Claims

1. A pixel structure of an active matrix organic light-emitting diode (AMOLED), disposed on a transparent substrate and comprising: an organic light-emitting diode (OLED); a data line; at least one scan line; at least one switch thin film transistor (TFT), having a first gate, a first source and a first drain, wherein the first gate is coupled to the scan line, while the first source is coupled to the data line; at least one driving thin film transistor (TFT), having a second gate, a second source and a second drain, wherein the second gate is coupled to the first drain, while the second drain is coupled to the OLED; and at least one storage capacitor having a first transparent electrode, a second transparent electrode and a dielectric layer, wherein the first transparent electrode is electrically connected to the first drain and the second gate.

2. The pixel structure of the AMOLED of claim 1, wherein the first transparent electrode is a transparent semiconductor layer, while the second transparent electrode is a transparent metal layer.

3. The pixel structure of the AMOLED of claim 2, wherein the material of the transparent metal comprises indium-tin-oxide (ITO) or indium zinc oxide (IZO).

4. The pixel structure of the AMOLED of claim 2, wherein the material of the transparent semiconductor comprises ZnO, Mg_xZn.sub.1-xO, Cd_xZn.sub.1-xO or CdO, or ZnO, Mg_xZn.sub.1-xO, Cd_xZn.sub.1-xO or CdO that have been doped with (a) an element that can be univalent or (b) Ni; or indium gallium zinc oxide (InGaZnO).

5. The pixel structure of the AMOLED of claim 1, wherein the area of the storage capacitor is about 50%~95% of the pixel area.

6. The pixel structure of the AMOLED of claim 1, wherein the first gate of the switch TFT is formed by an opaque metal layer or by a transparent metal layer and an opaque metal layer, wherein the resistance of the opaque metal layer is smaller than the transparent metal layer.

7. The pixel structure of the AMOLED of claim 1, wherein the second gate of the driving TFT is formed by an opaque metal layer or by a transparent metal layer and an opaque metal layer, wherein the resistance of the opaque metal layer is smaller than the transparent metal layer.

8. The pixel structure of the AMOLED of claim 1, wherein the first source and the first drain of the switch TFT are formed in a channel layer and the material of the channel layer is opaque doped semiconductor or transparent doped semiconductor.

9. The pixel structure of the AMOLED of claim 1, wherein the second source and the second drain of the driving TFT are formed in a channel layer and the material of the channel layer is opaque doped semiconductor or transparent doped semiconductor.

10. The pixel structure of the AMOLED of claim 1, wherein the OLED includes a white organic light-emitting layer and the pixel structure of the AMOLED further comprises a color filter disposed between the transparent substrate and the OLED.

11. The pixel structure of the AMOLED of claim 10, further comprising a transparent cover plate and another color filter, wherein the transparent cover plate is disposed on and covers the OLED, while the another color filter is disposed between the OLED and the transparent cover plate.

12. A storage capacitor of an AMOLED pixel structure, comprising: a first transparent electrode connected to a drain of a switch TFT of the pixel and a gate of a driving TFT of the pixel; a second transparent electrode; and a dielectric layer between the first transparent electrode and the second transparent electrode.

13. The storage capacitor of an AMOLED pixel structure of claim 12, wherein the first transparent electrode is a transparent semiconductor layer, while the second transparent electrode is a transparent metal layer.

14. The storage capacitor of an AMOLED pixel structure of claim 13, wherein the material of the transparent metal comprises indium-tin-oxide (ITO) or indium zinc oxide (IZO).

15. The storage capacitor of an AMOLED pixel structure of claim 13, wherein the material of the transparent semiconductor comprises ZnO, Mg_xZn.sub.1-xO, Cd_xZn.sub.1-xO or CdO, or ZnO, Mg_xZn.sub.1-xO, Cd_xZn.sub.1-xO or CdO that have been doped with (a) an element that can be univalent or (b) Ni; or indium gallium zinc oxide (InGaZnO).

16. The storage capacitor of an AMOLED pixel structure of claim 12, wherein the area of the storage capacitor is about 50%~95% of the pixel area.

17. A method for fabricating the pixel of an AMOLED, comprising: forming a patterned transparent semiconductor layer on a substrate to form at least one first channel layer of a switch TFT, at least one lower electrode of a storage capacitor and at least one second channel layer of a driving TFT, wherein the area of the storage capacitor lower electrode is about 50%~95% of the pixel area; forming a first dielectric layer over the substrate to serve as a first gate dielectric layer of the switch TFT, a dielectric layer of the storage capacitor and a second gate dielectric layer of the driving TFT; forming a first opaque metal gate of the switch TFT, a second opaque metal gate of the driving TFT and at least one scan line on the first dielectric layer; forming a first source and a first drain of the switch TFT in the first channel layer and forming a second source and a second drain of the driving TFT in the second channel layer; forming a patterned transparent metal layer on the first dielectric layer to serve as an upper electrode of the storage capacitor, wherein the area of the upper electrode is about 50%~95% of the pixel area; forming a data line over the substrate electrically connected to the first source of the switch TFT; and forming an OLED over the substrate electrically connected to the second drain of driving TFT.

18. The method for fabricating the pixel of an AMOLED of claim 17, wherein the material of the transparent semiconductor comprises ZnO, Mg_xZn.sub.1-xO, Cd_xZn.sub.1-xO or CdO, or ZnO, Mg_xZn.sub.1-xO, Cd_xZn.sub.1-xO or CdO that have been doped with (a) an element that can be univalent or (b) Ni; or indium gallium zinc oxide (InGaZnO).

19. The method for fabricating the pixel of an AMOLED of claim 17, wherein the material of the transparent metal comprises indium-tin-oxide (ITO) or indium zinc oxide (IZO).

20. The method for fabricating the pixel of an AMOLED of claim 17, wherein the step for forming the patterned transparent metal layer on the first dielectric layer includes forming the upper electrode of the storage capacitor, a first transparent metal gate of the switch TFT and a second transparent metal gate of the driving TFT.

21. The method for fabricating the pixel of an AMOLED of claim 20, wherein the step for forming the patterned transparent metal layer on the first dielectric layer is performed prior to the step for forming the first opaque metal gate of the switch TFT, the second opaque metal gate of the driving TFT and the scan line on the first dielectric layer.

22. The method for fabricating the pixel of an AMOLED of claim 20, wherein the step for forming the patterned transparent metal layer on the first dielectric layer is performed after the step for forming the first opaque metal gate of the switch TFT, the second opaque metal gate of the driving TFT and the scan line on the first dielectric layer.

23. The method for fabricating the pixel of an AMOLED of claim 17, wherein the OLED includes a white organic light-emitting layer and the step of the method further comprises forming a color filter on the substrate prior to forming the data line and the OLED but after forming the upper electrode of the storage capacitor.

24. The method for fabricating the pixel of an AMOLED of claim 23, further comprising a step for forming another color filter to cover the OLED after the step of forming the OLED.