Patent ID: 7615797
Filing Date: 2009-11-10
Classification: C04B,C09K,H01L,H05B,Y02B,Y10S

Abstract:
1. A light-emitting device comprising a light-emitting element and a phosphor layer comprising a red phosphor and a green phosphor, output light containing a red light-emitting component emitted by the red phosphor, a green light-emitting component emitted by the green phosphor, and a light-emitting component emitted by the light-emitting element, wherein the output light is white light, the red phosphor is a nitridoaluminosilicate-based nitride phosphor that is activated with Eu the green phosphor is activated either with Eu the light-emitting element is a blue light-emitting element that emits light having an emission peak in a wavelength range of 440 nm to less than 500 nm, all phosphors contained in the phosphor layer are either phosphors activated with Eu the red phosphor has an internal quantum efficiency of at least 80% under the excitation of light emitted by the blue light-emitting element, an excitation spectrum of all the phosphors contained in the phosphor layer has an excitation peak in a wavelength range shorter than a wavelength of the emission peak of light emitted by the blue light-emitting element, and the phosphor layer does not substantially contain an inorganic phosphor other than a nitride phosphor or an oxynitride phosphor.