System and method for matching electrode resistances in OLED light panels

• US 9,159,945 B2
• Filed: 12/13/2012
• Issued: 10/13/2015
• Est. Priority Date: 12/13/2012
• Status: Active Grant

• Current Assignee: Universal Display Corporation
• Original Assignee: Universal Display Corporation
• Inventors: Pang, Huiqing, Ma, Ruiqing
• Primary Examiner(s): Tran, Long K
• Application Number:
  US13/713,072
• Publication Number:
  US 20140166986A1
• Time in Patent Office: 1,034 Days
• Field of Search: 257/40, 257/79
• US Class Current: 1/1
• CPC Class Codes: H01J 1/62 Luminescent screens; Selection of materials for luminescent coatings on vessels
• CPC Class Codes: H10K 2101/00 Properties of the organic materials covered by group H10K85/00
• CPC Class Codes: H10K 2101/40 Interrelation of parameters between multiple constituent active layers or sublayers, e.g. HOMO values in adjacent layers
• CPC Class Codes: H10K 2101/80 Composition varying spatially, e.g. having a spatial gradient
• CPC Class Codes: H10K 2102/351 Thickness
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/15 Hole transporting layers
• CPC Class Codes: H10K 50/155 comprising dopants
• CPC Class Codes: H10K 50/805 Electrodes
• CPC Class Codes: H10K 50/81 Anodes
• CPC Class Codes: H10K 50/813 characterised by their shape
• CPC Class Codes: H10K 50/82 Cathodes
• CPC Class Codes: H10K 50/822 characterised by their shape
• CPC Class Codes: H10K 71/00 Manufacture or treatment specially adapted for the organic devices covered by this subclass
• CPC Class Codes: H10K 71/60 Forming conductive regions or layers, e.g. electrodes

Abstract

Provided are an OLED device and a method of manufacturing the OLED device that may provide improved luminance uniformity. The disclosed OLED may have a first electrode that has a first sheet resistance Rs, and a second electrode that has a second sheet resistance, wherein the second sheet resistance may be in the range of 0.3Rs-1.3Rs. In addition, the disclosed OLED may have a plurality of equal potential difference between points on a first electrode and a second electrode. The equal potential difference may be provided by a gradient resistance formed on at least one of the electrodes.

Claims

1. An organic light emitting device, comprising:

a first electrode having a first electrical sheet resistance Rs;

a second electrode having a second electrical sheet resistance in the range of about 0.3Rs-1.3Rs; and

an organic emissive layer disposed between the first electrode and the second electrode.

2. The device of claim 1, wherein the second electrical sheet resistance is further in the range of 0.5-1.2Rs.

3. The device of claim 1, wherein the second electrical sheet resistance is further in the range of 0.7-1.0Rs.

4. The device of claim 1, wherein the second electrical sheet resistance is equal to Rs.

5. The device of claim 1, wherein the first electrode has an electrode contact on a single edge of the first electrode.

6. The device of claim 5, wherein the electrode contact edge is less than about 25% of the total circumference of the first electrode.

7. The device of claim 1, wherein an electrode contact for a first electrode is on a single edge of the first electrode, and an electrode contact for the second electrode is on a single edge of the second electrode and opposite the electrode contact for the first electrode.

8. The device of claim 1, wherein at least one of the first and second electrodes has a gradient resistance where the gradient is in a current flow direction within the electrode.

9. The device of claim 1, wherein the device has at least one dimension of at least 2 cm.

10. The device of claim 1, wherein the device has at least one dimension of at least 10 cm.

11. The device of claim 1, wherein an active area of the device is at least 50 cm².

12. The device of claim 1, wherein an active area of the device is at least 72 cm².

13. The device of claim 1, further comprising:

a transport layer disposed between the first electrode and the second electrode, the transport layer having a non-uniform thickness.

14. The device of claim 1, further comprising an electrode contact for a first electrode located on a single edge of the first electrode, and an electrode contact for the second electrode located on a single edge of the second electrode, wherein the two electrode contacts are located at approximately the farthest locations from one another.

15. The device of claim 1, wherein the device outputs at a luminance uniformity greater than 80% at 1000 cd/m².

16. The device of claim 1, wherein the device has a 100% fill factor.

17. The device of claim 1, wherein the device is of a type selected from the group consisting of:

a display, and a light source.

18. A device, comprising:

a plurality of organic light emitting devices arranged in series, wherein each of the plurality of organic light emitting devices comprises;

a first electrode having a first electrical sheet resistance Rs;

a second electrode having a second electrical sheet resistance in the range of about 0.3Rs-1.3Rs; and

an organic layer disposed between the first electrode and the second electrode.

19. The device of claim 18, wherein the second electrical sheet resistance is further in the range of 0.5-1.2Rs.

20. The device of claim 18, wherein the second electrical sheet resistance is further in the range of 0.7-1.0Rs.

21. The device of claim 18, wherein the second electrical sheet resistance is equal to Rs.

22. The device of claim 18, wherein the device has at least one dimension of at least 2 cm.

23. The device of claim 18, wherein the device has at least one dimension of at least 10 cm.

24. The device of claim 18, wherein an active area of the device is at least 50 cm².

25. The device of claim 18, wherein an active area of the device is at least 72 cm².