Organic light emitting diode display with thin film transistors in portions of curved semiconductor layer
An organic light emitting diode display includes a substrate, a scan line on the substrate for transferring a scan signal, a data line crossing the scan line and for transferring a data signal, a driving voltage line crossing the scan line and for transferring a driving voltage, a switching thin film transistor coupled to the scan line and the data line, a driving thin film transistor coupled to a switching drain electrode of the switching thin film transistor, and an organic light emitting diode (OLED) coupled to a driving drain electrode of the driving thin film transistor, wherein a driving semiconductor layer of the driving thin film transistor is bent and in a plane substantially parallel to the substrate.
1. An organic light emitting diode display comprising:
a substrate;
a first voltage line;
a plurality of driving circuits on the substrate;
a plurality of organic light emitting diodes, each of the organic light emitting diodes being electrically coupled to a respective driving circuit;
wherein each of the driving circuits comprises:
a first thin film transistor implemented in a first portion of a semiconductor layer and coupled to a first scan line and a data line;
a second thin film transistor implemented in a second portion of the semiconductor layer and electrically coupled to the first voltage line and one of the organic light emitting diodes, the semiconductor layer electrically coupling the second thin film transistor to the first thin film transistor, the second portion of the semiconductor layer having a curved portion in a channel region of the second thin film transistor;
a gate insulating layer covering the second portion of the semiconductor layer;
a storage capacitor electrically coupled to a gate electrode of the second thin film transistor, the storage capacitor comprising:
a first capacitor plate comprising the gate electrode of the second thin film transistor;
a second capacitor plate overlapping the first capacitor plate; and
an insulating layer between the first capacitor plate and the second capacitor plate, the insulating layer covering the second thin film transistor; and
a third thin film transistor implemented in a third portion of the semiconductor layer and electrically coupled to the one of the organic light emitting diodes and the first capacitor plate, the semiconductor layer electrically coupling the third thin film transistor to the second thin film transistor,
wherein the curved portion of the second portion of the semiconductor layer is under the gate electrode of the second thin film transistor and is covered by the first capacitor plate.
2. The organic light emitting diode display according to claim 1 , further comprising a fourth thin film transistor implemented in a fourth portion of the semiconductor layer and electrically coupled to the first voltage line,
wherein the semiconductor layer electrically couples the fourth thin film transistor to the second thin film transistor.
3. The organic light emitting diode display according to claim 2 , further comprising a fifth thin film transistor implemented in a fifth portion of the semiconductor layer and electrically coupled to the one of the organic light emitting diodes,
wherein the semiconductor layer electrically couples the fifth thin film transistor to the second thin film transistor.
4. The organic light emitting diode display according to claim 3 , further comprising:
a second voltage line; and
a sixth thin film transistor implemented in a sixth portion of the semiconductor layer and electrically coupled to the second voltage line and the first capacitor plate,
wherein the semiconductor layer electrically couples the sixth thin film transistor to the third thin film transistor.
5. The organic light emitting diode display according to claim 4 , further comprising a seventh thin film transistor implemented in a seventh portion of the semiconductor layer and electrically coupled to the second voltage line and the one of the organic light emitting diodes,
wherein the semiconductor layer electrically couples the seventh thin film transistor to the fifth thin film transistor.
6. The organic light emitting diode display according to claim 4 , wherein the gate electrode of the sixth thin film transistor is configured to receive a signal from a second scan line.
7. The organic light emitting diode display according to claim 5 , wherein a gate electrode of the seventh thin film transistor is configured to receive a signal from a bypass control line.
8. The organic light emitting diode display according to claim 3 , wherein gate electrodes of the fourth and fifth thin film transistors are coupled together and are configured to receive a signal from a light emission control line.
9. The organic light emitting diode display according to claim 3 , further comprising a protective layer covering the plurality of driving circuits,
wherein each of the organic light emitting diodes further comprises a pixel electrode on the protective layer, the pixel electrode being electrically coupled to a drain electrode of the fifth thin film transistor through a contact hole.
10. The organic light emitting diode display according to claim 1 , wherein gate electrodes of the first and third thin film transistors are coupled together and are configured to receive a signal from the first scan line.
11. The organic light emitting diode display according to claim 1 , wherein the second capacitor plate is electrically coupled to the first voltage line.
12. The organic light emitting diode display according to claim 11 , wherein a periphery of the second capacitor plate completely surrounds a periphery of the first capacitor plate in a plan view.
13. The organic light emitting diode display according to claim 1 , wherein portions of the semiconductor layer are doped with N-type impurities.
14. The organic light emitting diode display according to claim 1 , wherein portions of the semiconductor layer are doped with P-type impurities.
15. The organic light emitting diode display according to claim 1 , further comprising a protective layer covering the plurality of driving circuits,
wherein each of the organic light emitting diodes further comprises a pixel electrode on the protective layer, the pixel electrode being electrically coupled to the second thin film transistor through a contact hole.
16. The organic light emitting diode display according to claim 1 , wherein the first capacitor plate and the first scan line are in the same material layer.
17. The organic light emitting diode display according to claim 1 , wherein the curved portion of the second portion of the semiconductor layer has a “S”-shape.
18. The organic light emitting diode display according to claim 1 , wherein the curved portion of the semiconductor layer has a partial “S”-shape.
19. The organic light emitting diode display according to claim 1 , wherein the curved portion of the second portion of the semiconductor layer has a “M”-shape.
20. The organic light emitting diode display according to claim 1 , wherein the curved portion of the second portion of the semiconductor layer has a “W”-shape.
21. The organic light emitting diode display according to claim 1 , wherein the third thin film transistor is electrically coupled to a gate electrode and a drain electrode of the second thin film transistor.
22. The organic light emitting diode display according to claim 1 , wherein the third thin film transistor has a dual gate electrode structure.