Fluoride phosphor, production method therefor, and light-emitting device
AssigneeNichia Corporation
InventorTomokazu Yoshida
Life of this patent
Estimating the term…
Abstract
Provided is a fluoride phosphor having higher durability. The fluoride phosphor includes a first fluoride and a second fluoride deposited on at least part of a surface of the first fluoride. The first fluoride has a composition containing an alkali metal, Si, Al, Mn, and F, wherein, when the number of moles of the alkali metal is taken as 2, the total number of moles of Si, Al, and Mn is 0.9 to 1.1; the number of moles of Al is more than 0 and less than 0.10; the number of moles of Mn is more than 0 and less than 0.20; and the number of moles of F is 5.9 to 6.1. The second fluoride has a composition which contains an alkali metal, Si, and F, and which is substantially free of Al and Mn.
Claims16
A fluoride phosphor comprising:
- a first fluoride having a composition containing an alkali metal, Si, Al, Mn, and F, wherein, when a number of moles of the alkali metal is taken as 2, a total number of moles of Si, Al, and Mn is 0.9 to 1.1;
- a number of moles of Al is more than 0 and equal to or less than 0.10;
- a number of moles of Mn is more than 0 and equal to or less than 0.20;
- and a number of moles of F is 5.9 to 6.1;
- and
- a second fluoride deposited on at least part of a surface of the first fluoride, the second fluoride having a composition which contains an alkali metal, Si, and F, and which is substantially free of Al and Mn,
- wherein a content of the second fluoride in the fluoride phosphor is not more than 30 mol %,
- wherein the alkali metal in the first fluoride comprises at least one selected from the group consisting of Li, Na, K, Rb and Cs, and
- wherein the alkali metal in the second fluoride comprises at least one selected from the group consisting of Li, Na, K, Rb and Cs.
A method of producing a fluoride phosphor, the method comprising:
- providing a first fluoride having a composition containing an alkali metal, Si, Al, Mn, and F, wherein, when a number of moles of the alkali metal is taken as 2, a total number of moles of Si, Al and Mn is 0.9 to 1.1;
- a number of moles of Al is more than 0 and equal to or less than 0.10;
- a number of moles of Mn is more than 0 and equal to or less than 0.20;
- and a number of moles of F is 5.9 to 6.1;
- bringing the first fluoride, first solution containing Si and F, and a second solution containing an alkali metal into contact with each other in the presence of a reducing agent to deposit, on at least part of a surface of the first fluoride, a second fluoride having a composition which contains an alkali metal, Si, and F, and which is substantially free of Al and Mn, to obtain a complex fluoride;
- and
- bringing the complex fluoride into contact with a fluorine-containing substance, and carrying out heat treatment at a temperature of not less than 400° C.
Dependencies are inferred from the claim text.