PARTICLES WITH QUANTUM DOTS AND METHOD OF MAKING THE SAME

• US 20170190965A1
• Filed: 05/29/2015
• Published: 07/06/2017
• Est. Priority Date: 06/03/2014
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: BUDD, Kenton D., SHARMA, Neeraj, DODGE, Bill H., HELLER, Daimon K, HAASE, Michael A., AKSIT, Mahmut
• Granted Patent: US 10,023,793 B2
• Time in Patent Office: Days
• 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 11/883 with zinc or cadmium
• CPC Class Codes: H01L 33/502 Wavelength conversion materials

Abstract

Particles comprising a composite core and a continuous inorganic coating covering the composite core, wherein the composite core comprises a continuous non-metallic inorganic matrix, ligands, and quantum dots, wherein the matrix comprise up to 40 volume percent, and wherein the coating has an average thickness up to 5 micrometers; and method of making the particles. Particles described here are useful, for example, to make articles (e.g., film).

Claims

1. A particle comprising a composite core and a continuous inorganic coating covering the composite core, wherein the composite core comprises a continuous non-metallic inorganic matrix, ligands, and quantum dots, wherein the matrix comprise up to 40 volume percent, and wherein the coating has an average thickness up to 5 micrometers.

2. The particle of claim 1, wherein the matrix comprises at least one of silica or metal oxide.

3. The particle of claim 1, wherein at least 60 volume percent of the particle is collectively the ligands and the quantum dots, based on the total volume of the composite core.

4. The particle of claim 1, wherein the matrix is aerogel.

5. The particle of claim 1, wherein the composite core further comprises a liquid.

6. The particle of claim 5, wherein greater than 60 volume percent of the particle is collectively the liquid, the ligands, and the quantum dots, based on the total volume of the composite core.

7. The particle of claim 5, wherein the liquid has vapor pressure at 25°

C. of greater than 1 torr.

8. The particle of claim 1, wherein the composite core comprises a mesoporous structure.

9. The particle of claim 1, wherein the particle has air stable light emission properties.

10. A film comprising a plurality of particles of claim 1.

11. The film of claim 8 further comprising polymer.

12. The film comprising the particle of claim 10, wherein the film exhibits external quantum efficiencies greater than 50.

13. A method of making a particle of claim 1, the method comprising:

providing a liquid having quantum dots dispersed therein;

infiltrating the liquid having the quantum dots into a porous inorganic particle; and

encapsulating the infiltrated particle with a continuous inorganic coating to provide the particle.

14. The method of claim 13, wherein encapsulating the infiltrated particle with a continuous inorganic coating is done via at least one of chemical vapor deposition, atomic layer deposition, sputtering, or evaporation.

15. The method of claim 13, wherein encapsulating the infiltrated particle with the inorganic high barrier coating is done at a pressure of at least 0.5 atmosphere.

16. The method of claim 14, wherein encapsulating the infiltrated particle with an inorganic high barrier material coating is done via chemical vapor deposition not exceeding a temperature of chemical vapor deposition of 220°

C.

17. The method of claim 16, wherein the deposition includes reacting a metal oxide precursor comprising at least one metal cation and a co-reactant to the metal oxide precursor and wherein the ratio of metal oxide precursor to the co-reactant is changed at least once during the process.