WO2006126819A1 - Light emitting device and phosphor of alkaline earth sulfide therefor - Google Patents

Light emitting device and phosphor of alkaline earth sulfide therefor Download PDF

Info

Publication number
WO2006126819A1
WO2006126819A1 PCT/KR2006/001923 KR2006001923W WO2006126819A1 WO 2006126819 A1 WO2006126819 A1 WO 2006126819A1 KR 2006001923 W KR2006001923 W KR 2006001923W WO 2006126819 A1 WO2006126819 A1 WO 2006126819A1
Authority
WO
WIPO (PCT)
Prior art keywords
light emitting
light
based phosphor
emitting device
alkaline earth
Prior art date
Application number
PCT/KR2006/001923
Other languages
French (fr)
Inventor
Kyung Nam Kim
Sang Mi Park
Tomizo Matsuoka
Original Assignee
Seoul Semiconductor Co., Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from KR1020050043785A external-priority patent/KR100657137B1/en
Priority claimed from KR1020050057892A external-priority patent/KR100666189B1/en
Application filed by Seoul Semiconductor Co., Ltd. filed Critical Seoul Semiconductor Co., Ltd.
Priority to US11/912,384 priority Critical patent/US8017961B2/en
Priority to EP06768577A priority patent/EP1888711B1/en
Priority to JP2008513363A priority patent/JP4896129B2/en
Publication of WO2006126819A1 publication Critical patent/WO2006126819A1/en

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C09DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09KMATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K11/00Luminescent, e.g. electroluminescent, chemiluminescent materials
    • C09K11/08Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
    • C09K11/77Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals
    • C09K11/7728Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals containing europium
    • C09K11/7729Chalcogenides
    • C09K11/7731Chalcogenides with alkaline earth metals
    • CCHEMISTRY; METALLURGY
    • C09DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09KMATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K11/00Luminescent, e.g. electroluminescent, chemiluminescent materials
    • C09K11/08Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
    • C09K11/77Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals
    • C09K11/7728Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals containing europium
    • C09K11/77342Silicates
    • CCHEMISTRY; METALLURGY
    • C09DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09KMATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K11/00Luminescent, e.g. electroluminescent, chemiluminescent materials
    • C09K11/08Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
    • C09K11/77Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals
    • C09K11/7728Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals containing europium
    • C09K11/7735Germanates
    • CCHEMISTRY; METALLURGY
    • C09DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09KMATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K11/00Luminescent, e.g. electroluminescent, chemiluminescent materials
    • C09K11/08Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
    • C09K11/88Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing selenium, tellurium or unspecified chalcogen elements
    • C09K11/881Chalcogenides
    • C09K11/886Chalcogenides with rare earth metals
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42Wire connectors; Manufacturing methods related thereto
    • H01L2224/44Structure, shape, material or disposition of the wire connectors prior to the connecting process
    • H01L2224/45Structure, shape, material or disposition of the wire connectors prior to the connecting process of an individual wire connector
    • H01L2224/45001Core members of the connector
    • H01L2224/45099Material
    • H01L2224/451Material with a principal constituent of the material being a metal or a metalloid, e.g. boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te) and polonium (Po), and alloys thereof
    • H01L2224/45138Material with a principal constituent of the material being a metal or a metalloid, e.g. boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te) and polonium (Po), and alloys thereof the principal constituent melting at a temperature of greater than or equal to 950°C and less than 1550°C
    • H01L2224/45144Gold (Au) as principal constituent
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42Wire connectors; Manufacturing methods related thereto
    • H01L2224/47Structure, shape, material or disposition of the wire connectors after the connecting process
    • H01L2224/48Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
    • H01L2224/4805Shape
    • H01L2224/4809Loop shape
    • H01L2224/48091Arched
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42Wire connectors; Manufacturing methods related thereto
    • H01L2224/47Structure, shape, material or disposition of the wire connectors after the connecting process
    • H01L2224/48Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
    • H01L2224/481Disposition
    • H01L2224/48151Connecting 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
    • H01L2224/48221Connecting 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
    • H01L2224/48245Connecting 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
    • H01L2224/48247Connecting 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 connecting the wire to a bond pad of the item
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/48Semiconductor devices having potential barriers 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
    • H01L33/50Wavelength conversion elements
    • H01L33/501Wavelength conversion elements characterised by the materials, e.g. binder
    • H01L33/502Wavelength conversion materials
    • H01L33/504Elements with two or more wavelength conversion materials
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02BCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B20/00Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Definitions

  • the present invention relates to a light emitting device and a phosphor therefor.
  • the present invention relates to a light emitting device which can be used as a liquid crystal display(LCD) backlight unit due to its excellent color reproducibility as well as a general lighting source or flash due to its improved color reproduction range, and an alkaline earth metal sulfide based phosphor therefor.
  • LCD liquid crystal display
  • a light emitting diode is a photoelectric conversion semiconductor device in which an N type semiconductor and a P type semiconductor are joined together, and emits light through recombination of electrons and holes.
  • Light emitting diodes include a red LED using GaAsP or the like, a green LED using GaP or the like, a blue LED using an InGaN/ AlGaN double hetero structure, and the like.
  • This light emitting diode is packaged and then used in manufacturing a variety of light emitting devices.
  • the light emitting device manufactured from the packaged light emitting diodes has characteristics of low power consumption, a long lifespan, installation in a narrow space, and strong resistance against vibration.
  • white LEDs in addition to single color LEDs, e.g. red, blue or green LEDs, have been placed on the market. As the white LEDs are applied to products for automobiles and illumination, it is expected that their demands will be rapidly increased.
  • the methods of implementing white color can be roughly classified into two types.
  • the first one is a method in which red, blue and green LEDs are arranged to be adjacent to one another and colors of light emitted from the respective devices are mixed to implement white light.
  • the respective light emitting diodes have different thermal or temporal characteristics, there are problems in that uniform light mixing cannot be obtained due to changes in a color tone according to usage environment, particularly, the occurrence of color spots, or the like, and thus, the brightness is not sufficiently high.
  • the circuit configurations for operating the respective light emitting diodes are complex, and it is difficult to implement perfect white light since it is difficult to obtain optimal conditions for mixing three color lights depending on the positions of the light emitting diodes due to the package configurations.
  • its Color Rendering Index (CRI) is as low as about 40, it is not suitable for the general lighting source or the flash.
  • the second one is a method in which a phosphor is disposed on an light emitting diode and the color of a portion of primary light emitted from the light emitting diode and the color of secondary light of which wavelength has been converted by the phosphor are mixed to implement white light.
  • a light emitting diode for emitting blue light is attached to a light emitting diode for emitting blue light
  • a phosphor that emits yellowish green or yellow using a portion of the blue light of the light emitting diode as an excitation source so that white light can be obtained by mixing the blue light emitted from the light emitting diode and the yellowish green or yellow light emitted from the phosphor.
  • a phosphor that absorbs the emitted ultraviolet rays and emits visible light ranging from blue to red in order to obtain white color.
  • the blue LED with a wavelength of 450 In order to obtain white light emission, the blue LED with a wavelength of 450 to
  • the blue light source causes the yellow phosphor to be excited and then to emit yellow light and, and thus, white light can be obtained by mixing the blue and yellow lights.
  • an object of the present invention is to provide a light emitting device in which at least one orthosilicate based phosphor for emitting light with wavelength bands of a green to yellow region and an alkaline earth metal sulfide based phosphor for emitting light with a wavelength band of a red region are provided above the LED for emitting blue light or ultraviolet rays, so that the light emitting device can emit the white light with excellent color rendering and thus can be used as a general lighting source or flash, and an alkaline earth metal sulfide based phosphor for use in the light emitting device.
  • Another object of the present invention is to provide a light emitting device for use in an LCD backlight unit wherein its color reproduction range can be improved maximum about 40 % as compared with the conventional white light emitting device composed of the blue LED and the yellow light emitting phosphor.
  • a light emitting device comprising a light emitting diode for emitting blue light, and at least one orthosilicate based phosphor for emitting light in a green to yellow region and an alkaline earth metal sulfide based phosphor for emitting light in a red region which are installed above the light emitting diode.
  • the orthosilicate based phosphor has a chemical formula of a(M 0) ' b(M
  • M is at least one element selected from the group consisting of Pb and Cu;
  • M is at least one element selected from the group consisting of Li, Na, K, Rb, Cs, Au and Ag; M is at least one element selected from the group consisting of B, Al, Ga and In; M v is at least one element selected from the group consisting of Ge, V, Nd, Ta, W, Mo, Ti, Zr and Hf; M is at least one element selected from the group consisting of Bi, Sn, Sb, Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; A is at least one element selected from the group consisting of F, Cl, Br and I; a, b, c, d, e, f, g, h, o, p, x and y are set in ranges of 0 ⁇ a ⁇ 2, 0 ⁇ b ⁇ 8,
  • B is at least one element selected from the l-x x 2 4 group consisting of Bi, Sn, Sb, Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er,
  • the orthosilicate based phosphor may emit light with a wavelength of 505 nm to
  • the alkaline earth metal sulfide based phosphor has a chemical formula of (Ca 5 Sr) Eu C (S Se ), wherein C is at least one element selected from the group l-x-y x y 1-z z consisting of Mn and Pb; x is set in a range of 0.0005 to 0.1 ; y is set in a range of 0 to 0.5; and z is set in a range of 0 to 1.
  • the alkaline earth metal sulfide based phosphor has a chemical formula of (Ca 5 Sr) l-x-y Eu x Pb y S, wherein x is set in a range of 0.0005 to 0.01; and y is set in a range of 0 to 0.5.
  • the alkaline earth metal sulfide based phosphor may emit light with a wavelength of 600 nm to 660 nm.
  • the alkaline earth metal sulfide based phosphor has a chemical formula of A Eu GeS , wherein A is at least one element selected from the group consisting of x-a a z
  • an orthosilicate based phosphor for emitting light in a green region and an alkaline earth metal sulfide based phosphor for emitting light in a red region are installed above the light emitting diode.
  • the light emitting diode may emit light with a wavelength of 420 nm to 480.
  • the light emitting device may further comprise a body and a molding portion for sealing the light emitting diode mounted on the body, wherein the orthosilicate based phosphor and the alkaline earth metal sulfide based phosphor are mixed and distributed in the molding portion.
  • the body may be one of a substrate, a heat sink and a lead terminal.
  • the light emitting device may further comprise a ultraviolet light emitting diode for emitting ultraviolet rays, wherein at least one of the orthosilicate based phosphor and the alkaline earth metal sulfide based phosphor is excited by light emitted from the ultraviolet light emitting diode to emit light.
  • a light emitting device comprising a light emitting diode for emitting blue light, and at least one orthosilicate based phosphor for emitting light in a green to yellow region and an alkaline earth metal sulfide based phosphor for emitting light in a red region which are installed above the light emitting diode, whereby its color rendering is improved in such a degree that the light emitting device can be used for a general lighting source or flash.
  • a light emitting device comprising a light emitting diode for emitting blue light, and at least one orthosilicate based phosphor for emitting light in a green to yellow region and an alkaline earth metal sulfide based phosphor for emitting light in a red region which are installed above the light emitting diode, whereby its color reproduction range is improved in such a degree that the light emitting device can be used for a LCD backlight unit.
  • an alkaline earth metal sulfide phosphor having a chemical formula, (Ca,Sr) l-x-y Eu x C y (S 1-z
  • C is at least one element selected from the group consisting of Mn and Pb; x is set in a range of 0.0005 to 0.1 ; y is set in a range of 0 to 0.5; and z is set in a range of 0 to 1.
  • the alkaline earth metal sulfide based phosphor has a chemical formula of (Ca,Sr) Eu Pb S, wherein x is set in a range of 0.0005 to 0.01; and y is set in a
  • a light emitting device includes an orthosilicate based phosphor and an alkaline earth metal sulfide based phosphor such that green, yellow and red lights with very excellent color rendering and reproducibility can be emitted under the excitation of light in a long wavelength ultraviolet region and blue region. Therefore, there is an advantage in that the light emitting device of the present invention can be applied to a variety of application fields, in which the light in the long wavelength ultraviolet region and the blue region may be used as an energy source, such as the green, red and white light emitting devices for ultraviolet light emitting diode, and bluelagoon, pink and white light emitting devices for blue light emitting diode.
  • At least one orthosilicate based phosphor for emitting light with wavelength bands of a green to yellow region and an alkaline earth metal sulfide based phosphor for emitting light with a red wavelength band are distributed together over the blue light emitting diode, so that white light with a continuous spectrum ranging from green to red can be implemented to provide a white light emitting device with more excellent color rendering. Since the light emitting device of the present invention can implement the white light with high CRI of at least 90, there is another advantage in that the light emitting device of the present invention can be used as a flash light source as well as a general lighting source.
  • the light emitting device of the present invention can be used as a LCD backlight source due to its excellent color reproducibility.
  • Fig. 1 is a sectional view showing a chip-type light emitting device according to the present invention.
  • Fig. 2 is a sectional view showing a top-type light emitting device according to the present invention.
  • Fig. 3 is a sectional view showing a lamp-type light emitting device according to the present invention.
  • Fig. 4 is a sectional view showing a light emitting device including a housing according to the present invention.
  • Fig. 5 is a graph illustrating emission spectra depending on the compositions of an orthosilicate based phosphor used in the light emitting device of the present invention.
  • Fig. 6 is a graph illustrating emission spectra depending on the compositions of an alkaline earth metal sulfide based phosphor used in the light emitting device of the present invention.
  • Fig. 7 is a graph illustrating emission spectra of the light emitting device of the present invention.
  • Fig. 8 is a graph illustrating the light emission spectra of the light emitting device together with the transmittance of a conventional LCD color filter.
  • the light emitting device of the present invention comprises at least one orthosilicate based phosphor for emitting light with wavelength band of a green to yellow region and an alkaline earth metal sulfide based phosphor for emitting light with a red wavelength band such that green, yellow and red lights with very excellent color rendering and reproducibility can be emitted under the excitation of light in a long wavelength ultraviolet region and blue region.
  • the orthosilicate based phosphor has a structure as represent by a chemical formula of chemistry figure 1 :
  • M is at least one element selected from the group consisting of Pb and Cu;
  • M 11 is at least one element selected from the group consisting of Be, Mg, Ca, Sr, Ba, Zn, Cd and Mn;
  • M is at least one element selected from the group consisting of Li, Na, K, Rb, Cs, Au and Ag;
  • M IV is at least one element selected from the group consisting of B, Al, Ga and In;
  • M is at least one element selected from the group consisting of Ge, V, Nd, Ta, W, Mo, Ti, Zr and Hf;
  • M is at least one element selected from the group consisting of Bi, Sn, Sb, Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu
  • a, b, c, d, e, f, g, h, o, p, x and y are set in the ranges of 0 ⁇ a ⁇ 2, 0 ⁇ b ⁇ 8, 0 ⁇ c ⁇ 4, 0 ⁇ d ⁇ 2, 0 ⁇ e ⁇ 2, 0 ⁇ f ⁇ 2, O ⁇ g ⁇ lO, 0 ⁇ h ⁇ 5, l ⁇ o ⁇ 2, l ⁇ p ⁇ 5, l ⁇ x ⁇ 2, and l ⁇ y ⁇ 5.
  • the orthosilicate based phosphor is expressed as the following chemical formula of chemistry figure 2:
  • B is at least one element selected from the group consisting of Bi, Sn, Sb, Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. Further, x is set in the range of 0 to 1 ; and Eu and B are set in the ranges of 0 to 0.2.
  • the phosphor expressed as the chemistry figure 3 emits light with a wavelength of
  • the phosphor expressed as the chemistry figure 4 emits light with a wavelength of 592 nm
  • the phosphor expressed as the chemistry figure 5 emits light with a wavelength of 605 nm.
  • the wavelength of the light emitted from the orthosilicate based phosphor can be controlled depending on its elements and compositions.
  • alkaline earth metal sulfide based phosphor has a structure as expressed in the following chemical formula of chemistry figure 6:
  • C is at least one element selected from the group consisting of Mn and Pb. Further, x is set in the range of 0.0005 to 0.1, y is set in the range of 0 to 0.5, and z is set in the range of 0 to 1.
  • the alkaline earth metal sulfide based phosphor has a structure as expressed in the chemical formula of chemistry figure 7:
  • x is set in the range of 0.0005 to 0.01
  • y is set in the range of 0 to 0.5.
  • the typical composition of the alkaline earth metal sulfide based phosphor may be expressed as the following chemical formulas of chemistry figure 8 to 10: [65] Chemistry Figure 8
  • the phosphor expressed as the chemistry figure 8 emits light with a wavelength of
  • the phosphor expressed as the chemistry figure 9 emits light with a wavelength of 630 nm
  • the phosphor expressed as the chemistry figure 10 emits light with a wavelength of 648 nm.
  • the wavelength of the light emitted from the alkaline earth metal sulfide based phosphor can be controlled depending on its elements and compositions.
  • More excellent green, yellow and red lights may be implemented under the excitation of light in the long wavelength ultraviolet region and the blue region by using the aforementioned phosphors according to the present invention.
  • the aforementioned phosphors may be used separately or together to implement various colors such as green, red and white colors.
  • the aforementioned phosphors may be used separately or together to implement various colors such as bluelagoon, pink, and white colors.
  • Fig. 1 is a sectional view showing a chip-type light emitting device according to the present invention.
  • the light emitting device comprises a substrate 10, first and second electrodes 30 and 35 formed on the substrate 10, a light emitting diode 20 mounted on the first electrode 30, and a molding portion 50 for sealing the light emitting diode 20.
  • At least one orthosilicate based phosphor 60 and an alkaline earth metal sulfide based phosphor 70 as described above are uniformly distributed in the molding portion 50.
  • the substrate 10 may be formed with a predetermined groove around its central region in which the light emitting diode 20 is mounted.
  • the groove may be formed in such a manner that a sidewall surface thereof can be inclined at a predetermined slope.
  • the sidewall surface with a predetermined inclination allows the light emitted from the light emitting diode 20 to be maximally reflected such that its luminous efficiency can be increased.
  • the first and the second electrodes 30 and 35 are electrodes which are formed on the substrate 10 and connected to anode and cathode terminals of the light emitting diode 20, respectively.
  • the first and the second electrodes 30 and 35 may be formed by using a printing technique.
  • the first and the second electrodes 30 and 35 are made of a metallic material such as copper or aluminum with excellent conductivity and configured to be electrically disconnected from each other.
  • the light emitting diode 20 is a GaN, InGaN, AlGaN or AlGaInN based blue light emitting diode.
  • a light emitting diode for emitting blue light in the range of 420 to 480 nm is used.
  • the present invention is not limited thereto but may further include a light emitting diode for emitting ultraviolet rays in the range of 250 to 410 nm as well as the blue light. Only one light emitting diode may be used, or a plurality of light emitting diodes may be used if desired.
  • the light emitting diode 20 is mounted on the first electrode 30 and electrically connected to the second electrode 35 through a wire 80.
  • the light emitting diode 20 can be connected to the first and second electrodes 30 and 35 through two wires 80, respectively.
  • the molding portion 50 for sealing the light emitting diode 20 is formed on the substrate 10. As described above, at least one orthosilicate based phosphor 60 and an alkaline earth metal sulfide based phosphor 70 are uniformly distributed in the molding portion 50.
  • the molding portion 50 may be formed through an injection process using a mixture of a predetermined transparent epoxy resin and the aforementioned phosphors 60 and 70. Alternatively, the molding portion 50 may be formed in such a manner that it is manufactured using a separate mold and then pressurized or heat treated.
  • the molding portion 50 may be formed into various shapes such as an optical lens type, a flat plate type, and a type in which unevenness is formed on its surface.
  • primary light is emitted from the light emitting diode 20 and allows the phosphors 60 and 70 to emit secondary lights each having converted wavelength such that color in a desired spectrum region can be implemented through the mixing of the primary and secondary lights. That is, the blue light is emitted from the blue light emitting diode and causes the orthosilicate based phosphor to emit green to yellow light and the alkaline earth metal sulfide based phosphor to emit red light.
  • a portion of the blue light i.e. the primary light
  • the secondary lights i.e. the secondary lights
  • the light emitting device of the present invention can implement the white light with a continuous spectrum ranging from green to red such that its color rendering can be improved.
  • FIG. 2 is a sectional view showing a top-type light emitting device according to the present invention.
  • the light emitting device comprises a substrate 10, first and second electrodes 30 and 35 formed on the substrate 10, and a light emitting diode 20 mounted on the first electrode 30.
  • the top-type light emitting device comprises a reflector 40 formed on the substrate 10 to encompass the light emitting diode 20, and a molding portion 50 filled into a central space of the reflector 40 for protecting the light emitting diode 20.
  • an inner sidewall of the reflector 40 which encompasses the light emitting diode can be formed to have a predetermined inclination. Such a configuration is preferable to maximize the reflection of light emitted from the light emitting diode 20 and to improve the luminous efficiency.
  • At least one orthosilicate based phosphor 60 and an alkaline earth metal sulfide based phosphor 70 are uniformly distributed in the molding portion 50. Accordingly, the primary light emitted from the light emitting diode 20 is mixed with the secondary lights each having the converted wavelength from the orthosilicate based phosphor 60 or the alkaline earth metal sulfide based phosphor 70 to implement the color in a desired spectrum range.
  • Fig. 3 is a sectional view showing a lamp-type light emitting device according to the present invention.
  • the light emitting device comprises a first lead terminal 90 with a reflecting portion 45 formed therein, and a second lead terminal 95 spaced apart from the first lead terminal 90 by a predetermined interval.
  • a light emitting diode 20 is mounted onto the reflecting portion 45 of the first lead terminal 90 and electrically connected to the second lead terminal 95 through a wire 80.
  • a molding portion 50 containing orthosilicate based and alkaline earth metal sulfide based phosphors 60 and 70 is formed on the light emitting diode 20.
  • An outer peripheral molding portion 55 manufactured through a mold is formed on front ends of the first and second lead terminals 90 and 95.
  • the molding portion 50 are uniformly distributed at least one orthosilicate based phosphor 60 and an alkaline earth metal sulfide based phosphor 70, which absorb light emitted from the light emitting diode 20 to convert the absorbed light into light with respective wavelength.
  • the outer peripheral molding portion 55 is made of a transparent epoxy resin to improve the transmittance of light emitted from the light emitting diode 20.
  • FIG. 4 is a sectional view showing a light emitting device including a housing according to the present invention.
  • the light emitting device comprises a housing 100 formed with first and second electrodes 30 and 35 on both sides thereof and formed with a through hole, a substrate 10 mounted into the through hole of the housing 100, and a light emitting diode 20 mounted on the substrate 10.
  • the substrate 10 may be formed of a certain material with excellent thermal conductivity to serve as a heat sink such that heat output from the light emitting diode 20 can be more effectively released.
  • the light emitting device further includes a molding portion 50 for sealing the light emitting diode 20. Further, in the molding portion 50 are uniformly distributed at least one orthosilicate based phosphor 60 and an alkaline earth metal sulfide based phosphor 70 as described above.
  • the first and the second electrodes 30 and 35 are configured to be connected to anode and cathode terminals of the light emitting diode 20, respectively.
  • the light emitting diode 20 is mounted on the substrate 10 and electrically connected to the first or second electrode 30 or 35 through the wires 80.
  • the present invention may be applied to articles with various structures, and the technical features of the present invention are not limited to the aforementioned embodiments but may be modified or changed in various ways.
  • Fig. 5 is a graph illustrating emission spectra depending on the compositions of an orthosilicate based phosphor used in the light emitting device of the present invention. As shown in the figure, the wavelength peak of the emitted light can be controlled in a range of from 505 nm to 605 nm depending on the composition of a host material and the concentration of a light-emitting central element, and excellent emission spectra can also be exhibited.
  • Fig. 6 is a graph illustrating emission spectra depending on the compositions of an alkaline earth metal sulfide based phosphor used in the light emitting device of the present invention. As shown in the figure, the wavelength peak of the emitted light can be controlled in a range of from 600 nm to 660 nm depending on the composition of a host material and the concentration of a light-emitting central element, and excellent emission spectra can also be exhibited.
  • Fig. 7 is a graph illustrating an emission spectrum of the light emitting device of the present invention using the blue light emitting diode and the two kinds of orthosilicate based phosphor and one alkaline earth metal sulfide based phosphor.
  • r phos r phors (Ba 045 Sr 045 Pb 0 1 ) 2 SiO 4 :Eu with an emission waveleng °th of
  • the primary light emitted from the blue light emitting diode is mixed with the secondary lights, i.e. green, yellow and red lights emitted from the phosphors excited by a portion of the primary light such that white light can be implemented. Accordingly, the color rendering of the present invention can be further improved as compared with the conventional white light emitting device which uses the blue light emitting diode and the yellow phosphor.
  • Fig. 8 is a graph illustrating emission spectra of the light emitting device of the present invention using the blue light emitting diode and one kind of orthosilicate based phosphor and one alkaline earth metal sulfide based phosphor, in addition to transmittance of a conventional LCD color filter.
  • aforementioned phosphors (Ba Sr Pb ) SiO :Eu with an emission wavelength of 515 nm and Ca Pb Eu
  • the primary light emitted from the blue light emitting diode is mixed with the secondary lights, i.e. green and red lights emitted from the phosphors excited by a portion of the primary light such that white light can be implemented. Accordingly, the color reproduction range of the present invention can be further improved as compared with the conventional white light emitting device.
  • the alkaline earth metal sulfide based phosphor has a chemical formula of (Ca,Sr) Eu C (S Se ), wherein C is at l-x-y x y 1-z z least one element selected from the group consisting of Mn and Pb, x is set in the range of 0.0005 to 0.1, y is set in the range of 0 to 0.5, and z is set in the range of 0 to 1.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Luminescent Compositions (AREA)
  • Led Device Packages (AREA)

Abstract

The present invention relates to a light emitting device comprising a light emitting diode for emitting blue light or ultraviolet rays, and at least one orthosilicate based phosphor for emitting light in a green to yellow region and an alkaline earth metal sulfide based phosphor for emitting light in a red region which are installed above the light emitting diode. According to the light emitting device of the present invention, white light with a continuous spectrum ranging from green to red can be implemented such that more excellent color rendering and color reproducibility can be obtained. Therefore, the light emitting device of the present invention can used in an liquid crystal display backlight unit as well as a general lighting source and flash light source.

Description

Description
LIGHT EMITTING DEVICE AND PHOSPHOR OF ALKALINE
EARTH SULFIDE THEREFOR
Technical Field
[1] The present invention relates to a light emitting device and a phosphor therefor.
More specifically, the present invention relates to a light emitting device which can be used as a liquid crystal display(LCD) backlight unit due to its excellent color reproducibility as well as a general lighting source or flash due to its improved color reproduction range, and an alkaline earth metal sulfide based phosphor therefor. Background Art
[2] A light emitting diode (LED) is a photoelectric conversion semiconductor device in which an N type semiconductor and a P type semiconductor are joined together, and emits light through recombination of electrons and holes.
[3] Light emitting diodes include a red LED using GaAsP or the like, a green LED using GaP or the like, a blue LED using an InGaN/ AlGaN double hetero structure, and the like.
[4] This light emitting diode is packaged and then used in manufacturing a variety of light emitting devices. The light emitting device manufactured from the packaged light emitting diodes has characteristics of low power consumption, a long lifespan, installation in a narrow space, and strong resistance against vibration. In recent years, white LEDs in addition to single color LEDs, e.g. red, blue or green LEDs, have been placed on the market. As the white LEDs are applied to products for automobiles and illumination, it is expected that their demands will be rapidly increased.
[5] In light emitting diode technologies, the methods of implementing white color can be roughly classified into two types. The first one is a method in which red, blue and green LEDs are arranged to be adjacent to one another and colors of light emitted from the respective devices are mixed to implement white light. However, since the respective light emitting diodes have different thermal or temporal characteristics, there are problems in that uniform light mixing cannot be obtained due to changes in a color tone according to usage environment, particularly, the occurrence of color spots, or the like, and thus, the brightness is not sufficiently high. Further, the circuit configurations for operating the respective light emitting diodes are complex, and it is difficult to implement perfect white light since it is difficult to obtain optimal conditions for mixing three color lights depending on the positions of the light emitting diodes due to the package configurations. Moreover, since its Color Rendering Index (CRI) is as low as about 40, it is not suitable for the general lighting source or the flash.
[6] The second one is a method in which a phosphor is disposed on an light emitting diode and the color of a portion of primary light emitted from the light emitting diode and the color of secondary light of which wavelength has been converted by the phosphor are mixed to implement white light. For example, to a light emitting diode for emitting blue light is attached a phosphor that emits yellowish green or yellow using a portion of the blue light of the light emitting diode as an excitation source, so that white light can be obtained by mixing the blue light emitted from the light emitting diode and the yellowish green or yellow light emitted from the phosphor. Alternatively, on an light emitting diode for emitting ultraviolet rays may be applied a phosphor that absorbs the emitted ultraviolet rays and emits visible light ranging from blue to red in order to obtain white color.
[7] In order to obtain white light emission, the blue LED with a wavelength of 450 to
470 nm and the yellow phosphor such as YAG:Ce or (Ba,Sr,Ca) SiO ;Eu may be generally used. The blue light source causes the yellow phosphor to be excited and then to emit yellow light and, and thus, white light can be obtained by mixing the blue and yellow lights.
[8]
Disclosure of Invention
Technical Problem
[9] However, there is a problem in that such a light emitting device has its lower color rendering, which is typically measured using the Color Rendering Index (CRI), due to the shortages of green and red spectra. That is, in a case where the white light emitting device obtained through the combination of the blue LED and the yellow phosphor is used as a general lighting source and particularly a flash light source for photographing, there may occur a color distortion phenomenon in which original colors of respective objects cannot be sufficiently expressed.
[10] Further, in a case where the light emitting device is used as a LCD backlight white light source, the color reproduction range which can be expressed after the white light has been transmitted through RGB filters becomes considerably narrow. As a result, there is a limitation in implementing images closer to natural colors.
[H]
Technical Solution
[12] The present invention is conceived to solve the aforementioned problem in the prior art. Accordingly, an object of the present invention is to provide a light emitting device in which at least one orthosilicate based phosphor for emitting light with wavelength bands of a green to yellow region and an alkaline earth metal sulfide based phosphor for emitting light with a wavelength band of a red region are provided above the LED for emitting blue light or ultraviolet rays, so that the light emitting device can emit the white light with excellent color rendering and thus can be used as a general lighting source or flash, and an alkaline earth metal sulfide based phosphor for use in the light emitting device.
[13] Another object of the present invention is to provide a light emitting device for use in an LCD backlight unit wherein its color reproduction range can be improved maximum about 40 % as compared with the conventional white light emitting device composed of the blue LED and the yellow light emitting phosphor.
[14] According to an aspect of the present invention for achieving objects, there is provided a light emitting device, comprising a light emitting diode for emitting blue light, and at least one orthosilicate based phosphor for emitting light in a green to yellow region and an alkaline earth metal sulfide based phosphor for emitting light in a red region which are installed above the light emitting diode.
[15] Preferably, the orthosilicate based phosphor has a chemical formula of a(M 0)'b(M
11O)-C(M111AVd(M111 0)'e(MIV O )'f(Mv O )"g(SiO )'h(MVI O ), wherein M1 is at least
2 2 3 o p 2 x y
II one element selected from the group consisting of Pb and Cu; M is at least one
III element selected from the group consisting of Be, Mg, Ca, Sr, Ba, Zn, Cd and Mn; M is at least one element selected from the group consisting of Li, Na, K, Rb, Cs, Au and Ag; M is at least one element selected from the group consisting of B, Al, Ga and In; Mv is at least one element selected from the group consisting of Ge, V, Nd, Ta, W, Mo, Ti, Zr and Hf; M is at least one element selected from the group consisting of Bi, Sn, Sb, Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; A is at least one element selected from the group consisting of F, Cl, Br and I; a, b, c, d, e, f, g, h, o, p, x and y are set in ranges of 0<a<2, 0<b<8, 0<c<4, 0<d<2, 0<e<2, 0<f<2, O≤g≤lO, 0<h<5, l≤o<2, l≤p<5, l≤x<2, and l≤y<5. [16] More preferably, the orthosilicate based phosphor has a chemical formula of
((Br5Sr5Ca) (Pb5Cu) ) SiO :Eu,B; wherein B is at least one element selected from the l-x x 2 4 group consisting of Bi, Sn, Sb, Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er,
Tm, Yb and Lu; x is set in a range of 0 to 1 ; and Eu and B are set in ranges of 0 to 0.2. [17] The orthosilicate based phosphor may emit light with a wavelength of 505 nm to
605 nm depending on compositions of the phosphor. [18] Preferably, the alkaline earth metal sulfide based phosphor has a chemical formula of (Ca5Sr) Eu C (S Se ), wherein C is at least one element selected from the group l-x-y x y 1-z z consisting of Mn and Pb; x is set in a range of 0.0005 to 0.1 ; y is set in a range of 0 to 0.5; and z is set in a range of 0 to 1.
[19] More preferably, the alkaline earth metal sulfide based phosphor has a chemical formula of (Ca5Sr) l-x-y Eu x Pb y S, wherein x is set in a range of 0.0005 to 0.01; and y is set in a range of 0 to 0.5. [20] The alkaline earth metal sulfide based phosphor may emit light with a wavelength of 600 nm to 660 nm. [21] Preferably, the alkaline earth metal sulfide based phosphor has a chemical formula of A Eu GeS , wherein A is at least one element selected from the group consisting of x-a a z
Ca and Sr; z=x+2; x is set in a range of 2 to 5; and a/x is set in a range of 0.0005 to 0.02.
[22] Preferably, an orthosilicate based phosphor for emitting light in a green region and an alkaline earth metal sulfide based phosphor for emitting light in a red region are installed above the light emitting diode.
[23] The light emitting diode may emit light with a wavelength of 420 nm to 480.
[24] Preferably, the light emitting device may further comprise a body and a molding portion for sealing the light emitting diode mounted on the body, wherein the orthosilicate based phosphor and the alkaline earth metal sulfide based phosphor are mixed and distributed in the molding portion. Herein, the body may be one of a substrate, a heat sink and a lead terminal.
[25] The light emitting device may further comprise a ultraviolet light emitting diode for emitting ultraviolet rays, wherein at least one of the orthosilicate based phosphor and the alkaline earth metal sulfide based phosphor is excited by light emitted from the ultraviolet light emitting diode to emit light.
[26] According to another aspect of the present invention, there is provided a light emitting device, comprising a light emitting diode for emitting blue light, and at least one orthosilicate based phosphor for emitting light in a green to yellow region and an alkaline earth metal sulfide based phosphor for emitting light in a red region which are installed above the light emitting diode, whereby its color rendering is improved in such a degree that the light emitting device can be used for a general lighting source or flash.
[27] According to a further aspect of the present invention, there is provided a light emitting device, comprising a light emitting diode for emitting blue light, and at least one orthosilicate based phosphor for emitting light in a green to yellow region and an alkaline earth metal sulfide based phosphor for emitting light in a red region which are installed above the light emitting diode, whereby its color reproduction range is improved in such a degree that the light emitting device can be used for a LCD backlight unit.
[28] According to a still further aspect of the present invention, there is provided an alkaline earth metal sulfide phosphor having a chemical formula, (Ca,Sr) l-x-y Eu x C y (S 1-z
Se ), wherein C is at least one element selected from the group consisting of Mn and Pb; x is set in a range of 0.0005 to 0.1 ; y is set in a range of 0 to 0.5; and z is set in a range of 0 to 1.
[29] Preferably, the alkaline earth metal sulfide based phosphor has a chemical formula of (Ca,Sr) Eu Pb S, wherein x is set in a range of 0.0005 to 0.01; and y is set in a
1 -x-y x y range of 0 to 0.5. [30]
Advantageous Effects
[31] According to the present invention, a light emitting device includes an orthosilicate based phosphor and an alkaline earth metal sulfide based phosphor such that green, yellow and red lights with very excellent color rendering and reproducibility can be emitted under the excitation of light in a long wavelength ultraviolet region and blue region. Therefore, there is an advantage in that the light emitting device of the present invention can be applied to a variety of application fields, in which the light in the long wavelength ultraviolet region and the blue region may be used as an energy source, such as the green, red and white light emitting devices for ultraviolet light emitting diode, and bluelagoon, pink and white light emitting devices for blue light emitting diode.
[32] In particular, at least one orthosilicate based phosphor for emitting light with wavelength bands of a green to yellow region and an alkaline earth metal sulfide based phosphor for emitting light with a red wavelength band are distributed together over the blue light emitting diode, so that white light with a continuous spectrum ranging from green to red can be implemented to provide a white light emitting device with more excellent color rendering. Since the light emitting device of the present invention can implement the white light with high CRI of at least 90, there is another advantage in that the light emitting device of the present invention can be used as a flash light source as well as a general lighting source.
[33] Further, the light emitting device of the present invention can be used as a LCD backlight source due to its excellent color reproducibility.
[34]
Brief Description of the Drawings
[35] Fig. 1 is a sectional view showing a chip-type light emitting device according to the present invention.
[36] Fig. 2 is a sectional view showing a top-type light emitting device according to the present invention.
[37] Fig. 3 is a sectional view showing a lamp-type light emitting device according to the present invention.
[38] Fig. 4 is a sectional view showing a light emitting device including a housing according to the present invention. [39] Fig. 5 is a graph illustrating emission spectra depending on the compositions of an orthosilicate based phosphor used in the light emitting device of the present invention.
[40] Fig. 6 is a graph illustrating emission spectra depending on the compositions of an alkaline earth metal sulfide based phosphor used in the light emitting device of the present invention.
[41] Fig. 7 is a graph illustrating emission spectra of the light emitting device of the present invention.
[42] Fig. 8 is a graph illustrating the light emission spectra of the light emitting device together with the transmittance of a conventional LCD color filter.
[43]
Best Mode for Carrying Out the Invention
[44] Hereinafter, a light emitting device according to the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to a preferred embodiment set forth herein but can be implemented in different forms. Rather, the preferred embodiment is merely provided to allow the present invention to be completely described herein and to fully convey the scope of the invention to those skilled in the art. In the drawings, like elements are designated by the same reference numerals.
[45] The light emitting device of the present invention comprises at least one orthosilicate based phosphor for emitting light with wavelength band of a green to yellow region and an alkaline earth metal sulfide based phosphor for emitting light with a red wavelength band such that green, yellow and red lights with very excellent color rendering and reproducibility can be emitted under the excitation of light in a long wavelength ultraviolet region and blue region.
[46] The orthosilicate based phosphor has a structure as represent by a chemical formula of chemistry figure 1 :
[47] Chemistry Figure 1
3(M 1 O) b(Mπ0) c (MmA) d(Mm2θ) e
Figure imgf000007_0001
CM^A) f g(SiO2) • hCM^O,) [48] In the chemistry figure 1, M is at least one element selected from the group consisting of Pb and Cu; M11 is at least one element selected from the group consisting of Be, Mg, Ca, Sr, Ba, Zn, Cd and Mn; M is at least one element selected from the group consisting of Li, Na, K, Rb, Cs, Au and Ag; MIV is at least one element selected from the group consisting of B, Al, Ga and In; M is at least one element selected from the group consisting of Ge, V, Nd, Ta, W, Mo, Ti, Zr and Hf; M is at least one element selected from the group consisting of Bi, Sn, Sb, Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; and A is at least one element selected from the group consisting of F, Cl, Br and I. [49] Further, in the chemical formula (1), a, b, c, d, e, f, g, h, o, p, x and y are set in the ranges of 0<a<2, 0<b<8, 0<c<4, 0<d<2, 0<e<2, 0<f<2, O≤g≤lO, 0<h<5, l≤o<2, l≤p<5, l≤x<2, and l≤y<5.
[50] Preferably, the orthosilicate based phosphor is expressed as the following chemical formula of chemistry figure 2:
[51] Chemistry Figure 2
( (Ba , Sr , Ca)1-JPb, Cu)X)2SiO4 = Eu , B
[52] In the chemistry figure 2, B is at least one element selected from the group consisting of Bi, Sn, Sb, Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. Further, x is set in the range of 0 to 1 ; and Eu and B are set in the ranges of 0 to 0.2.
[53] The typical composition of the orthosilicate based phosphor can be expressed as the following chemical formulas of chemistry figure 3 to 5:
[54] ChemistryFigure 3
Pb0 lBao.θδSro 95SiO4 : Eu
[55] ChemistryFigure 4
CucosSn 7Cao 25SiO4 = Eu [56] ChemistryFigure 5
Cuo 1Ba0 iSro.gCao 9SiO4 = Eu
[57] The phosphor expressed as the chemistry figure 3 emits light with a wavelength of
527 nm, the phosphor expressed as the chemistry figure 4 emits light with a wavelength of 592 nm, and the phosphor expressed as the chemistry figure 5 emits light with a wavelength of 605 nm. As such, the wavelength of the light emitted from the orthosilicate based phosphor can be controlled depending on its elements and compositions.
[58] Further, the alkaline earth metal sulfide based phosphor has a structure as expressed in the following chemical formula of chemistry figure 6:
[59] ChemistryFigure 6
(Ca , Sr )1-X-VEuxCy(S1-ZSe2)
[60] In the chemistry figure 6, C is at least one element selected from the group consisting of Mn and Pb. Further, x is set in the range of 0.0005 to 0.1, y is set in the range of 0 to 0.5, and z is set in the range of 0 to 1.
[61] Preferably, the alkaline earth metal sulfide based phosphor has a structure as expressed in the chemical formula of chemistry figure 7:
[62] ChemistryFigure 7
Figure imgf000008_0001
[63] In the chemistry figure 7, x is set in the range of 0.0005 to 0.01, and y is set in the range of 0 to 0.5. [64] The typical composition of the alkaline earth metal sulfide based phosphor may be expressed as the following chemical formulas of chemistry figure 8 to 10: [65] ChemistryFigure 8
Cao 947Pbo ceEuo 003S [66] ChemistryFigure 9
Cao 447S1O 51 D0 05EU0 003S
[67] ChemistryFigure 10
[68] The phosphor expressed as the chemistry figure 8 emits light with a wavelength of
650 nm, the phosphor expressed as the chemistry figure 9 emits light with a wavelength of 630 nm, and the phosphor expressed as the chemistry figure 10 emits light with a wavelength of 648 nm. As such, the wavelength of the light emitted from the alkaline earth metal sulfide based phosphor can be controlled depending on its elements and compositions.
[69] More excellent green, yellow and red lights may be implemented under the excitation of light in the long wavelength ultraviolet region and the blue region by using the aforementioned phosphors according to the present invention. In case of an ultraviolet LED, the aforementioned phosphors may be used separately or together to implement various colors such as green, red and white colors. Alternatively, in case of a blue LED, the aforementioned phosphors may be used separately or together to implement various colors such as bluelagoon, pink, and white colors.
[70] Hereinafter, the light emitting device in which the aforementioned phosphors are used according to the present invention will be described with reference to the accompanying drawings.
[71] Fig. 1 is a sectional view showing a chip-type light emitting device according to the present invention.
[72] Referring to this figure, the light emitting device comprises a substrate 10, first and second electrodes 30 and 35 formed on the substrate 10, a light emitting diode 20 mounted on the first electrode 30, and a molding portion 50 for sealing the light emitting diode 20. At least one orthosilicate based phosphor 60 and an alkaline earth metal sulfide based phosphor 70 as described above are uniformly distributed in the molding portion 50.
[73] The substrate 10 may be formed with a predetermined groove around its central region in which the light emitting diode 20 is mounted. At this time, the groove may be formed in such a manner that a sidewall surface thereof can be inclined at a predetermined slope. Here, since the light emitting diode 20 is mounted on a bottom surface of the groove, the sidewall surface with a predetermined inclination allows the light emitted from the light emitting diode 20 to be maximally reflected such that its luminous efficiency can be increased.
[74] The first and the second electrodes 30 and 35 are electrodes which are formed on the substrate 10 and connected to anode and cathode terminals of the light emitting diode 20, respectively. The first and the second electrodes 30 and 35 may be formed by using a printing technique. The first and the second electrodes 30 and 35 are made of a metallic material such as copper or aluminum with excellent conductivity and configured to be electrically disconnected from each other.
[75] The light emitting diode 20 is a GaN, InGaN, AlGaN or AlGaInN based blue light emitting diode. In the present embodiment, a light emitting diode for emitting blue light in the range of 420 to 480 nm is used. However, the present invention is not limited thereto but may further include a light emitting diode for emitting ultraviolet rays in the range of 250 to 410 nm as well as the blue light. Only one light emitting diode may be used, or a plurality of light emitting diodes may be used if desired.
[76] The light emitting diode 20 is mounted on the first electrode 30 and electrically connected to the second electrode 35 through a wire 80. Alternatively, in a case where the light emitting diode 20 is not mounted on the first electrode 30 or the second electrode 35 but formed on the substrate 10, it can be connected to the first and second electrodes 30 and 35 through two wires 80, respectively.
[77] Further, the molding portion 50 for sealing the light emitting diode 20 is formed on the substrate 10. As described above, at least one orthosilicate based phosphor 60 and an alkaline earth metal sulfide based phosphor 70 are uniformly distributed in the molding portion 50. The molding portion 50 may be formed through an injection process using a mixture of a predetermined transparent epoxy resin and the aforementioned phosphors 60 and 70. Alternatively, the molding portion 50 may be formed in such a manner that it is manufactured using a separate mold and then pressurized or heat treated. The molding portion 50 may be formed into various shapes such as an optical lens type, a flat plate type, and a type in which unevenness is formed on its surface.
[78] In such a light emitting device according to the present invention, primary light is emitted from the light emitting diode 20 and allows the phosphors 60 and 70 to emit secondary lights each having converted wavelength such that color in a desired spectrum region can be implemented through the mixing of the primary and secondary lights. That is, the blue light is emitted from the blue light emitting diode and causes the orthosilicate based phosphor to emit green to yellow light and the alkaline earth metal sulfide based phosphor to emit red light. Thus, a portion of the blue light, i.e. the primary light, may be mixed with the green, yellow and red lights, i.e. the secondary lights, to implement white light. Accordingly, the light emitting device of the present invention can implement the white light with a continuous spectrum ranging from green to red such that its color rendering can be improved.
[79] Fig. 2 is a sectional view showing a top-type light emitting device according to the present invention.
[80] Referring to this figure, the light emitting device comprises a substrate 10, first and second electrodes 30 and 35 formed on the substrate 10, and a light emitting diode 20 mounted on the first electrode 30. Such a configuration is almost identical with that of the chip-type light emitting device, and accordingly, detailed descriptions thereof will be replaced with those described above with reference to Fig. 1. However, the top-type light emitting device comprises a reflector 40 formed on the substrate 10 to encompass the light emitting diode 20, and a molding portion 50 filled into a central space of the reflector 40 for protecting the light emitting diode 20.
[81] In order to improve light brightness and light collecting capability, an inner sidewall of the reflector 40 which encompasses the light emitting diode can be formed to have a predetermined inclination. Such a configuration is preferable to maximize the reflection of light emitted from the light emitting diode 20 and to improve the luminous efficiency.
[82] At least one orthosilicate based phosphor 60 and an alkaline earth metal sulfide based phosphor 70 are uniformly distributed in the molding portion 50. Accordingly, the primary light emitted from the light emitting diode 20 is mixed with the secondary lights each having the converted wavelength from the orthosilicate based phosphor 60 or the alkaline earth metal sulfide based phosphor 70 to implement the color in a desired spectrum range.
[83] Fig. 3 is a sectional view showing a lamp-type light emitting device according to the present invention.
[84] Referring to this figure, the light emitting device comprises a first lead terminal 90 with a reflecting portion 45 formed therein, and a second lead terminal 95 spaced apart from the first lead terminal 90 by a predetermined interval. A light emitting diode 20 is mounted onto the reflecting portion 45 of the first lead terminal 90 and electrically connected to the second lead terminal 95 through a wire 80. A molding portion 50 containing orthosilicate based and alkaline earth metal sulfide based phosphors 60 and 70 is formed on the light emitting diode 20. An outer peripheral molding portion 55 manufactured through a mold is formed on front ends of the first and second lead terminals 90 and 95. In the molding portion 50 are uniformly distributed at least one orthosilicate based phosphor 60 and an alkaline earth metal sulfide based phosphor 70, which absorb light emitted from the light emitting diode 20 to convert the absorbed light into light with respective wavelength. The outer peripheral molding portion 55 is made of a transparent epoxy resin to improve the transmittance of light emitted from the light emitting diode 20.
[85] Fig. 4 is a sectional view showing a light emitting device including a housing according to the present invention.
[86] Referring to this figure, the light emitting device comprises a housing 100 formed with first and second electrodes 30 and 35 on both sides thereof and formed with a through hole, a substrate 10 mounted into the through hole of the housing 100, and a light emitting diode 20 mounted on the substrate 10. At this time, the substrate 10 may be formed of a certain material with excellent thermal conductivity to serve as a heat sink such that heat output from the light emitting diode 20 can be more effectively released. The light emitting device further includes a molding portion 50 for sealing the light emitting diode 20. Further, in the molding portion 50 are uniformly distributed at least one orthosilicate based phosphor 60 and an alkaline earth metal sulfide based phosphor 70 as described above.
[87] The first and the second electrodes 30 and 35 are configured to be connected to anode and cathode terminals of the light emitting diode 20, respectively. The light emitting diode 20 is mounted on the substrate 10 and electrically connected to the first or second electrode 30 or 35 through the wires 80.
[88] As described above, the present invention may be applied to articles with various structures, and the technical features of the present invention are not limited to the aforementioned embodiments but may be modified or changed in various ways.
[89] Fig. 5 is a graph illustrating emission spectra depending on the compositions of an orthosilicate based phosphor used in the light emitting device of the present invention. As shown in the figure, the wavelength peak of the emitted light can be controlled in a range of from 505 nm to 605 nm depending on the composition of a host material and the concentration of a light-emitting central element, and excellent emission spectra can also be exhibited.
[90] Fig. 6 is a graph illustrating emission spectra depending on the compositions of an alkaline earth metal sulfide based phosphor used in the light emitting device of the present invention. As shown in the figure, the wavelength peak of the emitted light can be controlled in a range of from 600 nm to 660 nm depending on the composition of a host material and the concentration of a light-emitting central element, and excellent emission spectra can also be exhibited.
[91] Fig. 7 is a graph illustrating an emission spectrum of the light emitting device of the present invention using the blue light emitting diode and the two kinds of orthosilicate based phosphor and one alkaline earth metal sulfide based phosphor. As the aforementioned r phos rphors, (Ba 045 Sr 045 Pb 0 1 ) 2 SiO 4 :Eu with an emission waveleng °th of
515 nm, (Sr 0 795 Ba 0 2 Pb 0 005 ) 2 SiO 4 :Eu with an emission wavelength of 565 nm, and Ca Pb Eu S with an emission wavelength of 650 nm were used.
0 897 0 1 0 003
[92] Referring to the figure, it can be noted that the primary light emitted from the blue light emitting diode is mixed with the secondary lights, i.e. green, yellow and red lights emitted from the phosphors excited by a portion of the primary light such that white light can be implemented. Accordingly, the color rendering of the present invention can be further improved as compared with the conventional white light emitting device which uses the blue light emitting diode and the yellow phosphor.
[93] Fig. 8 is a graph illustrating emission spectra of the light emitting device of the present invention using the blue light emitting diode and one kind of orthosilicate based phosphor and one alkaline earth metal sulfide based phosphor, in addition to transmittance of a conventional LCD color filter. As the aforementioned phosphors, (Ba Sr Pb ) SiO :Eu with an emission wavelength of 515 nm and Ca Pb Eu
045 045 0 1 2 4 0 897 0 1 0 003
S with an emission wavelength of 650 nm can be used.
[94] Referring to the figure, it can be noted that the primary light emitted from the blue light emitting diode is mixed with the secondary lights, i.e. green and red lights emitted from the phosphors excited by a portion of the primary light such that white light can be implemented. Accordingly, the color reproduction range of the present invention can be further improved as compared with the conventional white light emitting device.
[95] The present invention has been described with reference to the preferred embodiment and various specific modified embodiments. However, it may be understood to those skilled in the art that other specific embodiments different from the embodiments as specifically described above are also included within the scope and sprit of the present invention.
[96] For example, it has been described in the embodiment of the present invention that when intending to implement a light emitting device comprising a blue or ultra-violet light emitting diode and at least one orthosilicate based phosphor for emitting green to yellow light and an alkaline earth metal sulfide based phosphor for emitting red light above the blue light or ultra-violet light emitting diode, the alkaline earth metal sulfide based phosphor has a chemical formula of (Ca,Sr) Eu C (S Se ), wherein C is at l-x-y x y 1-z z least one element selected from the group consisting of Mn and Pb, x is set in the range of 0.0005 to 0.1, y is set in the range of 0 to 0.5, and z is set in the range of 0 to 1. [97] As an a modified embodiment, however, the alkaline earth metal sulfide based phosphor may have a chemical formula of A x-a Eu a GeS z , wherein A is at least one element selected from the group consisting of Ca and Sr, z=x+2, x is set in the range of 2 to 5, and a/x is set in the range of 0.0005 to 0.02.

Claims

Claims
[1] A light emitting device, comprising: a light emitting diode for emitting blue light; and at least one orthosilicate based phosphor for emitting light in a green to yellow region and an alkaline earth metal sulfide based phosphor for emitting light in a red region, the phosphors being installed above the light emitting diode.
[2] The light emitting device as claimed in claim 1, wherein the orthosilicate based phosphor has a chemical formula of a(M O) 'b(M O)- c(M A)'d(M 0) e(M 0 3)'f(Mv o Op )'g(SiO 2 )'h(MVI x O y ), wherein M1 is at least one element selected
TT from the group consisting of Pb and Cu; M is at least one element selected from the group consisting of Be, Mg, Ca, Sr, Ba, Zn, Cd and Mn; M111 is at least one element selected from the group consisting of Li, Na, K, Rb, Cs, Au and Ag; M is at least one element selected from the group consisting of B, Al, Ga and In; Mv is at least one element selected from the group consisting of Ge, V, Nd, Ta, W, Mo, Ti, Zr and Hf; MVI is at least one element selected from the group consisting of Bi, Sn, Sb, Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; A is at least one element selected from the group consisting of F, Cl, Br and I; a, b, c, d, e, f, g, h, o, p, x and y are set in ranges of 0<a<2, 0<b<8, 0<c<4, 0<d<2, 0<e<2, 0<f<2, O≤g≤lO, 0<h<5, l≤o<2, l≤p<5, l≤x<2, and l≤y<5.
[3] The light emitting device as claimed in claim 2, wherein the orthosilicate based phosphor has a chemical formula of ((Br5Sr5Ca) (Pb5Cu) ) SiO :Eu,B; wherein l-x x 2 4
B is at least one element selected from the group consisting of Bi, Sn, Sb, Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; x is set in a range of O to 1 ; and Eu and B are set in ranges of O to 0.2.
[4] The light emitting device as claimed in claim 2, wherein the orthosilicate based phosphor emits light with a wavelength of 505 nm to 605 nm depending on compositions of the phosphor.
[5] The light emitting device as claimed in claim 1, wherein the alkaline earth metal sulfide based phosphor has a chemical formula of (Ca5Sr) Eu C (S Se ), l-x-y x y 1-z z wherein C is at least one element selected from the group consisting of Mn and Pb; x is set in a range of 0.0005 to 0.1; y is set in a range of 0 to 0.5; and z is set in a range of 0 to 1.
[6] The light emitting device as claimed in claim 5, wherein the alkaline earth metal sulfide based phosphor has a chemical formula of (Ca5Sr) Eu Pb S, wherein x
1 -x-y x y is set in a range of 0.0005 to 0.01; and y is set in a range of 0 to 0.5.
[7] The light emitting device as claimed in claim 5, wherein the alkaline earth metal sulfide based phosphor emits light with a wavelength of 600 nm to 660 nm.
[8] The light emitting device as claimed in claim 1, wherein the alkaline earth metal sulfide based phosphor has a chemical formula of A Eu GeS , wherein A is at x-a a z least one element selected from the group consisting of Ca and Sr; z=x+2; x is set in a range of 2 to 5; and a/x is set in a range of 0.0005 to 0.02.
[9] The light emitting device as claimed in claim 1, wherein the at least one or- thosilicate based phosphor is for emitting light in a green.
[10] The light emitting device as claimed in claim 1, wherein the light emitting diode emits light with a wavelength of 420 nm to 480.
[11] The light emitting device as claimed in claim 1, further comprising a body and a molding portion for sealing the light emitting diode mounted on the body, wherein the orthosilicate based phosphor and the alkaline earth metal sulfide based phosphor are mixed and distributed in the molding portion.
[12] The light emitting device as claimed in claim 11, wherein the body is one of a substrate, a heat sink and a lead terminal.
[13] The light emitting device as claimed in claim 1, further comprising a ultraviolet light emitting diode for emitting ultraviolet rays, wherein at least one of the orthosilicate based phosphor and the alkaline earth metal sulfide based phosphor is excited by light emitted from the ultraviolet light emitting diode to emit light.
[14] A light emitting device, comprising: a light emitting diode for emitting blue light; and at least one orthosilicate based phosphor for emitting light in a green to yellow region and an alkaline earth metal sulfide based phosphor for emitting light in a red region, the phosphors being installed above the light emitting diode, whereby its color rendering is improved in such a degree that the light emitting device can be used for a general lighting source or flash.
[15] A light emitting device, comprising: a light emitting diode for emitting blue light; and at least one orthosilicate based phosphor for emitting light in a green to yellow region and an alkaline earth metal sulfide based phosphor for emitting light in a red region, the phosphors being installed above the light emitting diode, whereby its color reproduction range is improved in such a degree that the light emitting device can be used for a liquid crystal display (LCD) backlight unit.
[16] An alkaline earth metal sulfide based phosphor having a chemical formula:
(Ca5Sr) l-x-y Eu xC y(S 1-z Se z), wherein C is at least one element selected from the group consisting of Mn and Pb; x is set in a range of 0.0005 to 0.1; y is set in a range of 0 to 0.5; and z is set in a range of 0 to 1. [17] The alkaline earth metal sulfide based phosphor as claimed in claim 16, wherein the phosphor has a chemical formula of (Ca,Sr) Eu Pb S, wherein x is set in a
1 -x-y x y range of 0.0005 to 0.01; and y is set in a range of 0 to 0.5.
PCT/KR2006/001923 2005-05-24 2006-05-23 Light emitting device and phosphor of alkaline earth sulfide therefor WO2006126819A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US11/912,384 US8017961B2 (en) 2005-05-24 2006-05-23 Light emitting device and phosphor of alkaline earth sulfide therefor
EP06768577A EP1888711B1 (en) 2005-05-24 2006-05-23 Light emitting device and phosphor of alkaline earth sulfide therefor
JP2008513363A JP4896129B2 (en) 2005-05-24 2006-05-23 Light emitting device and alkaline earth metal sulfide phosphor for the same

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
KR10-2005-0043785 2005-05-24
KR1020050043785A KR100657137B1 (en) 2005-05-24 2005-05-24 White light emitting device having green phosphor of thiogallate and red phosphor of alkaline earth sulfide
KR10-2005-0057892 2005-06-30
KR1020050057892A KR100666189B1 (en) 2005-06-30 2005-06-30 Light emitting device

Publications (1)

Publication Number Publication Date
WO2006126819A1 true WO2006126819A1 (en) 2006-11-30

Family

ID=37452201

Family Applications (2)

Application Number Title Priority Date Filing Date
PCT/KR2006/001923 WO2006126819A1 (en) 2005-05-24 2006-05-23 Light emitting device and phosphor of alkaline earth sulfide therefor
PCT/KR2006/001921 WO2006126817A1 (en) 2005-05-24 2006-05-23 Green phosphor of thiogallate, red phosphor of alkaline earth sulfide and white light emitting device thereof

Family Applications After (1)

Application Number Title Priority Date Filing Date
PCT/KR2006/001921 WO2006126817A1 (en) 2005-05-24 2006-05-23 Green phosphor of thiogallate, red phosphor of alkaline earth sulfide and white light emitting device thereof

Country Status (6)

Country Link
US (2) US8017961B2 (en)
EP (3) EP1888711B1 (en)
JP (3) JP5052507B2 (en)
AT (1) ATE534720T1 (en)
TW (2) TWI325441B (en)
WO (2) WO2006126819A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102216421A (en) * 2008-08-12 2011-10-12 三星Led株式会社 Method for producing a beta-Sialon phosphor
US8188492B2 (en) * 2006-08-29 2012-05-29 Seoul Semiconductor Co., Ltd. Light emitting device having plural light emitting diodes and at least one phosphor for emitting different wavelengths of light
US8709838B2 (en) 2008-08-12 2014-04-29 Samsung Electronics Co., Ltd. Method for preparing a β-SiAlON phosphor

Families Citing this family (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101142519B1 (en) 2005-03-31 2012-05-08 서울반도체 주식회사 Backlight panel employing white light emitting diode having red phosphor and green phosphor
TWI325441B (en) 2005-05-24 2010-06-01 Seoul Semiconductor Co Ltd Green phosphor of thiogallate, red phosphor of alkaline earth sulfide and white light emitting device thereof
KR100601200B1 (en) 2005-06-17 2006-07-13 서울반도체 주식회사 Red fluorescent substance and light-emitting diode using the same
KR100642786B1 (en) * 2005-08-10 2006-11-03 서울반도체 주식회사 Red phosphor, method for manufacturing the same and light emitting device for using the same
KR100724591B1 (en) * 2005-09-30 2007-06-04 서울반도체 주식회사 Light emitting device and LCD backlight using the same
WO2007105845A1 (en) * 2006-03-16 2007-09-20 Seoul Semiconductor Co., Ltd. Fluorescent material and light emitting diode using the same
TWI426119B (en) * 2006-03-21 2014-02-11 Seoul Semiconductor Co Ltd Phosphor and light emitting diode using the same
KR100930171B1 (en) 2006-12-05 2009-12-07 삼성전기주식회사 White light emitting device and white light source module using same
TWI386970B (en) * 2008-11-18 2013-02-21 Ind Tech Res Inst Light-emitting device utilizing gaseous sulfur compounds
US9082349B2 (en) * 2011-08-30 2015-07-14 Sharp Laboratories Of America, Inc. Multi-primary display with active backlight
JP6058948B2 (en) * 2012-08-28 2017-01-11 日東光学株式会社 Optical filter, light source device, lighting device
EP2962530B1 (en) 2013-02-28 2017-05-03 Vilnius University Solid-state sources of light for preferential colour rendition
JP6266923B2 (en) * 2013-08-26 2018-01-24 シチズン電子株式会社 LED light emitting device
JP6256460B2 (en) 2015-12-28 2018-01-10 日亜化学工業株式会社 Method for producing thiogallate phosphor
JP6561976B2 (en) * 2016-12-02 2019-08-21 日亜化学工業株式会社 Method for producing thiogallate phosphor, method for producing light emitting device, thiogallate phosphor and light emitting device
KR102499057B1 (en) * 2020-08-10 2023-02-10 세종대학교산학협력단 Sulfide phosphor and light-emitting device comprising the same

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003021691A1 (en) * 2001-09-03 2003-03-13 Matsushita Electric Industrial Co., Ltd. Semiconductor light emitting device, light emitting apparatus and production method for semiconductor light emitting device
WO2003080763A1 (en) * 2002-03-25 2003-10-02 Philips Intellectual Property & Standards Gmbh Tri-color white light led lamp
US20050236958A1 (en) * 2004-04-23 2005-10-27 Harvatek Corporation White light-emitting device

Family Cites Families (75)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2110162A (en) 1938-03-08 Luminescent material
US2402760A (en) 1942-06-27 1946-06-25 Rca Corp Luminescent material
US3639254A (en) 1969-07-01 1972-02-01 Gte Laboratories Inc Alkaline earth thiogallate phosphors
DE10028266A1 (en) 2000-06-09 2001-12-13 Patent Treuhand Ges Fuer Elektrische Gluehlampen Mbh Luminescent material used for emitting green light is of the thiogallate class
US4065688A (en) 1977-03-28 1977-12-27 Westinghouse Electric Corporation High-pressure mercury-vapor discharge lamp having a light output with incandescent characteristics
US4303913A (en) 1978-08-25 1981-12-01 Matsushita Electric Industrial Co., Ltd. Fluorescent display device and display apparatus using the same
US4563297A (en) 1980-02-06 1986-01-07 Futaba Denshi Kogyo K.K. Fluorescent composition
JPS57128772A (en) 1981-02-02 1982-08-10 Hitachi Ltd Fluorescent substance
US5208462A (en) 1991-12-19 1993-05-04 Allied-Signal Inc. Wide bandwidth solid state optical source
US5598059A (en) 1994-04-28 1997-01-28 Planar Systems, Inc. AC TFEL device having a white light emitting multilayer phosphor
US5834053A (en) 1994-11-30 1998-11-10 The Regents Of The University Of California Blue light emitting thiogallate phosphor
US5656888A (en) 1995-11-13 1997-08-12 Sun; Sey-Shing Oxygen-doped thiogallate phosphor
TW383508B (en) 1996-07-29 2000-03-01 Nichia Kagaku Kogyo Kk Light emitting device and display
JP2927279B2 (en) 1996-07-29 1999-07-28 日亜化学工業株式会社 Light emitting diode
US6252254B1 (en) 1998-02-06 2001-06-26 General Electric Company Light emitting device with phosphor composition
US6429583B1 (en) * 1998-11-30 2002-08-06 General Electric Company Light emitting device with ba2mgsi2o7:eu2+, ba2sio4:eu2+, or (srxcay ba1-x-y)(a1zga1-z)2sr:eu2+phosphors
JP2000171796A (en) 1998-12-02 2000-06-23 Howa Bussan Kk Surface light source
US6680569B2 (en) 1999-02-18 2004-01-20 Lumileds Lighting U.S. Llc Red-deficiency compensating phosphor light emitting device
KR100683364B1 (en) 1999-09-27 2007-02-15 필립스 루미리즈 라이팅 캄파니 엘엘씨 A light emitting diode device that produces white light by performing complete phosphor conversion
US6686691B1 (en) 1999-09-27 2004-02-03 Lumileds Lighting, U.S., Llc Tri-color, white light LED lamps
EP1104799A1 (en) 1999-11-30 2001-06-06 Patent-Treuhand-Gesellschaft für elektrische Glühlampen mbH Red emitting luminescent material
JP4406490B2 (en) 2000-03-14 2010-01-27 株式会社朝日ラバー Light emitting diode
KR20010097147A (en) 2000-04-20 2001-11-08 박득일 Back Light Unit by Use of White LED and Emission Method of White Light in High Purity
WO2002011173A1 (en) 2000-07-28 2002-02-07 Osram Opto Semiconductors Gmbh Luminescence conversion based light emitting diode and phosphors for wavelength conversion
JP2002156531A (en) 2000-11-22 2002-05-31 Yuka Denshi Co Ltd Light transmission body and surface light source device using the same and liquid crystal display device
AT410266B (en) 2000-12-28 2003-03-25 Tridonic Optoelectronics Gmbh LIGHT SOURCE WITH A LIGHT-EMITTING ELEMENT
KR100407512B1 (en) 2001-02-19 2003-12-01 주식회사 이스트웰 Preparation Method of Green Color Emitting Stroutium-Europium-Thiogallium Phosphor
US6417019B1 (en) 2001-04-04 2002-07-09 Lumileds Lighting, U.S., Llc Phosphor converted light emitting diode
US6617782B2 (en) 2001-05-30 2003-09-09 Ifire Technology Inc. Thioaluminate phosphor material with a gadolinium co-activator
DE10146719A1 (en) 2001-09-20 2003-04-17 Patent Treuhand Ges Fuer Elektrische Gluehlampen Mbh Lighting unit with at least one LED as a light source
JP3931070B2 (en) 2001-10-22 2007-06-13 株式会社アドバンスト・ディスプレイ Planar light source device and liquid crystal display device including the same
CN1585812A (en) 2001-11-14 2005-02-23 沙诺夫公司 Red photoluminescent phosphors
JP2003301171A (en) 2002-02-06 2003-10-21 Tdk Corp Phosphor thin film, production process therefor, and el panel
JP4191937B2 (en) * 2002-02-15 2008-12-03 株式会社日立製作所 White light source and image display apparatus using the same
ATE363193T1 (en) 2002-03-27 2007-06-15 Ifire Technology Corp YTTRIUM-SUBSTITUTED BARIUM THIOALUMINATE PHOSPHORUS MATERIALS
JP4001766B2 (en) 2002-04-26 2007-10-31 富士フイルム株式会社 Liquid crystal display device and medical image display device using the same
TW563261B (en) 2002-06-07 2003-11-21 Solidlite Corp A method and of manufacture for tri-color white LED
CN100405620C (en) 2002-06-13 2008-07-23 美商克立股份有限公司 Saturated phosphor solid state emitter
KR100479073B1 (en) 2002-06-19 2005-03-25 엘지전자 주식회사 Apparatus of inspection for back light unit
JPWO2004007636A1 (en) 2002-07-16 2005-11-10 双葉電子工業株式会社 Composite nanoparticles and method for producing the same
JP2004094031A (en) 2002-09-02 2004-03-25 Sumitomo Rubber Ind Ltd Film monitor
US6809781B2 (en) * 2002-09-24 2004-10-26 General Electric Company Phosphor blends and backlight sources for liquid crystal displays
US6637905B1 (en) 2002-09-26 2003-10-28 Agilent Technologies, Inc. Method and system for providing backlighting utilizing a luminescent impregnated material
JP4201167B2 (en) 2002-09-26 2008-12-24 シチズン電子株式会社 Manufacturing method of white light emitting device
US6869753B2 (en) * 2002-10-11 2005-03-22 Agilent Technologies, Inc. Screen printing process for light emitting base layer
JP4529349B2 (en) 2002-11-08 2010-08-25 日亜化学工業株式会社 Nitride-based phosphor and light emitting device
JP2004296830A (en) 2003-03-27 2004-10-21 Solidlite Corp Method of manufacturing white light-emitting diode
JP4274843B2 (en) 2003-04-21 2009-06-10 シャープ株式会社 LED device and mobile phone device, digital camera and LCD display device using the same
US7125501B2 (en) * 2003-04-21 2006-10-24 Sarnoff Corporation High efficiency alkaline earth metal thiogallate-based phosphors
US7075225B2 (en) 2003-06-27 2006-07-11 Tajul Arosh Baroky White light emitting device
KR100518408B1 (en) 2003-08-22 2005-09-29 엘지.필립스 엘시디 주식회사 Dual liquid crystal display using of dual front light
JP2005072479A (en) 2003-08-27 2005-03-17 Sumitomo Electric Ind Ltd White light emitting device, phosphor, and its manufacturing method
JP2005079500A (en) 2003-09-03 2005-03-24 Lite-On Technology Corp White light emitting device
CN100472823C (en) 2003-10-15 2009-03-25 日亚化学工业株式会社 Light-emitting device
US7123796B2 (en) 2003-12-08 2006-10-17 University Of Cincinnati Light emissive display based on lightwave coupling
US7102152B2 (en) 2004-10-14 2006-09-05 Avago Technologies Ecbu Ip (Singapore) Pte. Ltd. Device and method for emitting output light using quantum dots and non-quantum fluorescent material
JP3909603B2 (en) 2003-12-19 2007-04-25 シャープ株式会社 Optical material, optical member, lighting device and display device
EP1715023B1 (en) 2004-01-16 2012-10-24 Mitsubishi Chemical Corporation Phosphor and including the same, light emitting apparatus, illuminating apparatus and image display
US7488990B2 (en) 2004-04-02 2009-02-10 Avago Technologies Ecbu Ip (Singapore) Pte. Ltd. Using multiple types of phosphor in combination with a light emitting device
US7391060B2 (en) 2004-04-27 2008-06-24 Matsushita Electric Industrial Co., Ltd. Phosphor composition and method for producing the same, and light-emitting device using the same
KR20050107033A (en) 2004-05-07 2005-11-11 삼성전자주식회사 A light emitting diode module and a liquid crystal display provided with the same
KR100665299B1 (en) 2004-06-10 2007-01-04 서울반도체 주식회사 Luminescent material
KR101189265B1 (en) 2004-06-14 2012-10-09 삼성디스플레이 주식회사 Liquid crystal display provided with an improved structure for discharging heat
KR20040088418A (en) 2004-09-15 2004-10-16 박재익 Tri-color white light emitted diode
KR100634304B1 (en) 2004-09-30 2006-10-16 서울반도체 주식회사 Fluorescent material and light emitting diode using the same
US20060082296A1 (en) 2004-10-14 2006-04-20 Chua Janet Bee Y Mixture of alkaline earth metal thiogallate green phosphor and sulfide red phosphor for phosphor-converted LED
JP4836429B2 (en) 2004-10-18 2011-12-14 株式会社東芝 Phosphor and light emitting device using the same
KR100611102B1 (en) 2004-12-06 2006-08-09 한국전자통신연구원 Service level agreement system and method for collecting performance data automatically
JP2008523169A (en) 2004-12-07 2008-07-03 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ Illumination system including a radiation source and a luminescent material
KR100666189B1 (en) 2005-06-30 2007-01-09 서울반도체 주식회사 Light emitting device
TWI325441B (en) 2005-05-24 2010-06-01 Seoul Semiconductor Co Ltd Green phosphor of thiogallate, red phosphor of alkaline earth sulfide and white light emitting device thereof
CN101175835B (en) 2005-05-24 2012-10-10 三菱化学株式会社 Phosphor and utilization thereof
KR100601200B1 (en) 2005-06-17 2006-07-13 서울반도체 주식회사 Red fluorescent substance and light-emitting diode using the same
TW200717866A (en) 2005-07-29 2007-05-01 Toshiba Kk Semiconductor light emitting device
US7859182B2 (en) 2005-08-31 2010-12-28 Lumination Llc Warm white LED-based lamp incoporating divalent EU-activated silicate yellow emitting phosphor

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003021691A1 (en) * 2001-09-03 2003-03-13 Matsushita Electric Industrial Co., Ltd. Semiconductor light emitting device, light emitting apparatus and production method for semiconductor light emitting device
WO2003080763A1 (en) * 2002-03-25 2003-10-02 Philips Intellectual Property & Standards Gmbh Tri-color white light led lamp
US20050236958A1 (en) * 2004-04-23 2005-10-27 Harvatek Corporation White light-emitting device

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8188492B2 (en) * 2006-08-29 2012-05-29 Seoul Semiconductor Co., Ltd. Light emitting device having plural light emitting diodes and at least one phosphor for emitting different wavelengths of light
CN102216421A (en) * 2008-08-12 2011-10-12 三星Led株式会社 Method for producing a beta-Sialon phosphor
US8709838B2 (en) 2008-08-12 2014-04-29 Samsung Electronics Co., Ltd. Method for preparing a β-SiAlON phosphor

Also Published As

Publication number Publication date
EP1888711A1 (en) 2008-02-20
EP2305776A2 (en) 2011-04-06
US8017961B2 (en) 2011-09-13
EP1888710B1 (en) 2011-11-23
EP2305776A3 (en) 2011-05-25
EP1888710A4 (en) 2010-09-01
TWI323947B (en) 2010-04-21
JP2009507935A (en) 2009-02-26
EP2305776B1 (en) 2013-03-06
TW200700537A (en) 2007-01-01
JP5052507B2 (en) 2012-10-17
WO2006126817A1 (en) 2006-11-30
TW200746451A (en) 2007-12-16
ATE534720T1 (en) 2011-12-15
TWI325441B (en) 2010-06-01
JP2012140627A (en) 2012-07-26
EP1888711A4 (en) 2011-02-23
US20080191228A1 (en) 2008-08-14
EP1888711B1 (en) 2012-11-14
JP2009507936A (en) 2009-02-26
EP1888710A1 (en) 2008-02-20
US8088302B2 (en) 2012-01-03
JP4896129B2 (en) 2012-03-14
US20080191229A1 (en) 2008-08-14

Similar Documents

Publication Publication Date Title
US8017961B2 (en) Light emitting device and phosphor of alkaline earth sulfide therefor
US7753553B2 (en) Illumination system comprising color deficiency compensating luminescent material
JP5604482B2 (en) Light emitting device
US8674380B2 (en) Light emitting device having plural light emitting diodes and plural phosphors for emitting different wavelengths of light
KR100666189B1 (en) Light emitting device
JP2009117825A (en) White light-emitting element
WO2004097949A1 (en) White semiconductor light emitting device
US8053798B2 (en) Light emitting device
US8487525B2 (en) Light emitting device including optical lens
US20090079327A1 (en) Green light emitting phosphor and light emitting device using the same
WO2008023954A1 (en) Light emitting device
CN101184824A (en) Light emitting device and phosphor of alkaline earth sulfide therefor
KR101039264B1 (en) Nitride Red Phosphors and White Light Emitting Diode Using Rare-earth-co-doped Nitride Red Phosphors
CN100490192C (en) Light-emitting diode
KR100707871B1 (en) Warm white light emitting device for lighting applications
KR100647823B1 (en) Warm white light emitting device for lighting applications
KR100684044B1 (en) White light emitting diode and method thereof
KR100966296B1 (en) Nitride red phosphors and white light emitting diode using rare-earth-co-doped nitride red phosphors
KR20110056186A (en) White light emitting diode package
KR20070022465A (en) Red phosphor, LED using the same and LCD

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 200680018490.1

Country of ref document: CN

121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 11912384

Country of ref document: US

WWE Wipo information: entry into national phase

Ref document number: 2006768577

Country of ref document: EP

ENP Entry into the national phase

Ref document number: 2008513363

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

NENP Non-entry into the national phase

Ref country code: RU

WWP Wipo information: published in national office

Ref document number: 2006768577

Country of ref document: EP