STABLE PHOSPHOR CONVERTED LED AND SYSTEM USING THE SAME
According to some embodiments, an apparatus and method are provided comprising: an enclosure defining a cavity within the enclosure, the cavity comprising a depth dimension; at least one LED chip; a layer comprising a blend of an encapsulant material and phosphor composition, the layer overlaying the at least one LED chip and disposed within the cavity; the phosphor composition comprising a yellow-green phosphor and a Mn 4+ doped complex fluoride phosphor of formula I, A x [MF y ]:Mn 4+ (I) where A is Li, Na, K, Rb, Cs, NR 4 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 [Mf y ] ion; and y is 5, 6, or 7; wherein the Mn 4+ doped complex fluoride phosphor of formula I comprises a d50 particle size of from about 1 micrometers to about 10 micrometers, and the LED lighting apparatus, when activated, emits visible light comprising a correlated color temperature (CCT) of from about 2500 K to about 3700 K. Numerous other aspects are provided.
1 . An LED lighting apparatus comprising:
an enclosure defining a cavity within the enclosure, the cavity comprising a depth dimension;
at least one LED chip;
a layer comprising a blend of an encapsulant material and phosphor composition, the layer overlaying the at least one LED chip and disposed within the cavity;
the phosphor composition comprising a yellow-green phosphor and a Mn 4+ doped complex fluoride phosphor of formula I,
A x [MF y ]:Mn 4+ (I)
where A is Li, Na, K, Rb, Cs, NR 4 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 [MF y ] ion; and y is 5, 6, or 7;
wherein the Mn 4+ doped complex fluoride phosphor of formula I comprises a d50 particle size of from about 1 micrometers to about 10 micrometers, and
the LED lighting apparatus, when activated, emits visible light comprising a correlated color temperature (CCT) of from about 2500 K to about 3700 K.
2 . The LED lighting apparatus of claim 1 , wherein the CCT is from about 2500 K to about 3500 K.
3 . The LED lighting apparatus of claim 1 , wherein the depth dimension is from about 200 microns to about 800 microns.
4 . The LED lighting apparatus of claim 1 , wherein the encapsulant material is at least one of: a low temperature glass, a thermoplastic, a thermoset polymer, and a resin.
5 . The LED lighting apparatus of claim 4 , wherein the resin is one of a silicone resin or an epoxy resin.
6 . The LED lighting apparatus of claim 1 , wherein the LED chip and the layer are partially covered by the enclosure.
7 . The LED lighting apparatus of claim 1 , wherein the encapsulant material forms the enclosure.
8 . The LED lighting apparatus of claim 1 , wherein the LED chip and encapsulant are at least partially covered by a lens.
9 . The LED lighting apparatus of claim 1 , wherein the layer comprising the blend of encapsulant material and phosphor composition is radiationally coupled to the LED chip.
10 . A method comprising:
receiving phosphor pre-cursor for a phosphor composition comprising a yellow-green phosphor and a Mn 4+ doped complex fluoride phosphor of formula I,
A x [Mf y ]:Mn 4+ (I)
where A is Li, Na, K, Rb, Cs, NR 4 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 [MF y ] ion; and y is 5, 6, or 7;
generating the phosphor pre-cursor for the phosphor composition of formula I having a d50 particle size of from about 1 micrometer to about 10 micrometers;
generating the phosphor composition of formula I from the generated phosphor pre-cursor having the d50 particle size of from about 1 micrometer to about 10 micrometers;
constructing an LED lighting apparatus with the generated phosphor composition; and
in a case that the constructed LED lighting apparatus is activated, emitting visible light comprising a CCT from about 2500K to about 3700K.
11 . The method of claim 10 , wherein constructing the LED lighting apparatus further comprises:
providing an enclosure defining a cavity;
generating a layer comprising a blend of an encapsulant material and the generated phosphor composition;
overlaying the generated layer over the at least one LED chip of the LED lighting apparatus, wherein the at least one LED chip is disposed within the cavity.
12 . The method of claim 11 , wherein the cavity has a depth dimension is from about 200 microns to about 800 microns.
13 . The method of claim 11 , wherein the layer is radiationally coupled to the at least one LED chip.
14 . The method of claim 10 , wherein generating the phosphor pre-cursor for the phosphor composition of formula I having the d50 particle size of from about 1 micrometer to about 10 micrometers further comprises:
milling the phosphor pre-cursor to the d50 particle size of from about 1 micrometer to about 10 micrometers.
15 . The method of claim 14 , further comprising:
determining the milled phosphor pre-cursor has the d50 particle size of from about 1 micrometer to about 10 micrometers via scanning electron microscopy (SEM).
16 . The method of claim 10 , wherein the CCT is from about 2500 K to about 3500 K.
17 . The method of claim 10 , wherein the encapsulant material is at least one of: a low temperature glass, a thermoplastic, a thermoset polymer, and a resin.