ORGANIC ELECTROLUMINESCENT DISPLAY DEVICE

• US 20100117999A1
• Filed: 04/03/2008
• Published: 05/13/2010
• Est. Priority Date: 04/05/2007
• Status: Abandoned Application

• Current Assignee: UDC Ireland Limited
• Original Assignee: UDC Ireland Limited
• Inventors: Tanaka, Atsushi, Nakayama, Masaya, Matsunaga, Atsushi
• Application Number:
  US12/594,532
• Publication Number:
  US 20100117999A1
• Time in Patent Office: Days
• US Class Current: 345/204
• 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: H05B 33/12 Light sources with substantially two-dimensional radiating surfaces
• CPC Class Codes: H10K 2102/311 Flexible OLED
• CPC Class Codes: H10K 59/1213 the pixel elements being TFTs
• CPC Class Codes: H10K 59/38 comprising colour filters or colour changing media [CCM]

Abstract

An organic electroluminescent display device includes at least a driving TFT and pixels which are formed by organic electroluminescent elements and are provided on a substrate of the TFT. The driving TFT includes at least a substrate, a gate electrode, a gate insulating film, an active layer, a source electrode, and a drain electrode. The driving TFT further includes a resistive layer between the active layer and at least one of the source electrode and the drain electrode. The pixels include at least one color-modified pixel which has a color filter that modifies the emission color of the color-modified pixel, and which emits light of the modified color.

Claims

1. An organic electroluminescent display device comprising at least a driving TFT and pixels which are formed by organic electroluminescent elements and are provided on a substrate of the TFT,

wherein the driving TFT includes at least a substrate, a gate electrode, a gate insulating film, an active layer, a source electrode, and a drain electrode;

the driving TFT further includes a resistive layer between the active layer and at least one of the source electrode and the drain electrode; and

the pixels include at least one color-modified pixel which has a color filter that modifies the emission color of the color-modified pixel, and which emits light of the modified color.

2. The organic electroluminescent display device according to claim 1, wherein the resistive layer has a lower electrical conductivity than that of the active layer.

3. The organic electroluminescent display device according to claim 1, wherein, in the at least one color-modified pixel, the color filter is provided at the side of the luminescent layer of the organic electroluminescent element from which light is extracted.

4. The organic electroluminescent display device according to claim 1, wherein the pixels include two or more kinds of pixel having respectively different emission colors, and at least one of the pixels is the at least one color-modified pixel.

5. The organic electroluminescent display device according to claim 4, wherein the two or more kinds of pixel having different emission colors include a red emitting pixel, a green emitting pixel, and a blue emitting pixel.

6. The organic electroluminescent display device according to claim 4, wherein the two or more kinds of pixel having respectively different emission colors include a white emitting pixel, a red emitting pixel, a green emitting pixel, and a blue emitting pixel.

7. The organic electroluminescent display device according to claim 6, wherein each of the red emitting pixel, the green emitting pixel, and the blue emitting pixel is a pixel in which the emission color of the white emitting pixel is modified by a color filter.

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

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

10. The organic electroluminescent display device according to claim 1, wherein electrical conductivity continuously varies between the resistive layer and the active layer.

11. The organic electroluminescent display device according to claim 1, wherein the active layer and the resistive layer include oxide semiconductors, which may be the same or different.

12. The organic electroluminescent display device according to claim 11, wherein the oxide semiconductor is an amorphous oxide semiconductor.

13. The organic electroluminescent display device according to claim 11, wherein the oxygen concentration in the active layer is lower than the oxygen concentration in the resistive layer.

14. The organic electroluminescent display device according to claim 11, wherein the oxide semiconductor is at least one selected from the group consisting of oxides of In, Ga, and Zn, or a composite oxide thereof.

15. The organic electroluminescent display device according to claim 14, wherein the oxide semiconductor includes In and Zn, and the composition ratio of Zn to In in the resistive layer is higher than that in the active layer.

16. The organic electroluminescent display device according to claim 15, wherein the electrical conductivity of the active layer is 10⁻

4 Scm<sup>−

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

1</sup>.

17. The organic electroluminescent display device according to claim 1, wherein the ratio of the electrical conductivity of the active layer to the electrical conductivity of the resistive layer is from 10² to 10⁸.

18. The organic electroluminescent display device according to claim 17, wherein the substrate is a flexible resin substrate.