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US 6,436,313 B1Granted
Rare earth doped halophosphate phosphor
AssigneeGeneral Electric Company
InventorsAlok Mani Srivastava, William Winder Beers, Thomas Frederick Soules, Holly Ann Comanzo
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Abstract
There is provided a halophosphate phosphor having the formula (Ca, Mg, Ba, Sr, Zn)5(PO4)3(F, Cl, Br): Sb3+, Mn2+ doped with at least one rare earth ion which has a higher charge carrier capture cross section than the phosphor lattice defects. The rare earth ion preferentially traps charge carriers and thus decreases the density of color centers. The rare earth ions are preferably trivalent ions selected from Eu3+, Sm3+, Yb3+, Tm3+, Ce3+, Tb3+ and Pr3+.
Claims16
A luminescent material comprising a halophosphate phosphor which comprises a phosphate ion and at least one counter-ion selected from the group consisting of Ca, Ba, Mg, Sr, and Zn;
- said halophosphate phosphor being doped with Sb3+, Mn2+, and at least an additional ion species selected from the group consisting of:
- (a) a trivalent rare earth metal ion when said at least one counter-ion is at least Zn;
- (b) Tb3+ when said at least one counter-ion is selected from the group consisting of Ba, Mg, Sr, and Zn;
- (c) at least a trivalent rare earth ion selected from the group consisting of:
- (1) Sm3+, Yb3+, Tm3+, Ce3+, and Pr3+;
- (2) Eu3+ and at least one ion selected from the group consisting of Sm3+, Yb3+, Tm3+, Ce3+, and Pr3+;
- and
- (3) Tb3+ and at least one ion selected from the group consisting of Yb3+, Tm3+, Ce3+, and Pr3+
- when said counter-ion is an alkaline earth metal ion.
6 more elements
A halophosphate phosphor comprising:
- A5(PO4)3G:Sb3+, Mn2+, R3+;
- wherein A comprises at least an ion of an element selected from the group consisting of Mg, Ba, Sr, and Zn;
- G comprises at least one ion of an element selected from the group consisting of fluorine, chlorine, and bromine;
- and
- R3+ comprises at least one ion so as to satisfy a condition selected from the group consisting of:
- (a) R3+ comprising a trivalent rare earth metal ion when A is at least Zn;
- and
- (b) R3+ is at least one trivalent rare earth ion selected from the group consisting of:
- (1) Sm3+, Yb3+, Tm3+, Ce3+, and Pr3+;
- (2) Eu3+ and at least one ion selected from the group consisting of Sm3+, Yb3+, Tm3+, Ce3+, and Pr3+;
- (3) Tb3+ and at least one ion selected from the group consisting of Yb3+ Tm3+, Ce3+, and Pr3+;
- and
- (4) Tb3+
- when A consists essentially of at least an element selected from the group consisting of Mg, Ba, and Sr.
11 more elements
A halophosphate phosphor comprising:
- A5(PO4)3G:Sb3+, Mn2+, R3+;
- wherein A comprises at least an ion of an element selected from the group consisting of Ca, Mg, Ba, Sr, and Zn;
- G comprises at least one ion of an element selected from the group consisting of fluorine, chlorine, and bromine;
- and
- R3+ comprises at least one ion selected from the group consisting of:
- (a) at least one trivalent rare earth ion selected from the group consisting of Eu3+, Sm3+, Yb3+, and Tm3+ and at least one trivalent rare earth ion selected from the group consisting of Ce3+ and Pr3+;
- (b) at least one trivalent rare earth ion selected from the group consisting of Yb3+ and Tm3+ and at least one trivalent rare earth ion selected from the group consisting of Ce3+, Pr3+, and Tb3+;
- and
- (c) Tb3+;
- at least one trivalent rare earth ion selected from the group consisting of Eu3+, Sm3+, Yb3+, and Tm3+;
- and at least one trivalent rare earth ion selected from the group consisting of Ce3+ and Pr3+.
8 more elements
A halophosphate phosphor comprising:
- A5(PO4)3G:
- Sb3+, Mn2+, R3+;
- wherein A comprises at least an ion of an element selected from the group consisting of Ca, Mg, Ba, Sr, and Zn;
- G comprises at least one ion of an element selected from the group consisting of fluorine, chlorine, and bromine;
- and
- R3+ comprises at least one trivalent rare earth ion;
- and
- wherein a concentration of each of said Sb3+, Mn2+, R3+ is in the range from about 1 ppm to about 500 ppm.
5 more elements
A fluorescent lamp, comprising:
- a lamp cover;
- a phosphor layer comprising a luminescent material on a surface of the cover;
- a lamp base;
- and
- at least one electrode;
- wherein said luminescent material comprises a halophosphate phosphor comprising:
- A5(PO4)3G:
- Sb3+, Mn2+, R3+;
- wherein A comprises at least an ion of an element selected from the group consisting of Mg, Ba, Sr, and Zn;
- G comprises at least one ion of an element selected from the group consisting of fluorine, chlorine, and bromine;
- and
- R3+ comprises at least one ion so as to satisfy a condition selected from the group consisting of:
- (a) R3+ comprising a trivalent rare earth metal ion when A is at least Zn;
- and
- (b) R3+ is at least one trivalent rare earth ion selected from the group consisting of:
- (1) Sm3+, Yb3+, Tm3+, Ce3+, and Pr3+;
- (2) Eu3+ and at least one ion selected from the group consisting of Sm3+, Yb3+, Tm3+, Ce3+, and Pr3+;
- (3) Tb3+ and at least one ion selected from the group consisting of Yb3+, Tm3+, Ce3+, and Pr3+;
- and
- (4) Tb3+
- when A consists essentially of at least an element selected from the group consisting of Mg, Ba, and Sr.
18 more elements
A fluorescent lamp comprising:
- a lamp cover;
- a phosphor on a surface of the cover;
- a lamp base;
- and
- at least one electrode;
- wherein said phosphor comprises a halophosphate phosphor which comprises a phosphate ion and at least one counter-ion selected from the group consisting of Ca, Ba, Mg, Sr, and Zn;
- said halophosphate phosphor being doped with Sb3+, Mn2+, and at least an additional ion species selected from the group consisting of:
- (a) a trivalent rare earth metal ion when said at least one counter-ion is at least Zn;
- (b) Tb3+ when said at least one counter-ion is selected from the group consisting of Ba, Mg, Sr, and Zn;
- (c) at least a trivalent rare earth ion selected from the group consisting of:
- (1) Sm3+, Yb3+, Tm3+, Ce3+, and Pr3+;
- (2) Eu3+ and at least one ion selected from the group consisting of Sm3+, Yb3+, Tm3+, Ce3+, and Pr3+;
- and
- (3) Tb3+ and at least one ion selected from the group consisting of Yb3+, Tm3+, Ce3+, and Pr3+
- when said at least one counter-ion is an alkaline earth metal ion.
12 more elements
A method of making a halophosphate phosphor, said method comprising:
- (a) combining to form a mixture compounds of:
- (1) at least one divalent metal element selected from the group consisting of Mg, Ba, Sr, and Zn;
- (2) phosphorus;
- (3) at least one halogen element selected from the group consisting of fluorine, chlorine, and bromine;
- (4) oxygen;
- (5) antimony;
- (6) manganese;
- and
- (7) at least one trivalent ion so as to satisfy a condition selected from the group consisting of:
- (i) said at least one trivalent ion comprising at least one trivalent rare earth ion when said at least one divalent metal element is at least Zn;
- (ii) when said divalent metal element is selected from the group consisting of Mg, Ba, and Sr, said at least one trivalent ion being selected from the group consisting of:
- (A) Sm3+, Yb3+, Tm3+, Ce3+, and Pr3+;
- (B) Eu3+ and at least one ion selected from the group consisting of Sm3+, Yb3+, Tm3+, Ce3+, and Pr3+;
- (C) Tb3+ and at least one ion selected from the group consisting of Yb3+, Tm3+, Ce3+, and Pr3+;
- and
- (D) Tb3+;
- and
- (b) heating said mixture to form a solid phosphor body.
15 more elements
A method for making a lamp, said method comprising:
- (a) preparing a halophosphate;
- (b) converting the solid phosphor body into a phosphor powder;
- (c) placing the phosphor powder in a suspension containing a solvent and a binder;
- (d) coating the suspension onto a surface of a lamp cover;
- (e) drying the suspension;
- and
- (f) heating the suspension to evaporate the binder;
- wherein said preparing said halophosphate comprises the steps of:
- (I) combining to form a mixture compounds of:
- (1) at least one divalent metal element selected from the group consisting of Mg, Ba, Sr, and Zn;
- (2) phosphorus;
- (3) at least one halogen element selected from the group consisting of fluorine, chlorine, and bromine;
- (4) oxygen;
- (5) antimony;
- (6) manganese;
- and
- (7) at least one trivalent ion so to satisfy a condition selected from the group consisting of:
- (i) said at least one trivalent ion comprising at least one trivalent rare earth ion when said at least one divalent metal element is at least Zn;
- (ii) when said divalent metal element is selected from the group consisting of Mg, Ba, and Sr, said at least one trivalent ion being selected from the group consisting of:
- (A) Sm3+, Yb3+, Tm3+, Ce3+, and Pr3+;
- (B) Eu3+ and at least one ion selected from the group consisting of Sm3+, Yb3+, Tm3+, Ce3+, and Pr3+;
- (C) Tb3+ and at least one ion selected from the group consisting of Yb3+, Tm3+, Ce3+, and Pr3+;
- and
- (D) Tb3+;
- and
- (II) heating said mixture to form a solid phosphor body.
23 more elements
A method of making a halophosphate phosphor, said method comprising:
- (a) combining to form a mixture compounds of:
- (1) Ca;
- (2) phosphorus;
- (3) at least one halogen element selected from the group consisting of fluorine, chlorine, and bromine;
- (4) oxygen;
- (5) antimony;
- (6) manganese;
- and
- (7) at least one trivalent ion so to satisfy a condition selected from the group consisting of:
- (i) Sm3+, Yb3+, Tm3+, Ce3+, and Pr3+;
- (ii) Eu3+ and at least one ion selected from the group consisting of Sm3+, Yb3+, Tm3+, Ce3+, and Pr3+;
- (iii) Tb3+ and at least one ion selected from the group consisting of Yb3+, Tm3+, Ce3+, and Pr3+;
- and
- (iv) a combination of trivalent rare earth ions, said combination excluding combinations consisting of ions selected from the group consisting of Dy3+, Eu3+, and Tb3+;
- and
- (b) heating said mixture to form a solid phosphor body.
13 more elements
A halophosphate phosphor comprising:
- Ca5(PO4)3G:
- Sb3+, Mn2+, R3+;
- wherein G comprises at least one ion of an element selected from the group consisting of fluorine and chlorine;
- and
- R3+ comprises at least one trivalent rare earth ion so to satisfy a condition selected from the group consisting of:
- (a) Sm3+, Yb3+, Tm3+, Ce3+, and Pr3+;
- (b) Eu3+ and at least one ion selected from the group consisting of Sm3+, Yb3+, Tm3+, Ce3+, and Pr3+;
- (c) Tb3+ and at least one ion selected from the group consisting of Yb3+, Tm3+, Ce3+, and Pr3+;
- and
- (d) a combination of trivalent rare earth ions, said combination excluding combinations consisting of ions selected from the group consisting of Dy3+, Eu3+, and Tb3+.
7 more elements
Dependencies are inferred from the claim text.