Active matrix organic light emitting device

• US 20050062408A1
• Filed: 09/01/2004
• Published: 03/24/2005
• Est. Priority Date: 09/23/2003
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Mobile Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Yoo, Jeong-Geun, Lee, Jeong-No
• Granted Patent: US 7,772,760 B2
• Time in Patent Office: Days
• US Class Current: 313/504
• CPC Class Codes: H10K 2102/3026 Top emission
• CPC Class Codes: H10K 2102/3031 Two-side emission, e.g. transparent OLEDs [TOLED]
• CPC Class Codes: H10K 50/81 Anodes
• CPC Class Codes: H10K 50/828 Transparent cathodes, e.g. comprising thin metal layers
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/123 Connection of the pixel electrodes to the thin film transistors [TFT]
• CPC Class Codes: H10K 59/32 Stacked devices having two or more layers, each emitting at different wavelengths
• CPC Class Codes: H10K 59/8051 Anodes
• CPC Class Codes: H10K 59/80524 Transparent cathodes, e.g. comprising thin metal layers

Abstract

An active matrix organic light emitting device having a structure where a plurality of emission layers having each separate current path are stacked. In the active matrix organic light emitting device of the present invention, a plurality of emission layers are stacked on an insulating substrate. A thin film transistor is formed on the insulating substrate and is connected in common with a number of electrode layers to independently drive the plurality of emission layers.

Claims

1. An active matrix organic light emitting device comprising:

a plurality of emission layers stacked on an insulating substrate;

one or more first electrodes formed between respective inner facing surfaces of two adjacent emission layers among the plurality of emission layers; and

a plurality of second electrodes each formed on respective outer surfaces of the two adjacent emission layers;

wherein the plurality of second electrodes are connected to each other.

2. The active matrix organic light emitting device of claim 1, wherein the one or more first electrodes act as common electrodes for the two adjacent emission layers.

3. The active matrix organic light emitting device of claim 1, wherein the one or more first electrodes act as cathode electrodes, and the plurality of second electrodes act as anode electrodes.

4. The active matrix organic light emitting device of claim 1, wherein the first electrode is opaque and the plurality of second electrodes are transparent, such that light from the two adjacent emission layers is emitted so that it radiates in opposite directions.

5. The active matrix organic light emitting device of claim 1, wherein:

the first electrode is transparent;

a second electrode, of the plurality of second electrodes, that is formed below a lowest emission layer of the plurality of emission layers is opaque; and

others of the plurality of second electrodes are transparent, such that light from the two adjacent emission layers is emitted so that it radiates away from the substrate.

6. The active matrix organic light emitting device of claim 1, wherein:

the first electrode is transparent; and

a second electrode, of the plurality of second electrodes, that is formed over an uppermost emission layer of the plurality of emission layers is opaque; and

others of the plurality of second electrodes are transparent, such that light from the two adjacent emission layers is emitted such that it radiates toward the substrate.

7. The active matrix organic light emitting device of claim 1, wherein:

the first electrode is transparent; and

each one of the plurality of second electrodes is transparent, such that light from the two adjacent emission layers of the plurality of emission layers is emitted so that it radiates in directions toward and away from the substrate.

8. The active matrix organic light emitting device of claim 1, wherein an insulating layer is interposed between two adjacent second electrodes of the plurality of second electrodes to insulate the two adjacent second electrodes.

9. An active matrix organic light emitting device comprising:

a plurality of emission layers stacked on an insulating substrate;

one or more first electrodes formed between respective facing surfaces of two adjacent emission layers among the plurality of emission layers; and

a plurality of second electrodes formed on respective outer surfaces of the two adjacent emission layers;

wherein each one of the plurality of emission layers has a separate current path.

10. The active matrix organic light emitting device of claim 9, wherein:

the first electrode is a cathode electrode acting as a common electrode for the two adjacent emission layers; and

the plurality of second electrodes act as an anode electrodes for each one of the plurality of emission layers.

11. The active matrix organic light emitting device of claim 9, wherein:

the plurality of second electrodes are connected to each other and are adapted to have the same level of voltage applied to them; and

each of the plurality of emission layers is independently driven to emit light in accordance with the voltage applied to the one or more first electrodes and the plurality of second electrodes.

12. The active matrix organic light emitting device of claim 9, wherein:

the one or more first electrodes are opaque; and

each of the plurality of second electrodes is transparent, so that light from the two adjacent emission layers is emitted in opposite directions.

13. The active matrix organic light emitting device of claim 9, wherein:

the one or more first electrodes are transparent;

a second electrode, of the plurality of second electrodes, formed below a lowest emission layer of the plurality of emission layers is opaque, and others of the plurality of second electrodes are transparent ones, so that light from the two adjacent emission layers is emitted so that it radiates away from the substrate.

14. The active matrix organic light emitting device of claim 9, wherein:

the one or more first electrodes are transparent;

a second electrode, of the plurality of second electrodes, formed over an uppermost emission layer of the plurality of emission layers is opaque; and

others of the plurality of second electrodes are transparent, such that light from the two adjacent emission layers is emitted so that it radiates toward the substrate.

15. The active matrix organic light emitting device of claim 9, wherein:

the one or more first electrodes are transparent; and

each one of the plurality of second electrodes is transparent, such that light from the two adjacent emission layers is emitted so that it radiates toward and away from the substrate.

16. An active matrix organic light emitting device comprising:

a plurality of emission layers stacked on an insulating substrate;

one or more first electrodes formed between inner facing surfaces of two adjacent emission layers of the plurality of emission layers;

a plurality of second electrodes formed on respective outer surfaces of the two adjacent emission layers; and

a thin film transistor formed on the insulating substrate,

wherein the thin film transistor is connected in common to the plurality of second electrodes to drive the plurality of emission layers independently.

17. The active matrix organic light emitting device of claim 16, wherein the one or more first electrodes act as cathode electrodes and the plurality of second electrodes act as anode electrodes.

18. The active matrix organic light emitting device of claim 16, wherein:

when the one or more first electrodes are opaque and the plurality of second electrodes are transparent, light from the two adjacent emission layers is emitted in opposite directions; and

when the one or more first electrodes are transparent, and the plurality of second electrodes are all transparent ones, light from the two adjacent emission layers is emitted so that it radiates toward and away from the substrate.

19. The active matrix organic light emitting device of claim 16, wherein:

when the one or more first electrodes are transparent, and a second electrode, of the plurality of second electrodes, formed below a lowest emission layer of the plurality of emission layers is opaque, and others of the plurality of second electrodes are transparent, light from the two adjacent emission layers is emitted so that it radiates away from the substrate; and

when the one or more first electrodes are transparent, and a second electrode, of the plurality of second electrodes, formed over the uppermost emission layer of the plurality of emission layers is opaque, and others of the plurality second electrodes are transparent, light from the two adjacent emission layers is emitted so that it radiates toward the substrate.

20. An active matrix organic light emitting device comprising:

a thin film transistor formed on an insulating substrate;

a first insulating layer formed on the insulating substrate covering the thin film transistor, and having a first contact hole exposing a portion of the thin film transistor;

a first electrode connected to the thin film transistor through the first contact hole;

a second insulating layer having a first opening exposing a portion of the first electrode;

a first emission layer formed on the first electrode within the first opening;

a second electrode formed on an entire surface of the substrate and having an isolation pattern;

a third insulating layer formed on the second insulating layer and having a second opening exposing a portion of the second electrode corresponding to the first opening, and a second contact hole exposing a portion of the first electrode corresponding to the isolation pattern;

a second emission layer formed on the exposed portion of the second electrode; and

a third electrode formed on the third insulating layer to connect the first electrode through the second contact hole.

21. The active matrix organic light emitting device of claim 20, wherein the first electrode a cathode acting as a common electrode for the first and second emission layers, and the second and third electrodes are anodes, to which the same level of voltage is applied.

22. The active matrix organic light emitting device of claim 20, wherein the first and third insulating layers are planarization layers and the second insulating layer is a pixel defining layer.

23. The active matrix organic light emitting device of claim 20, wherein the isolation pattern is formed in an engraved pattern of grooves or stripes.

24. The active matrix organic light emitting device of claim 20, wherein:

when the first electrode is opaque and the second and third electrodes are transparent, light from the first emission layer and the second emission layer is emitted in opposite directions;

when the first and second electrodes are transparent and the third electrode is opaque, the light from the first and second emission layers is emitted so that it radiates toward the substrate; and

when the first and third electrodes are transparent and the second electrode is opaque, the light from the first and second emission layers is emitted so that it radiates away from the substrate.

25. An active matrix organic light emitting device comprising:

a plurality of emission layers stacked on an insulating substrate;

a plurality of first electrodes, each one of the plurality of first electrodes formed on one surface of a corresponding one of the plurality of emission layers;

a plurality of second electrodes, each one of the plurality of second electrodes formed on another surface of the corresponding one of the plurality of emission layers; and

an insulating layer formed between adjacent ones of the plurality of first electrodes and the plurality of second electrodes;

wherein the plurality of first electrodes are connected to each other and are adapted to have a first voltage applied thereto, and the plurality of second electrodes are connected to each other and are adapted to have a second voltage applied thereto, such that ones of the plurality of emission layers connected between the first electrode and the second electrode each have separate current paths.

26. The active matrix organic light emitting device of claim 25, wherein each of the plurality of first electrodes acts as a cathode electrode and each of the plurality of second electrodes acts as an anode electrode.

27. The active matrix organic light emitting device of claim 25, wherein:

when the plurality of first electrodes is opaque and the plurality of second electrodes is transparent ones, light from the two adjacent emission layers is emitted in opposite directions; and

when the plurality of first electrodes is transparent, and the plurality of second electrodes is transparent, the light from the two adjacent emission layers is emitted so that it radiates toward and away from the substrate.

28. The active matrix organic light emitting device of claim 25, wherein:

when the plurality of first electrodes is transparent and a second electrode, of the plurality of second electrodes, formed below a lowest emission layer of the plurality of emission layers opaque, and others of the plurality of second electrodes are transparent, light from the two adjacent emission layers is emitted so that it radiates away from the substrate; and

when the plurality of first electrodes is transparent, and a second electrode, of the plurality of second electrodes, formed over an uppermost emission layer of the plurality of emission layers is opaque, and others of the plurality of second electrodes are transparent, light from the two adjacent emission layers is emitted so that it radiates toward the substrate.