Phosphor for light emitting device and method for manufacturing the same, and light emitting device using the same

摘要

A phosphor for light emitting device of an embodiment includes: a phosphor particle composed of at least one selected from an alkaline earth silicate phosphor, a lanthanum oxysulfide phosphor, and a zinc sulfide phosphor; and a surface treatment agent, provided to cover a surface of the phosphor particle, of at least one selected from a silane coupling agent and an acrylic emulsion. A luminance maintenance ratio of the phosphor represented by a formula: luminance B/luminance A×100(%), is 98% or more, wherein the luminance A is a luminance of the phosphor made to emit under a condition of temperature: 23° C., humidity: 40%, and the luminance B is a luminance of the phosphor made to emit under a condition of temperature: 23° C., humidity: 40% after leaving the phosphor under a condition of temperature: 60° C., humidity: 90% for 12 hours.

主权项

1. A phosphor for a light emitting device which has an LED chip emitting ultraviolet to blue light, comprising:
a phosphor particle composed of an europium and manganese-activated alkaline earth silicate phosphor emitting green to yellow light, the europium and manganese-activated alkaline earth silicate phosphor having a composition represented by a general formula:
(Sr2-x-y-z-uBaxMgyEuzMnu)SiO4 wherein x is a numeral (atomic ratio) satisfying 0.1≦x≦1.69,y is a numeral (atomic ratio) satisfying 0.01≦y≦0.05,z is a numeral (atomic ratio) satisfying 0.025≦z≦0.25, andu is a numeral (atomic ratio) satisfying 0.001≦u≦0.01; and
a surface treatment agent of at least one selected from a silane coupling agent and an acrylic emulsion, the surface treatment agent being provided to cover a surface of the phosphor particle, wherein a luminance maintenance ratio is 98% or more, wherein the luminance maintenance ratio is represented by a formula:
luminance B/luminance A×100(%),the luminance A is an initial luminance obtained by making the phosphor emit under a condition of a temperature of 23° C. and a humidity of 40%, and the luminance B is a luminance obtained by making the phosphor emit under a condition of a temperature of 23° C. and a humidity of 40% after leaving the phosphor under a condition of a temperature of 60° C. and a humidity of 90% for 12 hours.