Color stable Mn-activated oxidofluorides as conversion luminescent materials for LED-based solid state light sources
A compound of the general formula (I): A 3 BF 2 M 1−x T x O 2−2x F 4+2x doped with Mn(IV), in which A is selected from the group consisting of Li, Na, K, Rb, Cs, Cu, Ag, Tl, NH4, NR4 and mixtures of two or more thereof, where R is an alkyl or aryl group, B is selected from the group consisting of H and D and mixtures thereof, where D is Deuterium, M is selected from the group consisting of Cr, Mo, W, Te, Re and mixtures of two or more thereof, T is selected from the group consisting of Si, Ge, Sn, Ti, Pb, Ce, Zr, Hf and mixtures of two or more thereof, and 0≤x≤1.
1. A compound of the general formula (I):
A 3 BF 2 M 1−x T x O 2−2x F 4+2x (I)
doped with Mn(IV), wherein:
A is selected from the group consisting of Li, Na, K, Rb, Cs, Cu, Ag, TI, NH 4 , NR 4 and mixtures of two or more thereof, where R is an alkyl or aryl group;
B is selected from the group consisting of H and D and mixtures thereof, where D is Deuterium;
M is selected from the group consisting of Cr, Mo, W, Te, Re and mixtures of two or more thereof;
T is selected from the group consisting of Si, Ge, Sn, Ti, Pb, Ce, Zr, Hf and mixtures of two or more thereof; and
0<x≤1.
2. The compound according to claim 1 , wherein the index x is in a range of 0.1 and 0.9.
3. The compound according to claim 1 , wherein:
A is selected from the group consisting of Na, K, Cs and mixtures of two or three thereof;
M is selected from the group consisting of Mo, W and mixtures of Mo and W, where Cr, Te and/or Re may optionally be present;
T is selected from the group consisting of Si, Ti and mixtures of Si and Ti, where Ge, Sn, Pb, Ce, Zr, and/or Hf may optionally be present; and
0.0001<x≤0.40.
4. A compound of the general formula (I):
A 3 BF 2 M 1−x T x O 2−2x F 4+2x (I)
doped with Mn(IV), wherein:
A is selected from the group consisting of Li, Na, K, Rb, Cs, Cu, Ag, TI, NH 4 , NR 4 and mixtures of two or more thereof, where R is an alkyl or aryl group;
B is selected from the group consisting of H and D and mixtures thereof, where D is Deuterium;
M is selected from the group consisting of Cr, Mo, W, Te, Re and mixtures of two or more thereof;
T is selected from the group consisting of Si, Ge, Sn, Ti, Pb, Ce, Zr, Hf and mixtures of two or more thereof;
0≤x≤1; and
a surface of the compound is coated another compound.
5. A process for preparing the compound of claim 1 , comprising the steps of:
a) preparing a solution/suspension comprising A, B, M, T and Mn in an AF-containing solution;
b) stirring the suspension/solution; and
c) removing the solid obtained.
6. A luminophore or conversion luminophore configured to partially or completely convert UV light, violet light and/or blue light to light of a longer wavelength, the luminophore or conversion luminophore comprising the compound of claim 1 .
7. A radiation-converting mixture comprising the compound of claim 1 .
8. The radiation-converting mixture according to claim 7 , further comprising one or more further luminescent materials selected from conversion luminophores and semiconductor nanoparticles.
9. A light source comprising at least one primary light source and at least one compound of claim 1 .
10. The light source according to claim 9 , wherein the at least one primary light source comprises a luminescent indium aluminum gallium nitride.
11. The light source according to claim 10 , wherein the luminescent indium aluminum gallium nitride is a compound of the formula IniGajAlkN, where 0≤i, 0≤j, 0 ≤k and i+j+k=1.
12. A lighting unit comprising at least one light source of claim 9 .
13. A light emitting device, comprising:
a substrate;
a light emitting diode disposed on the substrate; and
a wavelength converter disposed on the substrate, wherein:
the wavelength converter includes a plurality of phosphors, and white light is formed by mixing light emitted from the light emitting diode and each of the plurality of phosphors; and
at least one of the plurality of phosphors is an Mn(IV)-activated luminescent material based on an oxidohalide host lattice; and
the wavelength converter includes a first wavelength converter and a second wavelength converter stacked one over another.
14. The light emitting device of claim 13 , wherein the at least one of the plurality of phosphors is configured to emit light in a same color range as that of the Mn(IV)-activated luminescent material based on the oxidohalide host lattice.
15. The light emitting device of claim 13 , wherein the at least one of the plurality of phosphors is configured to emit light in a different color range from that of the Mn(IV)-activated luminescent material based on the oxidohalide host lattice.
16. The light emitting device of claim 13 , wherein white light formed by mixing light emitted from the light emitting diode and each of the plurality of phosphors has a CRI of 90 or higher.
17. The light emitting device of claim 13 , wherein white light formed by mixing light emitted from the light emitting diode and each of the plurality of phosphors has a luminous efficiency exceeding 100%.
18. The light emitting device of claim 13 , wherein the wavelength converter is spaced apart from the light emitting diode.