Light-emitting diodes with light coupling and conversion layers

Patent metadata

Field	Value
Publication number	US-11004835-B2
Application number	US-201916527753-A
Country	US
Kind code	B2
Filing date	Jul 31, 2019
Priority date	Aug 9, 2018
Publication date	May 11, 2021
Grant date	May 11, 2021

Abstract

Light-emitting sub-pixels and pixels for micro-light-emitting diode-based displays are provided. Also provided are methods of fabricating individual sub-pixels, pixels, and arrays of the pixels. The sub-pixels include a double-layered film that includes a coupling layer disposed over a light-emitting diode and a light-emission layer disposed over the coupling layer.

First claim

What is claimed is:

1. A pixel comprising:
a substrate;
a red sub-pixel on the substrate, the red sub-pixel comprising:
a first light-emitting diode;
a first coupling layer disposed over the first light-emitting diode, wherein the first coupling layer comprises scattering particles disposed in a polymeric matrix; or is dome-shaped and comprises scattering particles in a polymeric matrix; and
a red light-emission layer comprising red-emitting quantum dots and scattering particles disposed in a polymeric matrix disposed over the first coupling layer;

a green sub-pixel on the substrate, the green sub-pixel comprising:
a second light-emitting diode;
a second coupling layer disposed over the second light-emitting diode, wherein the second coupling layer comprises scattering particles disposed in a polymeric matrix; or is dome-shaped and comprises scattering particles in a polymeric matrix; and
a green light-emission layer comprising green-emitting quantum dots and scattering particles disposed in a polymeric matrix disposed over the second coupling layer; and

a blue sub-pixel on the substrate, the blue sub-pixel comprising:
a third light-emitting diode.

2. The pixel of claim 1 , wherein the first light-emitting diode, the second light-emitting diode, and the third light-emitting diode are blue light-emitting diodes.

3. The pixel of claim 2 , wherein the blue light-emitting diodes are gallium nitride-based diodes.

4. The pixel of claim 1 , wherein the first light-emitting diode, the second light-emitting diode, and the third light-emitting diode are ultraviolet light emitting-diodes, and the blue sub-pixel comprises:
a third coupling layer disposed over the third light-emitting diode, wherein the third coupling layer is: (a) domed-shaped; (b) comprises scattering particles disposed in a polymeric matrix; or (c) dome-shaped and comprises scattering particles in a polymeric matrix; and
a blue light-emission layer comprising blue-emitting quantum dots and scattering particles disposed in a polymeric matrix disposed over the third coupling layer.

5. The pixel of claim 1 , wherein the first coupling layer is localized over the first light-emitting diode, the second coupling layer is localized over the second light-emitting diode, or the first and second coupling layers are localized over the first and second light-emitting diodes, respectively.

6. The pixel of claim 1 , wherein an emission surface area of the green sub-pixel is larger than an emission surface area of the red sub-pixel, and the emission surface area of the red sub-pixel is larger than an emission surface area of the blue sub-pixel.

7. A pixel comprising:
a substrate;
a red sub-pixel on the substrate, the red sub-pixel comprising:
a first light-emitting diode;
a first coupling layer disposed over the first light-emitting diode, wherein the first coupling layer: (a) is domed-shaped; (b) comprises scattering particles disposed in a polymeric matrix; or (c) is dome-shaped and comprises scattering particles in a polymeric matrix; and
a red light-emission layer comprising red-emitting quantum dots and scattering particles disposed in a polymeric matrix disposed over the first coupling layer;

a green sub-pixel on the substrate, the green sub-pixel comprising:
a second light-emitting diode;
a second coupling layer disposed over the second light-emitting diode, wherein the second coupling layer: (a) is domed-shaped; (b) comprises scattering particles disposed in a polymeric matrix; or (c) is dome-shaped and comprises scattering particles in a polymeric matrix; and
a green light-emission layer comprising green-emitting quantum dots and scattering particles disposed in a polymeric matrix disposed over the second coupling layer; and

a blue sub-pixel on the substrate, the blue sub-pixel comprising:
a third light-emitting diode, wherein the first coupling layer is separated from the red light-emission layer by an interfacial region having a quantum dot concentration gradient in which the concentration of red-emitting quantum dots in the interfacial region is lower near the first coupling layer than near the red light-emission layer, and/or wherein the second coupling layer is separated from the green light-emission layer by an interfacial region having a quantum dot concentration gradient in which the concentration of green-emitting quantum dots in the interfacial region is lower near the second coupling layer than near the green light-emission layer.

8. A color conversion display device comprising:
a display device substrate;
a plurality of the pixels arranged on the display device substrate, each pixel in the plurality of pixels comprising:
a substrate;
a red sub-pixel on the substrate, the red sub-pixel comprising:
a first light-emitting diode;
a first coupling layer disposed over the first light-emitting diode, wherein the first coupling layer comprises scattering particles disposed in a polymeric matrix; or is dome-shaped and comprises scattering particles in a polymeric matrix; and
a red light-emission layer comprising red-emitting quantum dots and scattering particles disposed in a polymeric matrix disposed over the first coupling layer;

a green sub-pixel on the substrate, the green sub-pixel comprising:
a second light-emitting diode;
a second coupling layer disposed over the second light-emitting diode, wherein the second coupling layer comprises scattering particles disposed in a polymeric matrix; or is dome-shaped and comprises scattering particles in a polymeric matrix; and
a green light-emission layer comprising green-emitting quantum dots and scattering particles disposed in a polymeric matrix disposed over the second coupling layer; and

a blue sub-pixel on the substrate, the blue sub-pixel comprising:
a third light-emitting diode; and

a translucent protective layer disposed over the plurality of pixels.

9. A method of forming a pixel on a substrate comprising a first light emitting-diode, a second light-emitting diode, and a third light-emitting diode, the method comprising:
forming a first sub-pixel confinement feature over the first light-emitting diode;
depositing a first film-forming ink composition comprising scattering particles and curable organic monomers into or onto the first sub-pixel confinement feature over the first light-emitting diode;
drying the first film-forming ink composition to form a first coupling layer;
depositing a first quantum dot-containing ink composition comprising red-emitting quantum dots, scattering particles, and curable organic monomers into or onto the first sub-pixel confinement feature;
drying the first quantum dot-containing ink composition to form a red light-emission layer comprising red-emitting quantum dots and scattering particles disposed in a polymeric matrix;
forming a second sub-pixel confinement feature over the second light-emitting diode;
depositing a second film-forming ink composition comprising scattering particles and curable organic monomers into or onto the second sub-pixel confinement feature over the second light-emitting diode;
drying the second film-forming ink composition to form a second coupling layer;
depositing a second quantum dot-containing ink composition comprising green-emitting quantum dots, scattering particles, and curable organic monomers into or onto the second sub-pixel confinement feature; and
drying the second quantum dot-containing ink composition to form a green light-emission layer comprising green-emitting quantum dots and scattering particles disposed in a polymeric matrix.

10. The method of claim 9 , wherein at least one of the first film-forming ink composition, the first quantum dot-containing ink c

Assignees

• Kateeva Inc

Inventors

• Pschenitzka Florian

Classifications

• H10H20/8514

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

• H10W90/00 Primary

  Package configurations · CPC title

• H10H29/882

  Scattering means · CPC title

• H10H29/8516

  having a non-uniform spatial arrangement or non-uniform concentration, e.g. patterned wavelength conversion layer, wavelength conversion layer with a concentration gradient · CPC title

• H10H29/8515

  not being in contact with the bodies · CPC title