The present invention relates to a red phosphor, a preparation method thereof and a light-emitting device prepared therefrom. A particle of the red phosphor consists of a phosphor inner core having a chemical formula of A.sub.x1Ge.sub.z1F.sub.6:y.sub.1Mn.sup.4+ and an outer shell having a chemical formula of B.sub.x2M.sub.z2F.sub.6:y.sub.2Mn.sup.4+, wherein 1.596≤x.sub.1≤2.2, 1.6≤x.sub.2≤2.2, 0.001≤y.sub.1≤0.2, 0≤y.sub.2≤0.2, 0.9≤z.sub.1≤1.1, and 0.9≤z.sub.2≤1.1; A and B are independently selected from alkali metal elements; and M is Si, or Si and Ge. The red phosphor provided by the present invention has high luminous efficiency and stability. Moreover, the phosphor alone or in combination with other luminescent materials can be used for preparing a light-emitting device with high performance.

A fluoride fluorescent material includes a composition including K, Ge, Mn.sup.4+, and F and having a molar ratio of K of 2, a total molar ratio of Ge and Mn.sup.4+ of 1, a molar ratio of Mn.sup.4+ 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.

The present invention relates to a red phosphor, a preparation method thereof and a light-emitting device prepared therefrom. A particle of the red phosphor consists of a phosphor inner core having a chemical formula of A.sub.x1Ge.sub.z1F.sub.6:y.sub.1Mn.sup.4+ and an outer shell having a chemical formula of B.sub.x2M.sub.z2F.sub.6:y.sub.2Mn.sup.4+, wherein 1.596≤x.sub.1≤2.2, 1.6≤x.sub.2≤2.2, 0.001≤y.sub.1≤0.2, 0≤y.sub.2≤0.2, 0.9≤z.sub.1≤1.1, and 0.9≤z.sub.2≤1.1; A and B are independently selected from alkali metal elements; and M is Si, or Si and Ge. The red phosphor provided by the present invention has high luminous efficiency and stability. Moreover, the phosphor alone or in combination with other luminescent materials can be used for preparing a light-emitting device with high performance.

A fluoride fluorescent material includes a composition including K, Ge, Mn.sup.4+, and F and having a molar ratio of K of 2, a total molar ratio of Ge and Mn.sup.4+ of 1, a molar ratio of Mn.sup.4+ 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.

Provided is a phosphor represented by the general formula: A.sub.2MF.sub.6:Mn. The elements A each represents an alkali metal element, the element M represents one or more tetravalent metallic elements selected from Si, Ge, Sn, Ti, Zr and Hf. The phosphor has a minimal light absorption rate in a wavelength range of 300 nm or more and 350 nm or less of 67% or less, and a maximum light absorption rate in a wavelength range of 400 nm or more and 500 nm or less of 65% or more. The phosphor has a Mn content of 0.3% by mass or more and 1.5% by mass or less.

Provided is a phosphor represented by the general formula: A.sub.2MF.sub.6:Mn. The elements A each represents an alkali metal element, the element M represents one or more tetravalent metallic elements selected from Si, Ge, Sn, Ti, Zr and Hf. The phosphor has a minimal light absorption rate in a wavelength range of 300 nm or more and 350 nm or less of 67% or less, and a maximum light absorption rate in a wavelength range of 400 nm or more and 500 nm or less of 65% or more. The phosphor has a Mn content of 0.3% by mass or more and 1.5% by mass or less.