Top-emission type organic light emitting diode display substrate

Patent metadata

Field	Value
Publication number	US-10468474-B2
Application number	US-201715741738-A
Country	US
Kind code	B2
Filing date	Aug 8, 2017
Priority date	Nov 29, 2016
Publication date	Nov 5, 2019
Grant date	Nov 5, 2019

Abstract

The present application discloses a top-emission type organic light emitting diode display substrate having a plurality of subpixel areas, in each of which the top-emission type organic light emitting diode display substrate includes a base substrate; a thin film transistor on the base substrate and including a drain electrode; and an organic light emitting diode on a side of the drain electrode distal to the base substrate. The organic light emitting diode includes a first electrode on a side of the drain electrode distal to the base substrate; an organic layer on a side of the first electrode distal to the drain electrode; and a second electrode on a side of the organic layer distal to the first electrode. The first electrode is a substantially transparent electrode and electrically connected to the drain electrode. The drain electrode is a reflective electrode. The second electrode is a substantially transparent electrode.

First claim

What is claimed is:

1. A top-emission type organic light emitting diode display substrate having a plurality of subpixel areas, in each of which the top-emission type organic light emitting diode display substrate comprising:
a base substrate;
a thin film transistor on the base substrate and comprising a drain electrode, the drain electrode is a reflective electrode; and
an organic light emitting diode on a side of the drain electrode distal to the base substrate;
wherein the organic light emitting diode comprises:
a first electrode on a side of the drain electrode distal to the base substrate, the first electrode is a substantially transparent electrode and electrically connected to the drain electrode;
an organic layer on a side of the first electrode distal to the drain electrode, the organic layer comprises an organic light emitting layer; and
a second electrode on a side of the organic layer distal to the first electrode, the second electrode is a substantially transparent electrode;
wherein the top-emission type organic light emitting diode display substrate further comprises:
a planarization layer on a side of the drain electrode distal to the base substrate; and
a passivation layer on a side of the planarization layer distal to the drain electrode;
wherein the drain electrode and the second electrode form a microcavity structure; and
an optical distance of the microcavity structure is substantially equal to a sum of optical path lengths of the passivation layer, the planarization layer, the organic layer, and the first electrode.

2. The top-emission type organic light emitting diode display substrate of claim 1 , wherein an orthographic projection of the drain electrode on the base substrate substantially covers that of a light emitting region of the organic light emitting layer.

3. The top-emission type organic light emitting diode display substrate of claim 2 , wherein the orthographic projection of the drain electrode on the base substrate substantially overlaps with that of the light emitting region of the organic light emitting layer.

4. The top-emission type organic light emitting diode display substrate of claim 1 , wherein the orthographic projection of the drain electrode on the base substrate substantially covers that of the first electrode layer.

5. The top-emission type organic light emitting diode display substrate of claim 4 , wherein the orthographic projection of the drain electrode on the base substrate substantially overlaps with that of the first electrode layer.

6. The top-emission type organic light emitting diode display substrate of claim 1 , wherein the microcavity structure has an optical distance substantially equal to a sum of optical path lengths of the passivation layer, the planarization layer, the organic layer, and the first electrode.

7. The top-emission type organic light emitting diode display substrate of claim 6 , wherein the optical distance is a non-integer multiple of 2πλ, λ is a wavelength of light emitted from the organic light emitting layer of the organic layer.

8. The top-emission type organic light emitting diode display substrate of claim 1 , wherein the drain electrode is made of a low-reflectivity metal material.

9. The top-emission type organic light emitting diode display substrate of claim 8 , wherein the drain electrode is made of molybdenum or nickel.

10. The top-emission type organic light emitting diode display substrate of claim 1 , wherein the second electrode is made of a metallic material.

11. The top-emission type organic light emitting diode display substrate of claim 10 , wherein the second electrode is made of magnesium:silver alloy.

12. The top-emission type organic light emitting diode display substrate of claim 1 , wherein the first electrode has a thickness in a range of approximately 800 Å to approximately 2000 Å.

13. The top-emission type organic light emitting diode display substrate of claim 1 , wherein the planarization layer has a thickness in a range of approximately 10000 Å to approximately 30000 Å.

14. A top-emission type organic light emitting diode display apparatus, comprising a top-emission type organic light emitting diode display substrate of claim 1 .

15. A top-emission type organic light emitting diode display substrate having a plurality of subpixel areas, in each of which the top-emission type organic light emitting diode display substrate comprising:
a base substrate;
a thin film transistor on the base substrate and comprising a drain electrode, the drain electrode is a reflective electrode; and
an organic light emitting diode on a side of the drain electrode distal to the base substrate;
wherein the organic light emitting diode comprises:
a first electrode on a side of the drain electrode distal to the base substrate, the first electrode is a substantially transparent electrode and electrically connected to the drain electrode;
an organic layer on a side of the first electrode distal to the drain electrode, the organic layer comprises an organic light emitting layer; and
a second electrode on a side of the organic layer distal to the first electrode, the second electrode is a substantially transparent electrode;
wherein the top-emission type organic light emitting diode display substrate further comprises:
a planarization layer on a side of the drain electrode distal to the base substrate; and
a passivation layer on a side of the planarization layer distal to the drain electrode;
wherein the drain electrode and the second electrode form a microcavity structure;
the planarization layer comprises a plurality of sub-layers; and
refractive indexes of the plurality of sub-layers of the planarization layer decrease along a thickness direction away from the base substrate.

16. The top-emission type organic light emitting diode display substrate of claim 15 , wherein the microcavity structure has an optical distance substantially equal to a sum of optical path lengths of the passivation layer, the planarization layer, the organic layer, and the first electrode.

17. The top-emission type organic light emitting diode display substrate of claim 16 , wherein the optical distance is a non-integer multiple of 2πλ, λ is a wavelength of light emitted from the organic light emitting layer of the organic layer.

18. A top-emission type organic light emitting diode display apparatus, comprising a top-emission type organic light emitting diode display substrate of claim 15 .

19. A method of forming a top-emission type organic light emitting diode display substrate having a plurality of subpixel areas, the method comprising, in each of the plurality of subpixel areas:
forming a thin film transistor comprising a drain electrode on the base substrate, the drain electrode is formed using a reflective conductive material; and
forming an organic light emitting diode on a side of the drain electrode distal to the base substrate;
wherein forming the organic light emitting diode comprises:
forming a first electrode on a side of the drain electrode distal to the base substrate, the first electrode is formed using a substantially transparent conductive material and formed to be electrically connected to the drain electrode;
forming an organic layer on a side of the first electrode distal to the drain electrode, the organic layer comprises an organic light emitting layer; and
forming a second electrode on a side of the organic layer distal to the first electrode, the second electrode is formed using a substantially transparent conductive mat

Assignees

• Boe Technology Group Co Ltd

Inventors

• Zhang Can
• Chen Xiaochuan

Classifications

• H01L2251/5315

  Electricity · mapped topic

• H01L27/3262 Primary

  Electricity · mapped topic

• H01L51/5234

  Electricity · mapped topic

• H01L51/102

  Electricity · mapped topic

• H01L51/5056

  Electricity · mapped topic