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US 2011/0031104 A1Published application
Carbon ion beam growth of isotopically-enriched graphene and isotope-junctions
AssigneesRaytheon Company, Arizona Board of Regents on Behalf of the University of Arizona
InventorsDelmar L. Barker, William R. Owens, John Warren Beck
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Abstract
Isotopically-enriched graphene and isotope junctions are epitaxially grown on a catalyst substrate using a focused carbon ion beam technique. The focused carbon ion beam is filtered to pass substantially a single ion species including a single desired carbon isotope. The ion beam and filtering together provide a means to selectively isotopically-enrich the epitaxially-grown graphene from given carbon precursor and to selectively deposit graphene enriched with different carbon isotopes in different regions.
Claims20
A method of making isotopically enriched graphene, comprising the steps of:
- (a) providing a catalyst substrate including a single crystal region on a surface of the substrate, said region having a hexagonal crystal lattice substantially lattice-matched to graphene;
- (b) providing a carbon ion beam source including a focusing aperture for generating a focused ion beam that is directed towards the substrate, said beam comprising a plurality of ion species, each species comprising a different electrically charged carbon isotope or a different electrically charged molecular ion containing one or more carbon isotopes;
- (c) accelerating the ion beam with an electric field towards the substrate;
- (d) using magnetic or electric field generating devices to separate the ion beam into a plurality of component ion beams according to the charge-to-mass ratio of the different ion species;
- (e) passing a selected component ion beam substantially comprised of a single ion species containing a single desired carbon isotope or molecular ion containing a single desired carbon isotope toward the substrate and filtering out the remaining component ion beams containing undesired ion species;
- and
- (f) directing the selected component ion beam onto the substrate to epitaxially grow isotopically-enriched graphene on the surface of the single crystal region of the substrate from the desired carbon isotope.
4 more elements
A method of making isotopically enriched graphene, comprising the steps of:
- (a) providing a catalyst substrate including a single crystal region on a surface of the substrate, said region having a hexagonal crystal lattice substantially lattice-matched to graphene;
- (b) providing one or more carbon ion beam sources, each source including a focusing aperture for generating a focused ion beam that is directed towards the substrate, said beam comprising a plurality of ion species, each species comprising a different electrically charged carbon isotope or a different electrically charged molecular ion containing one or more carbon isotopes;
- (c) accelerating the one or more ion beams with an electric field towards the substrate;
- (d) using magnetic or electric field generating devices to separate each of the one or more ion beams into a plurality of component ion beams according to the charge-to-mass ratio of the different ion species;
- (e) passing a first selected component ion beam substantially comprised of a single ion species containing a single first desired carbon isotope or molecular ion containing a single first desired carbon isotope toward the substrate and filtering out the remaining component ion beams containing undesired ion species;
- (f) directing the first selected component ion beam onto the substrate to epitaxially grow a first region of isotopically-enriched graphene on the surface of the single crystal region of the substrate from the first desired carbon isotope;
- (g) passing a second selected component ion beam substantially comprised of a single ion species containing a single second desired carbon isotope or molecular ion containing a single second desired carbon isotope toward the substrate and filtering out the remaining component ion beams containing undesired ion species;
- and
- (h) directing the second selected component ion beam onto the substrate to epitaxially grow a second region of isotopically-enriched graphene on the surface of the single crystal region of the substrate from the second desired carbon isotope,
- said first and second regions forming an isotope junction between the different first and second desired carbon isotopes in one or more graphene sheets.
7 more elements
A method of making isotopically enriched graphene, comprising the steps of:
- (a) providing a catalyst substrate including a single crystal region on a top surface of the substrate, said region having a hexagonal crystal lattice substantially lattice-matched to graphene;
- (b) providing a carbon ion beam source including a focusing aperture for generating a focused ion beam that is directed towards the substrate, said beam comprising a plurality of ion species, each species comprising a different electrically charged carbon isotope or a different electrically charged molecular ion containing one or more carbon isotopes;
- (c) accelerating the ion beam with an electric field towards the substrate;
- (d) using magnetic or electric field generating devices to separate the ion beam into a plurality of component ion beams according to the charge-to-mass ratio of the different ion species;
- (e) controlling the devices to pass first and then second selected component ion beams, each selected component ion beam substantially comprised of a single ion species containing a single desired carbon isotope or molecular ion containing a single desired carbon isotope, said desired carbon isotopes being different in the selected component ion beams, and filtering out the remaining component ion beams containing undesired ion species;
- and
- (f) directing the first and then the second selected component ion beams onto a backside of substrate to sequentially implant the respective desired carbon isotopes into the interior of the substrate and then diffusing and exsolving through the top surface to epitaxially grow isotopically-enriched upper and lower graphene sheets from the respective carbon isotopes on the top surface of the single crystal region of the substrate to form an isotope junction between the upper and lower graphene sheets.
4 more elements
Dependencies are inferred from the claim text.