Silicate-based phosphors and led lighting devices using the same
AssigneeLightscape Materials, Inc.
InventorsYongchi Tian, Perry Niel Yocom, Olga Zakharov, Alison Sides, Alan C. Thomas
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Abstract
Disclosed herein is a group of phosphors of the formula M2(SiO4)1-x-y-z(TiO4)x(ZrO4)y(HfO4)z:A,S and light emitting devices which utilize these phosphors.
Claims43
A light emitting device comprising:
- a. a light emitting diode which emits light having a first luminescence spectrum;
- and
- b. a phosphor which absorbs at least a portion of light of the first luminescence spectrum and emits light having a second luminescence spectrum which is different than the first luminescence spectrum;
- wherein the phosphor is a phosphor of formula I:
- M2(SiO4)1-x-y-z(TiO4)x(ZrO4)y(HfO4)z:A,S
- wherein M is one or more divalent metal ions, A is one or more activators, S is one or more co-activators;
- and 0<x, y, z<1 and x+y+z<1;
- wherein the phosphor is encapsulated with a coating comprising at least one product of hydrolysis of a metal or semiconductor alkoxide, metal alkyl, or metal or semiconductor tetrachloride.
A phosphor of formula I:
- M2(SiO4)1-x-y-z(TiO4)x(ZrO4)y(HfO4)z:A,S
- wherein M is one or more divalent metal ions;
- A is one or more activators;
- S is one or more co-activators;
- and 0<x, y, z<1 and x+y+z<1.
A phosphor having a mean peak excitation wavelength of from about 350 to about 380 nm and a mean peak emission wavelength of from about 515 to about 560 nm.
A phosphor having a mean intensity of from about 0.1 to about 0.4 a.u. at an emission wavelength of about 470 nm;
- a mean intensity of from about 0.8 to about 1.1a.u. at an emission wavelength of about 520 nm;
- and a mean intensity of from about 0.5 to about 0.8 at an emission wavelength of about 620 nm.
A phosphor having a mean intensity of from about 0.8 to about 1.1a.u. at an excitation wavelength of about 370 nm and a mean intensity of from about 0 to about 0.3 at an excitation wavelength of about 470 nm.
A light emitting device comprising a light emitting diode and a phosphor, wherein the phosphor has a mean peak excitation wavelength of from about 350 to about 380 nm and a mean peak emission wavelength from about 515 to about 560 nm.
Dependencies are inferred from the claim text.