Methods for producing n-doped graphene films
Provided are methods for producing n-doped graphene films. The method comprises contacting a graphene layer with an alkali metal-doped polymer layer. Compositions comprising (i) a substrate, (ii) a doped polymer, and (iii) graphene are also provided. The methods of the invention produce n-doped graphene films that are resistant to degradation, have high electrical conductivity, and low sheet resistance without altering the optical transmission of graphene.
1 . A method for producing an n-doped graphene film on a substrate wherein the method comprises:
(i) preparing a doped polymer solution free of graphene, the doped polymer solution comprising an alkali metal salt, a polymer and a solvent;
(ii) coating a surface of a substrate with the doped polymer solution to form a coated substrate; and
(iii) contacting an intrinsic graphene layer with the coated substrate to dope the intrinsic graphene layer, thereby producing the n-doped graphene film.
2 . The method of claim 1 , further comprising a heating step and a cooling step.
3 . The method of claim 1 , wherein the doped polymer solution is free of graphene.
4 . The method of claim 1 , wherein coating comprises spin coating, drop casting, blade coating or dip coating.
5 . The method of claim 1 , wherein the n-doped graphene film is on a growth substrate.
6 . The method of claim 1 , in which the method further comprises release of the growth substrate from the n-doped graphene film.
7 . The method of claim 6 , wherein the release of the growth substrate from the n-doped graphene film comprises chemical etching, electrochemical delamination, a heating step followed by a cooling step, or a heating step followed by a cooling step followed by mechanical peeling.
8 . The method of claim 1 , wherein the polymer is selected from the group consisting of polyamides, polyimides, polychloroethylenes, polyurethanes, polyvinylethers, polythioureas, polyacrylates, polycarbonates, polyesters, polyethylenes, polypropylenes, polysytrenes, PTFE, polyethylacetates, polyvinylacetates and fluoropolymers.
9 . The method of claim 8 , wherein the polymer is selected from the group consisting of poly(methyl methacrylate), polyvinylbutyral, ethylene-vinyl acetate, thermoplastic polyurethane, polyethylene terephthalate, thermoset ethylene-vinyl acetate, polycarbonate and polyethylene.
10 . The method of claim 1 , wherein the alkali-metal salt is selected from the group consisting of MClO 4 or MI, wherein M is selected from the group consisting of Li, Na and K.
11 . The method of claim 10 , wherein the concentration of M is in the range about 2% to about 45% by weight (w/w).
12 . The method of claim 1 , wherein the substrate is selected from the group consisting of polyamides, polyimides, polychloroethylenes, polyurethanes, polyvinylethers, polythioureas, polyacrylates, polycarbonates, polyesters, polyethylenes, polypropylenes, polysytrenes, nylons, polyethylacetates, polyvinylacetates and fluoropolymers.
13 . The method of claim 12 , wherein the substrate is selected from the group consisting of poly(methyl methacrylate), polycarbonate, polyethylene, polypropylene, polyester, nylon, and polyvinyl chloride.
14 . The method of claim 1 , wherein the solvent is selected from the group consisting of water, chlorobenzene, acetone, methanol, N-Methyl-2-pyrrolidone, tetrahydrofuran, dimethylformamide, hexane, toluene, isopropyl alcohol, acetonitrile, chloroform, acetic acid, 2-methoxyethanol, or n-butylamine.
15 . The method of claim 5 , wherein the growth substrate is a metal substrate.
16 . The method of claim 15 , wherein the metal substrate is selected from the group consisting of copper, nickel, platinum, and iridium.
17 . The method of claim 1 , wherein the substrate comprises an alkali metal salt incorporated within the substrate.
18 . The method of claim 1 , wherein the doped polymer solution comprises about 10 weight percent to about 50 weight percent poly(methyl methacrylate) and about 10 weight percent to about 50 weight percent NaClO 4 in a solvent, wherein the solvent is selected from the group consisting of chlorobenzene, N-Methyl-2-pyrrolidone, tetrahydrofuran, and dimethylformamide.
19 . The method of claim 1 , wherein the heating step is performed in the range of about 100° C. to about 160° C., and the temperature is held for a time ranging from about 5 minutes to about 4 hours.
20 . The method of claim 1 , wherein the cooling step is performed in the range of about −10° C. to about 20° C., and the temperature is held for a time ranging from about 5 minutes to about 4 hours.
21 . A method for producing an n-doped graphene film on a substrate wherein the method comprises:
(i) preparing a doped polymer solution free of graphene, the doped polymer solution comprising an alkali metal salt, a polymer and a solvent;
(ii) coating an intrinsic graphene layer with the doped polymer solution to form a coated graphene layer;
(iii) coating a surface of a substrate with the doped polymer solution to form a coated substrate; and
(iv) contacting the coated graphene layer with the coated substrate to dope the intrinsic graphene layer, thereby producing the n-doped graphene film.
22 . The method of claim 21 , further comprising a heating step and a cooling step.
23 . The method of claim 21 , wherein the doped polymer solution is free of graphene.
24 . The method of claim 21 , further comprising a mechanical peeling step.
25 . The method of claim 21 , wherein coating comprises spin coating, drop casting, blade coating or dip coating.
26 . The method of claim 21 , wherein the n-doped graphene film is on a growth substrate.
27 . The method of claim 21 , in which the method further comprises release of the growth substrate from the graphene.
28 . The method of claim 27 , wherein the release of the growth substrate from the graphene comprises chemical etching, electrochemical delamination, a heating step followed by a cooling step, or a heating step followed by a cooling step followed by a mechanical peeling step.
29 . The method of claim 21 , wherein the polymer is selected from the group consisting of polyamides, polyimides, polychloroethylenes, polyurethanes, polyvinylethers, polythioureas, polyacrylates, polycarbonates, polyesters, polyethylenes, polypropylenes, polysytrenes, PTFE, polyethylacetates, polyvinylacetates and fluoropolymers.
30 . The method of claim 29 , wherein the polymer is selected from the group consisting of poly(methyl methacrylate), polyvinylbutyral, ethylene-vinyl acetate, thermoplastic polyurethane, polyethylene terephthalate, thermoset ethylene-vinyl acetate, polycarbonate and polyethylene.
31 . The method of claim 21 , the alkali-metal salt is selected from the group consisting of MClO 4 or MI, wherein M is selected from the group consisting of Li, Na and K.
32 . The method of claim 31 , wherein the concentration of M is in the range about 2% to about 45% by weight (w/w).
33 . The method of claim 21 , wherein the solvent is selected from the group consisting of water, chlorobenzene, acetone, methanol, N-Methyl-2-pyrrolidone, tetrahydrofuran, dimethylformamide, hexane, toluene, isopropyl alcohol, acetonitrile, chloroform, acetic acid, 2-methoxyethanol, or n-butylamine.
34 . The method of claim 26 , wherein the growth substrate is a metal substrate.
35 . The method of claim 34 , wherein the metal substrate is selected from the group consisting of copper, nickel, platinum, and iridium.
36 . The method of claim 21 , wherein the doped polymer solution comprises about 10 weight percent to about 50 weight percent poly(methyl methacrylate) and about 10 weight percent to about 50 weight percent NaClO 4 in a solvent, wherein the solvent is selected from the group consisting of chlorobenzene, N-Methyl-2-pyrrolidone, tetrahydrofuran, and dimethylformamide.
37 . The method of claim 22 , wherein the heating step is performed in the range of about 100° C. to about 160° C., and the temperature is held for a time ranging from about 5 minutes to about 4 hours.
38 . The method of claim 23 , wherein the cooling step is performed in the range of about −10° C. to about 20° C., and the temperature is held for a time ranging from about 5 minutes to about 4 hours.
39 . The method of claim 1 , wherein the electron mobility of the graphene in the n-doped graphene film is greater than 2000 cm 2 /Vs.
40 . The method of claim 1 , wherein the charge carrier concentration of graphene in the n-doped graphene film is greater than 5×10 12 electrons per cm 2 .
41 . The method of claim 21 , wherein the electron mobility of graphene in the n-doped graphene film is greater than 2000 cm 2 /Vs.
42 . The method of claim 21 , wherein the charge carrier concentration of graphene in the n-doped graphene film is greater than 5×10 12 electrons per cm 2 .