Synthesis of nanoparticles

• US 20030032192A1
• Filed: 06/26/2002
• Published: 02/13/2003
• Est. Priority Date: 09/08/2000
• Status: Active Grant

• Current Assignee: Centrum für Angewandte Nanotechnologie (CAN) GmbH
• Original Assignee: Centrum für Angewandte Nanotechnologie (CAN) GmbH
• Inventors: Riwotzky, Carsten, Meysamy, Heike, Weller, Horst, Haase, Markus, Ibarra, Fernando, Haubold, Stephan
• Granted Patent: US 7,241,399 B2
• Time in Patent Office: Days
• US Class Current: 436/56
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C09D 11/03 characterised by features other than the chemical nature of the binder
• CPC Class Codes: C09D 11/50 Sympathetic, colour changing or similar inks
• CPC Class Codes: C09K 11/025 non-luminescent particle coatings or suspension media
• CPC Class Codes: C09K 11/595 with zinc or cadmium
• CPC Class Codes: C09K 11/621 Chalcogenides
• CPC Class Codes: C09K 11/666 Aluminates; Silicates
• CPC Class Codes: C09K 11/684 with alkaline earth metals
• CPC Class Codes: C09K 11/7727 Sulfates
• CPC Class Codes: C09K 11/7734 Aluminates
• CPC Class Codes: C09K 11/7736 Vanadates; Chromates; Molybdates; Tungstates
• CPC Class Codes: C09K 11/7738 with alkaline earth metals
• CPC Class Codes: C09K 11/7741 Sulfates
• CPC Class Codes: C09K 11/7755 Borates
• CPC Class Codes: C09K 11/7769 Oxides C09K11/7768 takes precedence
• CPC Class Codes: C09K 11/7772 Halogenides C09K11/7767 takes precedence
• CPC Class Codes: C09K 11/7774 Aluminates
• CPC Class Codes: C09K 11/77742 Silicates
• CPC Class Codes: C09K 11/7777 Phosphates
• CPC Class Codes: C09K 11/7792 : Aluminates
• CPC Class Codes: C09K 11/7794 : Vanadates; Chromates; Molybdates; Tungstates
• CPC Class Codes: C09K 11/7797 : Borates
• CPC Class Codes: C09K 11/7798 : Antimonates; Arsenates
• CPC Class Codes: G01N 2021/6439 : with indicators, stains, dyes, tags, labels, marks
• CPC Class Codes: G01N 21/6428 : Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" in vivo A61B5/00; immunoassay G01N33/53
• CPC Class Codes: Y10T 428/2991 : Coated
• CPC Class Codes: Y10T 436/13 : Tracers or tags

Abstract

The present invention relates to methods for the preparation of inorganic nanoparticles capable of fluorescence, wherein the nanoparticles consist of a host material that comprises at least one dopant. The synthesis of the invention in organic solvents allows to gain a considerably higher yield compared to the prior art synthesis in water. All kinds of objects can advantageously be marked and reliably authenticated by using an automated method on the basis of a characteristic emission. Further, the size distribution of the prepared nanoparticles is narrower which renders a subsequent size-selected separation process superfluous.

Claims

1. A method for synthesizing metal salt nanoparticles, comprising a crystal lattice or host lattice of which the cation is capable of being produced from a cation source and of which the anion is capable of being produced from a class of substances that serves as an anion source, in which method the host material can include compounds particularly from the group consisting of phosphates, halophosphates, arsenates, sulphates, borates, aluminates, gallates, silicates, germanates, oxides, vanadates, niobates, tantalates, wolframates, molybdates, alkalihalogenates, other halides, nitrides, sulphides, selenides, sulphoselenides, as well as oxysulphides, the method being characterized by the following steps:

a) preparation of a synthesis mixture, at least from

aa) an organic solvent which comprises at least one component controlling the crystal growth of the nanoparticles, in particular a component comprising a phosphororganic compound, or a monoalkylamine, particularly dodecylamine, or a dialkylamine, particularly bis(ethylhexyl)amine,

bb) a cation starting material which serves as cation source and which is soluble or at least dispersible in the synthesis mixture, particularly a metal salt starting compound, preferred a metal chloride or an alkoxide, or a metal acetate, and

cc) an anion starting material that serves as anion source, which is soluble or at least dispersible in the synthesis mixture and which is selected from said class of substances, said class of substances comprising;

aaa) free acids of the salts of the particular metal salt nanoparticles which are to be prepared, or

bbb) salts that are soluble or at least dispersible in the synthesis mixture, in particular salts with an organic cation, or metal salts, the latter preferably being alkali metal salts, or

ccc) organic compounds which release the anion beyond an increased synthesis minimum temperature, and a suitable, anion-donating substance is selected from the class of substances depending on a respective selection of the salt of the nanoparticles to be prepared, and

b) keeping the mixture at a predetermined synthesis minimum temperature during a synthesis period appropriate for said temperature.

2. The method according to claim 1, wherein

a) phosphoric acid is used as anion source for the preparation of nanoparticles with phosphorus-containing anions, wherein

boric acid is used as anion source for the preparation of nanoparticles with boron-containing anions, wherein hydrofluoric acid is used as anion source for the preparation of nanoparticles with fluorine-containing anions, wherein

b) in case of using a salt of the anion substance class that is sparingly soluble in the synthesis mixture, a complexing agent for the metal component of the metal salt is added to the synthesis mixture in order to improve the solubility of the salt, preferably a crown ether for alkali metal salts.

3. The method according to the preceding claim, wherein at least one of the following substances is comprised of the solvent as the phosphororganic compound for the growth controlling component:

a) esters of phosphinic acid, ((R₁—

)(R₂—

)(R₃—

O—

)P═

O),

b) diesters of phosphonic acid, ((R₁—

)(R₂O—

)(R₃—

O—

)P═

O),

c) triesters of phosphoric acid (trialkyl phosphates), ((R₁—

O—

)(R₂—

O—

)(R₃—

O—

)P═

O),

d) trialkyl phosphines, ((R₁—

)(R₂—

)(R₃—

)P), particularly trioctylphosphine (TOP),

e) trialkyl phosphine oxides, ((R₁—

)(R₂—

)(R₃—

)P═

O), particularly trioctylphosphine oxide (TOPO),

wherein R1, R2, R3 are branched or unbranched alkane chains comprising at least one carbon atom, or phenyl, tolyl, xylyl, or benzyl groups, or

f) a phosphoric amide, preferred tris-(dimethylamino)-phosphine, or

g) a phosphoric amide oxide, preferred tris-(dimethylamino)-phosphine oxide.

4. The method according to the preceding claim, wherein a triallyl phosphate or a trialkyl phosphine is used as a controlling component for the preparation of nanoparticles, and wherein per mol metal ions less than 10 mol, preferred 0.9 to 5 mol, and more preferred 0.95 to 2 mol of the controlling component is used.

5. The method according to one of the preceding claims, wherein at least one further component with preferably metal-chelating properties is added to the synthesis mixture, preferably in order to displace any water of crystallization present in the metal salt starting compounds, in particular

a) an ether compound, preferred dipentyl ether, dihexyl ether, diheptyl ether, dioctyl ether, dibenzyl ether, diisoamyl ether, ethylene glycol dibutyl ether, diethylene glycol dibutyl ether, or diphenyl ether, or/and

b) an alkane compound that boils above the synthesis minimum temperature, preferred dodecane or hexadecane, or/and

c) an amine compound, preferred dihexylamine, bis(2-ethylhexyl)amine, trioctylamine, tris(2-ethylhexyl)amine.

6. The method according to claim 3, wherein R1, R2, or R3 are branched or unbranched alkane chains carry at least one of the following groups:

carboxyl group (—

COOH), carboxylic acid ester group (—

COOR), amino groups (—

NH₂) and (—

NHR), hydroxyl group (—

OH), cyano group (—

CN), mercapto group (—

SH), bromine (—

Br) and chlorine (—

Cl), or combinations of these groups.

8. The method according to one of the preceding claims, wherein at least one of the group consisting of chlorides, bromides, iodides, alkoxides, metal acetates, or acetylacetonate is used as a starting material for the cation source.

9. The method according to one of the preceding claims, further comprising the following steps:

a) preparation of a first solution of the cation starting material in a—

preferably lower—

alcohol, particularly methanol, wherein preferably a metal salt is used which is non-oxidative and soluble in the synthesis mixture, and

b) mixing of the first solution with the solvent according to claim 1 or 2 in order to prepare the metal-chelating synthesis mixture,

c) keeping the synthesis mixture heated under inert gas, in particular under nitrogen.

10. The method according to the preceding claim further comprising the step of removing the preferably lower alcohol by distillation from the synthesis mixture during the synthesis

11. The method according to one of the preceding claims further comprising the step of:

Removing of one or more of the solvent components by distillation from the synthesis mixture, preferred under vacuum, preferred after the end of the synthesis period.

12. The method according to one of the preceding claims further comprising the step of:

Purifying the nanoparticles by washing with an alcohol, preferred with ethanol, or by diafiltration to get rid of attached by-products.

13. The method according to one of the preceding claims further comprising the step of:

Neutralizing the synthesis mixture using a base that is soluble in the synthesis mixture, preferred trihexylamine, triheptylamine, trioctylamine, tris(2-ethylhexyl)amine.

14. The method according to one of the preceding claims, wherein a hydrated metal salt is used as starting material.

15. The method according to one of the preceding claims which is used for synthesizing nanoparticles capable of fluorescence.

16. The method according to one of the preceding claims, wherein several different cation sources are used, particularly metal salt starting compounds, of which at least one metal is used as doping agent for the nanoparticles to be produced.

17. The method according to claim 1, wherein the crystal lattice or, in case of a doping, the host lattice comprises compounds of the type XY, wherein X is a cation of one or more elements of the main groups 1a, 2a, 3a, 4a, the subgroups 2b, 3b, 4b, 5b, 6b, 7b, or of the lanthanides of the periodical system, and wherein Y is either a polyatomic anion of one or more of the elements of the main groups 3a, 4a, 5a, of the subgroups 3b, 4b, 5b, 6b, 7b, and/or 8b as well as of elements of the main groups 6a, and/or 7, or a monoatomic anion of the main groups 5a, 6a, or 7a of the periodical system.

18. The method according to one of the preceding claims, wherein a phosphate ester, in particular a trialkyl phosphate, and preferred tributyl phosphate, is used as growth controlling component of the solvent for the preparation of LaPO₄ nanoparticles.

19. The method according to one of the preceding claims, wherein one ore more elements selected from a group comprising elements of the main groups 1a, 2a, or Al, Cr, Tl, Mn, Ag, Cu, As, Nb, Ni, Ti, In, Sb, Ga, Si, Pb, Bi, Zn, Co, and/or elements of the lanthanides are used for the doping.

20. The method according to one of the preceding claims, wherein two elements are used for the doping in different relative concentrations to each other, wherein one of the doping elements has a local maximum in the absorption spectrum for light, preferred for UV-light, and the other doping element has a fluorescence emission spectrum with at least one local maximum that has a distance Δ

λ

/λ

from the absorption maximum of the first doping element of at least 4%, preferred of more than 20%.

21. The method according to the preceding claim, wherein cerium and terbium are used for the doping and LaPO₄ as host material.

22. The method according to one of the preceding claims 1 to 19, wherein nanoparticles are synthesized using one of the following compounds:

LiI;

Eu;

NaI;

Tl;

CsI;

Tl;

CsI;

Na;

LiF;

Mg;

LiF;

Mg,Ti, LiF;

Mg,Na;

KMgF₃;

Mn;

Al₂O₃;

Eu;

BaFCl;

Eu;

BaFCl;

Sm;

BaFBr;

Eu;

BaFCl_0.5Br_0.5;

Sm;

BaY₂F₈;

A (A=Pr, Tm, Er, Ce);

BaSi₂O₅;

Pb;

BaMg₂Al₁₆O₂₇;

Eu;

BaMgAl₁₄O₂₃;

Eu;

BaMgAl₁₀O₁₇;

Eu;

(Ba, Mg)Al₂O₄;

Eu;

Ba₂P₂O₇;

Ti;

(Ba, Zn, Mg)₃Si₂O₇;

Pb;

Ce(Mg, Ba)Al₁₁O₁₉;

Ce_0.65Tb_0.35MgAl₁₁O₁₉;

MgAl₁₁O₁₉;

Ce,Tb;

MgF₂;

Mn;

MgS;

Eu;

MgS;

Ce;

MgS;

Sm;

MgS(Sm, Ce);

(Mg, Ca)S;

Eu;

MgSiO₃;

Mn;

3.5MgO.0.5MgF₂.GeO₂;

Mn;

MgWO₄;

Sm;

MgWO₄;

Pb;

6MgO.As₂O₅;

Mn;

(Zn, Mg)F₂;

Mn;

(Zn, Be)SO₄;

Mn;

Zn₂SiO₄;

Mn;

Zn₂SiO₄;

Mn,As;

ZnO;

Zn;

ZnO;

Zn,Si,Ga;

Zn₃(PO₄)₂;

Mn;

ZnS;

A (A=Ag, Al, Cu);

(Zn, Cd)S;

A (A=Cu, Al, Ag, Ni);

CdBO₄;

Mn;

CaF₂;

Dy;

CaS;

A (A=lanthanides, Bi);

(Ca, Sr)S;

Bi;

CaWO₄;

Pb;

CaWO₄;

Sm;

CaSO₄;

A (A=Mn, lanthanides);

3Ca₃(PO₄)₂.Ca(F, Cl)₂;

Sb, Mn;

CaSiO₃;

Mn, Pb;

Ca₂Al₂Si₂O₇;

Ce;

(Ca, Mg)SiO₃;

Ce;

(Ca, Mg)SiO₃;

Ti;

2SrO.6(B₂O₃).SrF₂;

Eu;

3Sr₃(PO₄)₂.CaCl₂;

Eu;

A₃(PO₄)₂.ACl₂;

Eu (A=Sr, Ca, Ba);

(Sr,Mg)₂P₂O₇;

Eu;

(Sr, Mg)₃(PO₄)₂;

Sn;

SrS;

Ce;

SrS;

Sm,Ce;

SrS;

Sm;

SrS;

Eu;

SrS;

Eu,Sm;

SrS;

Cu,Ag;

Sr₂P₂O₇;

Sn;

Sr₂P₂O₇;

Eu;

Sr₄Al₁₄O₂₅;

Eu;

SrGa₂S₄;

A (A=lanthanides, Pb);

SrGa₂S₄;

Pb;

Sr₃Gd₂Si₆O₁₈;

Pb,Mn;

YF₃;

Yb,Er;

YF₃;

Ln (Ln=lanthanides);

YLiF₄;

Ln (Ln=lanthanides);

Y₃Al₅O₁₂;

Ln (Ln=lanthanides);

YAl₃(BO₄)₃;

Nd,Yb;

(Y,Ga)BO₃;

Eu;

(Y,Gd)BO₃;

Eu;

Y₂Al₃Ga₂O₁₂;

Tb;

Y₂SiO₅;

Ln (Ln=lanthanides);

Y₂O₃;

Ln (Ln=lanthanides);

Y₂O₂S;

Ln (Ln=lanthanides);

YVO₄;

A (A=lanthanides, In);

Y(P,V)O₄;

Eu;

YTaO₄;

Nb;

YAlO₃;

A (A=Pr, Tm, Er, Ce);

YOCl;

Yb,Er;

LnPO₄;

Ce,Tb (Ln=lanthanides or mixtures of lanthanides);

LuVO₄;

Eu;

GdVO₄;

Eu;

Gd₂O₂S;

Tb;

GdMgB₅O₁₀;

Ce,Tb;

LaOBrTb;

La₂O₂S;

Tb;

LaF₃;

Nd,Ce;

BaYb₂F₈;

Eu;

NaYF₄;

Yb,Er;

NaGdF₄;

Yb,Er;

NaLaF₄;

Yb,Er;

LaF₃;

Yb,Er,Tm;

BaYF₅;

Yb,Er;

Ga₂O₃;

Dy;

GaN;

A (A=Pr, Eu, Er, Tm);

Bi₄Ge₃O₁₂;

LiNbO₃;

Nd,Yb;

LiNbO₃;

Er;

LiCaAlF₆;

Ce;

LiSrAlF₆;

Ce;

LiLuF₄;

A (A=Pr, Tm, Er, Ce);

Gd₃Ga₅O₁₂;

Tb;

Gd₃Ga₅O₁₂;

Eu;

Li₂B₄O₇;

Mn,SiO_x;

Er,Al (0<

x<

2).

23. The method according to one of the preceding claims 1 to 19, wherein nanoparticles are synthesized using one of the following compounds:

YVO₄;

Eu;

YVO₄;

Sm;

YVO₄;

Dy;

LaPO₄;

Eu;

LaPO₄;

Ce;

LaPO₄;

Ce,Tb;

ZnS;

Tb;

ZnS;

TbF₃;

ZnS;

Eu;

ZnS;

EuF₃;

Y₂O₃;

Eu;

Y₂O₂S;

Eu;

Y₂SiO₅;

Eu;

SiO₂;

Dy;

SiO₂;

Al;

Y₂O₃;

Tb;

CdS;

Mn;

ZnS;

Tb;

ZnS;

Ag;

ZnS;

Cu;

Ca₃(PO₄)₂;

Eu²⁺;

Ca₃(PO₄)₂;

Eu²⁺, Mn²⁺;

Sr₂SiO₄;

Eu²⁺;

or BaAl₂O₄;

Eu²⁺.

24. The method according to one of the preceding claims 1 to 19, wherein nanoparticles are synthesized using one of the following compounds:

MgF₂;

Mn;

ZnS;

Mn;

ZnS;

Ag;

ZnS;

Cu;

CaSiO₃;

A;

CaS;

A;

CaO;

A;

ZnS;

A;

Y₂O₃;

A, or MgF₂;

A (A=lanthanides).

25. The method according to one of the preceding claims, in particular according to claim 21, wherein a doping with terbium is achieved in the range from 0.5 to 30 mol percent, preferred from 5 to 25 mol percent and most preferred from 13 to 17 mol percent,

wherein the respective molar ratio between lanthanum and cerium is a ratio ranging from 0.13 to 7.5, preferred from 0.25 to 4, and most preferred from 0.9 to 1.1, and metal chloride salts serve as metal source.

26. The method according to claim 1 for synthesizing semiconductor (sc) nanoparticles, in particular of III-V- or of II-VI-semiconductors.

27. Nanoparticles prepared by using the method according to one of the preceding claims.

28. A substance, comprising nanoparticles according to the preceding claim.

31. The substance according to one of the two preceding claims, comprising two elements used for the doping in predetermined relative concentrations to each other, wherein one of the doping elements has a local maximum in the absorption spectrum for light, in particular for UV-light, and the other doping element has a fluorescence emission spectrum with at least one local maximum that has a distance Δ

λ

/λ

from the absorption maximum of the first doping element of at least 4%.

38. A nanoparticle carrier substance, in particular a carrier film, a carrier liquid, thereof in particular a carrier varnish or a carrier paint, or an aerosol, comprising doped nanoparticles according to claim 27, or a substance according to one of the claims 28 to 37.

39. The nanoparticle carrier substance according to the preceding claim, wherein the nanoparticles are embedded in a polymer, preferred a polymer film, in particular one made of polyethylene or polypropylene.

40. A polymer film, comprising doped nanoparticles according to claim 27 or a substance according to claim 28 to 37.

41. An object which is marked, into which the nanoparticles prepared by using the method according to one of the preceding claims 1 to 26 or into which a substance according to one of the claims 27 to 37 is/are incorporated such that

the particles or the substance is/are excitable by a predetermined energy source, preferred by electromagnetic irradiation, in particular radiation with a wavelength below 300 nm, or by irradiation by particles or electrons, and

that a fluorescence emission is caused, preferred in the visible range of light, in the UV-range, or in the near infra red-range (NIR), which is detectable externally to the object.

42. The object according to the preceding claim provided with a nanoparticle carrier substance according to one of the claims 38 or 39, or a polymer film according to claim 40.

43. The object according to the preceding claim, comprising a coating with a nanoparticle carrier substance.

46. The use of nanoparticles according to claim 27 or of a substance according to one of the claims 28 to 38 for the marking according to claim 44.

47. The use of nanoparticles according to claim 27 or of a substance according to one of the claims 28 to 38 for the marking of liquids or gases.

51. The use of doped nanoparticles according to claim 27 or of a substance according to one of the claims 28 to 39 for producing light in devices or lighting bodies.

52. The use of doped nanoparticles according to claim 27 or of a substance according to one of the claims 28 to 39 or of a polymer film according to claim 40 for the preparation of images which become visible only after an appropriate excitation.

55. The detection method according to one of the two preceding claims, comprising the steps of

recording and analysing the image of the fluorescence radiation source.

58. The device according to one of the two preceding claims, comprising

a means (30, 32, 34) for recording the image of the fluorescence source,

and a means (22, 24) for analysing the image of the fluorescence radiation source.

7. The method according to clam 3, wherein mixtures of the phosphororganic compounds are used.

29. A substance, comprising nanoparticles, comprising a crystal lattice or, in case of a doping, a host lattice, wherein

the host lattice comprises compounds of the type XY, wherein X is a cation of one or more elements of the main groups 1a, 2a, 3a, 4a, the subgroups 2b, 3b, 4b, 5b, 6b, 7b, or of the lanthanides of the periodical system, and wherein Y is either a polyatomic anion of one or more of the elements of the main groups 3a, 4a, 5a, of the subgroups 3b, 4b, 5b, 6b, 7b, and/or 8b as well as of elements of the main groups 6a, and/or 7, or a monoatomic anion of the main groups 5a, 6a, or 7a of the periodical system, and wherein

one ore more elements selected from a group comprising elements of the main groups 1a, 2a, or Al, Cr, Tl, Mn, Ag, Cu, As, Nb, Ni, Ti, In, Sb, Ga, Si, Pb, Bi, Zn, Co, and/or elements of the lanthanides are contained as a doping.

30. The substance according to the preceding claim, wherein the lattice comprises compounds particularly from one of the following groups:

phosphates, halophosphates, arsenates, sulphates, borates, aluminates, gallates, silicates, germanates, oxides, vanadates, niobates, tantalates, wolframates, molybdates, alkalihalogenates, other halides, nitrides, sulphides, selenides, sulphoselenides, or oxysulphides.

32. The substance according to claim 29, which comprises one or more of LiI:

Eu;

NaI;

Tl;

CsI;

Tl;

CsI;

Na;

LiF;

Mg;

LiF;

Mg,Ti, LiF;

Mg,Na;

KMgF₃;

Mn;

Al₂O₃;

Eu;

BaFCl;

Eu;

BaFCl;

Sm;

BaFBr;

Eu;

BaFCl_0.5Br_0.5;

Sm;

BaY₂F₈;

A (A=Pr, Tm, Er, Ce);

BaSi₂O₅;

Pb;

BaMg₂Al₁₆O₂₇;

Eu;

BaMgAl₁₄O₂₃;

Eu;

BaMgAl₁₀O₁₇;

Eu;

(Ba, Mg)Al₂O₄;

Eu;

Ba₂P₂O₇;

Ti;

(Ba, Zn, Mg)₃Si₂O₇;

Pb;

Ce(Mg, Ba)Al₁₁O₁₉;

Ce_0.65Tb_0.35MgAl₁₁O₁₉;

MgAl₁₁O₁₉;

Ce,Tb;

MgF₂;

Mn;

MgS;

Eu;

MgS;

Ce;

MgS;

Sm;

MgS(Sm, Ce);

(Mg, Ca)S;

Eu;

MgSiO₃;

Mn;

3.5MgO.0.5MgF₂.GeO₂;

Mn;

MgWO₄;

Sm;

MgWO₄;

Pb;

6MgO.As₂O₅;

Mn;

(Zn, Mg)F₂;

Mn;

(Zn, Be)SO₄;

Mn;

Zn₂SiO₄;

Mn;

Zn₂SiO₄;

Mn,As;

ZnO;

Zn;

ZnO;

Zn,Si,Ga;

Zn₃(PO₄)₂;

Mn;

ZnS;

A (A=Ag, Al, Cu);

(Zn, Cd)S;

A (A=Cu, Al, Ag, Ni);

CdBO₄;

Mn;

CaF₂;

Dy;

CaS;

A (A=lanthanides, Bi);

(Ca, Sr)S;

Bi;

CaWO₄;

Pb;

CaWO₄;

Sm;

CaSO₄;

A (A=Mn, lanthanides);

3Ca₃(PO₄)₂.Ca(F, Cl)₂;

Sb, Mn;

CaSiO₃;

Mn, Pb;

Ca₂Al₂Si₂O₇;

Ce;

(Ca, Mg)SiO₃;

Ce;

(Ca, Mg)SiO₃;

Ti;

2SrO.6(B₂O₃).SrF₂;

Eu;

3Sr₃(PO₄)₂.CaCl₂;

Eu;

A₃(PO₄)₂. ACl₂;

Eu (A=Sr, Ca, Ba);

(Sr,Mg)₂P₂O₇;

Eu;

(Sr, Mg)₃(PO₄)₂;

Sn;

SrS;

Ce;

SrS;

Sm,Ce;

SrS;

Sm;

SrS;

Eu;

SrS;

Eu,Sm;

SrS;

Cu,Ag;

Sr₂P₂O₇;

Sn;

Sr₂P₂O₇;

Eu;

Sr₄Al₁₄O₂₅;

Eu;

SrGa₂S₄;

A (A=lanthanides, Pb);

SrGa₂S₄;

Pb;

Sr₃Gd₂Si₆O₁₈;

Pb,Mn;

YF₃;

Yb,Er;

YF₃;

Ln (Ln=lanthanides);

YLiF₄;

Ln (Ln=lanthanides);

Y₃Al₅O₁₂;

Ln (Ln=lanthanides);

YAl₃(BO₄)₃;

Nd,Yb;

(Y,Ga)BO₃;

Eu;

(Y,Gd)BO₃;

Eu;

Y₂Al₃Ga₂O₁₂;

Tb;

Y₂SiO₅;

Ln (Ln=lanthanides);

Y₂O₃;

Ln (Ln=lanthanides);

Y₂O₂S;

Ln (Ln=lanthanides);

YVO₄;

A (A=lanthanides, In);

Y(P,V)O₄;

Eu;

YTaO₄;

Nb;

YAlO₃;

A (A=Pr, Tm, Er, Ce);

YOCl;

Yb,Er;

LnPO₄;

Ce,Tb (Ln=lanthanides or mixtures of lanthanides);

LuVO₄;

Eu;

GdVO₄;

Eu;

Gd₂O₂S;

Tb;

GdMgB₅O₁₀;

Ce,Tb;

LaOBrTb;

La₂O₂S;

Tb;

LaF₃;

Nd,Ce;

BaYb₂F₈;

Eu;

NaYF₄;

Yb,Er;

NaGdF₄;

Yb,Er;

NaLaF₄;

Yb,Er;

LaF₃;

Yb,Er,Tm;

BaYF₅;

Yb,Er;

Ga₂O₃;

Dy;

GaN;

A (A=Pr, Eu, Er, Tm);

Bi₄Ge₃O₁₂;

LiNbO₃;

Nd,Yb;

LiNbO₃;

Er;

LiCaAlF₆;

Ce;

LiSrAlF₆;

Ce;

LiLuF₄;

A (A=Pr, Tm, Er, Ce);

Gd₃Ga₅O₁₂;

Tb;

Gd₃Ga₅O₁₂;

Eu;

Li₂B₄O₇;

Mn,SiO_x;

Er,Al (0<

x<

2) as a material for the doped nanoparticles.

33. The substance according to claim 29, wherein the material for the doped nanoparticles comprises one or more of YVO₄:

Eu;

YVO₄;

Sm;

YVO₄;

Dy;

LaPO₄;

Eu;

LaPO₄;

Ce;

LaPO₄;

Ce,Tb;

ZnS;

Tb;

ZnS;

TbF₃;

ZnS;

Eu;

ZnS;

EuF₃;

Y₂O₃;

Eu;

Y₂O₂S;

Eu;

Y₂SiO₅;

Eu;

SiO₂;

Dy;

SiO₂;

Al;

Y₂O₃;

Tb;

CdS;

Mn;

ZnS;

Tb;

ZnS;

Ag;

ZnS;

Cu;

Ca₃(PO₄)₂;

Eu²⁺;

Ca₃(PO₄)₂;

Eu²⁺, Mn²⁺;

Sr₂SiO₄;

Eu²⁺;

or BaAl₂O₄;

Eu²⁺.

34. The substance according to claim 29, wherein the material for the doped nanoparticles comprises one or more of MgF₂:

Mn;

ZnS;

Mn;

ZnS;

Ag;

ZnS;

Cu;

CaSiO₃;

A;

CaS;

A;

CaO;

A;

ZnS;

A;

Y₂O₃;

A, or MgF₂;

A (A=lanthanides).

35. The substance according to claim 29, wherein the host lattice comprises a lanthanum or lanthanide compound, in particular LaPO₄, and wherein dopants of the group of lanthanides are contained.

36. The substance according to the preceding claim, comprising two dopants, in particular cerium and terbium, wherein one of the two is characterized as an energy absorber, in particular as a UV-light absorber, and the other as a fluorescence light emitter.

37. The substance according to one of the preceding claims 29 to 36, preferably comprising nanoparticles which are selected from the substance group consisting of rare earth metal phosphates, or IIIrd main group phosphates, or phosphates of calcium (Ca), strontium (Sr), or barium (Ba),

wherein the nanoparticles have a size, measured along their longest axis, of maximally 15 nm, preferred of maximally 10 nm, and most preferred of 4 to 5 nm with a standard deviation of less than 30%, preferred for each case of less than 10%.

48. The use of a UV-light absorbing substance according to claim 36 for converting UV-light into another form of energy.

49. The use of a UV-light absorbing substance according to claim 36 as a converter to visible light.

44. A use of nanoparticles, comprising one or more substances selected from the family of phosphors, in particular a use of wolframates, tantalates, borates, vanadates, sulphoxides, silicates, gallates, aluminates, halide compounds

for the marking of objects, in particular of banknotes, carriers for information, computer components, automobile components, motor elements, documents, locking devices, anti-burglary devices, objects transparent for visible light, jewellery, or of works of art, or for the making of finger-prints.

45. A use of doped nanoparticles for a marking according to the preceding claim.

50. A use of nanoparticles, comprising one or more substances selected from the family of phosphors, in particular a way of use of wolframates, tantalates, borates, vanadates, sulphoxides, silicates, gallates, aluminates, halide compounds

for producing light in devices or lighting bodies.

53. A detection method to recognize the fluorescence of a test substance (28) as identical with the fluorescence of a reference substance of a predetermined nanoparticle type having a fluorescence emission main peak (40), comprising the steps:

exciting the test substance (28) using an excitation method that is known to be suitable for the predetermined nanoparticle type,

filtering the spectral region of the main peak of the test substance (28),

filtering at least one secondary spectral region next to the main peak (40), where relatively to the intensity of the main peak a low or not any intensity is expected for the predetermined nanoparticle type,

quantifying the filtered emission intensities within the predetermined spectral regions, and

determining one or several relations of the filtered emission intensities to each other,

evaluating the correspondence of the test substance (28) with the reference substance on the basis of the relations.

54. The detection method according to the preceding claim, wherein apart from the main peak (40) two or more of the secondary spectral regions are filtered and evaluated.

56. A device to carry out the detection method according to claim 53, comprising

a means (26) for exciting the test substance (28) with an excitation spectrum that is known to be suitable for the predetermined nanoparticle type,

a means (12) for filtering the spectral region of the main peak of the test substance (28),

a means (10, 14) for filtering at least one secondary spectral region next to the main peak (40) where relatively to the intensity of the main peak a low or not any intensity is expected for the predetermined nanoparticle type,

a means (16, 18, 20) for quantifying the filtered emission intensities within the predetermined spectral regions,

a means (22) for determining one or several relations of the filtered emission intensities to each other,

a means (22, 24) for evaluating the correspondence of the test substance (28) with the reference substance on the basis of the relations.

57. The device according to the preceding claim, comprising a means (16, 20, 22, 24) for filtering and analysing two or more of the secondary spectral regions apart from the main peak (40).