LED Cap Containing Quantum Dot Phosphors

Patent metadata

Field	Value
Publication number	US-2016268486-A1
Application number	US-201615159538-A
Country	US
Kind code	A1
Filing date	May 19, 2016
Priority date	Nov 13, 2013
Publication date	Sep 15, 2016
Grant date	—

Abstract

An LED device has a cap containing one or more quantum dot (QD) phosphors. The cap may be sized and configured to be integrated with standard LED packages. The QD phosphor may be held within the well of the LED package, so as to absorb the maximum amount of light emitted by the LED, but arranged in spaced-apart relation from the LED chip to avoid excessive heat that can lead to degradation of the QD phosphor(s). The packages may be manufactured and stored for subsequent assembly onto an LED device.

First claim

What is claimed is:

1 . A cap for an LED package having a central well containing an LED and an upper surface surrounding the central well, said cap comprising:
a peripheral portion sized and configured to engage the upper surface of the LED package; a central portion depressed from the peripheral portion forming a cap well; and a plurality of quantum dots in the cap well, wherein the cap well is configured for a conformational fit with the central well of the LED package.

2 . The cap recited in claim 1 , further comprising;
a lid attached to the peripheral portion and covering the cap well.

3 . The cap recited in claim 2 , wherein the lid is transparent.

4 . The cap recited in claim 2 , wherein the lid is translucent.

5 . The cap recited in claim 2 , wherein the lid is shaped to provide a lens.

6 . The cap recited in claim 2 , wherein the lid is shaped to provide a lens array.

7 . The cap recited in claim 2 , wherein the lid comprises a light diffuser.

8 . The cap recited in claim 1 , wherein the cap well is spaced apart from the LED when the cap is engaged with the LED package.

9 . The cap recited in claim 1 , wherein the plurality of quantum dots comprise a first type of quantum dots that emit secondary light having a first wavelength and a second type of quantum dots that emit secondary light having a second wavelength.

10 . The cap recited in claim 9 , wherein the first type of quantum dots emit green light when excited by blue light and the second type of quantum dots emit red light when excited by blue light.

11 . The cap recited in claim 1 , wherein the quantum dots comprise a central core surrounded by at least one shell.

12 . The cap recited in claim 11 , wherein the shell material is different from the core material.

13 . The cap recited in claim 1 , wherein the quantum dots comprise a core comprising indium and phosphorus surrounded by a first shell comprising ZnS surrounded by a second shell comprising ZnO.

14 . The cap recited in claim 1 , wherein the quantum dots are cadmium-free quantum dots.

15 . The cap recited in claim 1 , wherein the quantum dots are suspended in a matrix.

16 . The cap recited in claim 15 , wherein the matrix comprises an acrylate polymer.

17 . The cap recited in claim 15 , wherein the matrix comprises an epoxy polymer.

18 . The cap recited in claim 1 , wherein the quantum dots are incorporated into beads.

19 . A light-emitting device comprising:
a package having a central well and an upper surface; an LED within the central well; a cap having a peripheral portion configured to engage the upper surface of the package and a central portion depressed from the peripheral portion forming a cap well; and a plurality of quantum dots in the cap well, wherein the cap well has a conformational fit with at least a portion of the central well.

20 . The light-emitting device recited in claim 19 , wherein the peripheral portion of the cap is attached to the upper surface of the package with an adhesive that is substantially impervious to oxygen.

21 . The light-emitting device recited in claim 19 , wherein the cap well comprises a base wall having a phosphor incorporated therein.

22 . The light-emitting device recited in claim 21 , wherein the phosphor is an inorganic phosphor.

23 . The light-emitting device recited in claim 21 , wherein the phosphor is a broad-emitting, yellow-green phosphor.

24 . The light-emitting device recited in claim 21 , wherein the phosphor comprises Ce:YAG.

25 . The light-emitting device recited in claim 21 , wherein the phosphor comprises Ce:LuAG.

26 . A light-emitting device comprising:
a package having a central well and an upper surface; an LED within the central well; a cap having a peripheral portion attached to the upper surface of the package; a central portion depressed from the peripheral portion forming a cap well; a base wall of the cap well having a phosphor incorporated therein; a plurality of quantum dots in the cap well.

27 . The light-emitting device recited in claim 26 wherein the LED is a blue LED, the phosphor is a broad-emitting, yellow-green phosphor, and the quantum dots are red-fluorescing quantum dots.

Assignees

• Nanoco Technologies Ltd

Inventors

• Harris James

Classifications

• H10H20/855

  Optical field-shaping means, e.g. lenses · CPC title

• H10H20/8515

  not being in contact with the bodies · CPC title

• H10H20/8514 Primary

  characterised by their shape, e.g. plate or foil · CPC title

• H10H20/8513 Primary

  having two or more wavelength conversion materials · CPC title

• H10H20/811

  having quantum effect structures or superlattices, e.g. tunnel junctions · CPC title