Classifications

• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B33/00—Electroluminescent light sources
  • H05B33/12—Light sources with substantially two-dimensional radiating surfaces
  • H05B33/14—Light sources with substantially two-dimensional radiating surfaces characterised by the chemical or physical composition or the arrangement of the electroluminescent material, or by the simultaneous addition of the electroluminescent material in or onto the light source
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
  • C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
  • C09K11/0883—Arsenides; Nitrides; Phosphides
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
  • C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
  • C09K11/77—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals
  • C09K11/7728—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals containing europium
  • C09K11/77347—Silicon Nitrides or Silicon Oxynitrides
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
  • C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
  • C09K11/77—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals
  • C09K11/7728—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals containing europium
  • C09K11/77348—Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10H—INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
  • H10H20/00—Individual inorganic light-emitting semiconductor devices having potential barriers, e.g. light-emitting diodes [LED]
  • H10H20/80—Constructional details
  • H10H20/85—Packages
  • H10H20/851—Wavelength conversion means
  • H10H20/8511—Wavelength conversion means characterised by their material, e.g. binder
  • H10H20/8512—Wavelength conversion materials
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
  • H01L2224/01—Means 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
  • H01L2224/42—Wire connectors; Manufacturing methods related thereto
  • H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
  • H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
  • H01L2224/4805—Shape
  • H01L2224/4809—Loop shape
  • H01L2224/48091—Arched
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
  • H01L2224/01—Means 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
  • H01L2224/42—Wire connectors; Manufacturing methods related thereto
  • H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
  • H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
  • H01L2224/481—Disposition
  • H01L2224/48151—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
  • H01L2224/48221—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
  • H01L2224/48245—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being metallic
  • H01L2224/48247—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being metallic connecting the wire to a bond pad of the item
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
  • H01L2924/15—Details of package parts other than the semiconductor or other solid state devices to be connected
  • H01L2924/181—Encapsulation

Definitions

• the pcLED lamp for general illumination application requires high optical energy flux (e.g., higher than 1 Watt/mm 2 ), which causes additional heating by a Stokes shift generated inside the phosphor crystals.
• Successful development of pcLED lamps for general illumination therefore, requires phosphors that can operate highly efficiently at temperatures of 100°C- 1 50°C. The risk is that it is difficult both to achieve 90% quantum yield at room temperature and to have high thermal stability at 100°C-150°C.
• the thermal stability of a phosphor's luminescence is an intrinsic property of the phosphor which is determined by the composition and the structure of the crystalline material.
• Nitride and oxynitride phosphors have been used in pcLEDs because of their excellent luminescence performance at the high temperature range mentioned above.
• Prominent examples include metal silicon nitride based phosphors and the sialon-based phosphors.
• the host crystals of these phosphor materials consist mainly of chemical bonds of Si-N, Al-N, Si-0 and Al-O, as well as hybrid bonds thereof, as the backbone of the structure. While these bonds are stable, the chemical bond between silicon and carbon (Si-C) has a thermal and chemical stability superior to them. Furthermore, carbon forms very stable chemical bond with many metal atoms.
• J0007J Carbidonitride phosphors can be comprised of carbon, silicon, germanium, nitrogen, aluminum, boron and other metals in the host crystal and one or more metal dopants as a luminescent activator.
• This class of phosphors has recently emerged as a color converter capable of converting near UV (nUV) or blue light to other light in the visible spectral range, e.g., blue, green, yellow, orange and red light.
• the host crystal of carbidonitride phosphors is comprised of -N-Si-C-, -N-Si-N-, and -C-Si-C- networks in which the strong covalent bonds of Si-C and Si-N serve as the main building blocks of the structure.
• the network structure formed by Si-C bonds has a strong absorption in the entire visible light spectral region, and therefore has been previously considered unsuitable for use in host materials for high efficiency phosphors.
• the present invention is directed to a novel family of silicon carbidonitride phosphors expressed by:
• A comprises a luminescence activator doped in the host crystal lattice at a concentration level from about 0.0001 mol% to about 50 mol%, preferably from about 0.001 mol% to about 20 mol%, relative to the mole amount of Sr.
• A can comprise at least one metal ion selected from the group including Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Mn, Bi, Sb, or a combination thereof, preferably Eu + , Ce 3+ , Tb J+ , Yb 2+ and Mn 2 ⁇ , or a combination thereof.
• the present invention is directed to a composition
• a composition comprising a silicon carbidonitride phosphor of formula (1 ) above.
• the composition further comprises one or more additional phosphors.
• the phosphor comprises a crystal of an orthorhombic or monoclinic system.
• the present invention is directed to a novel family of silicon carbidonitride phosphors expressed by:
• M(II) comprises at least one divalent cation, and may be selected from, but not limited to, the group including Be, Mg, Ca, Sr, Ba, Cu, Co, Ni, Pd, Zn, Cd and other divalent transition metal ions, or a combination, thereof, preferably from the group including Ca, Sr, Ba and other alkaline earth metal ions, or a combination thereof. In certain embodiments, M(II) comprises two or more divalent cations.
• A comprises a luminescence activator doped in the host crystal lattice at a concentration level from about 0.0001 mol% to about 50 mol%, preferably from about 0.001 mol% to about 20 mol%, relative to the mole amount of M(II).
• A can comprise at least one metal ion selected from the group including Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Mn, Bi, Sb, or a combination thereof, preferably Eu' ⁇ Ce' ⁇ Tb J , Yb and MiT * , or a combination thereof.
• the present invention is directed to a composition comprising a silicon carbidonitride phosphor of formula (2) above.
• the composition comprises one or more additional phosphors.
• the phosphor comprises a crystal of an orthorhombic or monoclinic system.
• the present invention is directed to a novel family of silicon carbidonitride phosphors expressed by:
• M(II) 2-w M(I) 2w Si 5 N 8 . [( 4x/3) + z ] C x 03z/2 : A wherein 0 ⁇ x ⁇ 5, 0 ⁇ w ⁇ 0.6, 0 ⁇ z ⁇ 3, and [(4x/3)+z] ⁇ 8.
• M(II) comprises at least one divalent cation, and may be selected from, but not limited to, the group including Be, Mg, Ca, Sr. Ba, Cu, Co, Ni, Pd, Zn, Cd and other divalent transition metal ions, or a combination thereof, preferably from the group including Ca, Sr, Ba and other alkaline earth metal ions, or a combination thereof. In certain embodiments, M(II) comprises two or more divalent cations.
• M(I) comprises at least one monovalent cation, and may be selected from, but not limited to, the group including Li, Na, K, Rb, Cu, Ag and Au, or a combination thereof, preferably from the group including Li, Na, and , or a combination thereof.
• M(I) comprises two or more monovalent cations. In order to compensate for the evaporation of M(I) at high temperature in firing processes, extra M(I) has been designed in this formulation.
• A comprises a luminescence activator doped in the host crystal lattice at the concentration level from about 0.0001 mol% to about 50 mol%, preferably from about 0.001 mol% to about 20 mol%, relative to total mole amount of M(II) and M(I).
• A can comprise at least one metal ion selected from the group including Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Mn, Bi, Sb, or a combination thereof, preferably Eu 2+ , Ce J+ , Tb 3+ , Yb 2+ and Mn 2+ , or a combination thereof.
• the present invention is directed to a composition comprising a silicon carbidonitride phosphor of formula (3) above.
• the composition comprises one or more additional phosphors.
• the phosphor comprises a crystal of an orthorhombic or monoclinic system.
• the present invention is directed to a novel family of silicon carbidonitride phosphors expressed by:
• M(II) comprises at least one divalent cation, and may be selected from, but not limited to, the group including Be, Mg, Ca, Sr, Ba, Cu, Co, Ni, Pd, Zn, Cd and other divalent transition metal ions, or a combination thereof, preferably from the group including Ca, Sr, Ba and other alkaline earth metal ions, or a combination thereof. In certain embodiments. M(II) comprises two or more divalent cations. M(I) comprises at least one monovalent cation, and may be selected from, but not limited to, the group including Li, Na, K, Rb, Cu, Ag and Au, or a combination thereof, preferably from the group including Li, Na, and K, or a combination thereof.
• M(I) comprises two or more monovalent cations. In order to for compensate the evaporation of M(I) at high temperature in firing processes, extra M(I) has been designed in this formulation.
• M(III) comprises at least one trivalent cation, and may be selected from, but not limited to, the group including B, Al, Ga, In, Sc, Y, or a combination thereof, preferably from the group including Al, Ga, and B, or a combination thereof. In certain embodiments, M(III) comprises two or more trivalent cations.
• A comprises a luminescence activator doped in the host crystal lattice at the concentration of from 0.0001 mol% to about 50 mol%, preferably from about 0.001 mol% to about 20 mol%, relative to the total mole amount of M(II) and M(I).
• A can comprise at least one metal ion selected from the group including Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Mn, Bi, and Sb, or a combination thereof, preferably Eu 2+ , Ce J+ , Tb 3+ , Yb 2+ and Mn 2+ , or a combination thereof.
• the present invention is directed to a composition comprising a silicon carbidonitride phosphor of formula (4) above.
• the composition comprises one or more additional phosphors.
• the phosphor comprises a crystal of an orthorhombic or monoclinic system.
• the present invention is directed to a novel family of carbidonitride phosphors expressed by;
• M(II) comprises at least one divalent cation, and may be selected from, but not limited to, the group including Be, Mg, Ca, Sr, Ba, Cu, Co, Ni, Pd, Zn, Cd and other divalent transition metal ions, or a combination thereof, preferably from the group including Ca, Sr, Ba and other alkaline earth metal ions, or a combination thereof.
• M(II) comprises two or more divalent cations.
• M(I) comprises at least one monovalent cation, and may be selected from, but not limited to, the group including Li, Na, K, Rb, Cu, Ag and Au, or a combination thereof, preferably from the group including Li, Na, and K, or a combination thereof.
• M(I) comprises two or more monovalent cations.
• M(III) comprises at least one trivalent cation, and may be selected from, but not limited to, the group including B, Al, Ga, In, Sc, Y, or a combination thereof, preferably from the group including Al, Ga, and B, or a combination thereof.
• M(III) comprises two or more trivalent cations.
• A comprises a luminescence activator doped in the host crystal lattice at the concentration of from 0.0001 mol% to about 50 mol%, preferably from about 0.001 mol% to about 20 -mol%, relative to the total mole amount of M(II) and M(I).
• A can comprise at least one metal ion selected from the group including Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Mn, Bi, and Sb, or a combination thereof, preferably Eu 2+ , Ce 3+ , Tb 3+ , Yb 2+ and Mn 2+ , or a combination thereof.
• D comprises at least one tetravalent cation selected from the group consisting of C, Si, Ge, Sn, Pb, Ti, Zr, and H f.
• D comprises Si.
• E comprises at least one trivalent anion selected from the group consisting of N, P, As, Sb, and Bi.
• E comprises N.
• C comprises a tetravalent anion of carbon.
• F comprises at least one divalent anion selected from the group consisting of O, S, Se, and Te.
• F comprises O.
• H comprises at least one monovalent anion selcted from the group consisting of F, CI, Br, and I.
• H comprises F.
• the present invention is directed to a composition comprising a phosphor of formula (5) above.
• the composition comprises one or more additional phosphors.
• the phosphor comprises a crystal of an orthorhombic or monoclinic system.
• the phosphors of the present invention emit light having a peak in wavelength range from about 400 nm to about 700 nm when excited by light having a peak in wavelength range from about 250 nm to about 500 nm.
• the present invention is directed to a light emitting device comprising a light source emitting a first luminescence spectrum and a phosphor composition, which, when irradiated with light from the light source, emits light having a second luminescence spectrum.
• the phosphor composition of the light emitting device of the present invention can comprise at least one phosphor having a formula selected from formulas (1 ), (2), (3), (4) and (5) as described above.
• the first luminescence spectrum has a peak in wavelength range from about 250 nm to about 700 nm. In certain embodiments, the first luminescence spectrum has a peak in wavelength range from about 400 nm to about 550 nm.
• the light source is a light emitting diode or a laser diode.
• the light emitting device further comprises one or more additional phosphors.
• the additional phosphor emits red, orange, yellow, green, or blue light when excited by a light source.
• the light emitting device further comprises a second phosphor having a formula selected from the group consisting of Cai -x Sr x Ga 2 S4:Eu 2+ (0 ⁇ x ⁇ l ), Cai. x . y .
• the light emitting device further comprises a second phosphor having a formula selected from the group consisting of:
• M(II) comprises at least one divalent cation
• M(I) comprises at least one monovalent cation
• M(III) comprises at least one trivalent cation
• H comprises at least one monovalent anion
• A comprises a luminescence activator doped in the host crystal.
• the light emitting device of the present invention comprises at least two additional phosphors. In certain embodiments, the light emitting device of the present invention further comprises at least one additional phosphor that emits light having a peak in wavelength range from about 350 nm to about 700 nm. In certain embodiments, the light emitting device of the present invention further comprises at least one additional phosphor that emits light having a peak in wavelength range from about 480 nm to about 640 nm. In certain embodiments, the light emitting device of the present invention further comprises at least one additional phosphor that emits light having a peak in wavelength range from about 520 nm to about 600 nm.
• the light emitting device of the present invention emits white light. In certain embodiments, the light emitting device of the present invention emits cool white light. In certain embodiments, the light emitting device of the present invention emits warm white light. In certain embodiments, the light emitting device of the present invention emits light having a peak in wavelength range from about 400 nm to about 600 nm. In certain embodiments, the light emitting device of the present invention emits light having a peak in wavelength range from about 520 nm to about 600 nm. In certain embodiments, the light emitting device of the present invention emits light having a peak in wavelength range from about 380 nm to about 750 nm. In certain embodiments, the light emitting device of the present invention emits light having a peak in wavelength range from about 400 nm to about 700 nm.
• activator refers to the atomic or ionic species that emits light with the , support of the host crystal.
• the activator may be doped in the host crystal in a very small amount, as further described herein.
• the activator can comprise a single element, such as, for example and without limitation, Eu 2+ , or can comprise multiple elements (i.e. co-activators), such as, for example and without limitation, a combination of two or more of Eu 2+ , Ce 3+ , Tb 3 ⁇ , Yb 2+ and Mn 2+ .
• co-activator refers to an additional activator in the same host crystal.
• dopant refers to an atomic or ionic species that is doped in a host crystal.
• grain refers to an agglomeration, aggregation, polycrystalline or polymorph of phosphor particles, where the particles are not easily separated as compared to phosphor particles of a powder.
• light source refers to any source of light capable of exciting or irradiating the phosphors of the present invention, including without limitation a Group III-V semiconductor quantum well-based light emitting diode, a laser diode, or a phosphor other than the phosphor of a light emitting device of the present invention.
• the light source of the present invention can either excite/irradiate the phosphor directly, or excite another system to thereby provide the excitation energy for the phosphor indirectly.
• particle refers to an individual crystal of phosphor.
• phosphor refers to a phosphor in any appropriate form, such as a phosphor particle, a phosphor grain, or phosphor powder comprised of phosphor particles, grains, or a combination thereof.
• a "phosphor composition” refers to a composition comprising a phosphor having the ratio of atoms specified for the particular phosphor. It may or may not be stoichiometric proportions. Impurities and one or more crystalline phases may be present in the composition.
• the term “pure” means higher than 98% pure for a particular crystalline phase, i.e., no more than 2% of a secondary phase.
• White light is light of certain chromaticity coordinate values (e.g., Commission Internationale de I'Eclairage (CIE)), which are well-known in the art.
• Correlated color temperature of a light source is the temperature of an ideal black-body radiator that radiates light of comparable hue to that light source. Higher color temperatures (5,000 K or more) are called cool colors (or “cool white”); lower color temperatures (2,700-3,000 ) are called warm colors (or “warm white”).
• Temperatures described herein for processes involving a substantial gas phase are of the oven or other reaction vessel in question, not of the reactants per se.
• M(I), M(II), and M(III) where M(I) is at least one monovalent cation, M(II) is at least one divalent cation, and M(III) is at least one trivalent cation.
• M(II) may be selected from the group consisting of Be, Mg, Ca, Sr, Ba, Cu, Co, Ni, Pd, Zn, and Cd; M(I) may be selected from the group consisting of Li, Na, K, Rb, Cu, Ag and Au; and M(III) is selected from the group consisting of B, Al, Ga, In, Sc, Y, La and Gd.
• the quantum efficiency (QE) was measured against the same internal standard sample.
• FIGURE 1 depicts the x-ray diffraction (XRD) patterns of samples 1.8, 1.7, 1.12, 1 . 1 1 , and 1.10 of phosphor composition (1 ).
• the bottom-most simulated pattern is for Sr ⁇ SisNs- The asterisk in the upper-most pattern indicates SiC as a second phase in sample 1 .8.
• FIGURE 2A depicts the Rietveld Refinement of the XRD powder diffraction for Sr 2 Si 5 Ns.(4x/3)C x :Eu 2 " (sample 1.7).
• Figure 2B depicts the projected crystal structure of Sr 2 Si5N 8 . (4x/3)C x :Eu 2+ (sample 1.7).
• FIGURE 4 depicts the effect of carbon content on emission spectra of samples 1 .10, 1. 12, 1.7, and 1.8 of phosphor composition (1 ) (Sr 2 Si5N 8 .( 4x /3 ) C x :Eu 2+ ) under blue excitation at 453 nm.
• FIGURE 5 depicts reflectance spectra of samples 1 .8, 1.7, 1.12, and 1.10 of phosphor composition (1 ).
• FIGURE 6 depicts thermal stability of sample 1.7 under blue excitation at 453 nm.
• FIGURE 7 depicts XRD patterns of samples 1 .22, 1.32, 1.27, 1.26, 1 .25, 1 .24, and 1.23 of phosphor composition ( 1 ).
• the bottom-most simulated pattern is for Sr 2 SisN 8 and is shown for reference.
• the asterisk in the upper-most pattern indicates SiC as a second phase in sample 1.22.
• FIGURE 8 depicts the Rietveld Refinement of the XRD pattern for Sr 2 Si 5 N g- [(4x/3)+z ] C x 0 3z/2 :Eu 2+ (sample 1.19).
• FIGURE 9 depicts the projected crystal structure of sample 1 .19 for Sr 2 Si 5 Ng.
• FIGURE 10 depicts the luminescence excitation and emission spectra of sample 1.19 of composition (1 ) (Sr2Si5N 8- [(4 X /3 )+zj C x 03 Z 2 :Eu + ) under blue excitation at 453 nm.
• FIGURE 11 depicts the reflectance spectra of samples 1.23, 1 .24, 1 .25, and 1 .26 for phosphor composition ( 1 ) (Sr 2 Si5N 8 .
• FIGURE 12 depicts the effect of carbon content on the emission spectra of samples 1 .23, 1.24, 1.25, and 1.26 of phosphor composition (1) (Sr 2 Si5N8-[(4x /3 )+z ] C x 03 Z/2 :Eu 2+ ) under blue excitation at 453 nm.
• FIGURE 13 depicts the thermal stability of samples 1.15 and 1.21 of phosphor composition (1 ) Sr 2 Si 5 N 8 .f(4. /3)+Z] C x 0 32 2:Eu 2+ under blue excitation at 453 nm.
• FIGURE 14A depicts the Rietveld Refinement of the XRD pattern of sample 2.2 for phosphor composition Ba 2 Si 5 N8-(4x/3 ) C x :Eu 2+ .
• FIGURE 14B depicts the projected crystal structure of sample 2.2.
• FIGURE 15 depicts the excitation and emission spectra of sample 2.2, as well as the reflectance spectra, for a phosphor of Ba 2 Si5 8-(4x /3) C x :Eu 2+ (sample 2.2) under blue excitation at 453 nm.
• FIGURE 16 depicts the thermal stability of sample 2.2 for phosphor composition (2) (Ba2Si5N8-( X /3 ) C x :Eu 2+ ) under blue excitation at 453 nm.
• FIGURE 17A depicts the Rietveld refinement of the XRD pattern of a phosphor of Ca 2 Si 5 N 8 . (4x/3 ) C x :Eu 2+ (sample 2.7).
• FIGURE 17B depicts the projection of the crystal structure of sample 2.7.
• FIGURE 18 depicts the excitation and emission spectra of sample 2.7, as well as the reflectance spectra, for a phosphor of Ca 2 Si 5 N 8-(4x ⁇ ) C x :Eu 2+ (sample 2.7) under blue excitation at 453 nm.
• FIGURE 19 depicts the thermal stability of sample 2.7 of phosphor composition (2) (Ca 2 Si 5 N 8 .(4x/3 ) C x :Eu 2+ ) under blue excitation at 453 nm. pattern of a phosphor (sample 2.4) of composition (2) [0062J
• FIGURE 21 depicts the excitation profile (left curve) and emission spectrum (right curve), as well as the reflectance spectra, of a phosphor (sample 2.4) for composition (2) (Sro. Bao.i)i.9Euo.i Si 5 N8-(4x/3)Cx:Eu 2+ under blue excitation at 453 nm.
• FIGURE 22 depicts the thermal stability of sample 2.4 of phosphor composition (2) ((Sro.9Bao . i)2Si5N8.(4 X /3 ) C x :Eu 2+ ) under blue excitation at 453 nm.
• FIGURE 23 depicts the XRD pattern of sample 3.3 of composition (3).
• the simulated pattern for S SisNg is shown for reference.
• FIGURE 24 depicts the excitation and emission spectra under blue excitation at 453 nm, as well as the reflectance spectra, for sample 3.3 of composition (3).
• FIGURE 25 depicts the thermal stability for sample 3.3 of composition (3) under blue excitation at 453 nm.
• FIGURE 26 depicts the XRD pattern for sample 4.15 of composition (4) Sri gSij fiCOrEu. The simulated pattern for Sr 2 Si 5 N is shown for reference.
• FIGURE 27 depicts the excitation and emission spectra under blue excitation at 453 nm, as well as the reflection spectra, for sample 4.15 of composition (4) Sri.9Si5N CO:Eu.
• FIGURE 28 depicts the thermal stability for sample 4.1 5 of composition (4) Sri. Si N6CO:Eu under blue excitation at 453 nm.
• FIGURE 29 depicts the Rietveld Refinement of the XRD pattern for sample 4.3 of composition (4) Sr2.wLi2wSi5- m Al m N 8-[( 4. /3)+z+m ] C x O ( 3 Z/2)+m :Eu 2+ .
• FIGURE 30 depicts the excitation and emission spectra under blue excitation at 453 nm, as well as the reflection spectra, for sample 4.3 of composition (4).
• FIGURE 31 depicts the thermal stability for sample 4.3 of composition (4) under blue excitation at 453 nm.
• FIGURE 33 depicts the projected crystal structure of sample 4.7 for Sr 2 .
• FIGURE 34 depicts the excitation and emission spectra (under, blue excitation at 453 nm), as well as the reflectance spectra, of Sr 2 .
• FIGURE 35 depicts the thermal stability for sample 4.6 of composition (4) under blue excitation at 453 nm.
• FIGURE 36 depicts an embodiment of the light ⁇ emitting device of the present invention.
• FIGURE 37 depicts an embodiment of the light emitting device of the present invention.
• FIGURE 38 depicts an embodiment of the light emitting device of the present invention.
• FIGURE 39 depicts an embodiment of the light emitting device of the present invention.
• FIGURE 40 depicts the emission spectrum of a pcLED comprising a blue-emitting LED emitting at 453 nm and a red-emitting phosphor of composition (1 ) (sample 1.29).
• FIGURE 41 depicts the emission spectra of the pcLEDs of Example 6.2.
• the curve with the higher peak is for Device I of Example 6.2.
• the curve with the lower peak is for Device II of Example 6.2.
• the present invention is directed to a novel family of silicon carbidonitride phosphors expressed by:
• A comprises a luminescence activator doped in the host crystal lattice at a concentration level from about 0.0001 mol% to about 50 mol%, preferably from about 0.001 mol% to about 20 mol%, relative to the mole amount of Sr.
• A can comprise at least one metal ion selected from the group including Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Mn, Bi, Sb, or a combination thereof, preferably Eu 2+ , Ce 3+ , Tb 3+ , Yb 2+ and Mn " , or a combination thereof.
• the present invention is directed to a novel family of silicon carbidonitride phosphors expressed by:
• M(II) comprises at least one divalent cation, and may be selected from, but not limited to, the group including Be, Mg, Ca, Sr, Ba, Cu, Co, Ni, Pd, Zn, Cd and other divalent transition metal ions, or a combination thereof, preferably from the group including Ca, Sr, Ba and other alkaline earth metal ions, or a combination thereof.
• A comprises a luminescence activator doped in the host crystal lattice at a concentration level from about 0.0001 mol% to about 50 mol%, preferably from about 0.001 mol% to about 20 mol%, relative to the mole amount of M(I1).
• A can comprise at least one metal ion selected from the group including Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Mn, Bi, Sb, or a combination thereof, preferably Eu 2+ , Ce 3+ , Tb J+ , Yb 2+ and Mn 2+ , or a combination thereof.
• the present invention is directed to a novel family of silicon carbidonitride phosphors expressed by:
• M(II) comprises at least one divalent cation, and may be selected from, but not limited to, the group including Be, Mg, Ca, Sr, Ba, Cu, Co, Ni, Pd, Zn, Cd and other divalent transition metal ions, or a combination thereof, preferably from the group including Ca, Sr, Ba and other alkaline earth metal ions, or a combination thereof.
• M(I) comprises at least one monovalent cation, and may be selected from, but not limited to, the group including Li, Na, K, Rb, Cu ; Ag and Au, or a combination thereof, preferably from the group including Li, Na, and K, or a combination thereof.
• A comprises a luminescence activator doped in the host crystal lattice at a concentration level from about 0.0001 mol% to about 50 mol%, preferably from about 0.001 mol% to about 20 mol%, relative to total mole amount of M(II) and M(I).
• A can comprise at least one metal ion selected from the group including Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Mn, Bi, Sb, or a combination thereof, preferably Eu 2+ , Ce J+ , Tb 3+ , Yb 2+ and Mn 2+ , or a combination thereof.
• the present invention is directed to a novel family of silicon carbidonitride based phosphors expressed by:
• M(II) 2.wM(I) 2w Si 5 - m M(III) m N8-f(4x/3) +2+ mlC x O(3z ⁇ ) + m:A wherein 0 ⁇ x ⁇ 5, 0 ⁇ w ⁇ 0.6, 0 ⁇ z ⁇ 3, 0 ⁇ m ⁇ 2, and [(4x/3)+z+m] ⁇ 8.
• M(II) comprises at least one divalent cation, and may be selected from, but not limited to, the group including Be, Mg, Ca, Sr, Ba, Cu, Co. Ni.
• M(I) comprises at least one monovalent cation, and may be selected from, but not limited to, the group including Li. Na, K, Rb, Cu, Ag and Au, or a combination thereof, preferably from the group including Li, Na, and K, or a combination thereof.
• extra M(I) has been designed in this formulation.
• M(III) comprises at least one trivalent cation, and may be selected from, but not limited to, the group including B, Al, Ga, In, Sc, Y, or a combination thereof, preferably from the group including Al and B, or a combination thereof.
• A comprises a luminescence activator doped in the host crystal lattice at the concentration of from 0.0001 mol% to about 50 mol%, preferably from about 0.001 mol% to about 20 mol%, relative to the total mole amount of M(II) and M(I).
• A can comprise at least one metal ion selected from the group including Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Mn, Bi, and Sb, or a combination thereof, preferably Eu 2+ , Ce 3+ , ⁇ + , Yb 2"1" and Mn 2+ , or a combination thereof.
• the present invention is directed to a novel family of silicon carbidonitride based phosphors expressed by
• M(I1) comprises at least one divalent cation selected from the group consisting of Be, Mg, Ca, Sr, Ba, Cu, Mn, Co, Ni, Zn, and Cd, prefereably Ca, Sr, and Ba;
• M(I) comprises at least one monovalent cation selected from the group consisting of Li, Na, K, Rb, Cs, Ag, and Au, preferably Li, Na, and K;
• M(III) comprises at least one trivalent cation selected from the group consisting of B, Al, Ga, In, Ti, Sc, Y, and La, preferably B, Al, and Ga;
• D comprises at least one
• At least one of the phosphor compositions of the present invention is used as a wavelength converter for a light emitting device.
• the light emitting device has a first illuminant which emits light having a peak in wavelength range from about 300 nm to about 750 nm, and a second illuminant which emits a visible light upon irradiation with light from the first illuminant, wherein the second illuminant contains at least one phosphor of the present invention.
• the first illuminant can, for example, emit light having a peak in wavelength range from about 300 nm to about 750 nm, preferably from about 400 nm to 670 nm or from about 350 nm to about 480 nm, and more preferably from about 420 nm to about 660 nm.
• the first illuminant is a laser diode or a light emitting diode (LED).
• the second illuminant containing one or more phosphor compositions of the invention When the second illuminant containing one or more phosphor compositions of the invention is irradiated with light from the first illuminant, it can, for example, emit light with a peak in wavelength range from about 460 nm to about 660 nm, preferably from about 480 nm to about 660 nm, and more preferably from about 500 nm to about 650 nm.
• the second illuminant comprises at least one additional phosphor.
• the additional phosphor or phosphors can, for example, emit light having a peak in wavelength range from about 480 nm to about 660 nm, preferably from about 500 nm to about 650 nm.
• luminescence activator A can be doped in the host crystal of the phosphor either substitutional ly or interstitially at a concentration level from about 0.0001 mol% to about 50 mol% relative to the total mol% of the respective divalent or divalent and monovalent cations. In certain embodiments, A is doped in the host crystal of the phosphor at a concentration level from about 0.001 mol% to about 20 mol% relative to the total mol% of the divalent or divalent and monovalent cations.
• A is doped in the host crystal of the phosphor at a concentration level from about 0.01 mol% to about 7 mol% relative to the total mol% of the divalent or divalent and monovalent cations. In other embodiments, A is doped in the host crystal of the phosphor at a concentration level from about 0.01 mol% to about 10 mol% relative to the total mol% of the divalent or divalent and monovalent cations.
• A comprises at least one co-activator.
• the co-activator may be selected from, but not limited to, the group including Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Mn, Bi, Sb, preferably Eu 2+ , Ce 3+ , Tb 3+ , Yb 2+ and Mn 2+ , and the group including halogen anions, F, CI, Br and I.
• the concentration level of the co-activator can be from about 0.0001 % to about 50% relative to the activator. In certain embodiments, the concentration level of the co-activator is from about .001 mol% to about 20 mol% relative to the activator.
• the co-activator is doped in the host crystal lattice of the phosphor at a concentration level from about 0.01 mol% to about 7 mol% relative to the activator.
• A is doped in the host crystal lattice of the phosphor at a concentration level from about 0.01 mol% to about 10 mol% relative to the activator.
• the phosphor compositions of the present invention maintain at least 60% of their relative emission intensity at temperatures up to 250°C. In other embodiments, the phosphor compositions of the present invention maintain at least 85% of their relative emission intensity at temperatures up to 250°C. In other embodiments, the phosphor compositions of the present invention maintain at least 90% of their relative emission intensity at temperatures up to 250°C. In certain embodiments, the phosphor compositions of the present invention maintain at least 60% of their relative emission intensity at temperatures up to 200°C. In certain embodiments, the phosphor compositions of the present invention maintain at least 85% of their relative emission intensity at temperatures up to 200°C.
• the phosphor compositions of the present invention maintain at least 90% of their relative emission intensity at temperatures up to 200°C. In certain embodiments, the phosphor compositions of the present invention maintain at least 60% of the relative emission intensity at temperatures up to 150°C. In certain embodiments, the phosphor compositions of the present invention maintain at least 85% of the relative emission intensity at temperatures up to 150°C. In further embodiments, the phosphor compositions of the present invention maintain at least 90% of the relative emission intensity at temperatures up to 150°C. In other embodiments, the phosphor compositions of the present invention maintain at least 95% of their relative emission intensity at temperatures up to 150°C.
• the shape of the phosphor particles can be spherical and/or rod- shaped.
• the median diameter of the phosphor particles of the present invention can be from about 2 to about 50 microns, preferably from about 4 to about 30 microns, and more preferably from about 5 to about 20 microns.
• the phosphor particles of the present invention can be from about 2 to about 10 microns in diameter, or from about 3 to about 9 microns in diameter.
• the phosphor is a grain. In other embodiments, the phosphor is a particle.
• the present invention further provides a light emitting device comprising: a light source emitting light of having a peak in wavelength range from about 200 to about 600 nm, preferably from about 350 to about 490 nm; and at least one phosphor composition of the present invention, where the phosphor composition is positioned to absorb at least a portion of the light output from the light source and effectively modifies the color of the light absorbed from the light source, resulting in an emission of a longer wavelength than that of the light absorbed from the light source.
• the phosphor compositions of the present invention can be mixed with a silicone resin to form a slurry.
• the phosphor-filled silicone can be applied to a LED chip as shown in Figures 36-39.
• the LED can, for example, emit light in the near ultraviolet (nUV) range (e.g., about 405 nm) or the blue range (e.g., about 450 nm).
• the light source used in the present invention can, for example, comprise a gallium nitride-based LED with a light-emitting layer comprising a quantum well structure.
• the light emitting device can include a phosphor of the present invention and a reflector located so as to direct light from the LED or the phosphor (see Figure 36).
• the phosphor of the present invention can be located on the surface of the LED ( Figures 36 and 37) or separated therefrom ( Figure 38).
• the light emitting device can further include a translucent material encapsulating the LED and the phosphor as seen in Figures 36-39.
• the light emitting device of the present invention comprises a light source, such as a LED, to either create excitation energy, or to excite another system to thereby provide the excitation energy for the phosphor of the present invention.
• a light source such as a LED
• Devices using the present invention can include, for example, and without limitation, white light producing light emitting devices, indigo light producing light emitting devices, blue light producing light emitting devices, green light producing light emitting devices, yellow light producing light emitting devices, orange light producing light emitting devices, pink light producing light emitting devices, red light producing light emitting devices, or light emitting devices with an output chromaticity defined by the line between the chromaticity of a phosphor of the present invention and that of at least one second light source.
• Headlights or other navigation lights for vehicles can be made with the light emitting devices of the present invention.
• the light emitting devices can be output indicators for small electronic devices, such as cell phones and personal digital assistants (PDAs).
• PDAs personal digital assistants
• the light emitting devices of the present invention also can be the backlights of the liquid crystal displays for TV, cell phones, PDAs and laptop computers.
• Luminaires for general illumination purpose can also be made with the lighting devices of the present invention. Given appropriate power supplies, room lighting can be based on devices of the invention.
• the warmth (i.e., amount of yellow/red chromaticity) of light emitting devices of the present invention can be manipulated by selection of the ratio of light from a phosphor of the present invention to light from a second source (including, a second phosphor).
• Semiconductor light source-based white light devices can be used, for example, in a self-emission type display for displaying a predetermined pattern or a graphic design on a display portion of an audio system, a household appliance, a measuring instrument, a medical appliance, and the like.
• Such semiconductor light source-based light devices also can be used, for example, and without limitation, as light sources of a back-light for a liquid crystal diode (LCD) display, a printer head, a facsimile, a copying apparatus, and the like.
• the light emitting devices of the present invention can emit light having a peak in wavelength range from about 350 nm to about 750 nm.
• the light emitting device can, for example, emit light having a peak in wavelength range of at least 350 nm, or at least 355 nm, or at least 340 nm, and so on in increments of 5 up to at least 750 nm.
• the light emitting device can, for example, emit light having a peak in wavelength range of at most 750 nm, or at most 745 nm, or at most 740 nm, and so on in increments of 5 down to at most 350 nm.
• Exemplary ranges for the peak in emission of the light emitting device of the present invention include, without limitation, from about 500 nm to about 650 nm, or from about 530 nm to about 560 nm, or from about 550 nm to about 600 nm, or from about 580 nm to about 660 nm.
• Suitable semiconductor light sources for use in the present invention also are any that create light that excites the phosphor compositions of the present invention, or that excites a different phosphor that in turn excites the phosphors of the present invention.
• the semiconductor light source e.g., a semiconductor chip
• III-V or II-VI quantum well structures meaning structures comprising compounds that combine elements of the periodic table of the chemical elements from Group III with those from Group V or elements from Group II with those from Group VI.
• nUV near ultraviolet
• the phosphor compositions of the present invention can be excited by light from a primary light source, such as, for example, a semiconductor light source (e.g., a LED) emitting light having a peak in wavelength range of about 300 to about 500 nm, from about 350 nm to about 480 nm or about 330 nm to about 390 nm, or from a secondary light source, such as, emissions from other phosphor(s) that emit light having a peak in wavelength range of about 300 nm to about 500 nm or about 350 nm to about 420 nm.
• a primary light source such as, for example, a semiconductor light source (e.g., a LED) emitting light having a peak in wavelength range of about 300 to about 500 nm, from about 350 nm to about 480 nm or about 330 nm to about 390 nm
• a secondary light source such as, emissions from other phosphor(s) that emit light having a peak in wavelength range of about 300
• Devices that use the phosphor compositions of the present invention can include, for example, and without limitation, mirrors, such as, dielectric mirrors, which direct light produced by the phosphor compositions of the present invention to the light output, rather than direct such light to the interior of the device (such as, the primary light source).
• mirrors such as, dielectric mirrors
• the light source (e.g., a LED) can, in certain embodiments, emit light having a peak in wavelength of at least about 200 nm, at least about 250 nm, at least about 255 nm, at least about 260 nm, and so on in increments of 5 nm up to at least about 600. In some embodiments, the light source emits light having a peak in wavelength of over 600 nm. The light source can, in certain embodiments, emit light having a peak in wavelength of at most about 600 nm, at most about 595 nm, at most about 590 nm, and so on in increments of 5 nm down to or less than about 200 nm.
• the light source emits light at less than 200 nm.
• the light source is a semiconductor light source.
• the LED chips are advantageously filled with a transparent encapsulant with a dome-like shape as shown in Figures 36-39.
• the encapsulant provides the mechanical protection on one hand, and the encapsulant further improves the optical property on the other hand (improved light emission of the LED die).
• the phosphor composition may be dispersed in an encapsulant. By the encapsulant, the LED chips disposed on the substrate and a polymer lens are bonded without containing a gas as much as possible. The LED die can be sealed directly by the encapsulant.
• the LED die is sealed with a transparent encapsulant (i.e., in this case, there are the transparent encapsulant and the encapsulant to contain the phosphor composition). Owing to the refraction indices close to each other, there is little loss of reflection at the interface.
• one or more LED chips are disposed on a substrate in a reflection mirror and the phosphor composition is dispersed in a lens disposed on the reflection mirror.
• one or more LED chips may be disposed on a substrate in a reflection mirror and the phosphor coated on the reflection mirror.
• the phosphor compositions of the present invention may be dispersed in an encapsulant such as silicone and epoxy resin.
• the phosphor-mixed encapsulant composition may be disposed on to the LED chip which is mounted on a substrate.
• the structure of the LED combined with the phosphor-mixed encapsulant composition can be sealed by a transparent encapsulant as protective layer.
• the outer transparent encapsulant layer is shaped in a dome shape for directing and distributing the output light ( Figures 36-39).
• one or more LED chips are mounted on a substrate and the phosphor-mixed encapsulant composition is disposed onto the multiple-chip device ( Figure 39).
• the phosphor compositions of the present invention can be dispersed in the light emitting device with a binder, a solidifier, a dispersant, a filler or the like.
• the binder can be, for example, and without limitation, a light curable polymer, such as an acrylic resin, an epoxy resin, a polycarbonate resin, a silicone resin, a glass, a quartz and the like.
• the phosphor of the present invention can be dispersed in the binder by methods known in the art. For example, in some cases, the phosphor can be suspended in a solvent with the polymer suspended, thus forming a phosphor-containing slurry composition, which then can be applied on the light emitting device and the solvent evaporated therefrom.
• the phosphor can be suspended in a liquid, such as, a pre-cured precursor to the resin to form a slurry, the slurry then can be dispersed on the light emitting device and the polymer (resin) cured thereon.
• Curing can be, for example, by heat, UV, or a curing agent (such as, a free radical initiator) mixed with the precursor.
• curing agent such as, a free radical initiator
• the binder used to disperse the phosphor particles in a light emitting device can be liquefied with heat, thereby forming a slurry, and then the slurry is dispersed on the light emitting device and allowed to solidify in situ.
• Dispersants meaning a substance that promotes the formation and stabilization of a mixture (e.g., a suspension) of one substance into another) include, for example, and without limitation, titanium oxides, aluminum oxides, barium titanates, silicon oxides, and the like.
• At least one of the additional phosphors is selected from the following: ( 1 ) one or more phosphor compositions that emit green light, including, for example and not limited to, Ca,. x Sr x Ga 2 S 4 :Eu 2+ (0 ⁇ x ⁇ l ), Cai. x . y .
• one or more additional phosphor compositions are added to the phosphor compositions of the present invention to make, for example and without limitation, white light LED lamps.
• the compositions of such additional phosphors can be, without limitation, as follows:
• M(II) is at least one divalent cation
• M(I) is at least one monovalent cation
• M(III) is at least one trivalent cation
• H is at least one monovalent anion
• A is a luminescence activator.
• one or more additional phosphor compositions are added to the phosphor compositions of the present invention to make, for example and without limitation, white light LED lamps.
• the compositions of such additional phosphors can be, without limitation, as follows:
• (il) comprises at least one divalent cation
• M(I) comprises at least one monovalent cation
• M(III) comprises at least one trivalent cation
• H comprises at least one monovalent anion
• A comprises a luminescence activator doped in the host crystal lattice.
• any of phosphors described herein may be used to create a light emitting device of the present invention.
• the multiple phosphor compositions are suspended in each matrix, and, in that case, these matrices can be disposed back and forth in the light propagation direction. Thereby, the matrix concentration can be reduced compared with the case that the different phosphor compositions are dispersed and mixed together.
• the phosphor samples were prepared by a solid state reaction with the starting materials of silicon nitride, silicon carbide, metal oxides, metal halidcs, metal nitrides and/or metals in molar ratios designed for each of the target phosphor compositions.
• Metal nitrides and europium nitride were prepared by the nitridation of the respective metal beforehand.
• Certain elements constituting the invented phosphor compositions and their source materials used in the preparation of the following examples are exemplified in Table 1. In the preparations, the source materials in powder form were weighed out, mixed and grinded in a glovebox under dried N 2 protection.
• Alkaline earth (Ca, Sr, Nitride, metal, silicide, alloy, carbide, amide and azide, oxide or Ba, Mg) carbonate
• Silicon nitride (S13N4), silicon oxynitride, Si, silicon carbide,
• silicide silicon amide, silicon carbodiimide, silicon oxide
• B Boron (B) Nitride (BN), boron carbide, boron oxide, boric acid
• Carbon (C) amide and azide e.g., Si(NCN) 2 , C 2 N 2 H 4 , C 2 N 2 (NH), C 3 N 3 (NH 2 )3,
• Metal nitride, silicide, amide and azide, halide, carbide, oxide or
• Alkali Li, Na, K
• Rare earth (Eu, Ce, Tb Rare earth nitride, rare earth oxide, rare earth metal, rare earth etc.) halide, rare earth hydride, rare earth amide and azide
• Example 1 Preparation and properties of phosphor compositions of family (1) Sr2SisN 8-
• Example 1.1 Sr2Si 5 8-
• ( x/3 .iC x 03 Z /2:Eu y + (z 0).
• strontium nitride Sr 2 N or Sr 3 N 2
• silicon nitride a-Si 3 N 4 or P-Si 3 N 4
• Figure 1 shows the XRD patterns of exemplary Sr 2 Si5Ng -( 4 X /3 ) C x :Eu " phosphors.
• the simulated diffraction pattern for the crystalline compound Sr 2 Si5N 8 is presented at the bottom position as reference.
• the XRD patterns of the phosphors with low carbon content, for example 1.10 have similar diffraction patterns with that of Sr 2 SisN 8 compound. Analyses of the observed XRD patterns indicate that the sample phosphors S ⁇ SisNs- ⁇ x / B j CxiEu 2 * are isotypical to Sr Si5N 8 . As the carbon content in the composition of Sr 2 Si5N -(4x/3 ) C x :Eu 2+ increases, the diffraction peaks render systematic displacement to lower diffraction angles (20) due to the incorporation of carbon in the lattice of In the samples with carbon content less than nitrogen content, the XRD patterns show pure single crystalline phase.
• Atom x/a y/b z/c u iso * ioo Site S.O.F
• Figures 2A and 2B show the Rietveld Refinement and the projected crystal structure of sample 1 .7.
• Figure 3 shows the representative luminescence excitation and emission spectra and optical reflection profile for sample 1.7.
• the excitation and reflectance spectra indicate that the phosphor absorbs, and is efficiently excited by, light in the range from 350 nm to 600 nm.
• the phosphor emits red light peaking at about 630 nm in the spectral range of 500 to 800 nm.
• the emission band shifts toward shorter wavelengths as shown in Figure 4 for 1 . 10 vs. 1 .12 and 1 .7 vs. 1 .8. while the absorption edge of Eu 2+ is blue shifted as shown in Figure 5.
• the relative emission intensity is plotted in Figure 6 as a function of the temperature, which demonstrates the silicon carbidonitride phosphors have high thermal stability, e.g., the lumen maintenance is about 90% at 150 °C. [00113] > 0).
• Samples of phosphor composition Sr2Si 5 Ns.[(4x/3)+ 2] C x 03 2 /2:Euy 2+ (i.e., composition (1 ) where z>0) were synthesized by a solid state reaction with the starting materials of strontium nitride (Sr 2 N or Sr 3 N 2 ), silicon nitride (a-Si 3 4 or P-Si 3 N 4 ), silicon carbide (a-SiC or ⁇ -SiC), europium oxide (Eu 2 0 3 ) in designed ratios listed in Table 5.
• the preparations followed the procedure of high temperature and post-firing treatments described above.
• the luminescence properties of the phosphor products along with the target chemical composition are listed in Table 6.
• the luminescence efficiency measured by quantum efficiency is enhanced by addition of carbon in certain range in the composition.
• the composition Sr 2 SijN8.[(4x/ 3)+ z ] C x 0 32 /2:Eu y 2+ is comprised of the same amount of Eu and varied amount of carbon (x)
• Figure 7 illustrates the XRD patterns of the phosphors with varying amounts of carbon in the composition S ⁇ SisNs ⁇ x ⁇ + zCxC ⁇ iEu 2 *.
• the simulated diffraction pattern for the crystalline compound S ⁇ SisNg is presented at the bottom position as reference.
• the XRD patterns for the phosphors with low carbon content are similar to that of Sr 2 SisN 8 compound. Analyses of the observed XRD patterns indicate that the phosphors Sr 2 Si5N 8 . As the carbon content increases, the diffraction pattern is changed, as observed for the samples 1.25, 1.26, 1 .27, 1.32 and 1 .22. In the phosphors with carbon content of x ⁇ 4, the XRD patterns show pure single crystalline phase. When the carbon content increases to x>4, however, the diffractions from SiC crystalline phase appear in a XRD pattern of 1 .22 in Figure 7. Figures 8 and 9 depict the Reitveld Refinement and projected crystal structure of sample 1.19.
• Atom x/a y/b z/c U iso * 100 Site S.O.F
• Figure 10 depicts the luminescence excitation and emission spectra representative of the phosphors of the composition of Sr 2 Si 5 N 8 -[(4. /3)+z]Cx0 3 ⁇ :Eu 2+ , as demonstrated by sample 1.19.
• the excitation profile shows an efficient excitation in the range from 350 nm to 550 run.
• the reflectance profile in Figure 1 1 shows a strong absorption in the same wavelength regime.
• the phosphor emits a red light at about 630 nm with a high quantum efficiency (-94.2%).
• the emission bands can be tuned not only by the Eu + concentration but also by the carbon content, as demonstrated in Figure 12.
• the blue shift of the emission band can be ascribed to the incorporation of carbon in the nitride lattice which results in the expansion of the host lattice evidenced by the displacement of the XRD toward lower angle in Figure 7.
• the blue shift of the emission peak is accompanied by the blue shift of the absorption edge of Eu 2+ as shown in Figure 1 1 .
• Example 2 Preparation and properties of phosphor compositions of family (2) M II)2Sis 8 .
• Samples of phosphor composition were made by a solid state reaction with the starting materials of strontium nitride (Sr 2 N or Sr 3 N2), calcium nitride (Ca 3 N 2 ), barium nitride (Ba 3 N2), silicon nitride (a-Si 3 N 4 or ⁇ -8 ⁇ 3 ⁇ 4), silicon carbide (oc-SiC or ⁇ -SiC), europium nitride (EuN) in designed ratios listed in Table 8.
• strontium nitride Sr 2 N or Sr 3 N2
• Ca 3 N 2 calcium nitride
• Ba 3 N2 barium nitride
• silicon nitride a-Si 3 N 4 or ⁇ -8 ⁇ 3 ⁇ 4
• silicon carbide oc-SiC or ⁇ -SiC
• EuN europium nitride
• the crystal structure data are summarized in Table 10.
• Figure 14B depicts the projected crystal structure of this sample. Under excitation in the wavelength range of 370- 520 nm. this phosphor emits orangish-yellow or orange-red light in the range of 580-650 nm peaking at about 590 nm ( Figure 15).
• the emission peak wavelength is dependent on the concentration of Eu in the composition as observed in Tables 8 and 9.
• This phosphor exhibits a good thermal stability of luminescence.
• the lumen maintenance is more than 80% at 150 °C as shown in Figure 16.
• Example 2.2 Ca ⁇ SisNg- ⁇ ⁇ CxiEu (Ca2Si5N8.
• the Rietveld refinement of the XRD pattern of this phosphor composition (sample 2.7) demonstrates that the resultant product is pure single phase carbidonitride whose XRD pattern is similar to that of Ca 2 Si5N8 nitride compound, as shown in Figure 17A. However, due to the incorporation of carbon into the lattice, the internal structure is deviated from the nitride lattice. The projection of the crystal structure is shown in Figure 17B.
• the determined crystal structure data are summarized in Table 1 1.
• the carbon atom is partially occupied the N position with the form of N l3] in the lattice, as visualized in a model in Figure 17B.
• the carbon atoms can also distribute statistically on all N (N l3, and N (2) ) in the structure of the phosphor. Therefore, the crystal structure data are not limited by the results given in the table.
• Atom x/a y/b z/c U iso * 100 Site S.O.F
• the thermal quenching profile of the phosphor is shown in Figure 19. The emission intensity of this phosphor decreases nonlinearly with the increase of temperature.
• Example 2.3 (Sr 0 .9Bao.i)i.9Euo.iSi 5 N 4x/3 ) Cx:Eu .
• the XRD pattern of this phosphor composition shows a pure crystalline phase (Figure 20).
• the diffraction pattern approximately matches the simulated pattern of Sr 2 Si 5 N 8 as shown in Figure 20.
• the diffractions shift to low diffraction angle (2 ⁇ ) relative to those of the simulated pattern of The shift of the diffractions are attributed to carbon content and Ba replacement for Sr in the crystal structure.
• Figure 21 shows the excitation and emission spectra (under blue excitation at 453 nm) the phosphor (sample 2.4) together with the reflectance profile of the phosphor. It is evident that the phosphor has a strong absorption in the spectral range of 370 to 550 nm, and can be efficiently excited by near-UV and blue lights. The absorbed energy from blue light can convert red light from the electron transition of 4f 5 5d l - 4f 7 of Eu 2+ .
• the emission band is located at relatively longer wavelength at about 632 nm with the incorporation of Ba (or Ca) as expected for this phosphor, i.e., red shift, and the emission peak can also be tuned by the content Eu 2+ in the composition.
• Figure 23 shows the XRD pattern of phosphor sample 3.3.
• the diffraction pattern shows a pure single phase and is similar to that of the phosphors in Example 1.2., suggesting that Sr ions in the crystal structure are partially substituted by Li or Na. It is seen that the reflection peaks are shifted to higher diffraction angles (2 ⁇ ) while the relative intensity of the peaks altered from those of compound. This fact suggests the shrinkage of the unit cell of the crystal owing to the replacement of Sr by smaller sized ions, Li or Na, in the crystal structure.
• the phosphors emit red light in a wavelength range of 550-750 nm.
• the emission peak varied in a wavelength range from 618 to 643 nm (Table 13) depending on the content of Eu, C, Li and Na in the phosphor composition.
• the sample of phosphor 3.3 efficiently emits red light in the wavelength range of 550-750 nm having peak at about 643 nm as shown in Figure 24.
• the thermal quenching of the luminescence emission of the phosphor is shown in Figure 25.
• the lumen maintenance is about 85% at 1 50°C, indicating that the phosphor has high thermal stability of emission.
• the powder mixture was fired at 1450 - 1750 °C for about 8- 12 hrs in a high temperature furnace under N 2 /H 2 atmosphere. After firing, the product was grinded and sieved, and washed with water.
• Table 1 The composition coefficients and luminescence properties of the phosphor products are listed in Table 1 5.
• Example 4.1 S -wLbvvSis s-i ⁇ xAjj+ziCxOsz ⁇ Eu.
• the cross-substitution of (CO) 6" -> 2N 3" is targeted to introduce less defects than those phosphor compositions having x ⁇ 3z/2.
• the phosphor product is a pure single phase crystal.
• the crystal structure of the phosphor is similar to that compound S ⁇ SisNg.
• This phosphor has high absorption in the spectral range of 370 - 550 nm and can be efficiently excited by near-UV and blue light, as shown in Figure 27, which emits red light with a emission peak at about 631 nm.
• the emission band of Eu can also be tuned by the incorporation of Al, B, and Li/Na, as well as changing C/N/O ratio.
• Example 4.2 Sr2-wLi2wSis -m Al m N8-
• Figure 29 shows the Rietveld refinement of the powder XRD pattern for an example of this phosphor (sample 4.3). It is clear that the obtained product is a pure single phase solid solution of silicon carbidonitride phosphor, whose structure is similar to that of Sr 2 SisN 8 nitride material. In this type of structure, Li and Al atoms are distributed on Sr and Si sites, respectively.
• Figure 30 illustrates the excitation, emission and diffuse reflection spectra of phosphor sample 4.3.
• This red emitting phosphor can be efficiently excited by near-UV and blue light and yields high quantum efficiency. Additionally, this kind of the phosphors processes high thermal stability, as shown in Figure 3 1 , with a small degradation of the emission intensity ( ⁇ 15% at 150 °C vs. the initial intensity at room temperature).
• the emission band of Eu 2+ is located at relatively long wavelength.
• Example 4.3 Sr -w Li2wSi5 -m Al m N 8 .
• C x O ( 3 Z /2 )+m :Eu (w 0).
• Rietveld refinement of the XRD pattern of this sample indicates that this product is a high purity single phase phosphor (see Figure 32).
• the structure of the phosphor is similar to that compound S ⁇ SisNs with slight divergence from the nitride structure due to the incorporation of C and Al-0 in the lattice.
• the crystal structure data are summarized in Table 1 7, and the projected crystal structure is shown in Figure 33.
• the thermal quenching of the phosphor is shown in Figure 35.
• the lumen maintenance is above 80% at 150 °C, indicating that this kind of phosphors has high thermal stability of Eu 2+ emission.
• Atom x/a y b z c U iso * 100 Site S.O.F
• the phosphor compositions of the present invention can be combined with a light emitting diode (LED) to form a lighting device.
• the lighting device generally generates a light emission with a color adjusted from that of the LED.
• a red-emitting carbidonitride phosphor composition of the present invention was mixed with a resin encapsulant to form a phosphor-filled slurry. The slurry was then applied onto a blue-emitting LED chip in the design shown in Figures 36-39.
• the phosphors were mixed with a silicone resin (silicone, Shin-Etsu LPS-251 1 ).
• Example 6.1 A pcLED consisting of a blue-emitting LED and a red emitting phosphor.
• Figure 40 shows the emission spectrum of the lighting device in which a red-emitting phosphor of the composition (1 ) (sample 1.29) is packaged with a blue-emitting LED in the lamp structure of Figure 37. The emission light has a pink color.
• Example 6.2 White light pcLEDs.
• White light pcLEDs were prepared by combining a red-emitting phosphor of composition (1) (sample 1.29) and a yellow- or green-emitting phosphor (2nd phosphor in table below) with a blue-emitting LED in the device structure shown in Figure 37.
• the phosphor blend is mixed in a silicone resin in the ratios listed in Table 20.
• the emission spectra of the pcLEDs are shown in Figure 41 .
• Table 21 The luminance performance of the pcLEDs.

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)

Priority Applications (6)

Applications Claiming Priority (4)

Publications (1)

Family

ID=45805985

Family Applications (1)

Country Status (7)

Families Citing this family (27)

Citations (10)

Family Cites Families (21)

• 2011
  • 2011-06-20 CN CN2011800434310A patent/CN103155707A/zh active Pending
  • 2011-06-20 WO PCT/US2011/041111 patent/WO2012033557A1/en not_active Ceased
  • 2011-06-20 US US13/164,623 patent/US8535566B2/en not_active Expired - Fee Related
  • 2011-06-20 EP EP11823901.1A patent/EP2614683A4/en not_active Withdrawn
  • 2011-06-20 JP JP2013528195A patent/JP5779651B2/ja not_active Expired - Fee Related
  • 2011-06-20 KR KR1020137007915A patent/KR20130066677A/ko not_active Ceased
  • 2011-06-20 KR KR1020147019974A patent/KR101521513B1/ko not_active Expired - Fee Related
  • 2011-06-20 SG SG2013012109A patent/SG187896A1/en unknown

Patent Citations (12)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events