Particles with quantum dots and method of making the same

• US 10,023,793 B2
• Filed: 05/29/2015
• Issued: 07/17/2018
• 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
• Primary Examiner(s): DANG, PHUC T
• Application Number:
  US15/313,671
• Publication Number:
  US 20170190965A1
• Time in Patent Office: 1,145 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

A marker composition and a package using same. The marker composition can include retroreflective particles and a dispersion medium, the blending ratio of the retroreflective particles being from 50 to 90 mass % on the basis of the total marker composition.

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 comprises up to 40 volume percent, wherein the coating has an average thickness up to 5 micrometers, and 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.

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 the matrix is aerogel.

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

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

6. The film of claim 5 further comprising polymer.

7. The film comprising the particle of claim 5, wherein the film exhibits external quantum efficiencies greater than 50.

8. 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 comprises up to 40 volume percent, wherein the coating has an average thickness up to 5 micrometers, wherein the composite core further comprises a liquid, and 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.

9. The particle of claim 8, wherein the liquid has vapor pressure at 25°

C. of greater than 1 torr.

10. 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 comprises up to 40 volume percent, wherein the coating has an average thickness up to 5 micrometers, and wherein the particle has air stable light emission properties.

11. A method of making 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 comprises up to 40 volume percent, wherein the coating has an average thickness up to 5 micrometers, 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.

12. The method of claim 11, 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.

13. The method of claim 12, 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.

14. The method of claim 13, 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.

15. The method of claim 11, wherein encapsulating the infiltrated particle with the inorganic high barrier coating is done at a pressure of at least 0.5 atmosphere.