Flexible display apparatus and method of manufacturing same

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

preparing a support substrate;

forming a first graphene oxide layer having a first electrical charge utilizing a first graphene oxide solution having the first electrical charge on the support substrate;

forming a second graphene oxide layer having a second electrical charge utilizing a second graphene oxide solution having the second electrical charge different from the first electrical charge on the first graphene oxide layer;

forming a flexible substrate on the second graphene oxide layer;

forming a display unit on the flexible substrate; and

separating the support substrate and the flexible substrate from each other along a smooth interface between the first graphene oxide layer and the second graphene oxide layer.

2. The method of claim 1 , wherein the support substrate comprises a glass substrate, a polymer film, or a silicon wafer.

3. The method of claim 1 , wherein the forming of the first graphene oxide layer having the first electrical charge on the support substrate comprises:

coating the first graphene oxide solution having the first electrical charge on the support substrate; and

drying the support substrate on which the first graphene oxide solution is coated.

4. The method of claim 3 , wherein the coating of the first graphene oxide solution on the support substrate is performed using any one selected from dip coating, spray coating, spin coating, screen coating, offset printing, inkjet printing, pad printing, knife coating, kiss coating, gravure coating, painting with a brush, ultrasound fine spray coating, and spray-mist coating.

5. The method of claim 3 , further comprising:

rinsing the support substrate on which the first graphene oxide solution is coated by using de-ionized (DI) water after the coating of the first graphene oxide solution having the first electrical charge on the support substrate and before the drying of the support substrate on which the first graphene oxide solution is coated.

6. The method of claim 1 , wherein the forming of the second graphene oxide layer having the second electrical charge on the first graphene oxide layer comprises: preparing the second graphene oxide solution having the second electrical charge; coating the second graphene oxide solution on the first graphene oxide layer; and drying the first graphene oxide layer on which the second graphene oxide solution is coated.

7. The method of claim 6 , wherein the coating of the second graphene oxide solution on the first graphene oxide layer is performed using any one selected from dip coating, spray coating, spin coating, screen coating, offset printing, inkjet printing, pad printing, knife coating, kiss coating, gravure coating, painting with a brush, ultrasound fine spray coating, and spray-mist coating.

8. The method of claim 6 , further comprising rinsing the support substrate on which the first graphene oxide solution is coated by using DI water after the coating of the second graphene oxide solution on the first graphene oxide layer and before the drying of the first graphene oxide layer on which the second graphene oxide solution is coated.

9. The method of claim 6 , wherein the second graphene oxide solution having the second electrical charge is formed by pouring a sulfuric acid solution into the first graphene oxide solution having the first electrical charge,

wherein the first electrical charge is a negative charge, and the second electrical charge is a positive charge.

10. The method of claim 1 , further comprising:

immersing the support substrate into a polymer electrolyte after the preparing of the support substrate and before the forming of the first graphene oxide layer having the first electrical charge on the support substrate, so that a surface of the support substrate has the second electrical charge.

11. The method of claim 10 , wherein the first electrical charge is a negative charge, the second electrical charge is a positive charge, and the polymer electrolyte is a positive-ionic polymer electrolyte.

12. The method of claim 11 , wherein the positive-ionic polymer electrolyte comprises poly(allyamine)hydrochloride (PAH), polydiallyldimethylammonium (PDDA), or poly(ethyleneimine) (PEI).

13. The method of claim 10 , wherein the first electrical charge is a positive charge, the second electrical charge is a negative charge, and the polymer electrolyte is a negative-ionic polymer electrolyte.

14. The method of claim 13 , wherein the negative-ionic polymer electrolyte comprises poly(4-styrenesulfonate) (PSS) or poly(acrylic)acid (PAA).

15. The method of claim 1 , wherein the separating of the support substrate and the flexible substrate comprises separating the first graphene oxide layer and the second graphene oxide layer from each other.

16. The method of claim 1 , wherein the flexible substrate is formed of a material selected from the group consisting of polyester, polyvinyl, polycarbonate, polyethylene, polyacetate, polyimide, polyethersulphone (PES), polyacrylate (PAR), polyethylenenaphthalate (PEN), and polyethyleneterephthalate (PET).

17. The method of claim 1 , wherein the separating of the support substrate and the flexible substrate comprises separating the support substrate and the flexible substrate from each other by using a peeling force.

18. The method of claim 1 , wherein the first graphene oxide layer having the first electrical charge and the second graphene oxide layer having the second electrical charge are bonded to each other by the Van der Waals force.

19. The method of claim 1 , further comprising:

forming an encapsulating layer on the display unit after the forming of the display unit on the flexible substrate and before the separating of the support substrate and the flexible substrate.

20. The method of claim 19 , wherein the first graphene oxide layer having the first electrical charge and the second graphene oxide layer having the second electrical charge stacks alternately on the support substrate.