Fluoride fluorescent material, light emitting device, and method for producing fluoride fluorescent material
AssigneeNichia Corporation
InventorTomokazu YOSHIDA
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Abstract
A fluoride fluorescent material includes a composition including K, Ge, Mn4+, and F and having a molar ratio of K of 2, a total molar ratio of Ge and Mn4+ of 1, a molar ratio of Mn4+ of more than 0 and less than 0.2, and a molar ratio of F of 6 in 1 mol of the composition, has a light emission spectrum having a first light emission peak in a range of 615 nm or more and less than 625 nm having a full width at half maximum of 6 nm or less, and a second light emission peak in a range of 625 nm or more and less than 635 nm, and has an internal quantum of 85% or more efficiency under excitation of light having a wavelength of 450 nm.
Claims12
A fluoride fluorescent material comprising a composition comprising K, Ge, Mn4+, and F and having a molar ratio of K of 2, a total molar ratio of Ge and Mn4+ of 1, a molar ratio of Mn4+ of more than 0 and less than 0.2, and a molar ratio of F of 6 in 1 mol of the composition,
- the fluoride fluorescent material having a light emission spectrum having a first light emission peak in a range of 615 nm or more and less than 625 nm having a full width at half maximum of 6 nm or less, and a second light emission peak in a range of 625 nm or more and less than 635 nm, and having an internal quantum efficiency of 85% or more under excitation of light having a wavelength of 450 nm.
A method for producing a fluoride fluorescent material, comprising:
- preparing fluoride particles comprising a composition comprising K, Ge, Mn4+, and F, and having a molar ratio of K of 2, a total molar ratio of Ge and Mn4+ of 1, a molar ratio of Mn4+ of more than 0 and less than 0.2, and a molar ratio of F of 6 in 1 mol of the composition;
- and
- bringing the fluoride particles into contact with a fluorine-containing substance, and subjecting to a heat treatment at a temperature of 400° C. or more.
Dependencies are inferred from the claim text.