	US 11,732,187 B2
	Chlorosilicate fluorescent material, method for producing the same, and light emitting device
Ryuta Miyai, Komatsushima (JP); Kazuya Nishimata, Anan (JP); and Shoji Hosokawa, Tokushima (JP)
Assigned to NICHIA CORPORATION, Anan (JP)
Filed by NICHIA CORPORATION, Anan (JP)
Filed on Oct. 23, 2019, as Appl. No. 16/661,063.
Claims priority of application No. 2018-201013 (JP), filed on Oct. 25, 2018; and application No. 2019-188728 (JP), filed on Oct. 15, 2019.
Prior Publication US 2020/0131437 A1, Apr. 30, 2020
Int. Cl. C09K 11/61 (2006.01); C09K 11/77 (2006.01); H01L 33/26 (2010.01)

CPC C09K 11/617 (2013.01) [H01L 33/26 (2013.01)]

12 Claims

1. A light emitting device, comprising: a light source having a light emission peak wavelength in a range of 250 nm or more and 485 nm or less; and a fluorescent member containing a chlorosilicate fluorescent material as a first fluorescent material, and a second fluorescent material and a third fluorescent material each having a light emission peak wavelength range different from that of the first fluorescent material,

wherein a larger amount of the chlorosilicate fluorescent material than the second fluorescent material and the third fluorescent material is unevenly distributed in a light emission side in the fluorescent member, and

wherein the chlorosilicate fluorescent material comprises a fluorescent material core having the chemical composition represented by the formula (I), and an oxide adhered on a surface of the fluorescent material core,

Ca_xEu_yMg_zSi₄O_aCl_b (I)

wherein a, b, x, y, and z each satisfy 7.0≤x≤7.94, 0.01≤y≤1.0, 7.76≤x+y≤7.90, 0.9≤z≤1.1, 15.6≤a≤16.1, and 1.90<b≤2.00,

wherein the oxide is at least one oxide selected from the group consisting of Al₂O₃, SiO₂, ZrO₂, and TiO₂, and

wherein the amount of the oxide adhered on the surface of the fluorescent material core is in a range of 2 parts by mass or more and 10 parts by mass or less relative to 100 parts by mass of the fluorescent material core in terms of metal contained in the oxide.