Conductive composite structure for electronic device, method of preparing the same, electrode for electronic device including the conductive composite structure, and electronic device including the conductive composite structure

1. A conductive composite structure comprising:

graphene; and

an organic composite layer comprising a conductive polymer having a work function of about 5.3 eV or lower,

wherein the graphene is included in a layer stacked on the organic composite layer,

wherein the organic composite layer has a thickness of 5 nm or less,

wherein a sheet resistance deviation of the conductive composite structure is about 8.3% or less,

wherein the sheet resistance of the conductive composite structure is in a range of about 500 Ω/square to about 1,000 Ω/square,

wherein a surface roughness of the conductive composite structure is in a range of about 2 nm to about 5 nm, and

wherein the organic composite layer comprises at least one selected from poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), acid-treated PEDOT:PSS, acid-treated PEDOT:PSS and an ionic liquid, and PEDOT:PSS and the ionic liquid.

2. The conductive composite structure of claim 1 , wherein the organic composite layer further comprises at least one dopant selected from the ionic liquid, a polymer ionic liquid, and a gold chloride, and an amount of the dopant is in a range of about 0.1 parts to about 20 parts by weight based on 100 parts by weight of the conductive polymer.

3. The conductive composite structure of claim 2 , wherein the ionic liquid is at least one compound selected from compounds each comprising:

i) at least one cation selected from an ammonium-based cation, a pyrrolidinium-based cation, a pyridinium-based cation, a pyrimidinium-based cation, an imidazolium-based cation, a piperidinium-based cation, a pyrazolium-based cation, an oxazolium-based cation, a pyridazinium-based cation, a phosphonium-based cation, a sulfonium-based cation, a triazolium-based cation, and a mixture thereof; and

ii) at least one anion selected from BF4-, PF6-, AsF6-, SbF6-, AlCl4-, HSO4-, ClO4-, CH3SO3-, CF3CO2-, Cl—, Br—, I—, SO4-, CF3SO3-, (FSO2)2N—, (C2F5SO2)2N—, (C2F5SO2)(CF3SO2)N—, and (CF3SO2)2N—.

4. The conductive composite structure of claim 3 , wherein the ionic liquid is at least one selected from N-methyl-N-propylpyrrolidinium bis(trifluoromethanesulfonyl)imide, N-butyl-N-methylpyrrolidium bis(3-trifluoromethylsulfonyl)imide, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide, and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide.

5. The conductive composite structure of claim 1 , wherein the organic composite layer and/or the conductive composite structure is acid-treated.

6. The conductive composite structure of claim 1 , wherein a contact angle of the organic composite layer with water is less than 100°.

7. The conductive composite structure of claim 1 , wherein the graphene layer further comprises at least one of a conductive polymer or a dopant.

8. The conductive composite structure of claim 1 , wherein the layer including the graphene is a passivation layer configured to protect the organic composite layer.

9. The conductive composite structure of claim 1 , wherein the organic composite layer is between the graphene and at least one supporting member.

10. The conductive composite structure of claim 9 , wherein the at least one supporting member includes at least one selected from the group consisting of glass, quartz, silicon/silicon oxide, polyethylenterephthalate, polycarbonate, polyethylene naphthalate, and polystyrene.

11. An electrode for an electronic device, the electrode comprising the conductive composite structure of claim 1 .

12. An electronic device comprising the conductive composite structure of claim 1 .

13. The electronic device of claim 12 , wherein the electronic device is an organic light-emitting device, an organic photovoltaic (OPV) cell, an organic energy storage (OES) device, or an organic thin-film transistor.