Organic light emitting device and method for manufacturing the same

• US 8,110,977 B2
• Filed: 06/22/2007
• Issued: 02/07/2012
• Est. Priority Date: 12/27/2006
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Hwang, Kwang Jo, Park, Jae Hee
• Primary Examiner(s): Williams, Joseph L
• Assistant Examiner(s): Lee, Brenitra
• Application Number:
  US11/821,164
• Publication Number:
  US 20080158108A1
• Time in Patent Office: 1,691 Days
• Field of Search: 313500-506, 345/77
• US Class Current: 313/500
• CPC Class Codes: G09G 2300/0439 Pixel structures
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: H10K 2102/3026 Top emission
• CPC Class Codes: H10K 59/126 Shielding, e.g. light-blocking means over the TFTs

Abstract

A top emission OLED includes a driving TFT including a channel region and source and drain electrodes. A power supply, a ground line, and a light emitting diode are electrically coupled to the TFT and an auxiliary electrode is electrically coupled to the ground line and to the source electrode of the driver transistor. The auxiliary electrode resides between the light emitting diode and the channel region of the driver transistor and is configured to shield the channel region of the driver transistor from an electric field generated by the light emitting diode.

Claims

1. An organic light emitting device comprising:

a driver transistor including a channel region and source and drain electrodes;

an insulating layer on the driver transistor and having a contact hole;

a ground line electrically coupled to the source electrode of the driver transistor;

a light emitting diode including a first electrode electrically coupled to the drain electrode of the driver transistor through the contact hole and overlying the driver transistor, an organic light emitting layer overlying the first electrode, and a second electrode overlying the organic light emitting layer; and

an auxiliary electrode formed from the ground line and electrically coupled to the source electrode of the driver transistor.

2. The organic light emitting device of claim 1, wherein the auxiliary electrode overlies the source electrode and at least a portion of the channel region and is separated therefrom by an insulating layer, and

wherein the auxiliary electrode is separated from the first electrode, is formed in the same layer as the ground line, and is formed between the first electrode and the channel region of the driver transistor.

3. The organic light emitting device of claim 1, wherein the auxiliary electrode overlies the source electrode and extends over the channel region to a point in proximity to the drain electrode and is separated therefrom by the insulating layer.

4. The organic light emitting device of claim 3, wherein the auxiliary electrode is separated from the channel region and the drain electrode by the insulating layer, and wherein auxiliary electrode encircles a perimeter of at least a portion of the channel region.

5. The organic light emitting device of claim 1, wherein the driver transistor is a p-type transistor.

6. The organic light emitting device of claim 1, wherein the auxiliary electrode is integral with the ground line, and

wherein the auxiliary electrode extends onto the channel region of the driver transistor from the ground line to cover at least the channel region.

7. The organic light emitting device of claim 1 further comprising:

a switching transistor electrically coupled to the driver transistor; and

a power line electrically coupled to the second electrode of the light emitting diode.

8. The organic light emitting device of claim 1, wherein the auxiliary electrode block a field effect of the channel region of the driver transistor.

15. The organic light emitting device of claim 1, wherein the auxiliary electrode covers an entire portion of the channel region.

16. The organic light emitting device of claim 1, wherein the first electrode overlaps the driver transistor with the insulating layer therebetween.

9. An organic light emitting device comprising:

a driving transistor including a channel region, a source electrode and a drain electrode;

an insulating layer on the driver transistor and having a contact hole;

a ground line electrically coupled to the source electrode of the driver transistor;

a light emitting diode including a first electrode electrically coupled to the drain electrode through the contact hole and overlying the driving transistor, an organic light emitting layer overlying the first electrode, and a second electrode overlying the organic light emitting layer; and

an auxiliary electrode formed to contact one upper surface of the source electrode and the ground line.

10. The organic light emitting device of claim 9, wherein the channel region has a ring shape and the auxiliary electrode encircles at least a portion of the channel region.

11. The organic light emitting device of claim 9, wherein a portion of the auxiliary electrode overlaps with a portion of the ground line,

wherein the auxiliary electrode is separated from the first electrode, and is formed between the first electrode and the channel region of the driver transistor, and

wherein the auxiliary electrode extends onto the channel region of the driver transistor from the source electrode to cover at least the channel region.

12. The organic light emitting device of claim 9 further comprising:

a switching transistor electrically coupled to the driver transistor; and

a power line electrically coupled to the second electrode of the light emitting diode.

13. The organic light emitting device of claim 9, wherein the auxiliary electrode comprises at least one selected from the group consisting of Al, an aluminum alloy, W, Cu, Mo, and Ti.

14. The organic light emitting device of claim 9, wherein the auxiliary electrode comprises at least one selected from the group consisting of indium tin oxide and indium zinc oxide.