Display apparatus that includes concavo-convex structure on upper surface of pixel defining layer and method of manufacturing the same
A display apparatus includes a light-emitting device with improved reliability while maintaining liquid-repellent properties of peripheral layers after plasma irradiation. The display apparatus includes: a substrate; a pixel electrode disposed on the substrate; a pixel defining layer disposed on the pixel electrode and having an opening that exposes a central portion of the pixel electrode; and a liquid-repellent layer disposed on the pixel defining layer and having an upper surface having a concavo-convex structure.
1. A display apparatus comprising:
a substrate;
a pixel electrode disposed on the substrate;
a pixel defining layer disposed on the pixel electrode, the pixel defining layer having an opening that exposes a central portion of the pixel electrode; and
at least one liquid-repellent layer disposed on the pixel defining layer, the at least one liquid-repellent layer including an upper surface having a concavo-convex structure induced by phase separation of two liquid-repellant agents,
wherein a surface roughness of the at least one liquid-repellent layer is 10 nm to 25 nm,
wherein the at least one liquid-repellant layer maintains a liquid repellant characteristic after plasma cleaning,
wherein the at least one liquid-repellent layer comprises a first liquid-repellent layer and a second liquid-repellent layer,
wherein the second liquid-repellent layer is located on the first liquid-repellent layer,
wherein the first liquid-repellent layer includes a first liquid-repellent agent and the second liquid-repellent layer includes a second liquid-repellent agent, and
wherein the first liquid-repellent agent has a first surface energy that is greater than a second surface energy of the second liquid-repellent agent.
2. The display apparatus of claim 1 , wherein
each of the first liquid-repellent agent and the second liquid-repellent agent has a surface energy of 15 dyne/cm or less, and a first surface energy of the first liquid-repellent agent is greater than a second surface energy of the second liquid-repellent agent by 4 dyne/cm to 10 dyne/cm.
3. The display apparatus of claim 1 , wherein
the at least one liquid-repellent layer comprises a polymeric material having a molecular weight between 8000 and 20000.
4. The display apparatus of claim 3 , wherein
the polymeric material comprises a main chain and a side chain, and a portion of the side chain has cross-linkable binding components with a ratio between 20% and 30% within 100% of side-chain components.
5. The display apparatus of claim 3 , wherein
the polymeric material has a glass transition temperature (Tg) of 200° C. or less.
6. The display apparatus of claim 1 , wherein
the at least one liquid-repellent layer has a thickness between 30 nm and 70 nm.
7. The display apparatus of claim 1 , wherein
the concavo-convex structure has a pattern in which a convex portion and a concave portion are repeatedly arranged, and the convex portion has a first width between 0.01 μm and 3 μm, and the concave portion has a second width between 0.01 μm and 3 μm.
8. The display apparatus of claim 1 , wherein
an upper surface of the first liquid-repellent layer has a concavo-convex structure and the second liquid-repellent layer is present on the upper surface of the first liquid-repellent layer.