phosphor (BAM: Mn phosphor), Y ₂ O ₂ S: Eu ³⁺ and (Sr, Ca) S: Eu ^{2 +} , Sulfide compound phosphors represented by ZnS: Cu, A1, etc., rare earth doped thiogallate phosphors such as CaGa ₂ S ₄ : Eu ²⁺ and SrGa ₂ S ₄ : Eu ²⁺ , or CaAl ₂ Phosphors containing at least one composition of O ₄ : aluminate such as Eu ²⁺ , (Ca, Sr, Ba,) _x Si _y O _z : silicate such as Eu ²⁺ , α-SiAlON, β -Commonly used wavelength conversion materials such as sialon-based phosphors such as SiAlON and nitride phosphors such as Sr ₂ Si ₅ N ₈ : Eu ²⁺ are mixed with one or more materials. Can be used. Further, if necessary, scattering materials such as barium sulfate, magnesium oxide, and silicon oxide may be mixed in each wavelength conversion material for assisting reflection of excitation light and wavelength-converted light.

  The wavelength conversion material 3 can be used by mixing an appropriate amount with the sealing portion 4 described above. The mixing amount in the case of mixing with the resin is not particularly limited, but is usually about 1 to 50% by weight of the entire material constituting the sealing portion. The wavelength converting material 3 may be used by being dispersed in the transparent substrate 7.

  When the mixture of the resin of the sealing portion 4 and the wavelength conversion material 3 is filled in the concave portion 8, the height of the filling is the same as the height of the horizontal plane formed on the opening surface or a state where it is recessed more than that. Is preferred. The filling material only needs to be in a concave state in the end, and even if a dent is formed when filling the material, the dent is formed after curing with a convex shape when filling the sealant in the sealing part 4. But the effect is the same.

Next, FIG. 2 shows a light emitting device having a structure different from that of FIG. 1 as a second embodiment of the present invention. This light emitting device is formed of a molded package having one or more housings 17 each having a recess 18, and the light emitting element 11 is mounted on the bottom of the recess 18 of the housing 17. Although not shown, the anode / cathode electrode of the light emitting element 11 is connected to an external power source through a lead formed integrally with the housing 17. The upper portion (opening) of the recess 18 is covered with a transparent member 14 such as a glass plate or a resin plate, whereby the light emitting element 11 is sealed in a space (sealing portion) in the recess 18. The sealing portion is maintained at a pressure lower than atmospheric pressure or filled with a gas such as an inert gas such as N ₂ or Ar. A phosphor layer 13 is formed on at least one surface of the transparent member 14. In the illustrated embodiment, a first phosphor layer 131 is formed on the outer surface of the transparent member 14 that is directly above the light emitting element 11 so as to have a larger area than the light emitting element 11. A second phosphor layer 132 is formed on the inner surface of the transparent member 14 corresponding to the periphery of the layer 131.

  By arranging the first and second phosphor layers on both surfaces of the transparent member 14 in this way, a part of the light emitted from the light emitting element 1 is wavelength-converted by the first phosphor layer 131 to the outside. The light that is emitted and reflected by the back surface of the first phosphor layer 131 is converted in wavelength by the second phosphor layer 132 formed on the inner surface, and is emitted to the outside.

  The materials constituting the first and second phosphor layers may be the same or different, and at least one of them contains the MgSiAlON phosphor of the present invention. The phosphor layer 13 can be formed by depositing a phosphor containing the MgSiAlON phosphor of the present invention by screen printing, spin coating or the like. The amount of the MgSiAlON phosphor contained in the phosphor layer 13 is not particularly limited, but the total phosphor amount relative to the resin is approximately 1 to 80% by weight, preferably 3 to 50% by weight from the viewpoint of workability and the like. . The thickness of the phosphor layer is preferably 500 μm or less, more preferably 10 to 150 μm, from the viewpoint of light extraction efficiency.

  As described above, two types of LEDs in which the phosphor of the present invention is combined with a near-ultraviolet LED have been described as embodiments of the light emitting device of the present invention. However, the phosphor of the present invention can be excited at a wavelength of 420 nm or less. The present invention is not limited to near-ultraviolet LEDs, and can also be used for fluorescent lamps and cold cathode fluorescent lamps (CCFL) that excite phosphors with ultraviolet to near-ultraviolet light having a wavelength of 140 to 420 nm that emit light from excited mercury gas or other gases.

  Examples of the MgSiAlON phosphor of the present invention and examples of the light emitting device will be described below.

1. Example of phosphor <Example 1>
Starting materials include MgO (Kanto Chemical 4N), Al ₂ O ₃ (Sumitomo Chemical AKP-Y3000), SiO ₂ (Furuuchi Chemical 5N), Si ₃ N ₄ (Ube Industries SN-E10) and Eu ₂ O ₃ (Fluuchi Chemical) 4N), and the mixing ratio (molar ratio) was (1-y / 2) MgO: aAl ₂ O ₃ : bSiO ₂ : cSi ₃ N ₄ : yEu ₂ O ₃ described in Table 1 (y = 0.04). , A = 1, b = 1, c = 1).
・ MgO (Kanto Chemical 4N) 0.500g
・ Al ₂ O ₃ (Sumitomo Chemical AKP-Y3000) 1.290g
・ SiO ₂ (Furuuchi Chemical 5N) 0.760g
・ Si ₃ N ₄ (Ube Industries SN-Elo) 1.775 g
・ Eu ₂ 0 ₃ (Furuuchi Chemical 4N) 0.045g

These materials were thoroughly mixed using an alumina mortar and pestle in a glove box having a nitrogen atmosphere with a moisture content of 1 ppm or less, and the powder was put into a BN crucible (electrochemistry). Place this sample in a multi-purpose high-temperature furnace (Fuji Denpa Kogyo Co., Ltd.) that uses resistance heating of graphite. First, raise the temperature to 800 ° C while maintaining the inside of the furnace at a vacuum of 1 × 10 ^-2 Pa or less, Firing was performed at 1600 ° C. for 2 hours in a nitrogen atmosphere at 9 atmospheres. When the sample was taken out after cooling, the fired product was a gray lump. The fired product was once again sufficiently pulverized using an alumina mortar and pestle in a nitrogen atmosphere glove box, and then returned to the BN crucible.

  The powder was fired at 1300 ° C. for 10 hours in a 1 atmosphere of nitrogen in a multipurpose high-temperature furnace using black spot resistance heating. The fired product was in a state where grayish white powder was agglomerated. The fired product was crushed to obtain the desired phosphor powder. Note that the heating rate during firing was 500 ° C./h. The obtained phosphor was measured with an X-ray diffractometer (Bruker Advanced D8) using Cu Kα rays. The results are shown in FIG.

As a result of the measurement, the X-ray diffraction pattern of MgAl ₂ Si ₄ 0 ₆ N ₄ reported in Non-Patent Document 2 and recorded in ICDD (International Center for Diffraction Data) is well matched, and MgAl ₂ Si ₄ 0 ₆ N ₄ was confirmed to be contained as a main phase, and MgAl ₂ 0 ₄ and Si ₃ N ₄ were contained as subphases.
Furthermore, the emission spectrum of the obtained phosphor at 365 nm excitation was measured with a spectrofluorometer (Hitachi F4500). The results are shown in FIG. The emission peak wavelength was 477 nm, and the chromaticity was (x, y) = (0.19, 0.28).

<Example 2>
The same starting materials as in Example 1 were used and weighed so that the mixing ratio (molar ratio) was the composition ratio shown in Table 1.
・ MgO 0.500g
・ Al ₂ O ₃ 1.331g
・ SiO ₂ 0.784g
・ Si ₃ N ₄ 1.831 g
・ Eu ₂ O ₃ 0.115g

  The others were fired in the same manner as in Example 1 to obtain the intended phosphor powder. FIG. 5 and Table 1 show the results of the emission spectrum measured at 365 nm excitation as measured in the same manner as in Example 1. The emission peak wavelength was 499 nm, the chromaticity was (x, y) = (0.24, 0.40), and the luminance was 170% with respect to the phosphor of Example 1.

<Example 3>
Using the same starting materials and MnCO ₃ (high purity chemical 3N or more) as in Example 1, the mixing ratio (molar ratio) was (1-y / 2-z) MgO: aAl ₂ O ₃ : bSiO ₂ : cSi ₃ N ₄ : Weighed so that yEu ₂ O ₃ : zMnCO ₃ had the composition ratio shown in Table 1.
・ MgO 0.500g
・ Al ₂ O ₃ 1.331g
・ SiO ₂ 0.784g
・ Si ₃ N ₄ 1.831 g
・ Eu ₂ O ₃ 0.115g
・ MnCO ₃ 0.045g

  Firing was carried out in the same manner as in Example 1 except that the firing temperature was 1650 ° C., to obtain the intended phosphor powder. The results of the emission spectrum (when excited at 365 nm) of the phosphor powder measured in the same manner as in Example 1 are shown in FIG. The emission peak wavelengths were 484 nm and 607 nm, and the chromaticity was (x, y) = (0.33, 0.36).

<Example 4>
The same starting materials as in Example 3 were used and weighed so that the mixing ratio (molar ratio) was the composition ratio shown in Table 1.
・ MgO 0.500g
・ Al ₂ O ₃ 1.345g
・ SiO ₂ 0.793g
・ Si ₃ N ₄ 1.851 g
・ Eu ₂ O ₃ 0.046g
・ MnCO ₃ 0.061g

  The others were fired in the same manner as in Example 1 to obtain the intended phosphor powder. The results of the emission spectrum (when excited at 365 nm) of the phosphor powder measured in the same manner as in Example 1 are shown in FIG. The emission peak wavelengths were 485 nm and 613 nm, the chromaticity was (x, y) = (0.35, 0.36), and the luminance was 63% with respect to the phosphor of Example 3.

<Example 5>
The same starting materials as in Example 3 were used and weighed so that the mixing ratio (molar ratio) was the composition ratio shown in Table 1.
・ MgO 0.500g
・ Al ₂ O ₃ 1.360g
・ SiO ₂ 0.801g
・ Si ₃ N ₄ 1.871 g
・ Eu ₂ O ₃ 0.047g
・ MnCO ₃ 0.077g

  The others were fired in the same manner as in Example 1 to obtain the intended phosphor powder. The results of the emission spectrum (when excited at 365 nm) of the phosphor powder measured in the same manner as in Example 1 are shown in FIG. The emission peak wavelengths were 471 nm and 623 nm, the chromaticity was (x, y) = (0.35, 0.32), and the luminance was 66% with respect to the phosphor of Example 3.

<Example 6>
The same starting materials as in Example 3 were used and weighed so that the mixing ratio (molar ratio) was the composition ratio shown in Table 1.
・ MgO 0.500g
・ Al ₂ O ₃ 1.345g
・ SiO ₂ 0.793g
・ Si ₃ N ₄ 1.851 g
・ Eu ₂ O ₃ 0.070g
・ MnCO ₃ 0.045g

  Firing was carried out in the same manner as in Example 1 except that the firing temperature was 1650 ° C., to obtain the intended phosphor powder. The results of the emission spectrum (when excited at 365 nm) of the phosphor powder measured in the same manner as in Example 1 are shown in FIG. The emission peak wavelengths were 479 nm and 602 nm, the chromaticity was (x, y) = (0.31,0.35), and the luminance was 135% with respect to the phosphor of Example 3.

<Example 7>
The same starting materials as in Example 3 were used and weighed so that the mixing ratio (molar ratio) was the composition ratio shown in Table 1.
・ MgO 0.500g
・ Al ₂ O ₃ 1.360g
・ SiO ₂ 0.801g
・ Si ₃ N ₄ 1.871 g
・ Eu ₂ O ₃ 0.070g
・ MnCO ₃ 0.061g

  Firing was carried out in the same manner as in Example 1 except that the firing temperature was 1650 ° C., to obtain the intended phosphor powder. The results of the emission spectrum (when excited at 365 nm) of the phosphor powder measured in the same manner as in Example 1 are shown in FIG. The emission peak wavelengths were 487 nm and 609 nm, the chromaticity was (x, y) = (0.35, 0.38), and the luminance was 102% with respect to the phosphor of Example 3.

<Example 8>
The same starting materials as in Example 1 were used and weighed so that the mixing ratio (molar ratio) was the composition ratio (y = 0.10, a = 0.5, b = 1, c = 0.33) shown in Table 1.
・ MgO 1.000g
・ Al ₂ O ₃ 1.331g
・ SiO ₂ 1.569g
・ Si ₃ N ₄ 1.221 g
・ Eu ₂ O ₃ 0.230g

Firing was carried out in the same manner as in Example 1 except that the firing temperature was 1750 ° C., to obtain the target phosphor powder. The result of the X-ray diffraction measurement of the obtained phosphor is shown in FIG. As a result of the measurement, similarly good agreement with X-ray diffraction pattern of MgAl ₂ Si ₄ O ₆ N ₄ as in Example 1, to contain MgAl ₂ Si ₄ O ₆ N ₄ as a main phase was confirmed. Further, MgAl ₂ O ₄ and Mg ₂ SiO ₄ were contained as subphases.
The results of the emission spectrum (when excited at 365 nm) of the phosphor powder measured in the same manner as in Example 1 are shown in FIG. The emission peak wavelength was 487 nm, the chromaticity was (x, y) = (0.21,0.36), and the luminance was 260% with respect to the phosphor of Example 1.

<Example 9>
The same starting materials as in Example 1 were used and weighed so that the mixing ratio (molar ratio) was the composition ratio shown in Table 1.
・ MgO 1.000g
・ Al ₂ O ₃ 1.367g
・ SiO ₂ 1.611g
・ Si ₃ N ₄ 1.254 g
・ Eu ₂ O ₃ 0.354g

  The others were fired in the same manner as in Example 8 to obtain the intended phosphor powder. The results of the emission spectrum (when excited at 365 nm) of the phosphor powder measured in the same manner as in Example 1 are shown in FIG. The emission peak wavelength was 502 nm, the chromaticity was (x, y) = (0.24, 0.41), and the luminance was 262% with respect to the phosphor of Example 1.

<Example 10>
The same starting materials as in Example 1 were used and weighed so that the mixing ratio (molar ratio) was the composition ratio shown in Table 1.
・ MgO 1.000g
・ Al ₂ O ₃ 1.405g
・ SiO ₂ 1.656g
・ Si ₃ N ₄ 1.289 g
・ Eu ₂ O ₃ 0.485g

  The others were fired in the same manner as in Example 8 to obtain the intended phosphor powder. The results of the emission spectrum (when excited at 365 nm) of the phosphor powder measured in the same manner as in Example 1 are shown in FIG. The emission peak wavelength was 503 nm, the chromaticity was (x, y) = (0.26, 0.44), and the luminance was 271% with respect to the phosphor of Example 1.

<Example 11>
The same starting materials as in Example 3 were used and weighed so that the mixing ratio (molar ratio) was the composition ratio shown in Table 1.
・ MgO 1.000g
・ Al ₂ O ₃ 1.345g
・ SiO ₂ 1.585g
・ Si ₃ N ₄ 1.234g
・ Eu ₂ O ₃ 0.093g
・ MnCO ₃ 0.121g

  Firing was carried out in the same manner as in Example 1 except that the firing temperature was 1700 ° C., to obtain the target phosphor powder. The results of the emission spectrum (when excited at 365 nm) of the phosphor powder measured in the same manner as in Example 1 are shown in FIG. The emission peak wavelengths were 471 nm and 602 nm, the chromaticity was (x, y) = (0.30, 0.30), and the luminance was 162% with respect to the phosphor of Example 3.

<Example 12>
The same starting materials as in Example 3 were used and weighed so that the mixing ratio (molar ratio) was the composition ratio shown in Table 1.
・ MgO 1.000g
・ Al ₂ O ₃ 1.360g
・ SiO ₂ 1.603g
・ Si ₃ N ₄ 1.247 g
・ Eu ₂ O ₃ 0.094g
・ MnCO ₃ 0.153g

  Firing was carried out in the same manner as in Example 1 except that the firing temperature was 1700 ° C., to obtain the intended phosphor powder. FIG. 15 and Table 1 show the results of the emission spectrum (when excited at 365 nm) of the phosphor powder measured in the same manner as in Example 1. The emission peak wavelengths were 470 nm and 621 nm, the chromaticity was (x, y) = (0.33, 0.31), and the luminance was 162% with respect to the phosphor of Example 3.

<Example 13>
The same starting materials as in Example 3 were used and weighed so that the mixing ratio (molar ratio) was the composition ratio shown in Table 1.
・ MgO 1.000g
・ Al ₂ O ₃ 1.437g
・ SiO ₂ 1.694g
・ Si ₃ N ₄ 1.318 g
・ Eu ₂ O ₃ 0.099g
・ MnCO ₃ 0.324g

Firing was carried out in the same manner as in Example 1 except that the firing temperature was 1700 ° C., to obtain the target phosphor powder. The results of the emission spectrum (when excited at 365 nm) of the phosphor powder measured in the same manner as in Example 1 are shown in FIG. The emission peak wavelengths were 469 nm and 653 nm, the chromaticity was (x, y) = (0.38, 0.31), and the luminance was 46% with respect to the phosphor of Example 3.

As can be seen from the results shown in Table 1 and FIGS. 3 and 5 to 16, when Mn is not contained (Examples 1, 2 and 8-10), blue having a single emission peak at 450 to 520 nm. A green phosphor was obtained. Further, in the blue to green phosphors, higher luminance was obtained in the phosphor (Examples 8 to 10) having a relatively small amount than the phosphors (Examples 1 and 2) having a relatively large nitrogen content. On the other hand, when Mn was contained (Examples 3-7 and 11-13), white phosphors having emission peaks at 450 to 520 nm and 590 to 660 nm were obtained.
The results of X-ray diffraction show only Example 1 and Example 8, but MgAl ₂ Si ₄ 0 ₆ N ₄ was confirmed to be the main phase in the phosphors of all Examples.

2. Example of light emitting device <Example L-1> (Example using blue to green phosphor)
A light-emitting element (LED) as shown in FIG. 1 is produced as follows using the phosphor obtained in Example 1, Example 2, Example 8, and Example 9 described above as a wavelength conversion material. did. First, a substrate 7 was prepared in which a concave portion 8 (an end surface angle of about 52 ° serving as a wall) was integrally molded with an extraction electrode 6 made of nylon resin having high reflectivity. As the semiconductor light-emitting element 1, an InGaN-based compound semiconductor (emission wavelength peak: 395 nm) formed on an n-type SiC substrate was prepared. The semiconductor light emitting device 1 was electrically bonded to the cathode 7 formed on the n-type substrate and the corresponding extraction electrode 6 with Ag paste, and fixed to the substrate 7. On the other hand, the anode electrode formed on the InGaN-based compound semiconductor and the extraction electrode corresponding to the anode electrode were secured by an Au wire.

A silicone resin mixed with each phosphor was filled up to the end of the opening of the recess 8 and heated at 150 ° C. for 2 hours to cure the resin, thereby manufacturing a light emitting device. The phosphor concentrations of Examples 1 and 2 were 40 wt% with respect to the silicone resin and mixed, and the phosphors of Examples 7 and 8 were 20 wt% with respect to the silicone resin.
Table 2 shows chromaticity coordinates of the light-emitting element thus manufactured.

<Example L-2> (Example using white phosphor)
A light emitting device (LED) as shown in FIG. 1 was produced in the same manner as in Example L-2 except that the phosphors of Examples 3 to 7 and Example 13 were used as the wavelength conversion material. Each phosphor concentration was 40 wt% with respect to the silicone resin. Table 3 shows chromaticity coordinates of the light-emitting element thus manufactured.

  From the results shown in Tables 2 and 3, it can be seen that the light emitting device of the present invention can emit light having substantially the same color as that of the phosphor. Thereby, it is possible to reduce the color variation caused by the variation in the emission wavelength of the semiconductor light emitting element.

3. Examples in which variation of white phosphor was evaluated <Examples L-3 and L-4>
A light emitting device (LED) as shown in FIG. 1 was produced in the same manner as in Example L-1, except that the phosphors of Example 11 and Example 12 were used as the wavelength conversion material. Each phosphor concentration was 40 wt% with respect to the silicone resin.

<Comparative Example 1>
Combined with blue-excited silicate phosphor as wavelength conversion material and blue LED (emission peak wavelength 462nm) as semiconductor light-emitting element so that the emission color (blue) has almost the same color tone as Example L-3 A light emitting device (LED) was produced in the same manner as in Example L-3.
<Comparative example 2>
Example: Using blue BAM phosphor as a wavelength conversion material and near-ultraviolet LED (emission peak wavelength: 395 nm) as a semiconductor light-emitting element so that the emission color (blue) has almost the same color as Example L-3. A light emitting device (LED) was fabricated in the same manner as L-3.

Eight light-emitting elements of Examples L-3 and L-4 and Comparative Examples 1 and 2 were produced, the standard deviation of each chromaticity coordinate was determined, and the degree of variation of each light-emitting element was evaluated. Table 4 shows the results of chromaticity coordinates and standard deviations of the phosphors and the light emitting elements.

  As shown in Table 4, it was confirmed that variations in chromaticity coordinates were reduced in the light emitting device of the present invention.

  The phosphor of the present invention can be applied to general illumination light sources such as LEDs, fluorescent lamps, and CCFLs. In particular, since white light can be obtained only with a phosphor, it is suitable for an LED manufactured together with a near-ultraviolet LED serving as an excitation light source.

The figure which shows one Embodiment of the light-emitting device with which this invention is applied. The figure which shows other embodiment of the light-emitting device to which this invention is applied. Example 1, illustrates the X-ray diffraction data of the phosphor of Example 8 and MgAl ₂ Si ₄ O ₆ N ₄ The figure which shows the excitation spectrum of the fluorescent substance of Example 1 The figure which shows the emission spectrum of the fluorescent substance of Example 2. The figure which shows the excitation spectrum of the fluorescent substance of Example 3 The figure which shows the excitation spectrum of the fluorescent substance of Example 4 The figure which shows the emission spectrum of the fluorescent substance of Example 5. The figure which shows the excitation spectrum of the fluorescent substance of Example 6 The figure which shows the emission spectrum of the fluorescent substance of Example 7. The figure which shows the excitation spectrum of the fluorescent substance of Example 8 The figure which shows the emission spectrum of the fluorescent substance of Example 9. The figure which shows the excitation spectrum of the fluorescent substance of Example 10 The figure which shows the emission spectrum of the fluorescent substance of Example 11. The figure which shows the emission spectrum of the fluorescent substance of Example 12. The figure which shows the excitation spectrum of the fluorescent substance of Example 13

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Light emitting element, 2 ... Lead wire, 3 ... Wavelength conversion material, 4 ... Sealing part, 6 ... Extraction electrode, 7 ... Base | substrate, 8 ... Recessed part

Claims (12)

A phosphor comprising MgAl ₂ Si ₄ O ₆ N ₄ as a main phase and Eu as an activator (Re).   The phosphor according to claim 1, further comprising Mn as an activator (Re). _3. The phosphor according to claim 1, comprising MgAl ₂ O ₄ and / or Si ₃ N ₄ as a subphase.   The phosphor according to any one of claims 1 to 3, wherein the phosphor has an emission peak between 450 and 520 nm, and the chromaticity is 0.15 ≦ x ≦ 0.28, 0.25 ≦ y ≦ on the CIExy chromaticity diagram. A blue to green phosphor characterized by 0.48.   The phosphor according to any one of claims 1 to 3, wherein the phosphor has an emission peak between 450 to 520 nm and 590 to 660 nm, and the chromaticity is 0.27 ≦ x ≦ on the CIExy chromaticity diagram. White phosphor characterized by 0.40, 0.28 ≦ y ≦ 0.40. The phosphor according to any one of claims 1 to 5,
The raw material compounds are MgO, Al ₂ O ₃ , SiO ₂ , Si ₃ N ₄ , Eu ₂ O ₃ , MnO, and the mixing ratio (molar ratio) MgO: Al ₂ O ₃ : SiO ₂ : Si ₃ N ₄ : Eu ₂ O ₃ : When MnO is represented by (1-y / 2-z): a: b: c: y: z, 0.04 ≦ y ≦ 0.2, 0 ≦ z ≦ 0.1, 0.5 ≦ a ≦ 1 , B = 1, and 0.33 ≦ c ≦ 1.   The method for producing a phosphor according to any one of claims 1 to 6, wherein the first step of mixing the raw material compounds and the step of firing the mixed raw material compounds in a nitrogen pressure atmosphere of 1.0 MPa or less. The manufacturing method which has a 2nd process, the 3rd process of grind | pulverizing a material after baking, and the 4th process annealed in nitrogen atmospheric pressure atmosphere. In the second step, the powder sample is fired at 1600-1800 ° C. for 2 hours in a nitrogen atmosphere at 9 atmospheres under pressure, and in the fourth step, the powder sample is fired for 10 hours at 1300 ° atmosphere in a nitrogen atmosphere. The manufacturing method of Claim 7 characterized by these.   A light emitting device comprising a combination of a wavelength converting material containing the phosphor according to any one of claims 1 to 5 and a light source that emits ultraviolet to near ultraviolet light having a wavelength of 140 nm to 420 mn.   The light-emitting device according to claim 9, wherein the light source is a near-ultraviolet LED that emits light at a wavelength of 300 to 420 nm.   The light emitting device according to claim 10, wherein the light emitting device is a white LED that obtains white light by light emission from one or more kinds of phosphors. The light emitting device according to claim 10, wherein the light emitting device is a white LED that obtains white light by light emission from only one kind of phosphor.

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