Mn-activated oxidohalides as conversion luminescent materials for LED-based solid state light sources
The present invention relates to Mn-activated luminescent materials, to a process for preparation thereof and to the use thereof as luminophores or conversion luminophores in light sources. The present invention further relates to a radiation-converting mixture comprising the luminescent material of the invention and a light source comprising the luminescent material of the invention or the radiation-converting mixture. The present invention further provides light sources, especially LEDs, and lighting units comprising a primary light source and the luminescent material of the invention or the radiation-converting mixture. The Mn-activated luminescent materials of the invention are especially suitable for creation of warm white light in LEDs.
1. Compound of the general formula (I):
AB 3 M 1−x X 6+2x O 2−2x :Mn(IV) x (I)
doped with Mn(IV), where the symbols and indices used are as follows:
A is selected from the group consisting of H and D and mixtures thereof, where D is deuterium;
B is selected from the group consisting of Li, Na, K, Rb, Cs, NH.sub.4, ND.sub.4, NR.sub.4 and mixtures of two or more thereof, where R is an alkyl or aryl radical;
X is selected from the group consisting of F and Cl and mixtures thereof;
M is selected from the group consisting of Cr, Mo, W, Re and mixtures of two or more thereof;
where x is: 0<x<1.0.
2. Compound according to claim 1 , where:
A is selected from the group consisting of H and D and mixtures thereof, where D is deuterium;
B is selected from the group consisting of Na, K, Cs and mixtures of two or three thereof;
X is F;
M is selected from the group consisting of Mo, W and mixtures of Mo and W, where Cr and/or Re may optionally be present; and
0.0001≤x≤0.40.
3. A composition comprising the compound according to claim 1 , characterized in that the compound has been coated on its surface with another compound.
4. Process for preparing a compound according to claim 1 , comprising the steps of:
a) preparing a solution/suspension comprising A, B, M and Mn in an AX-containing solution;
b) stirring the suspension/solution; and
c) removing the solid obtained.
5. A luminophore or conversion luminophore allowing partial or complete conversion of UV light, violet light and/or blue light to light of longer wavelength, said luminophore or conversion luminophore comprising a compound according to claim 1 .
6. Radiation-converting mixture comprising a compound according to claim 1 .
7. Radiation-converting mixture according to claim 6 , further comprising one or more further luminescent materials selected from conversion luminophores and semiconductor nanoparticles.
8. Light source comprising at least one primary light source and at least one compound according to claim 1 .
9. Light source according to claim 8 , wherein the primary light source comprises a luminescent indium aluminum gallium nitride.
10. Light source according to claim 9 , wherein the luminescent indium aluminum gallium nitride is a compound of the formula In i Ga j Al k N where 0≤i, 0≤j, 0≤k and i+j+k=1.
11. Lighting unit comprising at least one light source according to claim 8 .