Color stable red-emitting phosphors
AssigneeGeneral Electric Company
InventorsJames Edward Murphy, Anant Achyut Setlur, Florencio Garcia, Robert Joseph Lyons, Ashfaqul Islam Chowdhury, Nagaveni Karkada, Prasanth Kumar Nammalwar
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Abstract
A process for synthesizing a color stable Mn4+ doped phosphor includes contacting a precursor of formula I, in gaseous form at an elevated temperature with a fluorine-containing oxidizing agent to form the color stable Mn4+ doped phosphor Ax[MFy]:Mn4+ I wherein A is Li, Na, K, Rb, Cs, NR4 or a combination thereof; M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Hf, Y, La, Nb, Ta, Bi, Gd, or a combination thereof; R is H, lower alkyl, or a combination thereof; x is the absolute value of the charge of the [MFy] ion; and y is 5, 6 or 7.
Claims9
A lighting apparatus comprising a semiconductor light source;
- and a color stable Mn4+ doped phosphor of formula K2SiF6:Mn4+, wherein % intensity loss of the phosphor after exposure to light flux of at least 80 w/cm2 at a temperature of at least 50° C. for at least 21 hours is ≦4%.
A backlight device comprising a semiconductor light source;
- and a color stable Mn4+ doped phosphor of formula K2SiF6:Mn4+, wherein % intensity loss of the phosphor after exposure to light flux of at least 80 w/cm2 at a temperature of at least 50° C. for at least 21 hours is ≦4%.
A color stable Mn4+ doped phosphor of formula K2SiF6:Mn4+, wherein % intensity loss of the phosphor after exposure to light flux of at least 80 w/cm2 at a temperature of at least 50° C. for at least 21 hours is ≦4%.
Dependencies are inferred from the claim text.