Semiconductor light emitting nanoparticle

1. A semiconductor nano-sized light emitting material comprising a core, optionally one or more shell layers and a ligand coated onto the core or the outermost surface of the shell layers,

wherein the ligand is one or more metal phosphonate and/or derivatives thereof, and

wherein the metal phosphonate follows one of the following structures according to formula (I), (II), (III), (IV) and/or (V)

wherein M 2+ is a metal cation that is Mg, Ca, Ba, Cu, Fe, Zn or their mixtures, and M + is a metal cation that is Cu,

R is selected from the group consisting of alkyl, alkenyl, alkynyl, aryl and alkylaryl and wherein R comprises at least 2 and not more than 20 carbon atoms, and

wherein X is selected from the group consisting of hydroxyl, ester and ether.

2. The material according to claim 1 , wherein the metal phosphonate follows one of the following structures according to formula (I), (II), (III), (IV) and/or (V), and

wherein R further comprises at least one functional group selected from the group consisting of hydroxyl, carbonyl, carboxyl, ether, ester, amino, thio, silyl, sulfo and halogen.

3. The material according to claim 1 , wherein the metal cation M 2+ used for the metal phosphonate is Mg and/or Zn.

4. The material according to claim 1 , wherein the metal cation M 2+ used for the metal phosphonate is Zn.

5. The material according to claim 1 , wherein said semiconductor nano-sized light emitting material comprises a core and optionally one or more shell layers

wherein said core is formed from one, two or more compounds according to formula (VI),

[A 1 B 1 ]  (VI)

in which

[A 1 ] stands for a metal selected from the group consisting of zinc, cadmium, indium or their mixtures;

[B 1 ] stands for a non-metal selected form the group consisting of sulphur, selenium, phosphorous or their mixtures.

6. The semiconductor nano-sized light emitting material of claim 5 , wherein [A 1 B 1 ] stands for one, two or more compounds selected from the group consisting of CdS, CdSe, CdSeS, CdZnS, ZnS, ZnSe, ZnSeS, and InP.

7. The semiconductor nano-sized light emitting material according to claim 5 , wherein

[A 1 ] stands for indium; and

[B 1 ] stands for phosphorous.

8. The material according to claim 1 , wherein said shell of said semiconductor nano-sized light emitting material is formed from one, two or more compounds according to formula (VII)

[A 2 B 2 ]  (VII)

in which

[A 2 ] stands for a metal selected from the group consisting of zinc, cadmium or their mixtures;

[B 2 ] stands for a non-metal selected form the group consisting of sulphur, selenium, tellurium or their mixtures.

9. The material according to claim 8 , wherein [A 2 B 2 ] stands for one, two or more compounds selected from the group consisting of CdS, CdSe, CdSeS, CdZnS, ZnS, ZnSe and ZnSeS, ZnSeSTe.

10. The material of claim 9 , wherein said semiconductor nano-sized light emitting material comprises a core shell structure of the core [A 1 B 1 ] and at least one shell [A 2 B 2 ], said core/shell structure [A 1 B 1 ]/[A 2 B 2 ] being selected from the group consisting of

CdSeS/CdZnS

CdSe/ZnS

InP/ZnS

InP/ZnSe

InP(Zn)/ZnSe

ZnSe/CdS

ZnSe/ZnS

or their mixtures.

11. A process for manufacturing a semiconductor nano-sized light emitting material comprising a core, optionally one or more shell layers and metal phosphonate acid and/or derivatives thereof coated onto the core or the outermost surface of the shell layers,

comprising the following:

(a) providing at least one salt of at least one metal [A 1 ] and/or [A 2 ] optionally dissolved in a suitable solvent;

(b) adding at least one source of at least one non-metal [B 1 ] and/or [B 2 ] to obtain an intermediate compound [A 1 B 1 ] or [A 1 B 1 ]/[A 2 B 2 ];

(c) coating said intermediate compound [A 1 B 1 ]/[A 2 B 2 ] from (b), optionally in the presence of a solvent, by bringing it into contact with a source of metal phosphonate and/or derivatives thereof, and optionally

(d) subjecting said coated intermediate of (c) to illumination with light with a peak light wavelength of about 300 to about 650 nm to increase quantum yield of the nano-sized material,

wherein [A 1 ] stands for a metal selected from the group consisting of zinc, cadmium, indium and their mixtures;

[B 1 ] stands for a non-metal selected form the group consisting of sulphur, selenium, phosphorous and their mixtures,

[A 2 ] stands for a metal selected from the group consisting of zinc, cadmium or their mixtures;

[B 2 ] stands for a non-metal selected form the group consisting of sulphur, selenium, or their mixtures.

12. The process of claim 11 , wherein illumination is carried out using light with a peak light wavelength of about 365 to about 470 nm and/or intensities of about 0.025 to about 1 Wcm −2 .

13. A semiconductor nano-sized light emitting material comprising a core, optionally one or more shell layers and a ligand coated onto the core or the outermost surface of the shell layers, obtained by the following:

(a) providing at least one salt of at least one metal [A 1 ] and/or [A 2 ] optionally dissolved in a suitable solvent;

(b) adding at least one source of at least one non-metal [B 1 ] and/or [B 2 ] to obtain an intermediate compound [A 1 B 1 ]/[A 2 B 2 ];

(c) coating said intermediate compound [A 1 B 1 ]/[A 2 B 2 ] from (b), optionally in the presence of a solvent, by bringing it into contact with a source of a metal phosphonate and/or derivatives thereof,

wherein the metal phosphonate follows one of the following structures according to formula (I), (II), (III), (IV) and/or (V)

and optionally

(d) subjecting said coated intermediate of (c) to illumination with light with a peak light wavelength of about 300 to about 650 nm to increase quantum yield of the nano-sized material,

wherein M 2+ is Mg, Ca, Ba, Cu, Fe, Zn or their mixtures, and M + is Cu,

R is selected from the group consisting of alkyl, alkenyl, alkynyl, aryl and alkylaryl and wherein R comprises at least 2 and not more than 20 carbon atoms,

X is selected from the group consisting of hydroxyl, ester and ether,

[A 1 ] stands for a metal selected from the group consisting of zinc, cadmium, indium and their mixtures;

[B 1 ] stands for a non-metal selected form the group consisting of sulphur, selenium, phosphorous and their mixtures,

[A 2 ] stands for a metal selected from the group consisting of zinc, cadmium and their mixtures; and

[B 2 ] stands for a non-metal selected form the group consisting of sulphur, selenium, and their mixtures.

14. A composition comprising at least one semiconductor nano-sized light emitting material according to claim 1 , and at least one additional matrix material.

15. A formulation comprising one or more of the semiconductor nano-sized material according to claim 1 , and at least one solvent.

16. An optical medium comprising in said medium the semiconductor nano-sized light emitting material according to claim 1 .

17. An optical or electronic device comprising said optical medium according to claim 16 .

18. The semiconductor nano-sized light emitting material according to claim 1 , consisting of a core, optionally one or more shell layers and a ligand coated onto the core or the outermost surface of the shell layers.