Organic electroluminescent display unit and method for fabricating the same

• US 8,183,769 B2
• Filed: 10/19/2010
• Issued: 05/22/2012
• Est. Priority Date: 08/04/2010
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: Chang, Ting-Kuo, Fang, Chun-Hsiang
• Primary Examiner(s): MACCHIAROLO, PETER J
• Application Number:
  US12/907,033
• Publication Number:
  US 20120032582A1
• Time in Patent Office: 581 Days
• Field of Search: 313504-512, 345/76, 345/81
• US Class Current: 313/506
• CPC Class Codes: H10K 59/13 comprising photosensors that control luminance

Abstract

An organic electroluminescent display unit suitable to be electrically connected to a scan line and a data line including at least one transistor, a first photo-sensor, a second photo-sensor, a conductive layer, an organic electroluminescent layer and a cathode layer is provided. The conductive layer entirely covers the second photo-sensitive layer. A method of fabricating an organic electroluminescent display unit with the integrating a fabrication of a photo-sensor into a fabrication of the organic electroluminescent display panel is further provided. The cost for fabricating the organic electroluminescent display unit of the invention can be further reduced.

Claims

1. An organic electroluminescent display unit electrically connected to a scan line and a data line, comprising:

at least one transistor electrically connected to the scan line and the data line;

a first photo-sensor comprising a first reflective bottom electrode, a first photo-sensitive layer and a first transparent top electrode, wherein the first photo-sensitive layer is sandwiched between the first reflective bottom electrode and the first transparent top electrode;

a second photo-sensor comprising a second reflective bottom electrode, a second photo-sensitive layer and a second transparent top electrode, wherein the second photo-sensitive layer is sandwiched between the second reflective bottom electrode and the second transparent top electrode, and the first photo-sensor is electrically connected to the second photo-sensor;

a conductive layer comprising a reflective pixel electrode, a light-shielding pattern, and a connection pattern, wherein the reflective pixel electrode is electrically connected to the transistor, the light-shielding pattern is electrically connected to the second transparent top electrode and the light-shielding pattern entirely covers the second photo-sensitive layer, and the connection pattern is electrically connected to the first transparent top electrode, the first reflective bottom electrode, and the second reflective bottom electrode;

an organic electroluminescent layer disposed on the reflective pixel electrode; and

a cathode layer disposed on the organic electroluminescent layer.

2. The organic electroluminescent display unit as claimed in claim 1, wherein the transistor comprises a gate, a channel layer, a source, and a drain, the source and the drain are located on a portion of the channel layer, and the source and the drain are electrically insulated from each other.

3. The organic electroluminescent display unit as claimed in claim 2, wherein the channel layer is located above the gate.

4. The organic electroluminescent display unit as claimed in claim 2, wherein the first reflective bottom electrode. the second reflective bottom electrode, the source, and the drain are substantially fabricated with a same material.

5. The organic electroluminescent display unit as claimed in claim 1, wherein the connection pattern merely shields a portion of the first photo-sensitive layer such that the first photo-sensitive layer is capable of receiving an external light.

6. The organic electroluminescent display unit as claimed in claim 1 further comprising a passivation layer covering the transistor, the first photo-sensor, and the second photo-sensor.

7. The organic electroluminescent display unit as claimed in claim 6, wherein the passivation layer has a first contact window, a plurality of second contact windows, and a third contact window, the reflective pixel electrode is electrically connected to the transistor via the first contact window, the connection pattern is electrically connected to the first transparent top electrode, the first reflective bottom electrode, and the second reflective bottom electrode via the second contact windows, and the light-shielding pattern is electrically connected to the second transparent top electrode via the third contact window.

8. The organic electroluminescent display unit as claimed in claim 1, further comprising a pixel definition layer covering the conductive layer, wherein the pixel definition layer has an opening, the reflective pixel electrode is exposed by the opening, and the organic electroluminescent layer is disposed within the opening.

9. The organic electroluminescent display unit as claimed in claim 8, wherein the cathode layer covers the organic electroluminescent layer and the pixel definition layer.

10. The organic electroluminescent display unit as claimed in claim 9, wherein the cathode layer is a transparent cathode layer.

11. A method of fabricating an organic electroluminescent display unit, comprising:

forming at least one transistor on a substrate;

forming a first photo-sensor and a second photo-sensor electrically connected to the first photo-sensor on the substrate, the first photo-sensor comprising a first reflective bottom electrode, a first photo-sensitive layer, and a first transparent top electrode, the first photo-sensitive layer being sandwiched between the first reflective bottom electrode and the first transparent top electrode, and the second photo-sensor comprising a second reflective bottom electrode, a second photo-sensitive layer, and a second transparent top electrode, the second photo-sensitive layer being sandwiched between the second reflective bottom electrode and the second transparent top electrode;

forming a conductive layer comprising a reflective pixel electrode, a light-shielding pattern, and a connection pattern, wherein the reflective pixel electrode is electrically connected to the transistor, the light-shielding pattern is electrically connected to the second transparent top electrode and the light-shielding pattern entirely covers the second photo-sensitive layer, and the connection pattern is electrically connected to the first transparent top electrode, the first reflective bottom electrode, and the second reflective bottom electrode;

forming an organic electroluminescent layer on the reflective pixel electrode; and

forming a cathode layer on the organic electroluminescent layer.

12. The method of fabricating the organic electroluminescent display unit as claimed in claim 11, wherein a method of forming the transistor comprises:

forming a gate on the substrate;

forming a gate insulating layer on the substrate to cover the gate;

forming a channel layer on the gate insulating layer, and the channel layer being located above the gate; and

forming a source and a drain on a portion of the channel layer, the source being electrically insulated from the drain.

13. The method of fabricating the organic electroluminescent display unit as claimed in claim 11, further comprising forming a passivation layer to cover the transistor, the first photo-sensor, and the second photo-sensor.

14. The method of fabricating the organic electroluminescent display unit as claimed in claim 13, further comprising forming a first contact window, a plurality of second contact windows, and a third contact window in the passivation, wherein the reflective pixel electrode is electrically connected to the transistor via the first contact window, the connection pattern is electrically connected to the first transparent top electrode, the first reflective bottom electrode, and the second reflective bottom electrode via the second contact windows, and the light-shielding pattern is electrically connected to the second transparent top electrode via the third contact window.

15. The method of fabricating the organic electroluminescent display unit as claimed in claim 11, further comprising forming a pixel definition layer to cover the conductive layer, wherein the pixel definition layer has an opening, the reflective pixel electrode is exposed by the opening, and the organic electroluminescent layer is disposed within the opening.

16. The method of fabricating the organic electroluminescent display unit as claimed in claim 15, wherein the cathode layer covers the organic electroluminescent layer and the pixel definition layer.

17. The method of fabricating the organic electroluminescent display unit as claimed in claim 16, wherein the cathode layer is a transparent cathode layer.