Organic light emitting diode display having multi-layer stack structure

1. An organic light-emitting diode (OLED) display, comprising:

an anode electrode disposed over a substrate;

a cathode electrode disposed opposite the anode electrode;

a charge generation layer disposed between the anode electrode and the cathode electrode;

a first stack disposed between the charge generation layer and the cathode electrode and configured to comprise a first organic light-emitting layer, a first common layer disposed over the first organic light-emitting layer, and a second common layer disposed under the first organic light-emitting layer; and

a second stack disposed between the charge generation layer and the anode electrode,

wherein at least one of the first common layer and the second common layer covers a sidewall of the charge generation layer.

2. The OLED display of claim 1 , wherein the sidewall of the charge generation layer is separated from the cathode electrode with at least one of the first common layer and the second common layer interposed between the charge generation layer and the cathode electrode.

3. The OLED display of claim 1 , wherein the first common layer and the second common layer cover the sidewall of the charge generation layer.

4. The OLED display of claim 1 , wherein the second stack comprises:

a second organic light-emitting layer,

a third common layer disposed over the second organic light-emitting layer, and

a fourth common layer disposed under the second organic light-emitting layer.

5. The OLED display of claim 4 , wherein each of the first common layer and the third common layer comprises an electron transport layer.

6. The OLED display of claim 4 , wherein each of the second common layer and the fourth common layer comprises a hole transport layer.

7. The OLED display of claim 1 , wherein the second common layer is disposed on a portion of the charge generation layer,

wherein the first common layer is disposed on the charge generation layer to cover the second common layer, and

wherein the cathode electrode is disposed on the first common layer.

8. The OLED display of claim 1 , wherein the second common layer is disposed on the charge generation layer,

wherein the first common layer is disposed on a portion of the second common layer, and

wherein the cathode electrode is disposed on the second common layer to cover the first common layer.

9. The OLED display of claim 1 , wherein the second common layer is disposed on the charge generation layer,

wherein the first common layer is disposed on the second common layer, and

wherein the cathode electrode is disposed on the first common layer.

10. An organic light-emitting diode (OLED) display, comprising:

an anode electrode disposed over a substrate; a lower stack disposed over the anode electrode; a charge generation layer disposed over the lower stack; an upper stack disposed over the charge generation layer; a cathode electrode disposed over the upper stack; and

a contact blocking unit interposed between the cathode electrode and a sidewall at an end of the charge generation layer,

wherein the sidewall at the end of the charge generation layer is separated from the cathode electrode with the contact blocking unit interposed between the sidewall at the end of the charge generation layer and the cathode electrode.

11. The OLED display of claim 10 , wherein:

the upper stack comprises a first organic light-emitting layer, a first common layer disposed over the first organic light-emitting layer, and a second common layer disposed under the first organic light-emitting layer, and

the contact blocking unit comprises at least one of the first common layer and the second common layer.

12. The OLED display of claim 10 , wherein the lower stack comprises:

a second organic light-emitting layer,

a third common layer disposed over the second organic light-emitting layer, and

a fourth common layer disposed under the second organic light-emitting layer.