Patent ID: 7023019
Filing Date: 2006-04-04
Classification: C09K,F21S,F21Y,H01L,H05B,Y02B

Abstract:
1. A light-emitting semiconductor device comprising: a blue-light-emitting diode which emits blue light, the blue-light-emitting diode having a light extraction surface; and a luminescent layer which includes a yellow/yellowish phosphor that absorbs blue light emitted by the blue-light-emitting diode to emit a yellow/yellowish fluorescence, wherein the luminescent layer is exposed on the blue-light-emitting diode, the yellow/yellowish phosphor contains a compound expressed by the chemical formula: (where 0≦a1≦0.3, 0≦b2≦0.6, 0.005 <x<0.1), the yellow/yellowish phosphor has a particle size in the range from 0.5 μm to 30 μm, both inclusive, and is made of a silicate phosphor having an orthorhombic structure, and a portion of the luminescent layer located at least on the light extraction surface of the blue-light-emitting diode has a substantial thickness in the range from 50 μm to 1000 μm, both inclusive.