OLED display panel having fence structure under anode
An OLED panel includes a plurality of light-emitting elements, that each light-emitting element includes a fence structure on a substrate and in an opening of a pixel definition layer. A trench is formed between the fence structure and the pixel definition layer. Charge transport layer is disconnected at the trench by a shadowing effect of the fence structure during thermal evaporation of the charge transport layer. Therefore, lateral current leakage between two adjacent light-emitting elements is minimized.
1. An organic light-emitting diode (OLED) panel, comprising:
a pixel array comprising a plurality of light-emitting elements; wherein
each of the plurality of light-emitting elements comprises a fence structure, a first electrode layer, a pixel definition layer, a first charge transport layer, a light-emitting layer, a second charge transport layer, and a second electrode layer, that which are stacked on a substrate in sequence; and
the pixel definition layer comprises an opening that exposes part of the first electrode layer; a vertical projection of the fence structure on the substrate is located inside a vertical projection of the opening on the substrate; a trench is formed between a sidewall of the fence structure and a sidewall of the opening, and the first charge transport layer comprises a discontinued portion in the trench;
wherein a vertical projection of the fence structure on the substrate exhibits a substantially ring shape, and the fence structure comprises at least one notch which has a depth larger than 25% of the height of the fence structure.
2. The OLED panel of claim 1 , wherein geometric dimensions of the trench satisfy the equation arctangent
(
T
h
1
T
w
)
≥
2
5
∘
,
where T W is a width of the trench and T h1 is a depth of the trench on a side of the fence structure.
3. The OLED panel of claim 1 , wherein the sidewall of the opening has a slope angle β 1 satisfying the equation 70°≤β 1 ≤110°, wherein the slope angle β 1 is formed between the side wall of the opening and the first electrode layer and is subtended by the light-emitting layer.
4. The OLED panel of claim 1 , wherein geometric dimensions of the light-emitting element satisfies the equations T h1 >T h3 , T h2 >T h3 , and T h2 >T h1 , where T h1 is a depth of the trench on a side of the fence structure, T h2 is a height from the first electrode layer to a top surface of the pixel definition layer, T h3 is a total thickness of materials between the first electrode layer and the second electrode layer at a bottom of the trench, respectively.
5. The OLED panel of claim 1 , wherein the sidewall of the fence structure has a slope angle β 2 satisfying the equation 0°≤β 2 ≤80°, wherein the slope angle β 2 is formed between the side wall of the fence structure and the substrate and is subtended by the fence structure.
6. The OLED panel of claim 1 , wherein the fence structure comprises a conductive material.
7. The OLED panel of claim 1 , wherein a vertical projection of the fence structure on the substrate exhibits a substantially ring shape.
8. The OLED panel of claim 7 , wherein the fence structure comprises at least one notch which has a depth larger than 25% of the height of the fence structure.
9. The OLED panel of claim 1 , wherein an angle between a projection of a pathway of the notch on the substrate and a projection of the sidewall of the opening on the substrate is substantially less than 90 degrees.
10. The OLED panel of claim 1 , wherein a projection of a pathway of the notch on the substrate comprises a zigzag path that substantially no straight line from the sidewall of the opening can pass through.
11. The OLED panel of claim 1 , wherein the fence structure comprises a plateau and the trench width from the edge of the plateau to the sidewall of the opening remains substantially equal.
12. The OLED panel of claim 11 , wherein the plateau comprises at least one notch which has a depth larger than 25% of a height of the plateau.