Stabilized quantum dot composite and method of making a stabilized quantum dot composite

• US 10,347,799 B2
• Filed: 11/10/2017
• Issued: 07/09/2019
• Est. Priority Date: 11/10/2017
• Status: Active Grant

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Lotito, Kenneth, Gresback, Ryan, Griffiths, Ceri, Fini, Paul
• Primary Examiner(s): Patel, Ashok
• Application Number:
  US15/809,241
• Publication Number:
  US 20190148603A1
• Time in Patent Office: 606 Days
• Field of Search: None
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: C09K 11/025 non-luminescent particle coatings or suspension media
• CPC Class Codes: F21K 9/20 Light sources comprising attachment means
• CPC Class Codes: F21K 9/64 using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H10K 50/115 comprising active inorganic nanostructures, e.g. luminescent quantum dots
• CPC Class Codes: Y10S 977/774 Exhibiting three-dimensional carrier confinement, e.g. quantum dots
• CPC Class Codes: Y10S 977/892 Liquid phase deposition
• CPC Class Codes: Y10S 977/90 having step or means utilizing mechanical or thermal property, e.g. pressure, heat
• CPC Class Codes: Y10S 977/95 Electromagnetic energy

Abstract

A stabilized quantum dot composite includes a plurality of luminescent semiconducting nanoparticles embedded in a matrix comprising an ionic metal oxide. A method of making a stabilized quantum dot composite includes forming a mixture comprising a plurality of luminescent semiconducting nanoparticles dispersed in an aqueous solution comprising an ionic metal oxide. The mixture is dried to form a stabilized quantum dot composite comprising the plurality of luminescent semiconducting nanoparticles embedded in a matrix comprising the ionic metal oxide.

Claims

1. A stabilized quantum dot composite comprising:

a plurality of luminescent semiconducting nanoparticles embedded in a matrix comprising an ionic metal oxide having a chemical formula nA_xO_y.mB_zO_w, wherein A includes one or more elements selected from the group consisting of Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, wherein B includes one or more elements selected from the group consisting of B, Al, Ga, In, Si, Ge, Sn, and Pb, wherein x, y, z, and w are positive integers, and wherein n and m are stoichiometry coefficients.

2. The stabilized quantum dot composite of claim 1 having a morphology selected from the group consisting of:

a microparticle, a coating, and a macroscopic body.

3. The stabilized quantum dot composite of claim 1, wherein x=2, y=1, z=1, and w=2, and the chemical formula is nA₂O.mBO₂.

4. The stabilized quantum dot composite of claim 1, wherein A comprises K, wherein B comprises Si, and wherein the ionic metal oxide comprises potassium silicate.

5. The stabilized quantum dot composite of claim 4, wherein the potassium silicate comprises nK₂O.mSiO₂ in a molar ratio n:

m from about 1;

1.5 to about 1;

4.5.

6. The stabilized quantum dot composite of claim 1, wherein the luminescent semiconducting nanoparticles comprise a semiconductor selected from the group consisting of:

group IV, group II-VI semiconductors, group III-V semiconductors, group I-III-VI₂ semiconductors, and perovskite semiconductors.

7. The stabilized quantum dot composite of claim 6, wherein an interior of each of the luminescent semiconducting nanoparticles comprises the semiconductor, and further comprising a buffer layer surrounding the interior.

8. The stabilized quantum dot composite of claim 7, wherein the buffer layer comprises an oxide coating.

9. The stabilized quantum dot composite of claim 1 being optically transparent.

10. A light emitting device comprising:

a blue light emitting diode (LED) chip having a dominant wavelength of 425 nm to 475 nm in optical communication with the stabilized quantum dot composite of claim 1 for down conversion of light emitted from the blue LED chip.

11. The light emitting device of claim 10 disposed in a lighting fixture selected from the group consisting of:

omnidirectional light bulb, candelabra bulb, downlight, troffer, street light, outdoor light, canopy light, parking garage light, waveguide-based troffer, waveguide-based garage light, and lamp.

12. The light emitting device of claim 10, wherein a coating on the LED chip comprises the stabilized quantum dot composite.

13. The light emitting device of claim 10, wherein an optical lens overlying the LED chip comprises the stabilized quantum dot composite.

14. The light emitting device of claim 10, wherein a polymeric encapsulant on the LED chip comprises the stabilized quantum dot composite.

15. The light emitting device of claim 10, wherein a coated substrate positioned remote from the LED chip comprises the stabilized quantum dot composite.