Flexible display device and method of manufacturing flexible display device

1. A method of manufacturing a flexible display device, the method comprising:

forming a graphene adhesive layer on a carrier substrate;

forming a flexible substrate on the graphene adhesive layer;

forming a first barrier layer on the flexible substrate;

forming a display element part on the first barrier layer;

forming a protective film on the display element part;

separating the flexible substrate from the carrier substrate;

removing a remaining portion of the graphene adhesive layer from a surface of the flexible substrate; and

forming a second barrier layer on the surface of the flexible substrate, after removing the remaining portion of the graphene adhesive layer from the surface of the flexible substrate.

2. The method as claimed in claim 1 , further comprising removing an edge of the graphene adhesive layer to expose an upper surface of the carrier substrate, before forming the flexible substrate.

3. The method as claimed in claim 2 , wherein an edge of the flexible substrate contacts the exposed upper surface of the carrier substrate.

4. The method as claimed in claim 1 , wherein forming the graphene adhesive layer includes:

forming a first graphene oxide layer charged with a first electric charge; and

forming a second graphene oxide layer on the first graphene oxide layer, the second graphene oxide layer being charged with a second electric charge opposite to the first electric charge.

5. The method as claimed in claim 4 , wherein forming the first and second graphene oxide layers includes coating a solution including a graphene oxide charged with the first electric charge or the second electric charge.

6. The method as claimed in claim 1 , wherein forming the graphene adhesive layer includes using chemical vaporization deposition.

7. The method as claimed in claim 6 , wherein using the chemical vaporization deposition includes using a mask covering an edge of the carrier substrate.

8. The method as claimed in claim 1 , further comprising forming a cutting portion in the flexible substrate, before separating the flexible substrate from the carrier substrate, wherein the cutting portion overlaps the graphene adhesive layer.

9. The method as claimed in claim 8 , wherein the cutting portion is formed to have a shape surrounding the display element part in a plan view.

10. The method as claimed in claim 9 , wherein separating the flexible substrate from the carrier substrate includes:

adsorbing the protective film to a fixing stage;

adsorbing the carrier substrate to a fixing member;

bending the flexible substrate and the carrier substrate toward the fixing stage, such that an edge of the flexible substrate is adsorbed to the fixing stage; and

applying an external force to the flexible substrate and the carrier substrate in opposite directions, respectively.

11. The method as claimed in claim 1 , wherein the second barrier layer is formed of silicon oxycarbide (SiOC).

12. The method as claimed in claim 11 , wherein forming the second barrier layer includes:

forming an interfacial layer including silicon oxycarbide on the flexible substrate; and

forming an outer layer including at least one of silicon oxide, silicon nitride, and silicon oxynitride on the interfacial layer, such that the interfacial layer is between the flexile substrate and the outer layer.

13. The method as claimed in claim 1 , wherein the first barrier layer includes a multiple-layer structure of silicon oxide (SiO 2 )/silicon nitride (SiN)/silicon oxynitride (SiON).

14. The method as claimed in claim 1 , wherein the flexible substrate includes at least one of polyester, polyvinyl, polycarbonate, polyethylene, polypropylene, polyacetate, polyimide, polyethersulphone (PES), polyacrylate (PAR), polyethylenenaphthelate (PEN) and polyethyleneterephehalate (PET).

15. The method as claimed in claim 1 , wherein the carrier substrate includes at least one of glass, quartz, silicon and a polymer.