Fluorescent substance and process for producing the same, and luminescent element using the same
AssigneeDenki Kagaku Kogyo Kabushiki Kaisha
InventorsHideyuki Emoto, Masahiro Ibukiyama, Kenji Nomura
Life of this patent
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Abstract
Provided is a phosphor material for a white LED with a blue LED or ultraviolet LED as a light source. A phosphor comprises an α-sialon represented by the formula: (M1)X(M2)Y(Si)12−(m+n)(Al)m+n(O)n(N)16−n where M1 is at least one element selected from the group consisting of Li, Mg, Ca, Y and lanthanide metals (except for La and Ce), M2 is at least one element selected from Ce, Pr, Eu, Tb, Yb and Er, 0.3≦X+Y≦1.5, 0<Y≦0.7, 0.6≦m≦3.0, 0≦n≦1.5 and X+Y=m/2; and the oxygen content in a powder of the α-sialon is at most 0.4 mass % larger than a value calculated based on the formula.
Claims26
A powdery phosphor comprising an α-sialon represented by the formula:
- (M1)X(M2)Y(Si)12−(m+n)(Al)m+n(O)n(N)16−n, where M1 is at least one element selected from the group consisting of Li, Mg, Ca, Y and lanthanide metals (except for La and Ce), M2 is at least one element selected from Ce, Pr, Eu, Tb, Yb and Er, 0.3≦X+Y≦1.5, 0<Y≦0.7, 0.6≦m≦3.0, 0≦n≦1.5 and X+Y=m/2.
A powdery phosphor comprising an α-sialon represented by the formula:
- (M1)X(M2)Y(Si,Al)12(O,N)16, where 0.3≦X+Y≦1.5 and 0<Y≦0.7, wherein primary particles constituting a powder of the α-sialon have an average aspect ratio of at most 3, and wherein at least 80% (percentage by particle number) of the above primary particles have a diameter of from 3 to 10 μm.
A powdery phosphor comprising particles of a metal nitride or oxynitride, wherein a transparent film is formed on at least a part of a surface of each particle of the above metal nitride or oxynitride and in a thickness of (10 to 180)/n (unit:
- nanometer, n:
- a refractive index of the transparent film (from 1.2 to 2.5)).
A process for producing a phosphor comprising an α-sialon represented by the formula:
- CaX(M2)Y(Si)12−(m+n)(Al)m+n(O)n(N)16−n, where M2 is at least one element selected from Ce, Pr, Eu, Tb, Yb and Er, 0.3≦X+Y≦1.5, 0<Y≦0.7, 0.6≦m≦3.0, 0≦n≦1.5, and X+Y=m/2, wherein a calcium compound containing no oxygen is used as a raw material for Ca.
A process for producing a phosphor, comprising suspending in an organic solvent a powdery phosphor comprising an α-sialon represented by the formula:
- CaX(M2)Y(Si)12−(m+n)(Al)m+n (O)n(N)16−n, where M2 is at least one element selected from Ce, Pr, Eu, Tb, Yb and Er, 0.3≦X+Y≦1.5, 0<Y≦0.7, 0.6≦m≦3.0, 0≦n≦1.5 and X+Y=m/2;
- and dropwise adding an organic metal complex or a metal alkoxide in the suspension to form a transparent film in a thickness of (10 to 180)/n (unit:
- nanometer, n:
- a refractive index of the transparent film (from 1.2 to 2.5)) on at least a part of a surface of each particle of the α-sialon constituting the phosphor.
A process for producing a phosphor, comprising suspending in water a powdery phosphor comprising an α-sialon represented by the formula:
- CaX(M2)Y(Si)12−(m+n)(Al)m+n(O)n(N)16−n, where M2 is at least one element selected from Ce, Pr, Eu, Tb, Yb and Er, 0.3≦X+Y≦1.5, 0<Y≦0.7, 0.6≦m≦3.0, 0≦n≦1.5 and X+Y=m/2;
- and dropwise adding an aqueous solution of a metal salt with a pH being kept constant, to form a transparent film in a thickness of (10 to 180)/n (unit:
- nanometer, n:
- a refractive index of the transparent film (from 1.2 to 2.5)) on at least a part of a surface of each particle of the α-sialon constituting the phosphor.
Dependencies are inferred from the claim text.