GLASS COMPOSITE PARTICLES AND USES THEREOF

Abstract

A composite particle including a core and a shell, wherein the core has at least one inorganic nanoparticle and the shell is made of vitrified glass, methods for obtaining thereof and uses thereof. The uses include a film having a host material and at least one composite particle and an optoelectronic devise including at least one composite particle or the film.

Claims

1-15. (canceled)

16. A composite particle comprising a core and a shell, wherein the core comprises at least one inorganic nanoparticle and the shell is made of vitrified glass, and wherein the composite particle has an average size strictly inferior to 500 nm.

17. The composite particle according to claim 16, wherein the composite particle has an average diameter ranging from 5 nm to 500 nm.

18. The composite particle according to claim 16, wherein the composite particle exhibits a photoluminescence quantum yield (PLQY) of at least 5%.

19. The composite particle according to claim 16, wherein the composite particle is a vitrified glass particle comprising at least one inorganic nanoparticle.

20. The composite particle according to claim 16, wherein the at least one inorganic nanoparticle is a luminescent inorganic nanoparticle.

21. The composite particle according to claim 20, wherein the at least one luminescent inorganic nanoparticle is a semiconductor nanocrystal.

22. The composite particle according to claim 21, wherein the semiconductor nanocrystal comprises a material of formula M.sub.xN.sub.yE.sub.zA.sub.w, wherein: M is selected from the group consisting of Zn, Cd, Hg, Cu, Ag, Au, Ni, Pd, Pt, Co, Fe, Ru, Os, Mn, Tc, Re, Cr, Mo, W, V, Nd, Ta, Ti, Zr, Hf, Be, Mg, Ca, Sr, Ba, Al, Ga, In, Tl, Si, Ge, Sn, Pb, As, Sb, Bi, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Cs or a mixture thereof; N is selected from the group consisting of Zn, Cd, Hg, Cu, Ag, Au, Ni, Pd, Pt, Co, Fe, Ru, Os, Mn, Tc, Re, Cr, Mo, W, V, Nd, Ta, Ti, Zr, Hf, Be, Mg, Ca, Sr, Ba, Al, Ga, In, Tl, Si, Ge, Sn, Pb, As, Sb, Bi, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Cs or a mixture thereof; E is selected from the group consisting of O, S, Se, Te, C, N, P, As, Sb, F, Cl, Br, I, or a mixture thereof; A is selected from the group consisting of O, S, Se, Te, C, N, P, As, Sb, F, Cl, Br, I, or a mixture thereof; and w, x, y and z are independently a decimal number from 0 to 5, at the condition that when w is 0, x, y and z are not 0, when x is 0, w, y and z are not 0, when y is 0, w, x and z are not 0 and when z is 0, w, x and y are not 0.

23. The composite particle according to claim 16, wherein the shell comprises Si.sub.yO.sub.x, B.sub.yO.sub.x, P.sub.yO.sub.x, Ge.sub.yO.sub.x, As.sub.yO.sub.x, Al.sub.yO.sub.x, Fe.sub.yO.sub.x, Ti.sub.yO.sub.x, Zr.sub.yO.sub.x, Ni.sub.yO.sub.x, Zn.sub.yO.sub.x, CaO.sub.yO.sub.x, Na.sub.yO.sub.x, Ba.sub.yO.sub.x, K.sub.yO.sub.x, MgO.sub.yO.sub.x, Pb.sub.yO.sub.x, Ag.sub.yO.sub.x, V.sub.yO.sub.x, P.sub.yO.sub.x, Te.sub.yO.sub.x, MnO.sub.yO.sub.x or a mixture thereof; x and y are independently a decimal number from 0 to 10, at the condition that when x is 0, y is not 0, when y is 0, x is not 0.

24. A method for obtaining the composite particle according to claim 16, comprising the steps of: a) mixing in solution of: at least one precursor of at least one element selected from the group constituted by silicon, boron, phosphorus, germanium, arsenic, aluminium, iron, titanium, zirconium, nickel, zinc, calcium, sodium, barium, potassium, magnesium, lead, silver, vanadium, phosphorus, tellurium, manganese; optionally, at least one precursor of at least one heteroelement selected from the group constituted by cadmium, sulfur, selenium, indium, tellurium, mercury, tin, copper, nitrogen, gallium, antimony, thallium, molybdenum, palladium, cerium, tungsten, cobalt, manganese, silicon, boron, phosphorus, germanium, arsenic, aluminium, iron, titanium, zirconium, nickel, zinc, calcium, sodium, barium, potassium, magnesium, lead, vanadium; at least one colloidal solution comprising at least one inorganic nanoparticle (13); optionally, at least one organic solvent; optionally, at least one aqueous solvent; optionally, at least one base or one acid; optionally, water; and optionally, at least one surfactant; optionally, at least one solution comprising Al.sub.2O.sub.3, SiO.sub.2, MgO, ZnO, ZrO.sub.2, TiO.sub.2 nanoparticles, or a mixture thereof; b) forming droplets of said mixing solution; c) dispersing said droplets in a gas flow; d) heating said dispersed droplets at a temperature sufficient to obtain a vitrified shell around the composite particles; e) cooling of said composite particles; and f) separating and collecting said composite particles.

25. The method according to claim 24, wherein the droplets are formed by spray-drying or spray-pyrolysis.

26. The method according to claim 24, further comprising repeating steps d) to f) at least one time on the composite particles obtained at step f).

27. The method according to claim 24, further comprising the steps of: g) mixing the composite particles obtained by the method of the invention with at least one organic solvent; h) forming droplets of said mixing solution; i) dispersing said droplets in a gas flow; j) heating said dispersed droplets at a temperature sufficient to obtain a vitrified shell around the composite particles; k) cooling of said composite particles; l) separating and collecting said composite particles; and m) optionally, repeating at least once steps g) to l).

28. The method according to claim 24, further comprising the steps of: n) mixing the composite particles obtained by the method of the invention with: at least one precursor of at least one element selected from the group constituted by silicon, boron, phosphorus, germanium, arsenic, aluminium, iron, titanium, zirconium, nickel, zinc, calcium, sodium, barium, potassium, magnesium, lead, silver, vanadium, phosphorus, tellurium, manganese; optionally, at least one precursor of at least one hetero-element selected from the group constituted by cadmium, sulfur, selenium, indium, tellurium, mercury, tin, copper, nitrogen, gallium, antimony, thallium, molybdenum, palladium, cerium, tungsten, cobalt, manganese, silicon, boron, phosphorus, germanium, arsenic, aluminium, iron, titanium, zirconium, nickel, zinc, calcium, sodium, barium, potassium, magnesium, lead, vanadium; optionally, at least one colloidal solution comprising at least one inorganic nanoparticle; optionally, at least one organic solvent; optionally, at least one aqueous solvent; optionally, at least one base or one acid; optionally, water; and optionally, at least one surfactant; optionally, at least one solution comprising Al.sub.2O.sub.3, SiO.sub.2, MgO, ZnO, ZrO.sub.2, TiO.sub.2 nanoparticles, or a mixture thereof; o) forming droplets of said mixing solution; p) dispersing said droplets in a gas flow; q) heating said dispersed droplets at a temperature sufficient to obtain a vitrified shell round the composite particles; r) cooling of said composite particles; s) separating and collecting said composite particles; and t) optionally repeating at least once steps n) to s).

29. A film comprising a host material and at least one composite particle according to claim 16.

30. An optoelectronic device comprising at least one composite particle according to claim 16 or a film comprising a host material and said at least one composite particle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[1389] FIG. 1 illustrates a composite particle 1 comprising a non-vitrified core 11 and a shell 12, wherein the core 11 comprises one inorganic nanoparticle 13 and the shell 12 is made of vitrified glass.

[1390] FIG. 2 illustrates a composite particle 1 comprising a core and a shell 12, wherein the core comprises one spherical inorganic nanoparticle 131 and the shell 12 is made of vitrified glass.

[1391] FIG. 3 illustrates a composite particle 1 comprising a core and a shell 12, wherein the core comprises one quasi-2D inorganic nanoparticle 132 and the shell 12 is made of vitrified glass.

[1392] FIG. 4 illustrates a preferred embodiment of the invention, wherein the composite particle 1 comprises a core and a shell 12, wherein the core comprises two spherical inorganic nanoparticles 131 and the shell 12 is made of vitrified glass.

[1393] FIG. 5 illustrates a preferred embodiment of the invention, wherein the composite particle 1 comprises a core and a shell 12, wherein the core comprises two quasi-2D inorganic nanoparticles 132 and the shell 12 is made of vitrified glass.

[1394] FIG. 6 illustrates different inorganic nanoparticles 13.

[1395] FIG. 6A illustrates a core nanoparticle 13 without a shell 133.

[1396] FIG. 6B illustrates a core 133/shell 134 nanoparticle 13 with one shell 134.

[1397] FIG. 6C illustrates a core 133/shell (134, 135) nanoparticle 13 with two different shells (134, 135).

[1398] FIG. 6D illustrates a core 133/shell (134, 135, 136) nanoparticle 13 with two different shells (134, 135) surrounded by an oxide insulator shell 136.

[1399] FIG. 6E illustrates a core 133/crown 137 nanoparticle 13.

[1400] FIG. 7 illustrates a preferred embodiment of the invention, wherein the composite particle 1 comprises a core and a shell 12, wherein the core comprises one quasi-2D inorganic nanoparticle 132 and two spherical inorganic nanoparticles 131; and the shell 12 is made of vitrified glass.

[1401] FIG. 8 illustrates the device 2 applying the method of the invention: the gas flow originates from a gas supply 21, passes through the means for forming droplets 22 of mixing solution; the droplets are dispersed in the gas flow and carried in a tube 23, then heated in means for heating 24 to obtain composite particles 1; said composite particles 1 are cooled in means for cooling 25, then separated and collected by means for separating and collecting particles 26; wherein a pumping device 27 ensure the gas flow.

[1402] FIG. 9 illustrates an optoelectronic device.

[1403] FIG. 9A illustrates an optoelectronic device comprising a LED support 3, a LED chip 4 and composite particles 1 deposited on said LED chip 4, wherein the composite particles 1 cover the LED chip 4.

[1404] FIG. 9B illustrates an optoelectronic device comprising a LED support 3, a LED chip 4 and composite particles 1 deposited on said LED chip 4 wherein the composite particles 1 cover and surround the LED chip 4.

[1405] FIG. 10 illustrates a microsized LED 5 array comprising a LED support 3 and a plurality of microsized LED 5, wherein the pixel pitch D is the distance from the center of a pixel to the center of the next pixel.

[1406] FIG. 11 illustrates an optoelectronic device.

[1407] FIG. 11A illustrates an optoelectronic device comprising a LED support 3, a microsized LED 5 and composite particles 1 deposited on said microsized LED 5, wherein the composite particles 1 cover the microsized LED 5.

[1408] FIG. 11B illustrates an optoelectronic device comprising a LED support 3, a microsized LED 5 and composite particles 1 deposited on said microsized LED 5 wherein the composite particles 1 cover and surround the microsized LED 5.

[1409] FIG. 12 is TEM images showing inorganic nanoparticles (dark contrast) clearly embedded in a silica shell (bright contrast).

[1410] FIG. 13A-B is HR-TEM images showing a CdSe/CdZnS nanoplatelet with an atomically flat CdSe core.

[1411] FIG. 14A-C is STEM-HAADF images showing CdSe/CdS nanoplatelets with atomically flat CdSe cores.

[1412] FIG. 15 is TEM images showing inorganic nanoparticles (dark contrast) clearly embedded in a silica shell (bright contrast).

[1413] FIG. 16A shows the emission spectra of CdSe@CdS@ZnS nanoplatelets before and after encapsulation in silica glass.

[1414] FIG. 16B shows the emission intensity versus time for CdSe@CdS@ZnS nanoplatelets before and after encapsulation in silica glass.

EXAMPLES

[1415] The present invention is further illustrated by the following examples.

Example 1

Inorganic Nanoparticles 13 Preparation

[1416] CdSe Nanoplatelets

[1417] 170 mg of cadmium myristate (Cd(myr).sub.2) (0.3 mmol) and 15 mL of octadecene (ODE) are introduced in a three neck flask and are degassed under vacuum. The mixture is heated under agron flow at 250 C. and 1 mL of a dispersion of Se 100 mesh sonicated in ODE (0.1 M) are quickly injected. After 30 seconds, 80 mg of cadmium acetate (Cd(OAc).sub.2) (0.3 mmol) are introduced. The mixture is heated for 10 minutes at 250 C.

[1418] CdSe@CdZnS Nanoplatelets

[1419] In a three neck flask, 15 mL of trioctylamine are introduced and degassed under vacuum at 100 C. Then the reaction mixture is heated at 300 C. under argon and 5 mL of CdSe nanoplatelets in octadecene (ODE) are swiftly injected followed by the injection of 7 mL of 0.1 M octanethiol solution in ODE, 3.5 mL of 0.1 M cadmium oleate (Cd(OA).sub.2) in ODE and 3.5 mL of 0.1M zinc oleate (Zn(OA).sub.2) in ODE with syringe pumps at a constant rate over 90 min. After the addition, the reaction is heated at 300 C. for 90 minutes.

[1420] CdSe@CdS@ZnS Nanoplatelets

[1421] First step: CdSe@CdS Nanoplatelets

[1422] In a three neck flask, 15 mL of trioctylamine are introduced and degassed under vacuum at 100 C. Then the reaction mixture is heated at 300 C. under argon and 5 mL of CdSe nanoplatelets in octadecene (ODE) are swiftly injected followed by the injection of 7 mL of 0.1 M octanethiol solution in ODE and 7 mL of 0.1 M cadmium oleate (Cd(OA).sub.2) in ODE with syringe pumps at a constant rate over 90 min After the addition, the reaction is heated at 300 C. for 90 minutes. The resulting particles were washed with heptane and ethanol.

[1423] Second Step: CdSe@CdS@ZnS Nanoplatelets

[1424] In a three neck flask, 15 mL of trioctylamine are introduced and degassed under vacuum at 100 C. Then the reaction mixture is heated at 300 C. under argon and 5 mL of CdSe@CdS nanoplatelets in octadecene (ODE) are swiftly injected followed by the injection of 7 mL of 0.1 M octanethiol solution in ODE and 7 mL of 0.1 M zinc oleate (Zn(OA)2) in ODE with syringe pumps at a constant rate over 90 min After the addition, the reaction is heated at 300 C. for 90 minutes.

[1425] Silanization of CdSe@CdZnS Nanoplatelets

[1426] 1 mL of CdSe@CdZnS nanoplatelets suspended in hexane (1.0 M) were precipitated by addition of 500 L of ethanol and centrifugation at 6000 rpm for 10 minutes. The supernatant was discarded and the precipitate was recovered with 900 L of toluene. 100 L of n-octyltrimethoxysilane were added and the solution was stirred for 16 hours.

[1427] Ligand Exchanges

[1428] Exchange Ligands for Phase Transfer in Basic Aqueous Solution

[1429] 100 L of CdSe@CdZnS nanoplatelets suspended in heptane were mixed with 3-mercaptopropionic acid and heated at 60 C. for several hours. The nanoplatelets were then precipitated by centrifugation and redispersed in dimethylformamide Potassium tert-butoxide were added to the solution before adding ethanol and centrifugation. The final colloidal nanoparticles were redispersed in water.

[1430] Exchange Ligands for Phase Transfer in Acidic Aqueous Solution

[1431] 100 L of CdSe@CdZnS nanoplatelets suspended in a basic aqueous solution were mixed with ethanol and centrifugated. A PEG-based polymer was solubilized in water and added to the precipitated nanoplatelets. Acetic acid was dissolved in the colloidal suspension to control the acidic pH.

Example 2

Composite Particles 1 PreparationCdSe@CdZnS@SiO.SUB.2

[1432] 10 L of silanized CdSe@CdZnS nanoplatelets suspended in toluene (1.0 M) were added into a solution of 200 L of deionized water, 50 L of acetic acid, 150 L of TEOS and 5 mL of tetrahydrofuran previously prepared and stirred for 24 h. The mixture was then introduced into an atomization chamber and atomized through a tube furnace heated at 300 C. with a nitrogen flow of 40 cm.sup.3/s, as described in the invention. The composite particles 1 were collected at the surface of a PTFE hydrophilic filter with a pore size of 200 nm and then suspended in acetone using sonication for 10 minutes.

[1433] In FIG. 12, TEM images show inorganic nanoparticles 13 (dark contrast) clearly embedded in a silica shell 12 (bright contrast).

Example 3

Composite Particles 1 PreparationCdSe@CdZnS@Si.SUB.x.Na.SUB.y.Ca.SUB.z.O.SUB.v

[1434] 100 L of CdSe@CdZnS nanoplatelets suspended in tetrahydrofuran (1.0 M), 200 L of deionized water, 10 L of acetic acid, 400 L of polydiethoxysilane, 5 mg of calcium nitrate and 3 mg of sodium nitrate were added into an atomization chamber. After 10 minutes of magnetic stirring, the liquid mixture was sprayed towards a tube furnace heated at 525 C. with a nitrogen flow of 30 cm.sup.3/s, as described in the invention. The composite particles 1 were collected at the surface of a filter with a pore size of 1 m and then suspended in ethanol using sonication for 10 minutes.

Example 4

Composite Particles 1 PreparationCdSe@CdZnS@Si.SUB.x.Na.SUB.x.Ca.SUB.z.O.SUB.v

[1435] 100 L of CdSe@CdZnS nanoplatelets suspended in 1,2-propanediol (1.0 M), 200 L of deionized water, 10 L of acetic acid and 150 L of TEOS, 84 mg of calcium nitrate and 3 mg of sodium nitrate were added into an atomization chamber. After 10 minutes of magnetic stirring, the liquid mixture was sprayed towards a tube furnace heated at 300 C. with a nitrogen flow of 20 cm.sup.3/s, as described in the invention. The composite particles 1 were collected at the surface of a filter with a pore size of 1 m and then suspended in ethanol using sonication for 10 minutes.

Example 5

Composite Particles 1 PreparationCdSe@CdZnS@SiO.SUB.2

[1436] 100 L of CdSe@CdZnS nanoplatelets suspended in hexanol (1.0 M), 150 L of deionized water, 30 L of ammonium hydroxide (28w % in water) and 200 L of TEOS were added into an atomization chamber. After 12 hours of magnetic stirring, the liquid mixture was atomized through a tube furnace heated at 700 C. with a nitrogen flow of 40 cm.sup.3/s, as described in the invention. The composite particles 1 were collected at the surface of a filter with a pore size of 5 m and then suspended in hexanol using sonication for 10 minutes.

[1437] The resulting solution of composite particles 1 was introduced in the atomization chamber and sprayed towards a tube furnace at 1200 C. with a nitrogen flow of 100 cm.sup.3/s, as described in the invention. The composite particles 1 were collected on the tube wall by thermophoresis by using the cooling system, allowing to separate and select the composite particles 1 depending on their size. Said selected composite particles 1 were suspended in ethanol using sonication for 10 minutes. The second heating and cooling steps permit to ensure a better densification of the composite particles 1.

Example 6

Composite Particles 1 PreparationCdSe@SiO.SUB.2

[1438] 100 L of CdSe nanoplatelets suspended in tetrahydrofuran (1.0 M) were mixed with 2 L of N-Octadecyltrimethoxysilane. After 10 minutes of magnetic stirring, 150 L of deionized water, 10 L of acetic and 200 L of TEOS were added. The solution was transferred into an atomization chamber. After 10 minutes of magnetic stirring, the liquid mixture was sprayed towards a tube furnace heated at 1300 C. with a nitrogen flow of 30 cm.sup.3/s, as described in the invention. The composite particles 1 were collected at the surface of a filter with a pore size of 1 m and then suspended in ethanol using sonication for 10 minutes.

Example 7

Composite Particles 1 PreparationCdSe@CdZnS@Si.SUB.x.Na.SUB.x.Ca.SUB.z.O.SUB.v

[1439] 100 L of CdSe@CdZnS nanoplatelets suspended in tetrahydrofuran (1.0 M), 500 L of deionized water, 50 L of acetic acid, 400 L of polydiethoxysilane, 5 mg of calcium nitrate and 3 mg of sodium nitrate were added into an atomization chamber. After 10 minutes of magnetic stirring, the liquid mixture was sprayed towards a tube furnace heated at 525 C. with a nitrogen flow of 30 cm.sup.3/s, as described in the invention. The composite particles 1 were collected at the surface of a filter with a pore size of 1 m and then suspended in acetone using sonication for 10 minutes.

[1440] The resulting solution of composite particles 1 was introduced in the atomization chamber and sprayed towards a tube furnace at 1200 C. with a nitrogen flow of 100 cm.sup.3/s, as described in the invention. The composite particles 1 were collected on the tube wall by thermophoresis by using the cooling system, allowing to separate and select the composite particles 1 depending on their size. Said selected composite particles 1 were suspended in ethanol using sonication for 10 minutes. The second heating and cooling steps permit to ensure a better densification of the composite particles 1.

Example 8

Composite Particles 1 PreparationCdSe@CdZnS@Si.SUB.x.Na.SUB.x.Ca.SUB.z.O.SUB.v

[1441] 100 L of CdSe@CdZnS nanoplatelets suspended in 1,2-propanediol (1.0 M), 200 L of deionized water, 30 L of ammonia and 150 L of TEOS, 84 mg of calcium nitrate and 3 mg of sodium nitrate were added into an atomization chamber. After 10 minutes of magnetic stirring, the liquid mixture was sprayed towards a tube furnace heated at 300 C. with a nitrogen flow of 20 cm.sup.3/s, as described in the invention. The composite particles 1 were collected at the surface of a filter with a pore size of 1 m and then suspended in acetone using sonication for 10 minutes.

Example 9

Composite Particles 1 PreparationCdSe@SiO.SUB.2

[1442] 100 L of CdSe nanoplatelets suspended in hexane (1.0 M) were transferred to an aqueous solution by following a process of ligand exchange with 3-mercaptopropionic acid. The aqueous colloidal solution (1.0 M) was then mixed with 150 L of deionized water, 5 L of tetramethyl ammonium hydroxide and 200 L of TEOS. The solution was transferred into an atomization chamber. After 10 minutes of magnetic stirring, the liquid mixture was sprayed towards a tube furnace heated at 1200 C. with a nitrogen flow of 30 cm.sup.3/s, as described in the invention. The composite particles 1 were collected at the surface of a filter with a pore size of 1 m and then suspended in acetone using sonication for 10 minutes.

Example 10

Composite Particles Preparation from a Basic Aqueous SolutionCdSe@CdZnS@SiO.SUB.2

[1443] 100 L of a basic aqueous solution of CdSe@CdZnS nanoplatelets after a process of ligand exchange of said nanoplatelets were mixed with a basic aqueous solution of TEOS at 0.13M previously hydrolyzed for 24 hours. The solution was transferred into an atomization chamber. After 10 minutes of magnetic stirring, the liquid mixture was sprayed towards a tube furnace heated at 300 C., 600 C. or 1200 C. with a nitrogen flow, as described in the invention. The composite particles 1 were collected at the surface of a filter with a pore size of 1 m.

Example 11

Composite Particles Preparation from an Acidic Aqueous SolutionCdSe@CdZnS@SiO.SUB.2

[1444] 100 L of an acidic aqueous solution CdSe@CdZnS nanoplatelets after a process of ligand exchange of said nanoplatelets were mixed with an acidic aqueous solution of TEOS at 0.13M previously hydrolyzed for 24 hours. The solution was transferred into an atomization chamber. After 10 minutes of magnetic stirring, the liquid mixture was sprayed towards a tube furnace heated at 300 C., 600 C. or 1200 C. with a nitrogen flow, as described in the invention. The composite particles 1 were collected at the surface of a filter with a pore size of 1 m.

Example 12

Composite Particles Preparation from an Acidic Aqueous Solution with Hetero-Elements CdSe@CdZnS@Si.SUB.x.Cd.SUB.y.Zn.SUB.z.O.SUB.w .(with x, y, z and w are Independently a Decimal Number from 0 to 5)

[1445] 100 L of an acidic aqueous solution of CdSe@CdZnS nanoplatelets after a process of ligand exchange of said nanoplatelets were mixed with an acidic aqueous solution of TEOS at 0.13M previously hydrolyzed for 24 hours in presence of cadmium acetate at 0.01M and zinc oxide at 0.01M. The solution was transferred into an atomization chamber. After 10 minutes of magnetic stirring, the liquid mixture was sprayed towards a tube furnace heated at 300 C., 600 C. or 1200 C. with a nitrogen flow as described in the invention. The composite particles 1 were collected at the surface of a filter with a pore size of 1 m.

Example 13

Composite Particles Preparation from an Acidic Aqueous SolutionInP@ZnS @ SiO.SUB.2

[1446] 4 mL of an acidic solution of InP@ZnS nanoparticles after a process of ligand exchange of said nanoparticles were mixed with an acidic aqueous solution of TEOS at 0.13M previously hydrolyzed for 24 hours. The solution was transferred into an atomization chamber. After 10 minutes of magnetic stirring, the liquid mixture was sprayed towards a tube furnace heated at 300 C., 600 C. or 1200 C. with a nitrogen flow as described in the invention. The composite particles 1 were collected at the surface of a filter with a pore size of 1 m.

Example 14

Composite Particles Preparation from an Aqueous SolutionCH.SUB.5.N.SUB.2.-PbBr.SUB.3.@SiO.SUB.2

[1447] 100 L of an acidic solution of CH.sub.5N.sub.2-PbBr.sub.3 nanoparticles after a process of ligand exchange of said nanoparticles were mixed with an acidic aqueous solution of TEOS at 0.13M previously hydrolyzed for 24 hours. The solution was transferred into an atomization chamber. After 10 minutes of magnetic stirring, the liquid mixture was sprayed towards a tube furnace heated at 300 C., 600 C. or 1200 C. with a nitrogen flow as described in the invention. The composite particles 1 were collected at the surface of a filter with a pore size of 1 m.

Example 15

Composite Particles Preparation from an Aqueous SolutionCdSe@CdZnS-Au@ SiO.SUB.2

[1448] 100 L of an aqueous solution of gold nanoparticles and 100 L of an acidic aqueous solution of CdSe@CdZnS nanoplatelets after a process of ligand exchange of said nanoplatelets, were mixed together in an acedic aqueous solution of TEOS at 0.13M previously hydrolyzed for 24 hours. The solution was transferred into an atomization chamber. After 10 minutes of magnetic stirring, the liquid mixture was sprayed towards a tube furnace heated at 300 C., 600 C. or 1200 C. with a nitrogen flow as described in the invention. The composite particles were collected at the surface of a GaN substrate. The GaN substrate with the deposited composite particles was then cut into pieces of 1 mm1 mm and electricaly connected to get a LED emitting a mixture of the blue light and the light emitted by the fluorescent nanoparticles.

Example 16

Composite Particles Preparation from an Acidic Aqueous SolutionFe.SUB.3.O.SUB.4.-CdSe@CdZnS @ SiO.SUB.2

[1449] 100 L of an acidic aqueous solution of Fe.sub.3O.sub.4 nanoparticles and 100 L of an acidic aqueous solution of CdSe@CdZnS nanoplatelets after a process of ligand exchange of said nanoplatelets, were mixed together in an acedic aqueous solution of TEOS at 0.13M previously hydrolyzed for 24 hours. The solution was transferred into an atomization chamber. After 10 minutes of magnetic stirring, the liquid mixture was sprayed towards a tube furnace heated at 300 C., 600 C. or 1200 C. with a nitrogen flow as described in the invention. The composite particles 1 were collected at the surface of a filter with a pore size of 1 m. Example 17: CdSe @CdS @ ZnS @ SiO.sub.2

[1450] 100 L of CdSe@CdS@ZnS nanoplatelets suspended in an acidic aqueous solution after a process of ligand exchange were mixed with an acidic aqueous solution of TEOS at 0.13M previously hydrolyzed for 24 hours. The solution was transferred into an atomization chamber. After 10 minutes of magnetic stirring, the liquid mixture was sprayed towards a tube furnace heated at 300 C., 600 C. or 1200 CC with a nitrogen flow as described in the invention. The composite particles 1 were collected at the surface of a filter with a pore size of 1 m.

[1451] FIG. 16A shows the emission spectra of CdSe@CdS@ZnS nanoplatelets before and after encapsulation in silica glass. Bare CdSe@CdS@ZnS nanoplatelets exhibit an emission peak at 693 nm, and glass encapsulated CdSe@CdS@ZnS nanoplatelets exhibit an emission peak at 681 nm. The FWHM remains unchanged before or after encapsulation in glass.

[1452] FIG. 16B shows the emission intensity versus time for CdSe@CdS@ZnS nanoplatelets before and after encapsulation in silica glass. The encapsulation in silica glass improved the emission intensity versus time of said nanoplatelets.

[1453] The fluorescence properties of CdSe@CdS@ZnS are not impaired by the encapsulation in glass.

Example 18

Composite Particles Preparation from an Acidic Aqueous SolutionCdSe@ZnS@SiO.SUB.2

[1454] 100 L of an acidic aqueous solution of CdSe@ZnS nanoplatelets after a process of ligand exchange of said nanoplatelets were mixed with an acidic aqueous solution of TEOS at 0.13M previously hydrolyzed for 24 hours. The solution was transferred into an atomization chamber. After 10 minutes of magnetic stirring, the liquid mixture was sprayed towards a tube furnace heated at 300 C., 600 C. or 1200 C. with a nitrogen flow as described in the invention. The composite particles 1 were collected at the surface of a filter with a pore size of 1 m. Example 19: Composite particles preparation from an acidic aqueous solutionCdSe@ZnS @ Si.sub.xNa.sub.xCa.sub.zO.sub.v

[1455] 100 L of an acidic aqueous solution of CdSe@ZnS nanoplatelets after a process of ligand exchange of said nanoplatelets were mixed with an acidic aqueous solution comprising a mixture of TEOS, calcium nitrate and sodium nitrate previously hydrolyzed for 24 hours. The solution was transferred into an atomization chamber. After 10 minutes of magnetic stirring, the liquid mixture was sprayed towards a tube furnace heated at 1000 C. with a nitrogen flow as described in the invention. The composite particles 1 were collected at the surface of a filter with a pore size of 1 m.

Example 20

Composite Particles Preparation from an Acidic Aqueous SolutionCdSe@ZnS@Si.SUB.x.Pb.SUB.y.O.SUB.z

[1456] 100 L of an acidic aqueous solution of CdSe@ZnS nanoplatelets after a process of ligand exchange of said nanoplatelets were mixed with an acidic aqueous solution comprising a mixture of TEOS and lead acetate previously hydrolyzed for 24 hours. The solution was transferred into an atomization chamber. After 10 minutes of magnetic stirring, the liquid mixture was sprayed towards a tube furnace heated at 1000 C. or 1200 C. with a nitrogen flow as described in the invention. The composite particles 1 were collected at the surface of a filter with a pore size of 1 m.

Example 21

Composite Particles Preparation from an Acidic Aqueous SolutionCdSe@ZnS@SiO.SUB.2.-B.SUB.2.O.SUB.3.-Na.SUB.2.O-Al.SUB.2.O.SUB.3

[1457] 100 L of an acidic aqueous solution of CdSe@ZnS nanoplatelets after a process of ligand exchange of said nanoplatelets were mixed with an acidic aqueous solution comprising a mixture of TEOS, aluminum-tri-sec-butoxide, sodium nitrate and boron trichloride previously hydrolyzed for 24 hours. The solution was transferred into an atomization chamber. After 10 minutes of magnetic stirring, the liquid mixture was sprayed towards a tube furnace heated at 1000 C. or 1200 C. with a nitrogen flow as described in the invention. The composite particles 1 were collected at the surface of a filter with a pore size of 1 m.

Example 22

Composite Particles Preparation from a Basic Aqueous SolutionCdSe@ZnS@SixPbyOz

[1458] 100 L of a basic aqueous solution of CdSe@ZnS nanoplatelets after a process of ligand exchange of said nanoplatelets were mixed with a basic aqueous solution comprising a mixture of TEOS and lead acetate previously hydrolyzed for 16 hours. The solution was transferred into an atomization chamber. After 10 minutes of magnetic stirring, the liquid mixture was sprayed towards a tube furnace heated at 1000 C. or 1200 C. with a nitrogen flow as described in the invention. The composite particles 1 were collected at the surface of a filter with a pore size of 1 m.

Example 23

Composite Particles Preparation from an Basic Aqueous SolutionCdSe@ZilS@Si.SUB.x.O.SUB.2.-B.SUB.y.O.SUB.3.-Na.SUB.2.OAl.SUB.2.O.SUB.3

[1459] 100 L of a basic aqueous solution of CdSe@ZnS nanoplatelets after a process of ligand exchange of said nanoplatelets were mixed with a basic aqueous solution comprising a mixture of TEOS, aluminum-tri-sec-butoxide, sodium nitrate and boron trichloride previously hydrolyzed for 16 hours. The solution was transferred into an atomization chamber. After 10 minutes of magnetic stirring, the liquid mixture was sprayed towards a tube furnace heated at 1000 C. or 1200 C. with a nitrogen flow as described in the invention. The composite particles 1 were collected at the surface of a filter with a pore size of 1 m.

REFERENCES

[1460] 1Composite particle

[1461] 11Core

[1462] 12Shell

[1463] 13Inorganic nanoparticle

[1464] 131Spherical inorganic nanoparticle

[1465] 132Quasi 2D inorganic nanoparticle

[1466] 133Core

[1467] 134Shell

[1468] 135Shell

[1469] 136Insulator shell

[1470] 137Crown

[1471] 2Device

[1472] 21Gas supply

[1473] 22Means for forming droplets

[1474] 23Tube

[1475] 24Means for heating

[1476] 25Means for cooling

[1477] 26Means for separating and collecting particles

[1478] 27Pumping device

[1479] 3LED support

[1480] 4LED chip

[1481] 5microsized LED