Active matrix organic electroluminescent display device and method of fabricating the same
View Patent ↗An active matrix organic electroluminescent device includes a substrate, a buffer layer on the substrate, a thin film transistor on the buffer layer, a passivation layer on an entire surface of the substrate covering the thin film transistor, a first electrode disposed on the passivation layer to contact the thin film transistor through a contact hole formed in the passivation layer, a first bank layer disposed on the first electrode and on the passivation layer, the first bank layer having a first bank opening exposing a portion of the first electrode, a second bank layer disposed on the first bank layer to have a second bank opening aligned with the first bank opening, an organic electroluminescent layer formed within the first bank opening to electrically contact the first electrode and the first bank layer, and a second electrode formed on the organic electroluminescent layer and on the second bank layer within the first and second bank openings.
1. A method of fabricating an active matrix organic electroluminescent device, comprising steps of:
forming a buffer layer on a substrate;
forming a thin film transistor on the buffer layer;
forming a passivation layer over the substrate to cover the thin film transistor;
forming a first electrode on the passivation layer to electrically contact the thin film transistor through a contact hole formed in the passivation layer;
forming a first bank layer on the first electrode and on the passivation layer;
forming a second bank layer on the first bank layer;
forming a bank opening through the first and second bank layers to expose a portion of the first electrode;
forming an organic electroluminescent layer within the bank opening to contact the first electrode and the first bank layer; and
forming a second electrode on the organic electroluminescent layer and on the second bank layer,
wherein the bank opening is spaced apart from the thin film transistor, sidewalls of the first and second bank layers defining the bank opening are coplanar, and both the first and second bank layers include an organic material.
2. The method according to claim 1 , wherein the first bank layer includes a hydrophilic material.
3. The method according to claim 2 , wherein a thickness of the first bank layer is greater than a thickness of the organic electroluminescent layer.
4. The method according to claim 3 , wherein the thickness of the first bank layer is twice the thickness of the organic electroluminescent layer.
5. The method according to claim 1 , wherein the second bank layer includes a hydrophobic material.
6. The method according to claim 1 , wherein the organic electroluminescent layer is surrounded by the first bank layer.
7. The method according to claim 1 , wherein the organic electroluminescent layer does not contact the second bank layer.
8. The method according to claim 1 , wherein a thickness of the second bank layer is more than about 0.5 micrometers.
9. The method according to claim 1 , wherein the step of forming an organic electroluminescent layer includes an ink-jet process.
10. The method according to claim 1 , wherein the step of forming an organic electroluminescent layer includes a lithographic process.