ORGANIC ELECTROLUMINESCENCE DISPLAY DEVICE

• US 20100065845A1
• Filed: 04/03/2008
• Published: 03/18/2010
• Est. Priority Date: 04/10/2007
• Status: Abandoned Application

• Current Assignee: UDC Ireland Limited (Universal Display Corporation)
• Original Assignee: UDC Ireland Limited (Universal Display Corporation)
• Inventors: Nakayama, Masaya
• Application Number:
  US12/595,489
• Publication Number:
  US 20100065845A1
• Time in Patent Office: Days
• US Class Current: 257/43
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate
• CPC Class Codes: H10K 59/1201 Manufacture or treatment
• CPC Class Codes: H10K 59/1213 the pixel elements being TFTs
• CPC Class Codes: H10K 59/123 Connection of the pixel electrodes to the thin film transistors [TFT]

Abstract

The invention provides an organic electroluminescent display device comprising: an organic electroluminescent element comprising an organic layer comprising a luminescent layer disposed between a pixel electrode and an upper electrode; and a drive TFT that supplies an electric current to the organic electroluminescent element, wherein: the drive TFT comprises a substrate, a gate electrode, a gate insulation film, an active layer, a source electrode and a drain electrode, and wherein: an resistive layer is provided between the active layer and at least one of the source electrode and the drain electrode.

Claims

1. An organic electroluminescent display device comprising:

an organic electroluminescent element comprising an organic layer comprising a luminescent layer disposed between a pixel electrode and an upper electrode; and

a drive TFT that supplies an electric current to the organic electroluminescent element, wherein;

the drive TFT comprises a substrate, a gate electrode, a gate insulation film, an active layer, a source electrode and a drain electrode, and wherein;

a resistive layer is provided between the active layer and at least one of the source electrode and the drain electrode.

2. The organic electroluminescent display device according to claim 1, wherein the electroconductivity of the resistive layer is smaller than the electroconductivity of the active layer.

3. The organic electroluminescent display device according to claim 1, wherein the active layer is in contact with the gate insulation film and the resistive layer is in contact with the at least one of the source electrode and the drain electrode.

4. The organic electroluminescent display device according to claim 1, wherein the thickness of the resistive layer is greater than the thickness of the active layer.

5. The organic electroluminescent display device according to claim 1, wherein the electroconductivity between the resistive layer and the active layer changes continuously.

6. The organic electroluminescent display device according to claim 1, wherein the active layer and the resistive layer contain an oxide semiconductor.

7. The organic electroluminescent display device according to claim 6, wherein the oxide semiconductor is an amorphous oxide semiconductor.

8. The organic electroluminescent display device according to claim 6, wherein the oxygen concentration of the active layer is lower than the oxygen concentration of the resistive layer.

9. The organic electroluminescent display device according to claim 6, wherein the oxide semiconductor contains at least one selected from the group consisting of In, Ga and Zn, and a composite oxide thereof.

10. The organic electroluminescent display device according to claim 9, wherein the oxide semiconductor contains In and Zn, and wherein the composition ratio of Zn and In (expressed by Zn/In) of the resistive layer is higher than the composition ratio of Zn/In of the active layer.

11. The organic electroluminescent display device according to claim 1, wherein the electroconductivity of the active layer is 10⁻

4 Scm<sup>−

1</sup> or more and less than 10² Scm<sup>−

1</sup>.

12. The organic electroluminescent display device according to claim 1, wherein the ratio of the electroconductivity of the active layer to the electroconductivity of the resistive layer (electroconductivity of the active layer/electroconductivity of the resistive layer) is from 10² to 10⁸.

13. The organic electroluminescent display device according to claim 1, wherein the substrate is a flexible resin substrate.

14. The organic electroluminescent display device according to claim 1, wherein at least one of the source electrode and the drain electrode of the drive TFT, and the pixel electrode of the organic electroluminescent element, are made of the same material and are formed in the same process.

15. The organic electroluminescent display device according to claim 14, wherein the at least one of the source electrode and the drain electrode of the drive TFT is made of indium tin oxide or indium zinc oxide.

16. The organic electroluminescent display device according to claim 14, wherein an insulation film is formed on the periphery of the pixel electrode of the organic electroluminescent element.