Nano-YAG:Ce phosphor compositions and their methods of preparation
AssigneeIntematix Corporation
InventorsDejie Tao, Yi-Qun Li, Shifan Cheng
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Abstract
Disclosed herein are cerium doped, garnet phosphors emitting in the yellow region of the spectrum, and having the general formula (Y,A)3(Al,B)5(O,C)12:Ce3+, where A is Tb, Gd, Sm, La, Sr, Ba, Ca, and/or Mg, and substitutes for Y, B is Si, Ge, B, P, and/or Ga, and substitutes for Al, and C is F, Cl, N, and/or S, where C substitutes for O. Relative to a solid-state-reaction method, the instant co-precipitation methods provide a more homogeneous mixing environment to enhance the distribution of the Ce3+ activator in the YAG matrix. Such a uniform distribution has the benefit of an increased emission intensity. The primary particle size of the as-prepared phosphor is about 200 nm, with a narrow distribution.
Claims8
A cerium-doped, garnet-based phosphor having the formula:
- (Y,A)3(Al,B)5(O,C)12:Ce3+;
- where
- A is selected from the group consisting of Tb, Gd, Sm, La, Sr, Ba, Ca, and Mg, and where A substitutes for Y from in amounts ranging from about 0.1 to 100 percent;
- B is selected from the group consisting of Si, Ge, B, P, and Ga, and where B substitutes for Al in amounts ranging from about 0.1 to 100 percent;
- and
- C is selected from the group consisting of F, Cl, N, and S, and where C substitutes for O in amounts ranging from about 0.1 to 100 percent,
- wherein the garnet-based phosphor contains at least some Mg substituting for Y, at least some Si substituting for Al, and at least some F or Cl substituting for O.
A method of preparing a cerium-doped, garnet-based phosphor having the formula:
- (Y,A)3(Al,B)5(O,C)12:Ce3+;
- where
- A is selected from the group consisting of Mg, Tb, Gd, Sm, La, Sr, Ba, Ca, and where
- A substitutes for Y from in amounts ranging from about 0.1 to 100 percent;
- B is selected from the group consisting of Si, Ge, B, P, and Ga, and where B substitutes for Al in amounts ranging from about 0.1 to 100 percent;
- and
- C is selected from the group consisting of F, Cl, N, and S, and where C substitutes for O in amounts ranging from about 0.1 to 100 percent;
- the method comprising:
- 1) dissolving in de-ionized water desired amounts of Ce(NO3)3.6H2O, Y(NO3)3.6H2O, Al(NO3)3.9H2O and a compound selected from the group consisting of NH4X, AlX3, and YX3, and dissolving desired amounts of compounds of A, B, and C in de-ionized water, where X is selected from the group consisting of F and Cl;
- 2) adding the solution from step 1) to an ammonia solution in a dropwise manner;
- 3) aging the solution of step 2), and then filtering and washing the resultant precipitant with distilled water;
- 4) drying the precipitate of step 3);
- and
- 5) sintering the dried product of step 4) at about 1100° C. to 1500° C. in a reducing atmosphere,
- wherein the method includes substituting at least some Mg for Y, substituting at least some Si for Al, and substituting at least some F or Cl for O.
Dependencies are inferred from the claim text.