Nitride phosphor and method for producing nitride phosphor
AssigneeMitsubishi Chemical Corporation
InventorsRyo Koizumi, Yuhei Inata, Saiko Kiyohara, Masahito Isaka, Naoyuki Komuro, Kohei Matsuda
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Abstract
Provided is a nitride phosphor having two or more maximum absorption points in a range of 3,200 to 3,300 cm−1 in an infrared absorption (FT-IR) spectrum. The nitride phosphor of the present invention has excellent emission characteristics and is highly reliable when used in devices.
Claims20
A nitride phosphor having two or more maximum absorption points in a range of 3,200 to 3,300 cm−1 in an infrared absorption (FT-IR) spectrum, and comprising:
- a crystal phase having a chemical composition represented by the following Formula (1):
- M1xM2yM3z:
- M4 (1)
- wherein
- M1 represents at least one element selected from the group consisting of Y, La, Gd and Lu;
- M2 represents at least one element selected from the group consisting of Ge, Si, Hf, Zr, Al, Ga and Ti;
- M3 comprises N as an essential element and represents at least one element selected from the group consisting of N, O, F and Cl;
- M4 represents at least one activation element selected from the group consisting of Eu, Ce, Pr, Cr, Nd, Sm, Tb, Dy, Ho, Er, Tm, Yb and Mn;
- x satisfies 2.0≤x≤4.0;
- y satisfies 5.0≤y≤7.0;
- and
- z satisfies 10.0≤z≤12.0.
A nitride phosphor comprising a crystal phase that has a chemical composition represented by the following Formula (2),
- wherein when the value of a difference between a minimum ionic strength and a maximum ionic strength in a range of 200 to 400° C. in a detection chart for a molecular weight (m/z) of 44 measured by TPD-MS analysis is defined as 1, the value of a difference between a minimum ionic strength and a maximum ionic strength in a range of 500 to 650° C. is 0.5 or larger:
- MpSiqNr:Z (2)
- wherein
- M represents a rare-earth element, excluding an element used as an activator;
- Z represents the activator;
- p satisfies 2.7≤p≤3.3;
- q satisfies 5.4≤q≤6.6;
- and
- r satisfies 10≤r≤12.
A method of producing a nitride phosphor comprising a crystal phase that has a chemical composition represented by the following Formula (2), wherein the method comprises:
- preparing a raw material mixture of the nitride phosphor comprising the crystal phase that has the chemical composition represented by the following Formula (2);
- firing the raw material mixture;
- and
- heating a fired product obtained by the firing step in an atmosphere having an oxygen content of 10,000 ppm or less,
- wherein the crystal phase is a tetragonal crystal or an orthorhombic crystal:
- MpSiqNr:Z (2)
- wherein
- M represents a rare-earth element, excluding an element used as an activator;
- Z represents the activator;
- p satisfies 2.7≤p≤3.3;
- q satisfies 5.4≤q≤6.6;
- and
- r satisfies 10≤r≤12.
Dependencies are inferred from the claim text.