SYSTEMS AND METHODS FOR LOW TEMPERATURE GROWTH OF PRISTINE, DOPED AND NANOPOROUS GRAPHENE FILMS
Novel synthetic methods to produce layers or films and flakes of pristine graphene, heteroatom-doped graphene, nanoporous graphene or heteroatom-doped nanoporous graphene using specially designed molecular precursors at temperatures as low as 160° C. using a chemical vapor deposition (CVD) system. The methods enable the realization of graphene-based electronics and technologies due to the low-temperature synthesis, large-area coverage, and scalability of the CVD method by taking advantage of the precursors tendency to polymerize and fuse once on the catalytic metal substrates.
1 . A method of forming a graphene layer, comprising:
forming a polymer layer on a catalytic substrate by chemical vapor deposition of a graphene precursor on the catalytic substrate; and
raising a temperature of the polymer layer to at least about 160° C. to induce cyclodehydrogenation of the polymer layer to form a graphene layer on the catalytic substrate.
2 . The method according to claim 1 , wherein the graphene precursor comprises a polycyclic compound.
3 . A method of forming a graphene layer, comprising:
providing a catalytic substrate;
depositing a graphene precursor on the catalytic substrate by chemical vapor deposition of the graphene precursor to form a polymer layer on the catalytic substrate; and
raising a temperature of the polymer layer to at least about 160° C. to induce cyclodehydrogenation of the graphene precursor to form a graphene layer on the catalytic substrate.
4 . The method according to claim 3 , wherein the graphene precursor comprises a polycyclic compound.
5 . The method according to claim 3 , wherein the graphene precursor comprises a halogenated polycyclic aromatic compound.
6 . The method of claim 3 , wherein the graphene precursor comprises 3′,6′-dihalo-1,1′:2′,″-terphenyl (C 18 H 12 X 2 ), wherein Xis selected from Cl, Br, I or a combination thereof.
7 . The method of claim 3 , wherein the graphene precursor comprises 6,11-dihalo-1,2,3,4-tetraphenyltriphenylene (C 42 H 26 X 2 ), wherein X is selected from Cl, Br, I or a combination thereof.
8 . The method of claim 3 , wherein the graphene precursor comprises 2,3-di([1,1′-biphenyl]-4-yl)-6,11-dihalo-1,4-diphenyltriphenylene (C 54 H 34 X 2 ), wherein X is selected from Cl, Br, I or a combination thereof.
9 . The method of claim 3 , wherein the graphene precursor comprises 2-([1,1′:2′,1″-terphenyl]-3′-yl)-6,11-dihalo-1,4-diphenyltriphenylene (C 48 H 30 X 2 ), wherein X is selected from Cl, Br, I or a combination thereof.
10 . The method according to claim 3 , wherein the catalytic substrate comprises a metal substrate.
11 . The method according to claim 10 , wherein the metal substrate comprises one of Ni, Cu, Ag, Au, Al, Pd, Rh, Ir or Pt.
12 . The method according to claim 3 , wherein the catalytic substrate comprises polycrystalline Cu.
13 . The method according to claim 3 , wherein the raising the temperature induces planarization of the graphene layer.
14 . The method according to claim 3 , wherein the catalytic substrate is provided in a vacuum chamber.
15 . The method of claim 3 , wherein the catalytic substrate includes a catalytic material on a flexible, plastic substrate.
16 . The method of claim 3 , wherein the graphene layer is a graphene monolayer.
17 . The method of claim 3 , wherein the graphene precursor has carbon (C) atoms specifically substituted with group 13 elements, such as boron (B) atoms, and wherein the graphene layer comprises group-13-element-doped graphene such as B-doped graphene.
18 . The method of claim 3 , wherein the graphene precursor has carbon (C) atoms specifically substituted with nitrogen (N) atoms and wherein the graphene layer comprises N-doped graphene.
19 . The method of claim 3 , wherein the graphene precursor has carbon (C) atoms specifically substituted with sulfur (S) atoms and wherein the graphene layer comprises S-doped graphene.
20 . The method of claim 3 , wherein the graphene precursor contains N and S atoms and wherein the graphene layer comprises N,S-doped graphene, or wherein the graphene precursor contains B and N atoms and wherein the graphene layer comprises B,N-doped graphene.