Display device and manufacturing method thereof
A display device includes a pixel disposed in a display area. The pixel includes a first electrode; a first insulating layer disposed on the first electrode, and including openings, each of the openings exposing different areas of the first electrode and defining respective cells; light emitting elements disposed in the respective cells, each of the light emitting elements including a first end electrically connected to the first electrode; and a second end protruding upward from the first insulating layer; and a second electrode disposed on the light emitting elements, and electrically connected to the second ends of each of the light emitting elements.
1. A display device comprising:
a pixel disposed in a display area, the pixel comprising:
a first electrode;
a first insulating layer disposed on the first electrode, and including openings, each of the openings exposing different areas of the first electrode and defining respective cells;
light emitting elements disposed in the respective cells, each of the light emitting elements including:
a first end portion electrically connected to the first electrode;
a second end portion protruding upward from the first insulating layer; and
a side surface connecting the first end portion and the second end portion and including an upper side surface and a lower side surface;
a second electrode disposed on the light emitting elements, and electrically connected to the second end portion of each of the light emitting elements; and
first contact electrodes disposed in the openings, each of the first contact electrodes disposed in a corresponding one of the openings including:
a lower part contacting the first electrode,
a first protruding part covering a first lateral surface of each of the openings,
a second protruding part covering a second lateral surface of each of the openings opposite to the first lateral surface of each of the openings, and
a third protruding part contacting the upper side surface and the first end portion of each of the light emitting elements, wherein
the third protruding part is disposed between the first protruding part and the second protruding part in a horizontal direction.
2. The display device of claim 1 , wherein each of the openings has a width less than a length of each of the light emitting elements.
3. The display device of claim 2 , wherein each of the light emitting elements is disposed in a vertical direction or a diagonal direction with respect to the first electrode and the second electrode.
4. The display device of claim 1 , wherein the first end portion of each of the light emitting elements directly contacts the first electrode.
5. The display device of claim 1 , wherein the second end portion of each of the light emitting elements directly contacts the second electrode.
6. The display device of claim 1 , wherein
each of the openings has a substantially polygonal shape, a substantially circular shape, a substantially elliptical shape, or a shape substantially corresponding to a combination thereof in a plan view, and
each of the openings is adjacent to each other in an emission area of the pixel.
7. The display device of claim 1 , further comprising:
insulating patterns disposed in each of the openings and overlapping the first contact electrodes and the first end portion of each of the light emitting elements.
8. The display device of claim 7 , wherein the insulating patterns include an organic insulating material.
9. The display device of claim 1 , further comprising:
a second insulating layer disposed between the first insulating layer and the second electrode and surrounding each of the light emitting elements.
10. The display device of claim 9 , wherein
the second insulating layer includes an organic insulating material, and
portions of the second insulating layer enclose each of the openings of the first insulating layer.
11. The display device of claim 1 , wherein the pixel comprises at least one intermediate electrode spaced apart from the first electrode and the second electrode, and electrically connected between the first electrode and the second electrode by at least one light emitting element of the light emitting elements.
12. The display device of claim 11 , wherein
the pixel comprises intermediate electrodes, and
the intermediate electrodes are alternately disposed on a layer on which the first electrode is disposed and a layer on which the second electrode is disposed.
13. The display device of claim 1 , wherein each of the light emitting elements comprises rod-type light emitting elements or core-shell light emitting elements.
14. The display device of claim 1 , wherein
the first protruding part contacts the first lateral surface of each of the openings, and
the second protruding part contacts the second lateral surface of each of the openings.
15. The display device of claim 1 , wherein
the lower part and the light emitting elements overlap each other in a plan view,
the lower part and the third protruding part are continuously connected to each other, and
the second protruding part and the third protruding part are continuously connected to each other and uniformly disposed on a bottom surface and the first and second lateral surfaces of the corresponding one of the openings.
16. A method of fabricating a display device, the method comprising:
forming a first electrode on a base layer;
forming a first insulating layer on the first electrode;
forming an alignment electrode overlapping the first electrode and including first openings on the first insulating layer;
forming second openings overlapping the first openings in the first insulating layer, using the alignment electrode as a mask;
supplying light emitting elements on the base layer, and aligning the light emitting elements in cells formed by the first openings and the second openings by applying alignment signals to the first electrode and the alignment electrode;
electrically connecting first end portions of the light emitting elements to the first electrode by forming a conductive layer overlapping the alignment electrode and the light emitting elements after the light emitting elements are aligned, the conductive layer including:
contact electrodes disposed in the second openings, each of the contact electrodes including:
a lower part contacting the first electrode,
a first protruding part covering a first lateral surface of each of the second openings,
a second protruding part covering a second lateral surface of each of the second openings opposite to the first lateral surface of each of the second openings, and
a third protruding part contacting an upper side surface and the first end portion of each of the light emitting elements, the third protruding part disposed between the first protruding part and the second protruding part in a horizontal direction; and
forming a second electrode on second end portions of the light emitting elements to electrically connect the second electrode to the second end portions of the light emitting elements.
17. The method of claim 16 , wherein the electrically connecting of the first end portions of the light emitting elements to the first electrode further comprises:
forming an organic insulating layer on the conductive layer; and
etching the conductive layer and the organic insulating layer to have a height in the first openings and the second openings.
18. The method of claim 17 , wherein the alignment electrode outside the second openings is removed in the etching of the conductive layer.
19. The method of claim 18 , further comprising:
forming a second insulating layer overlapping the first insulating layer and the light emitting elements after the alignment electrode is removed; and
partially etching the second insulating layer in a thickness direction such that the second end portions of the light emitting elements are exposed.
20. The method of claim 16 , further comprising:
dividing a lower electrode pattern including the first electrode into the first electrode and at least one intermediate electrode, after the aligning of the light emitting elements and before the forming of the second electrode.
21. The method of claim 16 , wherein the forming of the second electrode comprises forming the second electrode and at least one intermediate electrode on different light emitting elements among the light emitting elements, respectively.