Quantum dot LED and OLED integration for high efficiency displays

• US 10,192,932 B2
• Filed: 08/23/2016
• Issued: 01/29/2019
• Est. Priority Date: 02/02/2016
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Steckel, Jonathan S., Mathai, Mathew K., Drzaic, Paul S., Yamamoto, Hitoshi
• Primary Examiner(s): Hall, Victoria K
• Application Number:
  US15/244,906
• Publication Number:
  US 20170221969A1
• Time in Patent Office: 889 Days
• CPC Class Codes: H10K 2101/10 Triplet emission
• CPC Class Codes: H10K 2102/331 Nanoparticles used in non-emissive layers, e.g. in packaging layer
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/115 comprising active inorganic nanostructures, e.g. luminescent quantum dots
• CPC Class Codes: H10K 50/131 with spacer layers between the electroluminescent layers
• CPC Class Codes: H10K 50/16 Electron transporting layers
• CPC Class Codes: H10K 50/19 Tandem OLEDs
• CPC Class Codes: H10K 59/32 Stacked devices having two or more layers, each emitting at different wavelengths
• CPC Class Codes: H10K 59/35 comprising red-green-blue [RGB] subpixels
• CPC Class Codes: H10K 71/12 using liquid deposition, e.g. spin coating
• CPC Class Codes: H10K 71/18 using non-liquid printing techniques, e.g. thermal transfer printing from a donor sheet

Abstract

Displays including hybrid pixels including an OLED subpixel and QD-LED subpixel are described. In an embodiment, OLED and QD-LED stacks are integrated into the same pixel with multiple common layers shared by the OLED and QD-LED stacks.

Claims

1. A display comprising:

a hybrid pixel including an organic light emitting diode (OLED) subpixel and a quantum dot light emitting diode (QD-LED) subpixel;

a common hole transport layer in the OLED subpixel and the QD-LED subpixel;

a common quantum dot layer over the common hole transport layer in the QD-LED subpixel and the QD-LED subpixel;

an organic emission layer over the common hole transport layer in the OLED subpixel and over the common quantum dot layer in the OLED subpixel, wherein the organic emission layer comprises a phosphorescent material;

a common electron transport layer over the common quantum dot layer in the QD-LED subpixel, and over the organic emission layer in the OLED subpixel;

a common top electrode layer over the common electron transport layer in the OLED subpixel and the QD-LED subpixel.

2. The display of claim 1, further comprising:

a common hole injection layer in the OLED subpixel and the QD-LED subpixel;

wherein the common hole transport layer is over the common hole injection layer in the OLED subpixel and the QD-LED subpixel.

3. The display of claim 1, further comprising:

a common electron injection layer over the common electron transport layer in the OLED subpixel and the QD-LED subpixel;

wherein the common top electrode layer is over the common electron injection layer in the OLED subpixel and the QD-LED subpixel.

4. The display of claim 1, further comprising:

a common nanoparticle electron transport layer comprising metal-oxide nanoparticles over the common quantum dot layer in the OLED subpixel and the QD-LED subpixel.

5. The display of claim 4, further comprising a common insulating layer between the common quantum dot layer and the common nanoparticle electron transport layer comprising metal-oxide nanoparticles in the OLED subpixel and the QD-LED subpixel.

6. The display of claim 1, further comprising:

a buffer transport layer over the common quantum dot layer in the OLED subpixel;

wherein the organic emission layer is over the buffer transport layer.

7. The display of claim 1, further comprising:

a buffer transport layer over the organic emission layer in the OLED subpixel.

8. The display of claim 1, further comprising a common buffer transport layer over the organic emission layer in the OLED subpixel, and over the common quantum dot layer in the QD-LED subpixel.

9. The display of claim 1, further comprising:

a common metal oxide nanoparticle hole transport layer comprising metal-oxide nanoparticles over the hole transport layer the OLED subpixel and the QD-LED subpixel;

wherein the common quantum dot layer is over the common metal oxide nanoparticle hole transport layer in the OLED subpixel and the QD-LED subpixel.

10. A method of forming a display comprising:

forming a common hole transport layer over a display backplane in using a first solution technique, wherein the common hole transport layer is formed over the display backplane in a hybrid pixel including an OLED subpixel and a QD-LED subpixel;

forming a common quantum dot layer over the common hole transport layer in the QD-LED subpixel and the OLED subpixel;

evaporating an organic emission layer over the common hole transport layer in the OLED subpixel and over the common quantum dot layer in the OLED subpixel, wherein the organic emission layer comprises a phosphorescent material;

evaporating a common electron transport layer over the common quantum dot layer in the QD-LED subpixel, and over the organic emission layer in the OLED subpixel; and

forming a common top electrode layer over the common electron transport layer in the OLED subpixel and the QD-LED subpixel.

11. The method of claim 10, wherein forming the common quantum dot layer comprises using a second solution-based technique.

12. The method of claim 11, wherein evaporating the common electron transport layer comprises evaporating the common electron transport layer over the common quantum dot layer in the OLED subpixel and the QD-LED subpixel.

13. The method of claim 11, further comprising forming a common nanoparticle electron transport layer comprising metal-oxide nanoparticles over the common quantum dot layer in the OLED subpixel and the QD-LED subpixel using a third solution-based technique.