Semiconductor nanoparticle-based materials

• US 8,957,401 B2
• Filed: 09/23/2010
• Issued: 02/17/2015
• Est. Priority Date: 09/23/2009
• Status: Active Grant

• Current Assignee: Nanoco Technologies Limited (Nanoco Group Plc)
• Original Assignee: Nanoco Technologies Limited (Nanoco Group Plc)
• Inventors: Pickett, Nigel, Naasani, Imad, Harris, James
• Primary Examiner(s): Kraig, William F
• Assistant Examiner(s): Crawford, Latanya N
• Application Number:
  US12/888,982
• Publication Number:
  US 20110068322A1
• Time in Patent Office: 1,608 Days
• Field of Search: 252/519.33, 257/789, 257/13, 257/9, 257/E33.008, 257/E31.051, 977/786, 977/787, 977/834
• US Class Current: 257/13
• CPC Class Codes: C09K 11/02 Use of particular materials as binders, particle coatings or suspension media therefor
• CPC Class Codes: C09K 11/025 non-luminescent particle coatings or suspension media
• CPC Class Codes: C09K 11/565 with zinc cadmium
• CPC Class Codes: C09K 11/70 containing phosphorus
• CPC Class Codes: C09K 11/883 with zinc or cadmium
• CPC Class Codes: H01L 2933/0025 relating to coatings
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil

Abstract

In various embodiments, the present invention relates to a plurality of coated primary particles, each primary particle including a primary matrix material and containing a population of semiconductor nanoparticles, wherein each primary particle is provided with a separate layer of a surface coating material. Various methods of preparing such particles are described. Composite materials and light-emitting devices incorporating such primary particles are also described.

Claims

1. A composition comprising:

a plurality of primary particles, each primary particle comprising a population of semiconductor nanoparticles dispersed in a primary matrix material;

a first surface coating material disposed upon the surface of the primary particles, wherein the surface coating material is a different material than the primary matrix material;

wherein the primary particles are dispersed within secondary particles comprising a secondary matrix material selected from the group consisting of a polymer, a resin, a monolith, a glass, a sol gel, an epoxy, a silicone, and a (meth)acrylate; and

wherein the secondary particles comprises a separate layer of a second surface coating material that provides the secondary particle with a protective barrier to prevent the passage or diffusion of potentially deleterious species from the external environment through the secondary matrix material to the primary matrix material.

2. A composition according to claim 1, wherein the plurality of primary particles are dispersed in the secondary matrix.

3. A composition of claim 1, wherein the surface coating material comprises a polymeric material.

4. A composition according to claim 3, wherein said primary particles possess an average diameter of around 20 nm to around 0.5 mm.

5. A composition according to claim 3, wherein said primary matrix material comprises a material selected from the group consisting of a polymer, a resin, a monolith, a glass, a sol gel, an epoxy, a silicone, and a (meth)acrylate.

6. A composition according to claim 3, wherein said surface coating material comprises a material providing the primary particles with a protective barrier to prevent the passage or diffusion of potentially deleterious species from the external environment through the primary matrix material to the semiconductor nanoparticles.

7. A composition according to claim 3, wherein the surface coating material is a barrier that hinders or prevents the passage of oxygen or an oxidising agent through the primary matrix material.

8. A composition according to claim 3, wherein the surface coating material is a barrier that hinders or prevents the passage of free radical species through the primary matrix material.

9. A composition according to claim 3, wherein the surface coating material is a barrier that hinders or prevents moisture passing through the primary matrix material.

10. A composition according to claim 3, wherein the surface coating material possesses a thickness of up to around 500 nm.

11. A composition according to claim 3, wherein the surface coating material possesses a thickness of around 5 to 100 nm.

12. A composition according to claim 3, wherein the polymeric material is a saturated or unsaturated hydrocarbon polymer, or is a polymer incorporating one or more heteroatoms or heteroatom-containing functional groups.

13. A composition according to claim 3, wherein the polymeric material comprises a material selected from the group consisting of an acrylate polymer, epoxide, polyamide, polyimide, polyester, polycarbonate, polythioether, polyacrylonitryl, polydiene, polystyrene polybutadiene copolymer, pyrelene, a silica-acrylate hybrid, polyetheretherketone, polyvinylidene fluoride, polydivinyl benzene, polyethylene, polypropylene, polyethylene terephthalate, polyisobutylene, polyisoprene, cellulose derivatives, and combinations thereof.

14. A composition according to claim 1, wherein the surface coating material comprises an inorganic material.

15. A composition according to claim 14, wherein the inorganic material is selected from the group consisting of a dielectric, a metal oxide, a metal nitride, and a silica-based material.

16. A composition according to claim 14, wherein the inorganic material is a metal oxide comprising oxide ions and one or more types of metal ion selected from group 2, 13, 14 or 15 of the periodic table, the transition metals, the d-block metals, or the lanthanide metals.

17. A composition according to claim 3 or 14, wherein said semiconductor nanoparticles contain ions selected from groups 11, 12, 13, 14, 15 and/or 16 of the periodic table, or one or more types of transition metal ion or d-block metal ion.

18. A light-emitting device including a primary light source in optical communication with a formulation comprising a plurality of coated primary particles according to claim 3 or 14 embedded in a host light-emitting diode encapsulation medium.

19. A light-emitting device including a primary light source in optical communication with a formulation comprising a composite material incorporating a plurality of coated primary particles according to claim 3 or 14 embedded in a host light-emitting diode encapsulation medium.