Luminescent composite materials

1. A composite material comprising a matrix and embedded therein luminescent crystals;

said luminescent crystals being selected from compounds of formula (I)

(M 1 A 1 ) a M 2 b X c   (I), wherein

A 1 represents one or more organic cations selected from the group consisting of ammonium, formamidinium, guanidinium, imidazolium, pyridinium, pyrrolidinium, protonated thiourea,

M 1 represents one or more alkaline metal cations selected from Cs, Rb, K, Na, Li,

M 2 represents one or more metal cations selected from the group consisting of Ge, Sn, Pb, Sb, Te and Bi,

X represents one or more anions selected from the group consisting of chloride, bromide, iodide, cyanide, thiocyanate, isothiocyanate and sulfide,

a represents 1-4,

b represents 1-2,

c represents 3-9; and

said matrix being selected from compounds of formula (II)

M 3 d X 2 e   (II), wherein

M 3 represents one or more metal cations selected from Li, Na, K, Rb, Mg, Ca, Sr, Ba, Ti, Y, Zr, Zn, and Al,

X 2 represents one or more anions selected from the group consisting of halides, pseudo-halides, perchlorates, sulfates, sulfites, phosphates and phosphites,

d represents 1 and e represents 1, 2 or 3, or

d represents 2 and e represents 1 or 3, or

d represents 3 and e represents 1 or 2,

said composite material being present as a population of microparticles having a diameter in the range of 50-200,000 nm, and wherein the compounds of formula (I) are present in a concentration of more than 10 wt %.

2. The composite material according to claim 1 , wherein the luminescent nanocrystals being selected from compounds of formula (I-1)

M 1 a M 2 b X c   (I-1), wherein

the substituents are as defined in claim 1 ; and/or

from compounds of formula (I-2)

A 1 a M 2 b X c   (I-2), wherein

the substituents are as defined in claim 1 ; and/or

from compounds of formula (I-3)

(M 1 A 1 ) a M 2 b X c   (I-3), wherein

M 2 is selected from Ge, Sn, Sb, and Bi.

3. The composite material according to claim 1 wherein the matrix being selected from compounds of formula (II-1a)

M 3 X 2 e   (II-1a), wherein

X 2 represents one or more anions selected from the group consisting of halides,

M 3 represents a cation as defined in claim 1 ,

e represents 1, 2 or 3; and/or

compounds of formula (II-1b)

M 3 X 2 e   (II-1b), wherein

X 2 represents one or more anions selected from the group consisting of pseudohalides, particularly (NCO) − and (SCN) − ,

M 3 represents a cation as defined in claim 1 ,

e represents 1, 2 or 3; and/or

compounds of formula (II-1c)

M 3 (ClO 4 ) e   (II-1c), wherein

M 3 represents a cation as defined in claim 1 ,

e represents 1, 2 or 3; and/or

compounds of formula (II-2)

M 3 d X 2 e   (II-2), wherein

X 2 represents one or more anions selected from the group consisting of sulfates,

M 3 represents a cation as defined in claim 1

d and e are as defined in claim 1 ; and/or

compounds of formula (II-3)

M 3 d X 2 e   (II-3), wherein

X 2 represents one or more anions selected from the group consisting of phosphates.

4. The composite material according to claim 1 , wherein

said luminescent crystals of formula (I) are of 3-500 nm in diameter; and/or

the size of luminescent crystals of formula (I) is at most ⅕ of the size of the composite material.

5. The composite material according to claim 1 , wherein

the amount of luminescent crystals of formula (I) is in the range of 0.1-50 mol %; and/or

the composite material is free of, or essentially free of, organic molecules.

6. The composite material according to claim 1 , wherein said composite material is free of organic molecules.

7. A formulation comprising (i) composite material according to claim 1 ; (ii) a polymer and/or pre-polymer and (iii) optionally solvent.

8. The formulation according to claim 7 , wherein

said polymer is selected from the group consisting of acrylate polymers, carbonate polymers, sulfone polymers, epoxy polymers, vinyl polymers, urethane polymers, styrene polymers and silicone polymers and cyclic olefin copolymers;

said pre-polymer is selected from the group consisting of acrylates, epoxies, urethanes, esters, and silicones; and

said optional solvent is selected from the group consisting of aliphatic hydrocarbons, aromatic hydrocarbons, ethers, esters, alcohols, ketones.

9. The formulation according to claim 7 , wherein said composite material

is present in an amount of 1-60 wt %; and/or

is homogeneously distributed within said formulation.

10. A component comprising a substrate and a multitude of layers wherein at least one of said layers comprises a formulation according to claim 7 .

11. The component of claim 10 which is devoid of a barrier layer.

12. An optoelectronic device comprising a source of light and

a composite material according to claim 1 .

13. The device according to claim 12 , selected from the group consisting of light emitting diode, in a QLED-, OLED-, or liquid crystal display.

14. A method for manufacturing a composite material according to claim 1 , comprising the step of concomitant crystallization of compounds of formula (I) and compounds of formula (II)

(M 1 A 1 ) a M 2 b X c   (I),

M 3 d X 2 e   (II),

from a solution comprising a solvent and a moles (A 1 +M 1 ), b moles M 2 , c moles X, d moles M 3 and e moles X 2 ,

wherein the molar ratio of the compounds of formula (I):the compounds of formula (II) is in the range of 0.1-50 mol %.

15. An optoelectronic device comprising a source of light and a formulation according to claim 7 .

16. An optoelectronic device comprising a source of light and a component according to claim 10 .