Graphene films and methods of making thereof
Provided are methods for forming graphene or functionalized graphene thin films. Also provided are graphene and functionalized graphene thin films formed by the methods. For example, electrophoretic deposition methods and stamping methods are used. Defect-free thin films can be formed. Patterned films can be formed. The methods can provide conformal coatings on non-planar substrates.
1. A functionalized graphene thin film disposed on a substrate, wherein the thin film is free of detectible pin-hole defects and the thin film has a dichroic ratio value of greater than −0.7 with respect to the substrate.
2. The functionalized graphene thin film of claim 1 , wherein the thin film has 1% per unit area or less defects per square centimeter, or wherein the film has 3% or less impurities.
3. The functionalized graphene thin film of claim 1 , wherein the surface contamination of the thin film with extraneous impurities is limited to 3% or less surface coverage.
4. The functionalized graphene thin film of claim 1 , wherein the thin film covers a continuous area of at least 16 square inches.
5. The functionalized graphene thin film of claim 1 , wherein the thin film is functionalized with functional groups selected from fluorides, chlorides, bromides, alkenes, alkynes, epoxides, alcohols, phenols, carboxylic acids, ketones, quinones, lactones, amines, amides, imines, diazo moieties, cyanides, isocyanides, thionylchlorides, thiols, sulfites, sulfates, or a combination thereof.
6. The functionalized graphene thin film of claim 1 , wherein the thin film is completely hydrogenated graphene.
7. A graphene thin film disposed on a substrate, wherein the thin film is free of detectible pin-hole defects, the thin film has 3% or less impurities, and the thin film has a dichroic ratio value of greater than −0.7 with respect to the substrate.
8. The graphene thin film of claim 7 , wherein the thin film covers a continuous area of at least 16 square inches.
9. A graphene thin film disposed on a substrate, wherein the thin film is free of detectible pin-hole defects, the surface contamination of the thin film with extraneous impurities is limited to 3% or less surface coverage, and the thin film has a dichroic ratio value of greater than −0.7 with respect to the substrate.
10. The graphene thin film of claim 9 , wherein the thin film covers a continuous area of at least 16 square inches.