WO2012046642A1 - Green light-emitting phosphor and light-emitting device - Google Patents

Green light-emitting phosphor and light-emitting device Download PDF

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Publication number
WO2012046642A1
WO2012046642A1 PCT/JP2011/072514 JP2011072514W WO2012046642A1 WO 2012046642 A1 WO2012046642 A1 WO 2012046642A1 JP 2011072514 W JP2011072514 W JP 2011072514W WO 2012046642 A1 WO2012046642 A1 WO 2012046642A1
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phosphor
light
sample
wavelength
light emitting
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PCT/JP2011/072514
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French (fr)
Japanese (ja)
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渡部　純也
武 高原
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株式会社ネモト・ルミマテリアル
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Priority to JP2012537673A priority Critical patent/JP5669855B2/en
Publication of WO2012046642A1 publication Critical patent/WO2012046642A1/en

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    • C—CHEMISTRY; METALLURGY
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    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
    • C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
    • C09K11/77—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals
    • C09K11/7766—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals containing two or more rare earth metals
    • C09K11/7774—Aluminates
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
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    • H01L33/00—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/48—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor body packages
    • H01L33/50—Wavelength conversion elements
    • H01L33/501—Wavelength conversion elements characterised by the materials, e.g. binder
    • H01L33/502—Wavelength conversion materials
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    • H01L2224/48225—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being non-metallic, e.g. insulating substrate with or without metallisation
    • H01L2224/48227—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being non-metallic, e.g. insulating substrate with or without metallisation connecting the wire to a bond pad of the item
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    • H01L2224/48151—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
    • H01L2224/48221—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
    • H01L2224/48245—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being metallic
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Definitions

  • the present invention relates to a phosphor capable of absorbing blue light from a light emitting element and emitting green light.
  • the present invention relates to a phosphor suitably used for a white light emitting diode that can be used for an illumination light source that requires color rendering properties, a liquid crystal backlight, and the like.
  • the present invention also relates to a semiconductor light emitting device using the phosphor.
  • a phosphor that absorbs blue light and ultraviolet light and converts the wavelength into visible light having a long wavelength such as red, yellow, and green.
  • semiconductor light emitting devices such as gallium nitride (GaN) blue light emitting diodes are used as visible light sources or ultraviolet light sources in the short wavelength region.
  • GaN gallium nitride
  • a semiconductor light-emitting device that is configured in combination with a phosphor that is a wavelength conversion material and emits visible light such as white has a feature of low power consumption and long life, and has recently attracted attention as a light-emitting source of an image display device or a lighting device. ing.
  • the phosphor that is the wavelength conversion material absorbs the visible light in the blue region emitted by the GaN-based blue light emitting diode, emits yellow light, and the light emitting diode that is not absorbed by the phosphor. It emits white light by mixing with blue light (see, for example, Patent Document 1).
  • the white light is formed by blue light and yellow light which is a complementary color thereof, there is a problem that the color rendering property is lacking.
  • the green light emitting phosphors are activated with alkaline earth metal sulfide phosphors having a rock salt type crystal structure (for example, cerium activated calcium sulfide (CaS: Ce) phosphors) and divalent europium.
  • alkaline earth metal orthosilicate phosphors for example, (Sr, Ba) 2 SiO 4 : Eu 2+ phosphor.
  • these sulfide phosphors and orthosilicate phosphors have a problem that they are still insufficient in terms of chemical stability, light emission luminance, and the like.
  • the green light-emitting phosphor a part of aluminum in the cerium-activated yttrium aluminum garnet (YAG: Ce) phosphor known as a yellow light-emitting phosphor is substituted with gallium (Ga).
  • gallium Ga
  • Y 3 (Al, Ga) 5 O 12 : Ce phosphors that emit green light by shifting the emission color to the short wavelength side are known (see, for example, Patent Document 1).
  • the luminance is reduced by substitution with gallium and a problem that the luminance is lowered at a high temperature.
  • the green light emitting phosphor is required to emit light having a shorter wavelength.
  • the wavelength at the intersection with the spectral locus on the extended line connecting the chromaticity coordinates x and y of the emission color from the point 3333 is the dominant wavelength.
  • a spectroscope or the like is used to obtain an emission spectrum when the phosphor is excited with 450 nm blue light.
  • the chromaticity coordinates x and y are obtained by calculation using the wavelength range of 470 nm to 780 nm, and the principal wavelength obtained from the chromaticity coordinates x and y is defined as the principal wavelength of the present application.
  • the emission colors of various phosphors are expressed at this dominant wavelength, for example, YAG: Ce phosphors have an emission color with a dominant wavelength of about 573 nm, and Y 3 (Al, Ga) partially substituted with gallium.
  • the 5 O 12 : Ce phosphor can have an emission color having a dominant wavelength of about 556 nm to about 568 nm, depending on the composition.
  • the Y 3 (Al, Ga) 5 O 12 : Ce phosphor has insufficient luminance and has a problem of luminance reduction at high temperatures.
  • the dominant wavelength has a shorter emission wavelength, for example, in the range of about 554 nm or more and about 562 nm or less, and has high emission luminance, high temperature
  • the light transmission color is closer to the transmission characteristic (spectral characteristic) of the color filter of the liquid crystal backlight, and the light transmission efficiency is improved, and vivid color reproduction is possible.
  • the transmittance peak is around 520 to 530 nm. Therefore, even in the case of a liquid crystal backlight light source, as described above, it emits light at a shorter wavelength side and has high emission luminance.
  • color rendering in the present specification includes the meaning of color reproducibility in such a liquid crystal backlight application.
  • the conventional green light-emitting phosphor has a high emission luminance, can maintain the emission luminance even at a high temperature, and satisfies the market needs for further improving the color rendering properties of the semiconductor light emitting device. Can not.
  • the present invention has a light emission color in a range where the dominant wavelength is about 554 nm or more and about 562 nm, has a high light emission luminance, and has a lower decrease in light emission luminance at high temperatures.
  • An object is to provide an excellent green light emitting phosphor suitable for a semiconductor light emitting device.
  • a green light-emitting phosphor having a specific composition described below has an emission color in a range where the dominant wavelength is approximately 554 nm or more and approximately 562 nm.
  • the present invention has been found to be a phosphor having excellent characteristics necessary for a semiconductor light emitting device having high color rendering properties, such as having a high light emission luminance and less decrease in light emission luminance at high temperatures.
  • the garnet-based green light-emitting phosphor of the first invention is represented by the formula (Lu 1-x Ce x ) 3 + d Al 5-d O 12 , where x is 0.005 ⁇ x ⁇ 0.14. , D is characterized by 0.03 ⁇ d ⁇ 0.5.
  • the main wavelength has a light emission color in a range of about 554 nm to about 562 nm, and
  • the green light-emitting phosphor has excellent characteristics necessary for a semiconductor light-emitting device with high color rendering properties such as high emission luminance and less decrease in emission luminance at high temperatures.
  • the garnet-based green light-emitting phosphor of the second invention is the garnet-based green light-emitting phosphor of the first invention, wherein d is 0.045 ⁇ d ⁇ 0.2. And by setting it as the range of the value of said d, it becomes a green type light emission fluorescent substance which has a more preferable luminescent color and luminescent luminance.
  • a semiconductor light emitting device is characterized by comprising at least the garnet green light emitting phosphor and the semiconductor light emitting element according to the first or second invention. Further, by using the garnet green light emitting phosphor according to the first or second, an efficient semiconductor light emitting device that is excellent in color rendering and has little luminance decrease at high output because there is little luminance decrease at high temperature, Become.
  • the main wavelength has an emission color in the range of about 554 nm or more and about 562 nm, has high emission luminance, and lowers emission luminance at high temperatures. It is possible to obtain a green light-emitting phosphor having excellent characteristics that can be suitably used for a semiconductor light-emitting device having characteristics and high color rendering properties.
  • the semiconductor light emitting device having at least the garnet green light emitting phosphor and the semiconductor light emitting element of the present invention the luminance is reduced even at high output because of excellent color rendering and little luminance decrease at high temperature. Therefore, an efficient semiconductor light emitting device with a small amount of light can be obtained.
  • FIG. 1 is a powder X-ray diffraction pattern of a phosphor according to an embodiment of the present invention.
  • FIG. 4 is a detail of 2 ⁇ in the range of 55 to 60 ° in the powder X-ray diffraction pattern of the phosphor according to the embodiment of the present invention. It is sectional drawing which showed the semiconductor light-emitting device in one embodiment of this invention. It is sectional drawing which showed the semiconductor light-emitting device in another one Embodiment of this invention.
  • lutetium oxide Li 2 O 3
  • alumina Al 2 O 3
  • cerium Ce
  • a predetermined amount of these phosphor raw materials and, for example, barium fluoride (BaF 2 ) or strontium fluoride (SrF 2 ) as a flux are weighed and mixed sufficiently using ball mill mixing or the like to obtain a mixed powder of the raw materials.
  • the amount of flux at this time is about 0.1% to 10% of the total mass of the raw materials.
  • This mixed powder is more preferably filled in a heat-resistant container such as an alumina crucible, put in an electric furnace, and in a reducing atmosphere such as a nitrogen-oxygen mixed gas stream, for example, at a firing temperature of about 1000 ° C. to 1800 ° C. Is fired at a firing temperature of 1400 ° C. to 1600 ° C. for about 2 hours to 12 hours. Cool after firing, and disperse and grind with a ball mill or the like.
  • cleaning with water and acid is performed to remove residual flux, and then a phosphor having a predetermined particle size is obtained through a drying step and a sie
  • the oxide was mainly illustrated as a phosphor raw material, if it is a compound which decomposes
  • fluorides such as barium fluoride (BaF 2 ) and strontium fluoride (SrF 2 ) were shown as fluxes, other than these, halides such as chlorides, halides of elements constituting phosphors, It is also possible to use boric acid.
  • alkaline earth metal hydrogen phosphates such as barium hydrogen phosphate (BaHPO 4 ), strontium hydrogen phosphate (SrHPO 4 ), lithium phosphate (Li 3 PO 4 ), and alkali metal phosphorus Acid salts may be added.
  • FIG. 6 is a cross-sectional view showing a semiconductor light emitting device according to an embodiment of the present invention.
  • This semiconductor light emitting device has a mount 10 that is a cup-shaped recess at the tip of a lead frame 101.
  • a semiconductor light emitting element 11 having an insulating substrate is fixed to the cup-shaped mount 10 with an adhesive 12 made of, for example, an epoxy resin, as a semiconductor light emitting element that emits light in the blue region from the near ultraviolet.
  • a P-type electrode 13a provided on the upper surface of the semiconductor light emitting element 11 is connected to the electrode portion 13b of the lead frame 101 by a metal wire 15a made of, for example, Au, Al, Cu or the like.
  • An N-type electrode 14a provided on the upper surface of the semiconductor light emitting element 11 is connected to the electrode portion 14b of the right lead frame 102 by a metal wire 15b.
  • the fluorescent substance 21 is fully mixed and filled in the cup-shaped mount part 10. Further, the upper portions of the semiconductor light emitting element 11 and the lead frames 101 and 102 are sealed with a mold resin 30 such as a transparent epoxy resin to form a shell-shaped semiconductor light emitting device.
  • a mold resin 30 such as a transparent epoxy resin
  • the mount 10 of the lead frame 101 is formed in a cup shape in order to efficiently collect the light emitted from the semiconductor light emitting element 11, and is emitted.
  • the light has directivity toward the upper side of FIG.
  • the semiconductor light emitting device 11 is disposed on the bottom of the cup-shaped mount portion 10 and the mount portion 10 is filled with a phosphor 21, and the phosphor 21 emits the near-ultraviolet light emitted from the semiconductor light emitting device 11.
  • Light of a blue region for example, light having a wavelength of 390 nm to 470 nm is wavelength-converted, and light of a green region, a red region, or the like is emitted from the phosphor 21.
  • the phosphor 21 is filled in the cup-shaped mount 10 to efficiently convert the light from the semiconductor light-emitting element 11 and increase the brightness of the semiconductor light-emitting device. It is not necessary to fill the entire body with the phosphor 21, and it may be filled in a concave shape or a convex shape as necessary. Further, the phosphor 21 may be dispersed in the sealing resin 30 instead of filling the cup-shaped mount 10.
  • FIG. 7 is a cross-sectional view showing a semiconductor light emitting device according to another embodiment of the present invention.
  • a semiconductor light emitting element 11 having an insulating substrate is bonded to a rectangular parallelepiped printed wiring board 16 made of glass epoxy having heat resistance, for example, with an adhesive 12 made of epoxy resin.
  • the P-type electrode 13a and the N-type electrode 14a provided on the upper surface of the semiconductor light emitting element 11 are connected to the electrode portions 16a and 16b on the upper surface of the printed wiring board 16 by metal wires 15a and 15b, respectively.
  • Electrodes 16a and 16b are routed to the lower surface of the printed wiring board 16 as a mounting surface through a through-hole having a circular arc cross section (not shown) that connects the upper surface and the lower surface of the printed wiring board 16, and this mounting is performed. It extends to both ends of the surface.
  • the printed wiring board 16 may use an insulating film.
  • a mold resin 32 such as a translucent epoxy resin as a sealing resin in which the phosphor 21 is dispersed so as to cover the entire semiconductor light emitting element 11 on the printed wiring board 16 is shown in FIG.
  • a semiconductor light emitting device having a chip part shape is formed by forming a trapezoidal cross section as shown.
  • the phosphor 21 includes at least a garnet-based green light-emitting phosphor according to an embodiment of the present invention. Further, in addition to the green-based light-emitting phosphor of the present invention, the phosphor 21 emits light in the red region.
  • the phosphor may be a mixture containing an oxynitride phosphor, a CaAlSiN 3 phosphor, a sulfide phosphor, or the like.
  • the selection of the red light-emitting phosphor can be appropriately selected according to the light emission characteristics of the garnet-based green light-emitting phosphor of the present invention.
  • the semiconductor light-emitting device of the present invention is not limited to the above structure, and light from the near ultraviolet to blue region emitted from the semiconductor light-emitting element 11 is garnet-based green light emission according to an embodiment of the present invention.
  • the green light-emitting phosphor of the present invention and its characteristics will be described in comparison with a conventional green light-emitting phosphor.
  • Sample 1- (1) For the obtained Sample 1- (1), first, the particle size distribution was measured with a laser diffraction particle size distribution analyzer (model: SALD-2100, manufactured by Shimadzu Corporation). The result is shown in FIG. The average particle size D50 at this time was 25.0 ⁇ m. Next, an emission spectrum was measured using a spectrofluorometer (model: F-4500, manufactured by Hitachi, Ltd.) with excitation light at 450 nm. The result is shown in FIG.
  • chromaticity coordinates x and y in the CIE1931XYZ color system were calculated from the obtained emission spectrum according to Japanese Industrial Standard JIS-Z-8724.
  • the wavelength range to be calculated was set from 470 nm to 780 nm in order to avoid the influence of blue light near 450 nm used as excitation light.
  • the dominant wavelength and the stimulation purity were determined according to the Japanese Industrial Standard JIS-Z-8701 appendix. As a result, the dominant wavelength was 561.0 nm and the stimulation purity was 83.5%.
  • Y 3 (Al, Ga) 5 O 12 Ce phosphors and Lu 3 Al 5 O 12 : Ce phosphors of stoichiometric composition are used as emission colors.
  • the phosphors having the following composition were prepared in which the main wavelength of the sample was approximately the same as 561.0 nm of Sample 1- (1), and were designated as Comparative Example 2- (1) and Comparative Example 3- (1), respectively.
  • Comparative Example 2- (1): (Y 0.975 Ce 0.025 ) 3 (Al 0.6 Ga 0.4 ) 5 O 12 Comparative Example 3- (1): (Lu 0.98 Ce 0.02 ) 3 Al 5 O 12
  • a YAG: Ce phosphor was also prepared as Comparative Example 1 as a conventional yellow light-emitting phosphor.
  • Comparative Example 1 (Y 0.975 Ce 0.025 ) 3 Al 5 O 12
  • a phosphor was prepared in the same manner as Sample 1- (1).
  • Comparative Example 2- (1), and Comparative Example 3- (1) thus obtained the emission spectrum was measured in the same manner as Sample 1- (1), and the chromaticity coordinates x, y were calculated. The dominant wavelength and stimulation purity were determined.
  • the light emission luminance when actually excited by a blue LED and the luminance maintenance ratio at a high temperature were measured.
  • a plurality of light emitting diodes having an emission peak wavelength at 460 nm at room temperature (about 25 ° C.) are used as an excitation light source and directed toward the target phosphor sample. Irradiate.
  • the light from the emitted phosphor is measured using a luminance meter (model: LS-110, manufactured by Konica Minolta).
  • a sharp cut filter (model: Y-50 manufactured by HOYA CANDEO OPTRONICS) that cuts a wavelength of 500 nm or less is installed in the front part of the luminance meter to remove the influence of blue light as excitation light.
  • the obtained light emission luminance was the relative light emission luminance with Comparative Example 1 as 100.
  • the change in emission luminance when the temperature of the phosphor was changed was measured by an apparatus having the following configuration.
  • the top of an aluminum plate with a thickness of about 5 mm and a vertical and horizontal length of about 45 mm and a cylindrical recess with a diameter of about 30 mm and a depth of about 2 mm is used as a sample holder, and from the side to the center of the bottom A reaching horizontal hole was provided, and a temperature sensor was inserted into the horizontal hole so that the temperature of the sample holder could be measured.
  • the sample holder is filled with the target phosphor powder and placed on a hot plate so that the measurement holder can be heated.
  • the phosphor is irradiated toward the phosphor, and the emitted light is emitted from the phosphor using a luminance meter (model: LS-100 manufactured by Konica Minolta). taking measurement.
  • a sharp cut filter model: Y-50 manufactured by HOYA CANDEO OPTRONICS
  • a wavelength of 500 nm or less is installed in the front part of the luminance meter to remove the influence of blue light as excitation light.
  • the temperature and brightness of the sample holder were recorded while changing the temperature of the phosphor powder in the sample holder from room temperature (about 25 ° C.) to about 200 ° C. using a hot plate.
  • Temperature sensor Platinum resistance thermometer Pt100 (model: TR-8110, manufactured by T & D)
  • Data logger Memory high logger (model: 8420-50 manufactured by Hioki Electric Co., Ltd.)
  • the results are obtained by taking the relative luminance maintenance rate with the horizontal axis representing temperature and the vertical axis representing emission luminance at a temperature of 25 ° C. as 100%.
  • the plotted graph is shown in FIG.
  • the relative light emission luminance at 200 ° C. with the light emission luminance of Comparative Example 1 at room temperature (25 ° C.) as 100 was also obtained.
  • an emission spectrum was measured in the same manner as Sample 1- (1), chromaticity coordinates x and y were calculated, and a dominant wavelength and stimulation purity were obtained.
  • Y 3 (Al, Ga) 5 O 12 : Ce phosphor and a Lu 3 Al 5 O 12 : Ce phosphor having a stoichiometric composition are used as conventional phosphors.
  • the phosphor having the following composition in which the dominant wavelength of the emission color is almost the same as 556.2 nm of Sample 1- (2) is the same as in Comparative Example 2- (1) and Comparative Example 3- (1).
  • Comparative Example 2- (2) and Comparative Example 3- (2) respectively.
  • Comparative Example 2- (2) (Y 0.99 Ce 0.01 ) 3 (Al 0.63 Ga 0.37 ) 5 O 12
  • the emission spectrum was measured in the same manner as Sample 1- (2), and the chromaticity coordinates x and y were calculated. Stimulation purity was determined.
  • the emission luminance when actually excited by a blue LED and the luminance maintenance ratio at high temperature are shown in Sample 1. -Measured in the same manner as (1).
  • the main wavelength, stimulation purity, relative emission luminance, and relative emission luminance at 200 ° C. are collectively shown. It is shown in 2.
  • the Ce concentration x was fixed at 0.03.
  • the value of d and the characteristics of the phosphor will be described. Except for changing the composition ratio of each element as shown in Table 3, phosphors were prepared in the same manner as Sample 1- (1) in Example 1, and Samples 2- (1) to 2- (12). For Sample 2- (1) to Sample 2- (12), the main wavelength, the stimulation purity, and the relative light emission luminance with Comparative Example 1 as 100 were measured in the same manner as in Example 1, and the results were also obtained. The results are shown in Table 3 together with the result of (1).
  • Samples 2- (3) to 2- (10) and Sample 1- (1) that is, samples having a d value of 0.03 or more and 0.5 or less have stoichiometric compositions.
  • the dominant wavelength is shifted to the short wavelength side by 2 nm or more, and that the relative light emission luminance hardly deteriorates and has preferable characteristics.
  • a sample having a d value of 0.045 or more has a dominant wavelength shifted to the short wavelength side by about 3 nm or more, which is more preferable.
  • the value of d when the value of d exceeds 0.2, the shift effect of the dominant wavelength is not so great and the stimulation purity tends to decrease, so the value of d is more than 0.045 and less than 0.2. It can be said that it is preferable.
  • the value of d when the value of d is too small as less than 0.03, the effect of shifting the dominant wavelength is small, and when the value of d exceeds 0.5 and is too large, the emission luminance is lowered. From the above, it can be said that the value of d is preferably 0.03 or more and 0.5 or less, and more preferably 0.045 or more and 0.2 or less.
  • sample 2- (1) which is a Lu 3 Al 5 O 12 : Ce phosphor having a stoichiometric composition
  • sample 1- (1) which is an example of the embodiment of the present invention
  • FIG. 5 shows an X-ray diffraction pattern in which mechanical errors at the time of measurement are corrected by superimposing data obtained by measuring only Y 2 O 3 , particularly by adjusting using a peak position near 57.5 °. .
  • sample 1- (1) which is an example of the embodiment of the present invention, is slightly smaller than sample 2- (1), which is a LuAG: Ce phosphor having a stoichiometric composition.
  • the garnet structure is one crystal structure of a complex oxide of metal ions A, B, and C.
  • the general formula is represented by A 3 B 2 C 3 O 12 .
  • A is at an 8-coordinate site surrounded by 8 oxygen atoms.
  • B is in a six-coordinate site surrounded by six oxygen atoms.
  • C is at a tetracoordinate site surrounded by four oxygen atoms.
  • Lu 3+ In the case of lutetium aluminum garnet (LuAG) is if the stoichiometric composition, Lu 3+ to 8 coordination sites, Al 3+ to 6 coordination sites, the Al 3+ in tetracoordinate site containing respectively
  • Lu 3+ enters a part of the 6-coordinate site where Al 3+ originally contained while maintaining the crystal structure of garnet. Such a phenomenon is called anti-site. Since Lu 3+ has a larger ionic radius than Al 3+, the crystal lattice of the 6-coordinate site spreads and the lattice constant increases. This is consistent with the fact that the peak position of powder X-ray diffraction is shifted to the lower angle side, that is, the lattice constant is increased.
  • This phenomenon can also be inferred from a change in the emission color of the phosphor. That is, as described in the background art, in a conventional Y 3 Al 5 O 12 : Ce phosphor, Y 3 (Al, Ga) 5 O 12 : Ce in which a part of Al is substituted with Ga having a large ion radius is The emission color is also shifted to a shorter wavelength than the emission color of the Y 3 Al 5 O 12 : Ce phosphor. At this time, Ga 3+ replaces the 6-coordinate Al 3+ described above. Since the ionic radius of Ga 3+ is also larger than that of Al 3+ , it is considered that the crystal lattice of the six-coordinate site is expanded.
  • the phosphor of the present invention also has a d value larger than 0, which is the stoichiometric composition, as described above, becomes Al poor, and Lu 3+ enters a part of the 6-coordinate site originally containing Al 3+.
  • the crystal lattice of the 6-coordinate site is widened, and it is presumed that the effect of shifting the emission color of the phosphor to a short wavelength was obtained as in the case of Ga substitution, without using Ga.
  • the feature of the present invention is to shift the emission wavelength of the phosphor to the short wavelength side by maintaining the LuAG garnet structure and expanding the crystal lattice of the six-coordinated sites while maintaining the excellent features. It can be said that it was successful.
  • Samples 3- (2) to 3- (7) Sample 1- (1)
  • Sample 1- (2) that is, a sample having a Ce concentration x of 0.005 or more and 0.14 or less has a dominant wavelength in the range of about 554 nm to about 562 nm and a relative emission luminance of about 70 or more.
  • the relative emission luminance is somewhat inferior in combination with the use or other phosphors, there are sufficient cases where it is desired to select the dominant wavelength, and therefore the sample in the range of the Ce concentration x can be preferably used.
  • a sample having a Ce concentration x in the range of 0.01 or more and 0.05 or less preferably has a relative light emission luminance of 90 or more.
  • the garnet-based green light-emitting phosphor characterized by 0.5 has an emission color in the range where the main wavelength is about 554 nm or more and about 562 nm, has high emission luminance, and emission luminance at high temperature It can be seen that the phosphor has excellent characteristics necessary for a semiconductor light emitting device with high color rendering properties, such as less deterioration.
  • x is 0.01 ⁇ x ⁇ 0.05, and d is 0.045 ⁇ d ⁇ 0.2.
  • the garnet-based green light-emitting phosphor of the present invention has a luminescent color in the range of the main wavelength of about 554 nm or more and about 562 nm, has a high emission luminance, and has a lower decrease in emission luminance at high temperatures. Since it has excellent characteristics suitable for a light-emitting device, it can be suitably used for a semiconductor light-emitting device that requires color rendering properties and high output. In addition, the semiconductor light emitting device of the present invention is excellent in color rendering properties, and since the luminance is hardly lowered even at high output, it can be suitably used particularly for an illumination light source or a liquid crystal backlight light source.

Abstract

Disclosed is a green light-emitting phosphor with excellent color rendering properties and optimal for high output-capable semiconductor light-emitting devices. The disclosed garnet-based green light-emitting phosphor is represented by the formula (Lu1-xCex)3+dAl5-dO12, wherein x is 0.005≦x≦0.14 and d is 0.03≦d≦0.5. The dominant wavelength contains an emission color in the vicinity of 562nm but not less than 554nm, has high emission luminance, and minimal decrease in emission luminance at high temperatures. The resulting green light-emitting phosphor has excellent color rendering properties and is optimal for semiconductor light-emitting devices capable of high output.

Description

緑色系発光蛍光体および発光装置Green light emitting phosphor and light emitting device
　本発明は、発光素子からの青色系の光を吸収し、緑色系の光を発光可能な蛍光体に関する。特に、演色性を求められる照明用光源や、液晶のバックライト等に利用可能な白色系発光ダイオードに好適に用いられる蛍光体に関する。およびこの蛍光体を用いた半導体発光装置に関する。 The present invention relates to a phosphor capable of absorbing blue light from a light emitting element and emitting green light. In particular, the present invention relates to a phosphor suitably used for a white light emitting diode that can be used for an illumination light source that requires color rendering properties, a liquid crystal backlight, and the like. The present invention also relates to a semiconductor light emitting device using the phosphor.
　従来から、青色系の光や紫外線を吸収し、赤色や黄色や緑色等の長波長の可視光に波長変換する蛍光体を用い、この蛍光体を組み合わせることで白色等の可視光を得ることが知られている。
　特に、短波長領域の可視光線または紫外線の光源としては、半導体発光素子、例えば窒化ガリウム（ＧａＮ）系青色発光ダイオード等が用いられている。そして、波長変換材料である蛍光体と組み合わせて構成し白色等の可視光を発する半導体発光装置は、消費電力が小さく寿命が長い特徴があり、近年画像表示装置または照明装置の発光源として注目されている。 Conventionally, it is possible to obtain visible light such as white by using a phosphor that absorbs blue light and ultraviolet light and converts the wavelength into visible light having a long wavelength such as red, yellow, and green. Are known.
In particular, semiconductor light emitting devices such as gallium nitride (GaN) blue light emitting diodes are used as visible light sources or ultraviolet light sources in the short wavelength region. A semiconductor light-emitting device that is configured in combination with a phosphor that is a wavelength conversion material and emits visible light such as white has a feature of low power consumption and long life, and has recently attracted attention as a light-emitting source of an image display device or a lighting device. ing.
　そして、この半導体発光装置は、波長変換材料である蛍光体が、ＧａＮ系青色発光ダイオードの発する青色領域の可視光を吸収して黄色光を発光し、この蛍光体に吸収されなかった発光ダイオードの青色光との混色によって、白色に発光する（例えば特許文献１参照。）。
しかしながら、この白色光は青色光とその補色である黄色光とで形成されるため、演色性に欠けるという問題がある。 In this semiconductor light emitting device, the phosphor that is the wavelength conversion material absorbs the visible light in the blue region emitted by the GaN-based blue light emitting diode, emits yellow light, and the light emitting diode that is not absorbed by the phosphor. It emits white light by mixing with blue light (see, for example, Patent Document 1).
However, since the white light is formed by blue light and yellow light which is a complementary color thereof, there is a problem that the color rendering property is lacking.
　この青色光と黄色光とで形成された白色光の演色性を改善したものとして、例えば青色光発光ダイオードと緑色系発光蛍光体と赤色発光蛍光体とを組み合わせて白色光を形成するものがある（例えば特許文献２参照。）。
　上記緑色系発光蛍光体としては、例えば岩塩型結晶構造をもつアルカリ土類金属硫化物蛍光体（例えばセリウム付活硫化カルシウム（ＣａＳ：Ｃｅ）蛍光体）や、２価のユウロピウムで付活されたアルカリ土類金属オルトケイ酸塩蛍光体（例えば（Ｓｒ,Ｂａ）２ＳｉＯ４：Ｅｕ２＋蛍光体）などが挙げられる。
　しかしながら、これらの硫化物系蛍光体やオルトケイ酸塩蛍光体では、化学的な安定性や発光輝度等の面で、まだまだ不充分であるという問題がある。 As an improvement in the color rendering properties of white light formed by blue light and yellow light, for example, there is one that forms white light by combining a blue light emitting diode, a green light emitting phosphor, and a red light emitting phosphor. (For example, refer to Patent Document 2).
Examples of the green light emitting phosphors are activated with alkaline earth metal sulfide phosphors having a rock salt type crystal structure (for example, cerium activated calcium sulfide (CaS: Ce) phosphors) and divalent europium. Examples thereof include alkaline earth metal orthosilicate phosphors (for example, (Sr, Ba) 2 SiO 4 : Eu 2+ phosphor).
However, these sulfide phosphors and orthosilicate phosphors have a problem that they are still insufficient in terms of chemical stability, light emission luminance, and the like.
　これらの他に緑色系発光蛍光体としては、黄色発光蛍光体として知られているセリウム付活イットリウムアルミニウムガーネット（ＹＡＧ：Ｃｅ）蛍光体のうち、アルミニウムの一部をガリウム（Ｇａ）で置換することにより発光色を短波長側にシフトさせて、緑色領域の光を発光させた蛍光体、例えばＹ３（Ａｌ,Ｇａ）５Ｏ１２：Ｃｅ蛍光体が知られている（例えば特許文献１参照。）。
　しかしながら、ガリウムで置換することによって発光輝度が低下する問題や、高温時において発光輝度が低下するという問題がある。特に近年、高出力タイプの発光素子を用いることが求められているため、高出力時に発光素子が発する熱の影響による輝度低下は重大な問題となっている。
　また、母体のイットリウムの箇所の一部にルテチウム（Ｌｕ）を用いたガーネット系蛍光体も提案されている（例えば特許文献３参照。）。母体の一部にルテチウムを用いることにより発光色が短波長側にシフトすることも知られており、また上記特許文献１のガリウムで置換したガーネット系蛍光体と比較して高温時の発光輝度が低下しにくいといった特徴を持つ（例えば特許文献４参照。）。しかしながら、発光輝度自体が不充分であり、さらなる高輝度な緑色系発光蛍光体が求められている。 In addition to these, as the green light-emitting phosphor, a part of aluminum in the cerium-activated yttrium aluminum garnet (YAG: Ce) phosphor known as a yellow light-emitting phosphor is substituted with gallium (Ga). For example, Y 3 (Al, Ga) 5 O 12 : Ce phosphors that emit green light by shifting the emission color to the short wavelength side are known (see, for example, Patent Document 1). ).
However, there is a problem that the luminance is reduced by substitution with gallium and a problem that the luminance is lowered at a high temperature. Particularly in recent years, since it is required to use a high-output type light-emitting element, a decrease in luminance due to the influence of heat generated by the light-emitting element at a high output is a serious problem.
In addition, a garnet phosphor using lutetium (Lu) as a part of the base yttrium is also proposed (see, for example, Patent Document 3). It is also known that the emission color shifts to the short wavelength side by using lutetium as a part of the matrix, and the emission luminance at high temperature is higher than that of the garnet-based phosphor substituted with gallium in Patent Document 1 above. It has a feature that it is difficult to decrease (see, for example, Patent Document 4). However, the light emission luminance itself is insufficient, and a green light emitting phosphor with higher luminance is demanded.
　別の観点からは、半導体発光装置の演色性をより向上させるために、緑色系発光蛍光体としてはより短波長側の発光色が求められている。発光色を日本工業規格ＪＩＳ－Ｚ－８７０１の附属書で定義されている「主波長」で表す場合、すなわちＣＩＥ１９３１ＸＹＺ表色系において無彩色の色度座標であるｘ＝０．３３３３、ｙ＝０．３３３３の点から、発光色の色度座標ｘ，ｙを結んだ延長線上にあるスペクトル軌跡との交点の波長が主波長である。ここで分光器等を用いて、４５０ｎｍの青色光で蛍光体を励起した場合の発光スペクトルを得る。このうち４７０ｎｍから７８０ｎｍの波長範囲を用いて色度座標ｘ、ｙを計算により求め、この色度座標ｘ、ｙから主波長を求めたものを本出願の主波長と定義する。この主波長で各種蛍光体の発光色を表現したとき、例えばＹＡＧ：Ｃｅ系蛍光体は主波長が約５７３ｎｍ付近の発光色を有し、ガリウムで一部を置換したＹ３（Ａｌ,Ｇａ）５Ｏ１２：Ｃｅ蛍光体は、組成にもよるが主波長が約５５６ｎｍから５６８ｎｍ付近の発光色を有することが可能ではある。
　しかしながら、上述のようにＹ３（Ａｌ,Ｇａ）５Ｏ１２：Ｃｅ蛍光体は輝度が不充分であり、高温時における輝度低下という問題がある。このため、さらなる半導体発光装置の演色性の向上という市場ニーズより、主波長がより短波長側、例えば約５５４ｎｍ以上約５６２ｎｍ以下の範囲に発光色を有し、かつ高い発光輝度を有し、高温時の発光輝度低下がより少ない優れた緑色系発光蛍光体が求められている。
　なお、例えば液晶バックライトの光源用途の場合、液晶バックライトのカラーフィルターの透過特性（分光特性）に近い発光色であるほど、光の透過効率が良くなり鮮やかな色再現が可能となる。緑色の場合は、透過率のピークは約５２０～５３０ｎｍ前後にあることから、液晶バックライトの光源用途の場合においても、上述のように、より短波長側で発光し、かつ高い発光輝度を有し、高温時の発光輝度低下がより少ない優れた緑色系発光蛍光体が求められている。以下、本明細書中における「演色性」には、このような液晶バックライト用途における色再現性の意味も含めるものとする。 From another point of view, in order to further improve the color rendering properties of the semiconductor light emitting device, the green light emitting phosphor is required to emit light having a shorter wavelength. When the emission color is represented by “main wavelength” defined in the annex of Japanese Industrial Standard JIS-Z-8701, that is, in the CIE1931XYZ color system, achromatic chromaticity coordinates x = 0.3333, y = 0 The wavelength at the intersection with the spectral locus on the extended line connecting the chromaticity coordinates x and y of the emission color from the point 3333 is the dominant wavelength. Here, a spectroscope or the like is used to obtain an emission spectrum when the phosphor is excited with 450 nm blue light. Among these, the chromaticity coordinates x and y are obtained by calculation using the wavelength range of 470 nm to 780 nm, and the principal wavelength obtained from the chromaticity coordinates x and y is defined as the principal wavelength of the present application. When the emission colors of various phosphors are expressed at this dominant wavelength, for example, YAG: Ce phosphors have an emission color with a dominant wavelength of about 573 nm, and Y 3 (Al, Ga) partially substituted with gallium. The 5 O 12 : Ce phosphor can have an emission color having a dominant wavelength of about 556 nm to about 568 nm, depending on the composition.
However, as described above, the Y 3 (Al, Ga) 5 O 12 : Ce phosphor has insufficient luminance and has a problem of luminance reduction at high temperatures. For this reason, from the market need for further improvement in color rendering properties of semiconductor light emitting devices, the dominant wavelength has a shorter emission wavelength, for example, in the range of about 554 nm or more and about 562 nm or less, and has high emission luminance, high temperature There is a need for an excellent green light-emitting phosphor with less emission luminance reduction at the time.
For example, in the case of a light source application of a liquid crystal backlight, the light transmission color is closer to the transmission characteristic (spectral characteristic) of the color filter of the liquid crystal backlight, and the light transmission efficiency is improved, and vivid color reproduction is possible. In the case of green, the transmittance peak is around 520 to 530 nm. Therefore, even in the case of a liquid crystal backlight light source, as described above, it emits light at a shorter wavelength side and has high emission luminance. However, there is a need for an excellent green light-emitting phosphor that causes less decrease in light emission luminance at high temperatures. Hereinafter, “color rendering” in the present specification includes the meaning of color reproducibility in such a liquid crystal backlight application.
特開平１０－２４２５１３号公報（第１－２頁）（第５頁）JP-A-10-242513 (page 1-2) (page 5) 特許第４１０１４６８号公報（第１－２頁）Japanese Patent No. 4101468 (page 1-2) 特開２００５－８８４４号公報（第１－２頁）Japanese Patent Laying-Open No. 2005-8844 (page 1-2) 中国特許第２００７１０１３２０１４．９号明細書（図２、図６）Chinese Patent No. 200710132014.9 (FIGS. 2 and 6)
　このように、従来の緑色系発光蛍光体では、高い発光輝度を有し、高温時でも発光輝度を維持でき、かつ、さらなる半導体発光装置の演色性の向上も両立させるという市場ニーズを満たすことができない。
　本発明は、この市場ニーズを満たす目的のため、主波長が約５５４ｎｍ以上約５６２ｎｍ付近の範囲に発光色を有し、かつ高い発光輝度を有し、高温時の発光輝度低下がより少ないといった、半導体発光装置に好適な優れた緑色系発光蛍光体を提供することにある。 As described above, the conventional green light-emitting phosphor has a high emission luminance, can maintain the emission luminance even at a high temperature, and satisfies the market needs for further improving the color rendering properties of the semiconductor light emitting device. Can not.
For the purpose of satisfying this market need, the present invention has a light emission color in a range where the dominant wavelength is about 554 nm or more and about 562 nm, has a high light emission luminance, and has a lower decrease in light emission luminance at high temperatures. An object is to provide an excellent green light emitting phosphor suitable for a semiconductor light emitting device.
　発明者らは、上記の課題を解決するために種々の検討を行った結果、次に掲げる特定の組成の緑色系発光蛍光体は、主波長が約５５４ｎｍ以上約５６２ｎｍ付近の範囲に発光色を有し、かつ高い発光輝度を有し、高温時の発光輝度低下がより少ないといった、演色性の高い半導体発光装置に必要な優れた特性を有している蛍光体であることを見出した。 As a result of various studies conducted by the inventors to solve the above problems, a green light-emitting phosphor having a specific composition described below has an emission color in a range where the dominant wavelength is approximately 554 nm or more and approximately 562 nm. The present invention has been found to be a phosphor having excellent characteristics necessary for a semiconductor light emitting device having high color rendering properties, such as having a high light emission luminance and less decrease in light emission luminance at high temperatures.
　第１の発明のガーネット系の緑色系発光蛍光体は、（Ｌｕ１－ｘＣｅｘ）３＋ｄＡｌ５－ｄＯ１２の式で表され、ｘは、０．００５≦ｘ≦０．１４であり、ｄは、０．０３≦ｄ≦０．５であることを特徴としている。
　そして、上記の組成のセリウム付活ルテチウム・アルミニウム・ガーネット（ＬｕＡＧ：Ｃｅ）系の緑色系発光蛍光体とすることにより、主波長が約５５４ｎｍ以上約５６２ｎｍ付近の範囲に発光色を有し、かつ高い発光輝度を有し、高温時の発光輝度低下がより少ないといった、演色性の高い半導体発光装置に必要な優れた特性を有している緑色系発光蛍光体となる。 The garnet-based green light-emitting phosphor of the first invention is represented by the formula (Lu 1-x Ce x ) 3 + d Al 5-d O 12 , where x is 0.005 ≦ x ≦ 0.14. , D is characterized by 0.03 ≦ d ≦ 0.5.
And, by using a cerium-activated lutetium-aluminum-garnet (LuAG: Ce) -based green light-emitting phosphor having the above composition, the main wavelength has a light emission color in a range of about 554 nm to about 562 nm, and The green light-emitting phosphor has excellent characteristics necessary for a semiconductor light-emitting device with high color rendering properties such as high emission luminance and less decrease in emission luminance at high temperatures.
　第２の発明のガーネット系の緑色系発光蛍光体は、第１の発明のガーネット系の緑色系発光蛍光体において、ｄは、０．０４５≦ｄ≦０．２であることを特徴としている。
　そして、上記のｄの値の範囲とすることにより、より好ましい発光色と発光輝度を有する緑色系発光蛍光体となる。 The garnet-based green light-emitting phosphor of the second invention is the garnet-based green light-emitting phosphor of the first invention, wherein d is 0.045 ≦ d ≦ 0.2.
And by setting it as the range of the value of said d, it becomes a green type light emission fluorescent substance which has a more preferable luminescent color and luminescent luminance.
　第３の発明に係る半導体発光装置は、第１または第２の発明に係るガーネット系の緑色系発光蛍光体と半導体発光素子とを少なくとも具備したことを特徴としている。そして、第１または第２に係るガーネット系の緑色系発光蛍光体を用いることにより、演色性に優れ、かつ高温時の輝度低下が少ないため高出力時に輝度低下が少ない効率の良い半導体発光装置となる。 A semiconductor light emitting device according to the third invention is characterized by comprising at least the garnet green light emitting phosphor and the semiconductor light emitting element according to the first or second invention. Further, by using the garnet green light emitting phosphor according to the first or second, an efficient semiconductor light emitting device that is excellent in color rendering and has little luminance decrease at high output because there is little luminance decrease at high temperature, Become.
　本発明のガーネット系緑色系発光蛍光体によれば、主波長が約５５４ｎｍ以上約５６２ｎｍ付近の範囲に発光色を有し、かつ高い発光輝度を有し、高温時の発光輝度低下がより少ないといった特性を有しており、演色性の高い半導体発光装置に好適に用いることができる優れた特性を有している緑色系発光蛍光体を得ることができる。
　また、本発明のガーネット系緑色系発光蛍光体と半導体発光素子とを少なくとも具備した半導体発光装置によれば、演色性に優れ、かつ高温時の輝度低下が少ないため、高出力時においても輝度低下が少ない効率の良い半導体発光装置を得ることができる。 According to the garnet-based green light-emitting phosphor of the present invention, the main wavelength has an emission color in the range of about 554 nm or more and about 562 nm, has high emission luminance, and lowers emission luminance at high temperatures. It is possible to obtain a green light-emitting phosphor having excellent characteristics that can be suitably used for a semiconductor light-emitting device having characteristics and high color rendering properties.
In addition, according to the semiconductor light emitting device having at least the garnet green light emitting phosphor and the semiconductor light emitting element of the present invention, the luminance is reduced even at high output because of excellent color rendering and little luminance decrease at high temperature. Therefore, an efficient semiconductor light emitting device with a small amount of light can be obtained.
本発明の一実施の形態の蛍光体の粒度分布を示すグラフである。It is a graph which shows the particle size distribution of the fluorescent substance of one embodiment of this invention. 本発明の一実施の形態の蛍光体の発光スペクトルを示すグラフである。It is a graph which shows the emission spectrum of the fluorescent substance of one embodiment of this invention. 本発明の一実施の形態の蛍光体の温度に対する輝度維持率を示すグラフである。It is a graph which shows the luminance maintenance factor with respect to the temperature of the fluorescent substance of one embodiment of this invention. 本発明の一実施の形態の蛍光体の粉末Ｘ線回折図形である。1 is a powder X-ray diffraction pattern of a phosphor according to an embodiment of the present invention. 本発明の一実施の形態の蛍光体の粉末Ｘ線回折図形のうち、２θが５５～６０°の範囲の詳細である。FIG. 4 is a detail of 2θ in the range of 55 to 60 ° in the powder X-ray diffraction pattern of the phosphor according to the embodiment of the present invention. 本発明の一実施の形態における半導体発光装置を示した断面図である。It is sectional drawing which showed the semiconductor light-emitting device in one embodiment of this invention. 本発明の別の一実施の形態における半導体発光装置を示した断面図である。It is sectional drawing which showed the semiconductor light-emitting device in another one Embodiment of this invention.
　以下、本発明の一実施の形態におけるガーネット系緑色系発光蛍光体を製造する工程を説明する。
　まず蛍光体原料として、ルテチウム（Ｌｕ）の原料として例えば酸化ルテチウム（Ｌｕ２Ｏ３）と、アルミニウムの原料として例えばアルミナ（Ａｌ２Ｏ３）と、賦活剤としてのセリウム（Ｃｅ）の原料として例えば酸化セリウム（ＣｅＯ２）とを用意する。
これら蛍光体原料と、フラックスとして例えばフッ化バリウム（ＢａＦ２）やフッ化ストロンチウム（ＳｒＦ２）等とを所定量を秤量し、ボールミル混合等を用いて十分に混合し原料の混合粉末を得る。このときのフラックスの量は、原料の総質量の０．１％～１０％程度用いる。
　この混合粉末を耐熱性容器、例えばアルミナるつぼ等に充填して、電気炉に入れて、還元雰囲気中例えば窒素－酸素混合ガス気流中で、例えば約１０００℃から１８００℃の焼成温度で、より好ましくは１４００℃から１６００℃の焼成温度で、約２時間から１２時間の間焼成を行う。焼成後に冷却し、ボールミル等により分散・粉砕する。次に残留フラックス除去のために水および酸により洗浄を行い、次いで乾燥工程、篩別工程を経て、所定の粒度の蛍光体を得る。 Hereinafter, a process for producing a garnet-based green light-emitting phosphor according to an embodiment of the present invention will be described.
First, as a phosphor raw material, for example, lutetium oxide (Lu 2 O 3 ) as a raw material for lutetium (Lu), for example, alumina (Al 2 O 3 ) as a raw material for aluminum, and as a raw material for cerium (Ce) as an activator, for example. Prepare cerium oxide (CeO 2 ).
A predetermined amount of these phosphor raw materials and, for example, barium fluoride (BaF 2 ) or strontium fluoride (SrF 2 ) as a flux are weighed and mixed sufficiently using ball mill mixing or the like to obtain a mixed powder of the raw materials. The amount of flux at this time is about 0.1% to 10% of the total mass of the raw materials.
This mixed powder is more preferably filled in a heat-resistant container such as an alumina crucible, put in an electric furnace, and in a reducing atmosphere such as a nitrogen-oxygen mixed gas stream, for example, at a firing temperature of about 1000 ° C. to 1800 ° C. Is fired at a firing temperature of 1400 ° C. to 1600 ° C. for about 2 hours to 12 hours. Cool after firing, and disperse and grind with a ball mill or the like. Next, cleaning with water and acid is performed to remove residual flux, and then a phosphor having a predetermined particle size is obtained through a drying step and a sieving step.
　なお、蛍光体原料として主に酸化物を例示したが、この他に高温で分解され酸化物となる化合物、例えば炭酸塩、シュウ酸塩、水酸化物等であれば蛍光体材料として用いることができる。
　また、フラックスとしてフッ化バリウム（ＢａＦ２）やフッ化ストロンチウム（ＳｒＦ２）のようなフッ化物を示したが、この他に塩化物等のハロゲン化物や、蛍光体を構成する元素のハロゲン化物、ホウ酸、を用いることも可能である。また、これらのフッ化物にさらに、リン酸水素バリウム（ＢａＨＰＯ４）、リン酸水素ストロンチウム（ＳｒＨＰＯ４）、リン酸リチウム（Ｌｉ３ＰＯ４）といったアルカリ土類金属のリン酸水素塩やアルカリ金属リン酸塩を加えてもよい。 In addition, although the oxide was mainly illustrated as a phosphor raw material, if it is a compound which decomposes | disassembles at high temperature into an oxide, for example, a carbonate, an oxalate, a hydroxide, etc., it can use as a phosphor material. it can.
Moreover, although fluorides such as barium fluoride (BaF 2 ) and strontium fluoride (SrF 2 ) were shown as fluxes, other than these, halides such as chlorides, halides of elements constituting phosphors, It is also possible to use boric acid. In addition to these fluorides, alkaline earth metal hydrogen phosphates such as barium hydrogen phosphate (BaHPO 4 ), strontium hydrogen phosphate (SrHPO 4 ), lithium phosphate (Li 3 PO 4 ), and alkali metal phosphorus Acid salts may be added.
　続いて、本発明の一実施の形態として、上記ケイ酸塩系蛍光体を具備した半導体発光装置の構成について説明する。
　図６は、本発明の一実施の形態における半導体発光装置を示した断面図である。
　この半導体発光装置は、リードフレーム１０１の先端に、カップ形状の凹みであるマウント部１０を有する。このカップ形状のマウント部１０に、近紫外から青色領域の光を放出する半導体発光素子として、例えば絶縁基板を有する半導体発光素子１１が例えばエポキシ樹脂等からなる接着剤１２で固定されている。上記半導体発光素子１１の上面に設けられたＰ型電極１３ａが、例えばＡｕ、Ａｌ、Ｃｕ等からなる金属ワイヤー１５ａによってリードフレーム１０１の電極部１３ｂに接続されている。また、上記半導体発光素子１１の上面に設けられたＮ型電極１４ａが、金属ワイヤー１５ｂによって右側のリードフレーム１０２の電極部１４ｂに接続されている。
　そして、カップ形状のマウント部１０内に、蛍光体２１が充分に混合されて充填されている。さらに、上記半導体発光素子１１およびリードフレーム１０１，１０２の上部を、例えば透明なエポキシ樹脂等のモールド樹脂３０によって封止して、砲弾形状の半導体発光装置を形成している。
　この図６に示した砲弾形状の半導体発光装置は、半導体発光素子１１から放出された光を効率良く集光するために、リードフレーム１０１のマウント部１０がカップ形状に形成されており、放射される光が図６の上方に向かう指向性を有している。
　さらに、半導体発光素子１１をカップ形状のマウント部１０の底に配置すると共に、このマウント部１０に蛍光体２１を充填して、これら蛍光体２１によって、半導体発光素子１１から放出された近紫外から青色領域、例えば３９０ｎｍから４７０ｎｍの波長の光を波長変換して、蛍光体２１から緑色領域や赤色領域等の光が放出される。
　そして、半導体発光素子１１から放出された光と、蛍光体２１から放出された光との混色により、図６の半導体発光装置から白色領域の光が放射される。
　ここで、蛍光体２１をカップ形状のマウント部１０に充填することで、半導体発光素子１１からの光を効率良く変換させて、半導体発光装置の輝度を高めているのだが、必ずしもマウント部１０内全体に蛍光体２１を充填する必要はなく、必要に応じて凹状に充填しても、また凸状に充填してもより。
　さらに、蛍光体２１をカップ状のマウント部１０内に充填するのではなく、封止樹脂３０内に分散させてもよい。 Subsequently, as an embodiment of the present invention, a configuration of a semiconductor light emitting device including the silicate phosphor will be described.
FIG. 6 is a cross-sectional view showing a semiconductor light emitting device according to an embodiment of the present invention.
This semiconductor light emitting device has a mount 10 that is a cup-shaped recess at the tip of a lead frame 101. For example, a semiconductor light emitting element 11 having an insulating substrate is fixed to the cup-shaped mount 10 with an adhesive 12 made of, for example, an epoxy resin, as a semiconductor light emitting element that emits light in the blue region from the near ultraviolet. A P-type electrode 13a provided on the upper surface of the semiconductor light emitting element 11 is connected to the electrode portion 13b of the lead frame 101 by a metal wire 15a made of, for example, Au, Al, Cu or the like. An N-type electrode 14a provided on the upper surface of the semiconductor light emitting element 11 is connected to the electrode portion 14b of the right lead frame 102 by a metal wire 15b.
And the fluorescent substance 21 is fully mixed and filled in the cup-shaped mount part 10. Further, the upper portions of the semiconductor light emitting element 11 and the lead frames 101 and 102 are sealed with a mold resin 30 such as a transparent epoxy resin to form a shell-shaped semiconductor light emitting device.
In the shell-shaped semiconductor light emitting device shown in FIG. 6, the mount 10 of the lead frame 101 is formed in a cup shape in order to efficiently collect the light emitted from the semiconductor light emitting element 11, and is emitted. The light has directivity toward the upper side of FIG.
Further, the semiconductor light emitting device 11 is disposed on the bottom of the cup-shaped mount portion 10 and the mount portion 10 is filled with a phosphor 21, and the phosphor 21 emits the near-ultraviolet light emitted from the semiconductor light emitting device 11. Light of a blue region, for example, light having a wavelength of 390 nm to 470 nm is wavelength-converted, and light of a green region, a red region, or the like is emitted from the phosphor 21.
Then, white light is emitted from the semiconductor light emitting device of FIG. 6 due to the color mixture of the light emitted from the semiconductor light emitting element 11 and the light emitted from the phosphor 21.
Here, the phosphor 21 is filled in the cup-shaped mount 10 to efficiently convert the light from the semiconductor light-emitting element 11 and increase the brightness of the semiconductor light-emitting device. It is not necessary to fill the entire body with the phosphor 21, and it may be filled in a concave shape or a convex shape as necessary.
Further, the phosphor 21 may be dispersed in the sealing resin 30 instead of filling the cup-shaped mount 10.
　図７は、本発明の別の一実施の形態における半導体発光装置を示した断面図である。
　この半導体発光装置は、例えば耐熱性を有するガラスエポキシからなる直方体形状のプリント配線基板１６上に、エポキシ樹脂からなる接着剤１２によって、絶縁性基板を有する半導体発光素子１１を接着している。この半導体発光素子１１の上面に設けられたＰ型電極１３ａとＮ型電極１４ａは、金属ワイヤー１５ａ，１５ｂによって、プリント配線基板１６上面の電極部１６ａ，１６ｂに各々接続されている。これら電極部１６ａ，１６ｂは、プリント配線基板１６の上面と下面とを接続する図示しない断面円弧状のスルーホールを介して、実装面としてのプリント配線基板１６の下面に引き回されて、この実装面の両端部まで延びている。なお、上記プリント配線基板１６は、絶縁性フィルムを用いてもよい。
　そして、上記プリント配線基板１６上に、上記半導体発光素子１１全体を覆うように、蛍光体２１を分散させた封止樹脂としての例えば透光性のエポキシ樹脂等のモールド樹脂３２を、図７に示すような台形断面をなすように形成して、チップ部品形状の半導体発光装置を形成している。 FIG. 7 is a cross-sectional view showing a semiconductor light emitting device according to another embodiment of the present invention.
In this semiconductor light emitting device, a semiconductor light emitting element 11 having an insulating substrate is bonded to a rectangular parallelepiped printed wiring board 16 made of glass epoxy having heat resistance, for example, with an adhesive 12 made of epoxy resin. The P-type electrode 13a and the N-type electrode 14a provided on the upper surface of the semiconductor light emitting element 11 are connected to the electrode portions 16a and 16b on the upper surface of the printed wiring board 16 by metal wires 15a and 15b, respectively. These electrode portions 16a and 16b are routed to the lower surface of the printed wiring board 16 as a mounting surface through a through-hole having a circular arc cross section (not shown) that connects the upper surface and the lower surface of the printed wiring board 16, and this mounting is performed. It extends to both ends of the surface. The printed wiring board 16 may use an insulating film.
Then, a mold resin 32 such as a translucent epoxy resin as a sealing resin in which the phosphor 21 is dispersed so as to cover the entire semiconductor light emitting element 11 on the printed wiring board 16 is shown in FIG. A semiconductor light emitting device having a chip part shape is formed by forming a trapezoidal cross section as shown.
　蛍光体２１とは、本発明の一実施の形態であるガーネット系緑色系発光蛍光体を少なくとも含んでおり、さらに本発明の緑色系発光蛍光体に加えて、赤色領域の光を発光する他の蛍光体、例えば酸窒化物系蛍光体や、ＣａＡｌＳｉＮ３系蛍光体、硫化物系蛍光体等を含んだ混合物であってもよい。この赤色発光蛍光体の選択は、本発明のガーネット系緑色系発光蛍光体の発光特性等にあわせ、適宜選択できる。
　本発明の半導体発光装置は、上記の構造に限定されるものではなく、半導体発光素子１１から放出された近紫外から青色領域の光が、本発明の一実施の形態であるガーネット系緑色系発光蛍光体を少なくとも含んだ蛍光体２１によって波長変換され、そして半導体発光装置１１から放出された光と、蛍光体２１から放出された光との混色により、白色領域の光が放射される半導体発光装置であればよい。 The phosphor 21 includes at least a garnet-based green light-emitting phosphor according to an embodiment of the present invention. Further, in addition to the green-based light-emitting phosphor of the present invention, the phosphor 21 emits light in the red region. The phosphor may be a mixture containing an oxynitride phosphor, a CaAlSiN 3 phosphor, a sulfide phosphor, or the like. The selection of the red light-emitting phosphor can be appropriately selected according to the light emission characteristics of the garnet-based green light-emitting phosphor of the present invention.
The semiconductor light-emitting device of the present invention is not limited to the above structure, and light from the near ultraviolet to blue region emitted from the semiconductor light-emitting element 11 is garnet-based green light emission according to an embodiment of the present invention. A semiconductor light emitting device in which light in a white region is emitted by color mixing of light emitted from the semiconductor light emitting device 11 and light emitted from the phosphor 21 by wavelength conversion by the phosphor 21 containing at least the phosphor. If it is.
　次に、上記一実施の形態の実施例として、本発明の緑色系発光蛍光体とその特性について、従来の緑色系発光蛍光体と比較して説明する。 Next, as an example of the above embodiment, the green light-emitting phosphor of the present invention and its characteristics will be described in comparison with a conventional green light-emitting phosphor.
　原料として１９３．０ｇの酸化ルテチウム（Ｌｕ２Ｏ３）（Ｌｕとして０．９７モル）、５．１６４ｇの酸化セリウム（ＣｅＯ２）（Ｃｅとして０．０３モル）、８０．７２ｇのアルミナ（Ａｌ２Ｏ３）（Ａｌとして１．５８３３モル）とを秤量し、さらにフラックスとして８．４ｇのフッ化バリウム（ＢａＦ２）（原料質量の約３％）を秤量し、これら原料とフラックスとをボールミルを用いて充分によく混合する。
　この混合物をアルミナるつぼに充填し、１４２０℃で窒素ガス９７％＋水素ガス３％の混合ガスによる還元雰囲気中にて、８時間焼成する。
　その後室温まで約３時間かけて徐々に冷却し、得られた焼成物を、ボールミルによる分散およびミリング工程、水および酸による洗浄工程、乾燥工程そして篩別工程（３５０メッシュ通過）を経て、目的の緑色系発光蛍光体を得た。これを試料１－（１）とした。この試料１－（１）の組成比は（Ｌｕ０．９７Ｃｅ０．０３）３Ａｌ４．７５Ｏ１１．６２５と表すことができるが、本来のガーネット系結晶の式である、（Ｌｕ１－ｘＣｅｘ）３＋ｄＡｌ５－ｄＯ１２の式で表した場合は、ｘ＝０．０３、ｄ＝０．０９６８である。 193.0 g of lutetium oxide (Lu 2 O 3 ) (0.97 mol as Lu), 5.164 g of cerium oxide (CeO 2 ) (0.03 mol as Ce), 80.72 g of alumina (Al 2 O 3 ) (1.5833 mol as Al), and 8.4 g of barium fluoride (BaF 2 ) (about 3% of the mass of the raw material) as a flux. Use and mix well enough.
This mixture is filled in an alumina crucible and fired at 1420 ° C. for 8 hours in a reducing atmosphere with a mixed gas of 97% nitrogen gas + 3% hydrogen gas.
Thereafter, it is gradually cooled to room temperature over about 3 hours, and the obtained fired product is subjected to a dispersion and milling step by a ball mill, a washing step with water and an acid, a drying step and a sieving step (through 350 mesh), A green-based phosphor was obtained. This was designated as Sample 1- (1). The composition ratio of Sample 1- (1) can be expressed as (Lu 0.97 Ce 0.03 ) 3 Al 4.75 O 11.625 , which is the formula of the original garnet crystal (Lu 1 If expressed in equation -x Ce x) 3 + d Al 5-d O 12, x = 0.03, a d = 0.0968.
　得られた試料１－（１）について、まずレーザー回折式粒度分布測定装置（型式：ＳＡＬＤ－２１００　島津製作所製）で粒度分布を測定した。この結果を図１に示す。このときの平均粒径Ｄ５０は、２５．０μｍであった。
　次に、分光蛍光光度計（型式：Ｆ－４５００　日立製作所製）を用い、励起光を４５０ｎｍとして発光スペクトルを測定した。この結果を図２に示す。 For the obtained Sample 1- (1), first, the particle size distribution was measured with a laser diffraction particle size distribution analyzer (model: SALD-2100, manufactured by Shimadzu Corporation). The result is shown in FIG. The average particle size D50 at this time was 25.0 μm.
Next, an emission spectrum was measured using a spectrofluorometer (model: F-4500, manufactured by Hitachi, Ltd.) with excitation light at 450 nm. The result is shown in FIG.
　そして、得られた発光スペクトルから、日本工業規格ＪＩＳ－Ｚ－８７２４に準じてＣＩＥ１９３１ＸＹＺ表色系における色度座標ｘ，ｙを算出した。このとき、計算対象とした波長範囲は、励起光として用いた４５０ｎｍ付近の青色光の影響を避けるため、４７０ｎｍから７８０ｎｍまでとした。算出した結果、試料１－（１）の色度座標は、ｘ＝０．３７３、ｙ＝０．５７１であった。
　さらに、得られた色度座標ｘ，ｙから、日本工業規格ＪＩＳ－Ｚ－８７０１附属書に準じて、主波長および刺激純度を求めた。その結果、主波長は５６１．０ｎｍ、刺激純度は８３．５％であった。 Then, chromaticity coordinates x and y in the CIE1931XYZ color system were calculated from the obtained emission spectrum according to Japanese Industrial Standard JIS-Z-8724. At this time, the wavelength range to be calculated was set from 470 nm to 780 nm in order to avoid the influence of blue light near 450 nm used as excitation light. As a result of the calculation, the chromaticity coordinates of Sample 1- (1) were x = 0.373 and y = 0.571.
Furthermore, from the obtained chromaticity coordinates x, y, the dominant wavelength and the stimulation purity were determined according to the Japanese Industrial Standard JIS-Z-8701 appendix. As a result, the dominant wavelength was 561.0 nm and the stimulation purity was 83.5%.
　次に、比較のため、従来の蛍光体として、Ｙ３（Ａｌ，Ｇａ）５Ｏ１２：Ｃｅ蛍光体と、化学量論組成のＬｕ３Ａｌ５Ｏ１２：Ｃｅ蛍光体の中から、発光色の主波長が試料１－（１）の５６１．０ｎｍとほぼ同じとなる、次の組成の蛍光体を作成し、それぞれ比較例２－（１）、比較例３－（１）とした。
　比較例２－（１）：（Ｙ０．９７５Ｃｅ０．０２５）３（Ａｌ０．６Ｇａ０．４）５Ｏ１２
　比較例３－（１）：（Ｌｕ０．９８Ｃｅ０．０２）３Ａｌ５Ｏ１２
　また参考のため、従来の黄色発光蛍光体として、ＹＡＧ：Ｃｅ蛍光体も、比較例１として作成した。
　比較例１：（Ｙ０．９７５Ｃｅ０．０２５）３Ａｌ５Ｏ１２
　これら比較例らの製造については、さらにイットリウムの原料として酸化イットリウム（Ｙ２Ｏ３）、ガリウムの原料として酸化ガリウム（Ｇａ２Ｏ３）を用い、それぞれ組成比に合わせた原料を用いた以外は、試料１－（１）と同様に蛍光体を作成した。
　こうして得られた比較例１、比較例２－（１）、比較例３－（１）についても、試料１－（１）と同様に発光スペクトルを測定し、色度座標ｘ，ｙを算出し、主波長と刺激純度を求めた。 Next, for comparison, as conventional phosphors, Y 3 (Al, Ga) 5 O 12 : Ce phosphors and Lu 3 Al 5 O 12 : Ce phosphors of stoichiometric composition are used as emission colors. The phosphors having the following composition were prepared in which the main wavelength of the sample was approximately the same as 561.0 nm of Sample 1- (1), and were designated as Comparative Example 2- (1) and Comparative Example 3- (1), respectively.
Comparative Example 2- (1): (Y 0.975 Ce 0.025 ) 3 (Al 0.6 Ga 0.4 ) 5 O 12
Comparative Example 3- (1): (Lu 0.98 Ce 0.02 ) 3 Al 5 O 12
For reference, a YAG: Ce phosphor was also prepared as Comparative Example 1 as a conventional yellow light-emitting phosphor.
Comparative Example 1: (Y 0.975 Ce 0.025 ) 3 Al 5 O 12
The preparation of these comparative examples, et al., Further yttrium oxide as a raw material of yttrium (Y 2 O 3), a gallium oxide (Ga 2 O 3) used as a raw material for the gallium, except for using the combined feed to each composition ratio A phosphor was prepared in the same manner as Sample 1- (1).
For Comparative Example 1, Comparative Example 2- (1), and Comparative Example 3- (1) thus obtained, the emission spectrum was measured in the same manner as Sample 1- (1), and the chromaticity coordinates x, y were calculated. The dominant wavelength and stimulation purity were determined.
　さらに、実際に青色ＬＥＤで励起した際の発光輝度と、高温時における輝度維持率を測定した。
　まず、実際に青色ＬＥＤで励起した際の発光輝度を測定するために、室温（約２５℃）において４６０ｎｍに発光ピーク波長を有する発光ダイオードを複数用いて励起光源とし、対象の蛍光体試料に向けて照射する。発光した蛍光体からの光を、輝度計（型式：ＬＳ－１１０　コニカミノルタ製）を用いて測定する。このとき輝度計の前段部分に５００ｎｍ以下の波長をカットするシャープカットフィルター（型式：Ｙ－５０　HOYA CANDEO OPTRONICS社製）を設置し励起光である青色光の影響を除去している。
　得られた発光輝度は、比較例１を１００とした相対発光輝度とした。 Furthermore, the light emission luminance when actually excited by a blue LED and the luminance maintenance ratio at a high temperature were measured.
First, in order to measure the light emission luminance when actually excited by a blue LED, a plurality of light emitting diodes having an emission peak wavelength at 460 nm at room temperature (about 25 ° C.) are used as an excitation light source and directed toward the target phosphor sample. Irradiate. The light from the emitted phosphor is measured using a luminance meter (model: LS-110, manufactured by Konica Minolta). At this time, a sharp cut filter (model: Y-50 manufactured by HOYA CANDEO OPTRONICS) that cuts a wavelength of 500 nm or less is installed in the front part of the luminance meter to remove the influence of blue light as excitation light.
The obtained light emission luminance was the relative light emission luminance with Comparative Example 1 as 100.
　次に高温時における輝度維持率を測定するため、蛍光体の温度を変化させた場合における発光輝度の変化を、以下の構成の装置により測定した。
　厚さ約５ｍｍ程度、縦横の長さが約４５ｍｍ程度のアルミニウム板の上面に、直径約３０ｍｍ深さ約２ｍｍの円柱状の凹部を設けたものを試料ホルダとし、さらに側面から底部の中央部分に到達する横穴を設けてこの横穴に温度センサを挿入して試料ホルダの温度を測定できるようにした。
　この試料ホルダに対象となる蛍光体粉末を詰め込み、この測定ホルダを加熱できるようにホットプレート上に置く。さらに４６０ｎｍに発光ピーク波長を有する発光ダイオードを複数用いて励起光源としこの蛍光体に向けて照射して、発光した蛍光体からの光を輝度計（型式：ＬＳ－１００　コニカミノルタ製）を用いて測定する。このとき輝度計の前段部分に５００ｎｍ以下の波長をカットするシャープカットフィルター（型式：Ｙ－５０　HOYA CANDEO OPTRONICS社製）を設置し励起光である青色光の影響を除去している。
　ホットプレートにより試料ホルダ中の蛍光体粉末の温度を室温（約２５℃）から約２００℃まで変化させながら、試料ホルダの温度と輝度を記録した。
　温度センサ：白金測温抵抗体Ｐｔ１００（型式：ＴＲ－８１１０　ティアンドディ社製）
　データロガー：メモリハイロガー（型式：８４２０－５０　日置電機社製）
　得られた結果を、横軸に温度を、縦軸に温度２５℃のときの発光輝度を１００％とした相対的な輝度維持率をとり、代表として比較例１、比較例２－（１）および試料１－（１）についてプロットした。プロットしたグラフを図３に示す。また、このようにして得られた輝度維持率から、室温（２５℃）における比較例１の発光輝度を１００とした２００℃における相対発光輝度も求めた。 Next, in order to measure the luminance maintenance rate at a high temperature, the change in emission luminance when the temperature of the phosphor was changed was measured by an apparatus having the following configuration.
The top of an aluminum plate with a thickness of about 5 mm and a vertical and horizontal length of about 45 mm and a cylindrical recess with a diameter of about 30 mm and a depth of about 2 mm is used as a sample holder, and from the side to the center of the bottom A reaching horizontal hole was provided, and a temperature sensor was inserted into the horizontal hole so that the temperature of the sample holder could be measured.
The sample holder is filled with the target phosphor powder and placed on a hot plate so that the measurement holder can be heated. Furthermore, using a plurality of light emitting diodes having an emission peak wavelength at 460 nm as an excitation light source, the phosphor is irradiated toward the phosphor, and the emitted light is emitted from the phosphor using a luminance meter (model: LS-100 manufactured by Konica Minolta). taking measurement. At this time, a sharp cut filter (model: Y-50 manufactured by HOYA CANDEO OPTRONICS) that cuts a wavelength of 500 nm or less is installed in the front part of the luminance meter to remove the influence of blue light as excitation light.
The temperature and brightness of the sample holder were recorded while changing the temperature of the phosphor powder in the sample holder from room temperature (about 25 ° C.) to about 200 ° C. using a hot plate.
Temperature sensor: Platinum resistance thermometer Pt100 (model: TR-8110, manufactured by T & D)
Data logger: Memory high logger (model: 8420-50 manufactured by Hioki Electric Co., Ltd.)
The results are obtained by taking the relative luminance maintenance rate with the horizontal axis representing temperature and the vertical axis representing emission luminance at a temperature of 25 ° C. as 100%. As a representative, Comparative Example 1 and Comparative Example 2- (1) And for sample 1- (1). The plotted graph is shown in FIG. In addition, from the luminance maintenance rate obtained in this way, the relative light emission luminance at 200 ° C. with the light emission luminance of Comparative Example 1 at room temperature (25 ° C.) as 100 was also obtained.
　以上、比較例１、比較例２－（１）、比較例３－（１）および試料１－（１）について、主波長、刺激純度、相対発光輝度および温度２００℃における相対発光輝度をまとめて表１に示す。 As described above, with respect to Comparative Example 1, Comparative Example 2- (1), Comparative Example 3- (1) and Sample 1- (1), the main wavelength, stimulation purity, relative emission luminance, and relative emission luminance at a temperature of 200 ° C. are summarized. Table 1 shows.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　表１に示す結果より、主波長が５６１ｎｍ付近の蛍光体である比較例２－（１）、比較例３－（１）および試料１－（１）を比較すると、従来の蛍光体である比較例２－（１）および比較例３－（１）と比較して本発明の蛍光体である試料１－（１）は、両者より相対発光輝度が高いことが明らかであり、また刺激純度も高いことが明らかであり、さらに２００℃における相対発光輝度も圧倒的に優れていることがわかる。
　このように、同等の主波長を得るための蛍光体としては、従来の蛍光体と比較して、本発明のガーネット系緑色系発光蛍光体が優れた特徴を有していることがわかる。 From the results shown in Table 1, when Comparative Example 2- (1), Comparative Example 3- (1) and Sample 1- (1), which are phosphors having a dominant wavelength near 561 nm, are compared, Compared with Example 2- (1) and Comparative Example 3- (1), it is clear that Sample 1- (1), which is a phosphor of the present invention, has a higher relative light emission luminance than both, and the excitation purity is also high. It is clear that it is high, and the relative light emission luminance at 200 ° C. is overwhelmingly excellent.
Thus, it can be seen that, as a phosphor for obtaining an equivalent dominant wavelength, the garnet-based green light-emitting phosphor of the present invention has superior characteristics as compared with conventional phosphors.
　次に、発光色の主波長が、上記５６１ｎｍ前後より、さらに短波長側の例を示す。
　原料として１９６．９８ｇの酸化ルテチウム（Ｌｕ２Ｏ３）（Ｌｕとして０．９９モル）と１．７２１ｇの酸化セリウム（ＣｅＯ２）（Ｃｅとして０．０１モル）とを用いた他は、前記試料１－（１）と全く同様に蛍光体を作成し、これを試料１－（２）とした。この試料１－（２）の組成比は（Ｌｕ０．９９Ｃｅ０．０１）３Ａｌ４．７５Ｏ１１．６２５と表すことができるが、本来のガーネット系結晶の式である、（Ｌｕ１－ｘＣｅｘ）３＋ｄＡｌ５－ｄＯ１２の式で表した場合は、ｘ＝０．０１、ｄ＝０．０９６８である。
　得られた試料１－（２）について、試料１－（１）と同様に発光スペクトルを測定し、色度座標ｘ，ｙを算出し、主波長と刺激純度を求めた。その結果、色度座標はｘ＝０．３４４、ｙ＝０．５７７、主波長は５５６．２ｎｍ、刺激純度は７６．７％であった。 Next, an example in which the dominant wavelength of the emission color is on the shorter wavelength side than the above-mentioned 561 nm is shown.
The sample was used except that 196.98 g of lutetium oxide (Lu 2 O 3 ) (0.99 mol as Lu) and 1.721 g of cerium oxide (CeO 2 ) (0.01 mol as Ce) were used as raw materials. A phosphor was prepared in exactly the same manner as 1- (1), and this was designated as Sample 1- (2). The composition ratio of Sample 1- (2) can be expressed as (Lu 0.99 Ce 0.01 ) 3 Al 4.75 O 11.625 , which is the formula of the original garnet crystal (Lu 1 -X Ce x ) 3 + d Al 5 -dO 12 , x = 0.01 and d = 0.0968.
With respect to the obtained Sample 1- (2), an emission spectrum was measured in the same manner as Sample 1- (1), chromaticity coordinates x and y were calculated, and a dominant wavelength and stimulation purity were obtained. As a result, the chromaticity coordinates were x = 0.344, y = 0.777, the dominant wavelength was 556.2 nm, and the stimulation purity was 76.7%.
　試料１－（２）との比較のため、従来の蛍光体として、Ｙ３（Ａｌ，Ｇａ）５Ｏ１２：Ｃｅ蛍光体と、化学量論組成のＬｕ３Ａｌ５Ｏ１２：Ｃｅ蛍光体のなかから、発光色の主波長が試料１－（２）の５５６．２ｎｍとほぼ同じとなる、次の組成の蛍光体を上記比較例２－（１）および比較例３－（１）と同様に作成し、それぞれ比較例２－（２）、比較例３－（２）とした。
　比較例２－（２）：（Ｙ０．９９Ｃｅ０．０１）３（Ａｌ０．６３Ｇａ０．３７）５Ｏ１２
　比較例３－（２）：（Ｌｕ０．９９５Ｃｅ０．００５）３Ａｌ５Ｏ１２
　こうして得られた比較例２－（２）、比較例３－（２）についても、試料１－（２）と同様に発光スペクトルを測定し、色度座標ｘ，ｙを算出し、主波長と刺激純度を求めた。
　さらに、これら試料１－（２）、比較例２－（２）および比較例３－（２）について、実際に青色ＬＥＤで励起した際の発光輝度と、高温時における輝度維持率を、試料１－（１）と同様に測定した。
　以上、比較例１、比較例２－（２）、比較例３－（２）および試料１－（２）について、主波長、刺激純度、相対発光輝度および２００℃における相対発光輝度をまとめて表２に示す。 For comparison with Sample 1- (2), Y 3 (Al, Ga) 5 O 12 : Ce phosphor and a Lu 3 Al 5 O 12 : Ce phosphor having a stoichiometric composition are used as conventional phosphors. Among them, the phosphor having the following composition in which the dominant wavelength of the emission color is almost the same as 556.2 nm of Sample 1- (2) is the same as in Comparative Example 2- (1) and Comparative Example 3- (1). To Comparative Example 2- (2) and Comparative Example 3- (2), respectively.
Comparative Example 2- (2): (Y 0.99 Ce 0.01 ) 3 (Al 0.63 Ga 0.37 ) 5 O 12
Comparative Example 3- (2): (Lu 0.995 Ce 0.005 ) 3 Al 5 O 12
For Comparative Examples 2- (2) and 3- (2) thus obtained, the emission spectrum was measured in the same manner as Sample 1- (2), and the chromaticity coordinates x and y were calculated. Stimulation purity was determined.
Further, with respect to Sample 1- (2), Comparative Example 2- (2) and Comparative Example 3- (2), the emission luminance when actually excited by a blue LED and the luminance maintenance ratio at high temperature are shown in Sample 1. -Measured in the same manner as (1).
As described above, for Comparative Example 1, Comparative Example 2- (2), Comparative Example 3- (2), and Sample 1- (2), the main wavelength, stimulation purity, relative emission luminance, and relative emission luminance at 200 ° C. are collectively shown. It is shown in 2.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　表２に示す結果より、主波長が５５６ｎｍ付近の蛍光体である比較例２－（２）、比較例３－（２）および試料１－（２）を比較すると、従来の蛍光体である比較例２－（２）および比較例３－（２）と比較して本発明の蛍光体である試料１－（２）は、両者より相対発光輝度が高いことが明らかであり、また刺激純度も高いことが明らかであり、さらに２００℃における相対発光輝度も圧倒的に優れていることがわかる。
　このように、主波長が５５６ｎｍ付近の蛍光体においても、従来の蛍光体と比較して、本発明のガーネット系緑色系発光蛍光体が優れた特徴を有していることがわかる。 From the results shown in Table 2, when Comparative Example 2- (2), Comparative Example 3- (2), and Sample 1- (2), which are phosphors having a dominant wavelength near 556 nm, are compared, a comparison is made with a conventional phosphor. Compared with Example 2- (2) and Comparative Example 3- (2), Sample 1- (2), which is a phosphor of the present invention, clearly has a higher relative light emission luminance than both, and the excitation purity is also high. It is clear that it is high, and the relative light emission luminance at 200 ° C. is overwhelmingly excellent.
Thus, it can be understood that the garnet-based green light-emitting phosphor of the present invention has excellent characteristics even in a phosphor having a dominant wavelength of around 556 nm as compared with a conventional phosphor.
　次に、本発明の別の形態の実施例として、本発明の緑色系発光蛍光体（Ｌｕ１－ｘＣｅｘ）３＋ｄＡｌ５－ｄＯ１２においてＣｅ濃度であるｘを０．０３に固定したときのｄの値と蛍光体の特性について説明する。
　表３に示す通りに各元素の組成比を変化させた他は、前記実施例１中の試料１－（１）と同様に蛍光体を作成し、それぞれ試料２－（１）ないし試料２－（１２）とした。
　これら試料２－（１）ないし試料２－（１２）についても、実施例１と同様に主波長、刺激純度、比較例１を１００とした相対発光輝度を測定し、同じくその結果を試料１－（１）の結果とともに表３に示した。 Next, as an example of another aspect of the present invention, in the green light emitting phosphor (Lu 1-x Ce x ) 3 + d Al 5 -dO 12 of the present invention, the Ce concentration x was fixed at 0.03. The value of d and the characteristics of the phosphor will be described.
Except for changing the composition ratio of each element as shown in Table 3, phosphors were prepared in the same manner as Sample 1- (1) in Example 1, and Samples 2- (1) to 2- (12).
For Sample 2- (1) to Sample 2- (12), the main wavelength, the stimulation purity, and the relative light emission luminance with Comparative Example 1 as 100 were measured in the same manner as in Example 1, and the results were also obtained. The results are shown in Table 3 together with the result of (1).
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
　表３に示す結果より、試料２－（３）ないし試料２－（１０）および試料１－（１）、すなわちｄの値が０．０３以上０．５以下の試料は、化学量論組成の試料２－（１）と比較して、主波長が２ｎｍ以上短波長側にシフトしており、かつ相対発光輝度もほとんど低下することなく、好ましい特徴を有していることがわかる。さらに、ｄの値が０．０４５以上の試料は、主波長がほぼ３ｎｍ以上短波長側にシフトしており、より好ましいことがわかる。なお、ｄの値が０．２を超えた場合については主波長のシフト効果がそれほど大きくなく、かつ刺激純度が低下傾向にあることから、ｄの値は０．０４５以上０．２以下がより好ましいといえる。
　なお、ｄの値が０．０３未満と小さすぎる場合には主波長をシフトさせる効果も小さく、またｄの値が０．５を超えて大きすぎる場合には発光輝度が低下する。
　以上のことから、ｄの値は、０．０３以上０．５以下が好ましく、０．０４５以上０．２以下がより好ましいといえる。 From the results shown in Table 3, Samples 2- (3) to 2- (10) and Sample 1- (1), that is, samples having a d value of 0.03 or more and 0.5 or less have stoichiometric compositions. Compared to Sample 2- (1), it can be seen that the dominant wavelength is shifted to the short wavelength side by 2 nm or more, and that the relative light emission luminance hardly deteriorates and has preferable characteristics. Furthermore, it can be seen that a sample having a d value of 0.045 or more has a dominant wavelength shifted to the short wavelength side by about 3 nm or more, which is more preferable. Note that when the value of d exceeds 0.2, the shift effect of the dominant wavelength is not so great and the stimulation purity tends to decrease, so the value of d is more than 0.045 and less than 0.2. It can be said that it is preferable.
In addition, when the value of d is too small as less than 0.03, the effect of shifting the dominant wavelength is small, and when the value of d exceeds 0.5 and is too large, the emission luminance is lowered.
From the above, it can be said that the value of d is preferably 0.03 or more and 0.5 or less, and more preferably 0.045 or more and 0.2 or less.
　ここで、本発明の緑色系発光蛍光体が、化学量論組成のＬｕ３Ａｌ５Ｏ１２：Ｃｅ蛍光体とどのような違いがあるのかを、粉末Ｘ線回折分析を行い確かめた。
　ｄの値が０すなわち化学量論組成の試料２－（１）とｄの値が０．０９６８の試料１－（１）について、Ｘ線回折装置（型式：ＸＲＤ－６１００　島津製作所製）により、Ｃｕ管球を用いて粉末Ｘ線回折分析を行った。その結果である粉末Ｘ線回折図形を図４に示す。図４から明らかなように、化学量論組成のＬｕ３Ａｌ５Ｏ１２：Ｃｅ蛍光体である試料２－（１）と、本発明の実施例の一例である試料１－（１）では、その粉末Ｘ線回折図形はほとんど同一であり、試料１－（１）はルテチウム・アルミニウム・ガーネット（ＬｕＡＧ）の構造を維持していることがわかる。 Here, it was confirmed by powder X-ray diffraction analysis how the green light-emitting phosphor of the present invention is different from the stoichiometric Lu 3 Al 5 O 12 : Ce phosphor.
For sample 2- (1) having a d value of 0, that is, a stoichiometric composition, and sample 1- (1) having a d value of 0.0968, an X-ray diffractometer (model: XRD-6100, manufactured by Shimadzu Corporation) Powder X-ray diffraction analysis was performed using a Cu tube. The resulting powder X-ray diffraction pattern is shown in FIG. As is clear from FIG. 4, in sample 2- (1) which is a Lu 3 Al 5 O 12 : Ce phosphor having a stoichiometric composition and sample 1- (1) which is an example of the embodiment of the present invention, The powder X-ray diffraction patterns are almost the same, and it can be seen that Sample 1- (1) maintains the structure of lutetium, aluminum, and garnet (LuAG).
　さらに、試料２－（１）と試料１－（１）それぞれに、測定時の誤差を補正するための指標として酸化イットリウム（Ｙ２Ｏ３）を質量％で１０％添加し十分混合したものを用いて、２θで５５°～６０°の範囲を精密に測定した。同様にＹ２Ｏ３のみを測定したデータと重ね合わせ、特に５７．５°付近のピーク位置を用いて調整することにより測定時の機械的な誤差を補正したＸ線回折図形を図５に示す。この図５から明らかなように、化学量論組成のＬｕＡＧ：Ｃｅ蛍光体である試料２－（１）と比べて、本発明の実施例の一例である試料１－（１）は僅かではあるが、ピークが全体的に２θとして低角度側にシフトしていることがわかる。
　波長λのＸ線で粉末Ｘ線回折を行うと、結晶の格子面間隔Ｄと回折角度θの間にはブラッグの式Ｄ＝λ／（２sinθ）という関係式がある。
　低角度側にピーク位置がシフトしているということは、上記式においてθが小さくなるので、結晶の格子定数が大きくなっていることを意味している。 Furthermore, 10% by mass of yttrium oxide (Y 2 O 3 ) was added to each of Sample 2- (1) and Sample 1- (1) as an index for correcting measurement errors, and mixed sufficiently. Using, the range from 55 ° to 60 ° at 2θ was precisely measured. Similarly, FIG. 5 shows an X-ray diffraction pattern in which mechanical errors at the time of measurement are corrected by superimposing data obtained by measuring only Y 2 O 3 , particularly by adjusting using a peak position near 57.5 °. . As is clear from FIG. 5, sample 1- (1), which is an example of the embodiment of the present invention, is slightly smaller than sample 2- (1), which is a LuAG: Ce phosphor having a stoichiometric composition. However, it can be seen that the peak is shifted to the low angle side as 2θ as a whole.
When powder X-ray diffraction is performed with X-rays having a wavelength λ, there is a relational expression of Bragg's equation D = λ / (2sinθ) between the lattice spacing D of the crystal and the diffraction angle θ.
The fact that the peak position is shifted to the low angle side means that θ is small in the above formula, and the lattice constant of the crystal is large.
　ところで、ガーネット構造は、金属イオンＡ，Ｂ，Ｃの複合酸化物の一つの結晶構造である。その一般式はＡ３Ｂ２Ｃ３Ｏ１２で表される。Ａは８個の酸素に囲まれた８配位のサイトにある。Ｂは６個の酸素に囲まれた６配位のサイトにある。またＣは４個の酸素に囲まれた４配位のサイトにある。ルテチウム・アルミニウム・ガーネット（ＬｕＡＧ）の場合には、化学量論組成なら、８配位のサイトにＬｕ３＋、６配位のサイトにＡｌ３＋、４配位のサイトにＡｌ３＋がそれぞれ入っているが、（Ｌｕ＋Ｃｅ）とＡｌのバランスをＡｌプアにすると、ガーネットの結晶構造を維持したまま本来Ａｌ３＋が入っていた６配位のサイトの一部にＬｕ３＋が入ることになる。このような現象をアンチサイトという。Ａｌ３＋よりＬｕ３＋の方がイオン半径が大きいため、６配位のサイトの結晶格子が広がり格子定数が大きくなる。このことは、粉末Ｘ線回折のピーク位置が低角度側にシフト、つまり格子定数が大きくなっている事実と一致する。 By the way, the garnet structure is one crystal structure of a complex oxide of metal ions A, B, and C. The general formula is represented by A 3 B 2 C 3 O 12 . A is at an 8-coordinate site surrounded by 8 oxygen atoms. B is in a six-coordinate site surrounded by six oxygen atoms. C is at a tetracoordinate site surrounded by four oxygen atoms. In the case of lutetium aluminum garnet (LuAG) is if the stoichiometric composition, Lu 3+ to 8 coordination sites, Al 3+ to 6 coordination sites, the Al 3+ in tetracoordinate site containing respectively However, when the balance of (Lu + Ce) and Al is Al poor, Lu 3+ enters a part of the 6-coordinate site where Al 3+ originally contained while maintaining the crystal structure of garnet. Such a phenomenon is called anti-site. Since Lu 3+ has a larger ionic radius than Al 3+, the crystal lattice of the 6-coordinate site spreads and the lattice constant increases. This is consistent with the fact that the peak position of powder X-ray diffraction is shifted to the lower angle side, that is, the lattice constant is increased.
　なお、この現象は蛍光体の発光色の変化からも推測できる。
　すなわち背景技術で述べた通り、従来のＹ３Ａｌ５Ｏ１２：Ｃｅ蛍光体において、Ａｌの一部をイオン半径の大きいＧａで置換したＹ３（Ａｌ，Ｇａ）５Ｏ１２：Ｃｅは、その発光色もＹ３Ａｌ５Ｏ１２：Ｃｅ蛍光体の発光色よりも短波長にシフトしている。このとき、Ｇａ３＋は上記説明の６配位のＡｌ３＋を置換する。Ｇａ３＋のイオン半径もＡｌ３＋より大きいため、６配位のサイトの結晶格子が広がると考えられる。
　本発明の蛍光体も、上記の通りｄの値が化学量論組成である０よりも大きく、Ａｌプアとなり、本来Ａｌ３＋が入っていた６配位のサイトの一部にＬｕ３＋が入るため、６配位のサイトの結晶格子が広がり、Ｇａを用いずとも、結果として上記Ｇａ置換と同様に蛍光体の発光色が短波長にシフトするという効果が得られたものと推測される。 This phenomenon can also be inferred from a change in the emission color of the phosphor.
That is, as described in the background art, in a conventional Y 3 Al 5 O 12 : Ce phosphor, Y 3 (Al, Ga) 5 O 12 : Ce in which a part of Al is substituted with Ga having a large ion radius is The emission color is also shifted to a shorter wavelength than the emission color of the Y 3 Al 5 O 12 : Ce phosphor. At this time, Ga 3+ replaces the 6-coordinate Al 3+ described above. Since the ionic radius of Ga 3+ is also larger than that of Al 3+ , it is considered that the crystal lattice of the six-coordinate site is expanded.
The phosphor of the present invention also has a d value larger than 0, which is the stoichiometric composition, as described above, becomes Al poor, and Lu 3+ enters a part of the 6-coordinate site originally containing Al 3+. The crystal lattice of the 6-coordinate site is widened, and it is presumed that the effect of shifting the emission color of the phosphor to a short wavelength was obtained as in the case of Ga substitution, without using Ga.
　すなわち本発明の特徴は、ＬｕＡＧのガーネット構造を維持し、その優れた特徴を維持したまま６配位のサイトの結晶格子を広げることにより、蛍光体の発光波長を短波長側にシフトさせることに成功したものであると言える。 That is, the feature of the present invention is to shift the emission wavelength of the phosphor to the short wavelength side by maintaining the LuAG garnet structure and expanding the crystal lattice of the six-coordinated sites while maintaining the excellent features. It can be said that it was successful.
　次に、本発明の緑色系発光蛍光体（Ｌｕ１－ｘＣｅｘ）３＋ｄＡｌ５－ｄＯ１２においてｄの値を０．０９６８に固定したときのＣｅの濃度ｘと蛍光体の特性について説明する。
　表４に示す通りにＣｅ濃度、すなわちＬｕをＣｅに置換する量を変化させた他は、前記実施例１中の試料１－（１）と同様に蛍光体を作成し、それぞれ試料３－（１）ないし試料３－（９）とした。
　これら試料３－（１）ないし試料３－（９）についても、実施例１と同様に主波長、刺激純度、比較例１を１００とした相対発光輝度を測定し、同じくその結果を試料１－（１）および試料１－（２）の結果とともに表４に示した。 Next, the concentration x of Ce and the characteristics of the phosphor when the value of d is fixed at 0.0968 in the green light-emitting phosphor (Lu 1-x Ce x ) 3 + d Al 5 -dO 12 of the present invention will be described. To do.
As shown in Table 4, phosphors were prepared in the same manner as Sample 1- (1) in Example 1 except that the Ce concentration, that is, the amount of replacing Lu with Ce was changed. 1) to Sample 3- (9).
For these samples 3- (1) to 3- (9), as in Example 1, the main wavelength, the stimulation purity, and the relative emission luminance with respect to Comparative Example 1 as 100 were measured. The results are shown in Table 4 together with the results of (1) and Sample 1- (2).
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
　表４に示す結果より、Ｃｅ濃度ｘを変化させることで、主波長および相対発光輝度が変化することがわかるが、試料３－（２）ないし試料３－（７）、試料１－（１）および試料１－（２）、すなわちＣｅ濃度ｘが０．００５以上０．１４以下の範囲の試料は、主波長が約５５４ｎｍから約５６２ｎｍの範囲にあり、かつ相対発光輝度もほぼ７０以上となっていることがわかる。用途や他の蛍光体との組合せにおいて、多少相対発光輝度が劣ったとしても主波長を選択したいケースも十分にあるため、上記Ｃｅ濃度ｘの範囲の試料は好適に用いることができる。
　さらに、Ｃｅ濃度ｘが０．０１以上０．０５以下の範囲の試料は、相対発光輝度が９０以上と、より好ましいことがわかる。
　なお、Ｃｅ濃度ｘが０．００５未満と小さすぎる場合には発光輝度がさらに低下し、またＣｅ濃度ｘが０．１４を超えて大きすぎる場合には著しく発光輝度が低下するとともに、主波長も長波長側に移動する。
　以上のことから、Ｃｅ濃度ｘは、０．００５以上０．１４以下が好ましく、０．０１以上０．０５以下がより好ましいといえる。
　この傾向は、ｄ＝０．０９６８以外の場合、すなわちｄが０．０３以上０．５以下の場合でも、同様の傾向であることを確認した。 From the results shown in Table 4, it can be seen that changing the Ce concentration x changes the dominant wavelength and the relative emission luminance. Samples 3- (2) to 3- (7), Sample 1- (1) Sample 1- (2), that is, a sample having a Ce concentration x of 0.005 or more and 0.14 or less has a dominant wavelength in the range of about 554 nm to about 562 nm and a relative emission luminance of about 70 or more. You can see that Even if the relative emission luminance is somewhat inferior in combination with the use or other phosphors, there are sufficient cases where it is desired to select the dominant wavelength, and therefore the sample in the range of the Ce concentration x can be preferably used.
Furthermore, it can be seen that a sample having a Ce concentration x in the range of 0.01 or more and 0.05 or less preferably has a relative light emission luminance of 90 or more.
When the Ce concentration x is too small as less than 0.005, the light emission luminance is further reduced, and when the Ce concentration x exceeds 0.14, the light emission luminance is remarkably lowered and the main wavelength is also reduced. Move to long wavelength side.
From the above, it can be said that the Ce concentration x is preferably 0.005 or more and 0.14 or less, and more preferably 0.01 or more and 0.05 or less.
It was confirmed that this tendency was the same even when d = 0.0968, that is, when d was 0.03 or more and 0.5 or less.
　以上のことから、（Ｌｕ１－ｘＣｅｘ）３＋ｄＡｌ５－ｄＯ１２の式で表され、ｘは、０．００５≦ｘ≦０．１４であり、ｄは、０．０３≦ｄ≦０．５であることを特徴としたガーネット系緑色系発光蛍光体は、主波長が約５５４ｎｍ以上約５６２ｎｍ付近の範囲に発光色を有し、かつ高い発光輝度を有し、高温時の発光輝度低下がより少ないといった、演色性の高い半導体発光装置に必要な優れた特性を有している蛍光体であることがわかる。なお、より好ましいｘまたはｄの範囲としては、ｘは、０．０１≦ｘ≦０．０５であり、ｄは、０．０４５≦ｄ≦０．２である。 From the above, it is expressed by the formula (Lu 1-x Ce x ) 3 + d Al 5 -dO 12 , where x is 0.005 ≦ x ≦ 0.14 and d is 0.03 ≦ d ≦ The garnet-based green light-emitting phosphor characterized by 0.5 has an emission color in the range where the main wavelength is about 554 nm or more and about 562 nm, has high emission luminance, and emission luminance at high temperature It can be seen that the phosphor has excellent characteristics necessary for a semiconductor light emitting device with high color rendering properties, such as less deterioration. In addition, as a more preferable range of x or d, x is 0.01 ≦ x ≦ 0.05, and d is 0.045 ≦ d ≦ 0.2.
　本発明のガーネット系緑色系発光蛍光体は、主波長が約５５４ｎｍ以上約５６２ｎｍ付近の範囲に発光色を有し、かつ高い発光輝度を有し、高温時の発光輝度低下がより少ないといった、半導体発光装置に好適な優れた特徴を有するため、特に演色性や高出力を求められる半導体発光装置等に好適に用いることができる。また、本発明の半導体発光装置は、演色性に優れ、高出力時にも輝度が低下しにくいことから、特に照明用光源や液晶バックライト用光源等に好適に用いることができる。 The garnet-based green light-emitting phosphor of the present invention has a luminescent color in the range of the main wavelength of about 554 nm or more and about 562 nm, has a high emission luminance, and has a lower decrease in emission luminance at high temperatures. Since it has excellent characteristics suitable for a light-emitting device, it can be suitably used for a semiconductor light-emitting device that requires color rendering properties and high output. In addition, the semiconductor light emitting device of the present invention is excellent in color rendering properties, and since the luminance is hardly lowered even at high output, it can be suitably used particularly for an illumination light source or a liquid crystal backlight light source.

Claims (3)

  1. 　（Ｌｕ１－ｘＣｅｘ）３＋ｄＡｌ５－ｄＯ１２の式で表され、
    ｘは、０．００５≦ｘ≦０．１４であり、ｄは、０．０３≦ｄ≦０．５であることを特徴としたガーネット系緑色系発光蛍光体。     (Lu 1−x Ce x ) 3 + d Al 5−d O 12
    x is 0.005 ≦ x ≦ 0.14, and d is 0.03 ≦ d ≦ 0.5.
  2. 　ｄは、０．０４５≦ｄ≦０．２であることを特徴とした請求項１記載のガーネット系緑色系発光蛍光体。 2. The garnet green light-emitting phosphor according to claim 1, wherein d is 0.045 ≦ d ≦ 0.2.
  3. 　請求項１または２に記載のガーネット系の緑色系発光蛍光体と半導体発光素子とを少なくとも具備したことを特徴とした半導体発光装置。 A semiconductor light-emitting device comprising at least the garnet-based green light-emitting phosphor according to claim 1 or 2 and a semiconductor light-emitting element.
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Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014002723A1 (en) * 2012-06-26 2014-01-03 電気化学工業株式会社 Fluorescent material, light-emitting device, and lighting device
WO2014002722A1 (en) * 2012-06-26 2014-01-03 電気化学工業株式会社 Fluorescent material, light-emitting device, and lighting device
KR101516522B1 (en) * 2014-03-11 2015-05-04 희성금속 주식회사 Lutetium garnet phosphor and light emitting diodes comprising the same
JP2015528187A (en) * 2012-07-18 2015-09-24 コーニンクレッカ フィリップス エヌ ヴェ Adjustable correlated color temperature LED-based white light source with mixing chamber and remote phosphor exit window
JPWO2015129586A1 (en) * 2014-02-27 2017-03-30 京セラ株式会社 Solar cell module
CN111944350A (en) * 2020-08-27 2020-11-17 兰州大学 YAG Ce-based warm white fluorescent automobile paint and preparation method thereof
CN112358878A (en) * 2020-11-19 2021-02-12 陕西彩虹新材料有限公司 Method for manufacturing laser display green fluorescent powder
WO2021054336A1 (en) * 2019-09-17 2021-03-25 Ｚｉｇｅｎライティングソリューション株式会社 Light emitting device, and illumination device
CN112646579A (en) * 2019-10-09 2021-04-13 松下知识产权经营株式会社 Phosphor and semiconductor light-emitting device using the same
US11322660B2 (en) 2018-12-06 2022-05-03 Panasonic Intellectual Property Management Co., Ltd. Phosphor and semiconductor light emitting device using the same

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108603956B (en) 2016-03-10 2021-02-09 松下知识产权经营株式会社 Light emitting device

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005008844A (en) * 2003-02-26 2005-01-13 Nichia Chem Ind Ltd Phosphor, and light emitter using the same

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1067423C (en) * 1996-06-28 2001-06-20 电子科技大学 High-lightness high-distinguishability single-crystal colour projection display bube
US7038370B2 (en) * 2003-03-17 2006-05-02 Lumileds Lighting, U.S., Llc Phosphor converted light emitting device
DE102007010719A1 (en) * 2007-03-06 2008-09-11 Merck Patent Gmbh Phosphors consisting of doped garnets for pcLEDs

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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