Abstract: A method of electrically activating a structure having one or more graphene layers formed on a silicon carbide layer includes subjecting the structure to an oxidation process so as to form a silicon oxide layer disposed between the silicon carbide layer and a bottommost of the one or more graphene layers, thereby electrically activating the bottommost graphene layer.

Abstract: Transistor devices having nanoscale material-based channels and techniques for the fabrication thereof are provided. In one aspect, a transistor device includes a substrate; an insulator on the substrate; a gate embedded in the insulator with a top surface of the gate being substantially coplanar with a surface of the insulator; a dielectric layer over the gate and insulator; a channel comprising a carbon nanostructure material formed on the dielectric layer over the gate, wherein the dielectric layer over the gate and the insulator provides a flat surface on which the channel is formed; and source and drain contacts connected by the channel. A method of fabricating a transistor device is also provided.

Abstract: A photosensitive monolayer is self-assembled on an oxide surface. The chemical compound of the photosensitive monolayer has three components. A first end group provides covalent bonds with the oxide surface for self assembly on the oxide surface. A photosensitive group that dissociates upon exposure to ultraviolet radiation is linked to the first end group. A second end group linked to the photosensitive group provides hydrophobicity. Upon exposure to the ultraviolet radiation, the dissociated photosensitive group is cleaved and forms a hydrophilic derivative in the exposed region, rendering the exposed region hydrophilic. Carbon nanotubes or nanocrystals applied in an aqueous dispersion are selectively attracted to the hydrophilic exposed region to from electrostatic bonding with the hydrophilic surface of the cleaved photosensitive group.

Abstract: A photosensitive monolayer is self-assembled on an oxide surface. The chemical compound of the photosensitive monolayer has three components. A first end group provides covalent bonds with the oxide surface for self assembly on the oxide surface. A photosensitive group that dissociates upon exposure to ultraviolet radiation is linked to the first end group. A second end group linked to the photosensitive group provides hydrophobicity. Upon exposure to the ultraviolet radiation, the dissociated photosensitive group is cleaved and forms a hydrophilic derivative in the exposed region, rendering the exposed region hydrophilic. Carbon nanotubes or nanocrystals applied in an aqueous dispersion are selectively attracted to the hydrophilic exposed region to from electrostatic bonding with the hydrophilic surface of the cleaved photosensitive group.

Abstract: The present invention provides a method for selectively placing carbon nanotubes on a substrate surface by using functionalized carbon nanotubes having an organic compound that is covalently bonded to such carbon nanotubes. The organic compound comprises at least two functional groups, the first of which is capable of forming covalent bonds with carbon nanotubes, and the second of which is capable of selectively bonding metal oxides. Such functionalized carbon nanotubes are contacted with a substrate surface that has at least one portion containing a metal oxide. The second functional group of the organic compound selectively bonds to the metal oxide, so as to selectively place the functionalized carbon nanotubes on the at least one portion of the substrate surface that comprises the metal oxide.

Abstract: A photosensitive monolayer is self-assembled on an oxide surface. The chemical compound of the photosensitive monolayer has three components. A first end group provides covalent bonds with the oxide surface for self assembly on the oxide surface. A photosensitive group that dissociates upon exposure to ultraviolet radiation is linked to the first end group. A second end group linked to the photosensitive group provides hydrophobicity. Upon exposure to the ultraviolet radiation, the dissociated photosensitive group is cleaved and forms a hydrophilic derivative in the exposed region, rendering the exposed region hydrophilic. Carbon nanotubes or nanocrystals applied in an aqueous dispersion are selectively attracted to the hydrophilic exposed region to from electrostatic bonding with the hydrophilic surface of the cleaved photosensitive group.

Abstract: A method for separating carbon nanotubes comprises: providing a mixture of carbon nanotubes; introducing an organic molecule having an end group capable of being chelated by a metal ion to the mixture of carbon nanotubes to covalently bond the organic molecule to at least one of the mixture of carbon nanotubes; and introducing a metal salt to the mixture of carbon nanotubes to chelate the end group of the organic molecule with the metal ion of the metal salt; and centrifuging the mixture of carbon nanotubes to cause the separation of the carbon nanotubes based on a density differential of the carbon nanotubes.

Abstract: Techniques for producing atomic step-free silicon carbide surfaces are provided. In one aspect, a method for eliminating atomic steps from a silicon carbide surface is provided. The method comprises the following step. The silicon carbide and a silicon-containing gas are contacted at a temperature, background pressure, and for a length of time sufficient to re-arrange the silicon carbide to an atomic step-free surface. The silicon carbide surface can be the top of a mesa or the bottom of a hole patterned in a silicon carbide wafer.

Abstract: A photosensitive monolayer is self-assembled on an oxide surface. The chemical compound of the photosensitive monolayer has three components. A first end group provides covalent bonds with the oxide surface for self assembly on the oxide surface. A photosensitive group that dissociates upon exposure to ultraviolet radiation is linked to the first end group. A second end group linked to the photosensitive group provides hydrophobicity. Upon exposure to the ultraviolet radiation, the dissociated photosensitive group is cleaved and forms a hydrophilic derivative in the exposed region, rendering the exposed region hydrophilic. Carbon nanotubes or nanocrystals applied in an aqueous dispersion are selectively attracted to the hydrophilic exposed region to from electrostatic bonding with the hydrophilic surface of the cleaved photosensitive group.

Abstract: The present invention provides a method for selectively placing carbon nanotubes on a substrate surface by using functionalized carbon nanotubes having an organic compound that is covalently bonded to such carbon nanotubes. The organic compound comprises at least two functional groups, the first of which is capable of forming covalent bonds with carbon nanotubes, and the second of which is capable of selectively bonding metal oxides. Such functionalized carbon nanotubes are contacted with a substrate surface that has at least one portion containing a metal oxide. The second functional group of the organic compound selectively bonds to the metal oxide, so as to selectively place the functionalized carbon nanotubes on the at least one portion of the substrate surface that comprises the metal oxide.

Abstract: A method for separating carbon nanotubes comprises: providing a mixture of carbon nanotubes; introducing an organic molecule having an end group capable of being chelated by a metal ion to the mixture of carbon nanotubes to covalently bond the organic molecule to at least one of the mixture of carbon nanotubes; and introducing a metal salt to the mixture of carbon nanotubes to chelate the end group of the organic molecule with the metal ion of the metal salt; and centrifuging the mixture of carbon nanotubes to cause the separation of the carbon nanotubes based on a density differential of the carbon nanotubes.

Abstract: A method which permits large-scale separation of a semiconducting carbon nanotube from a mixture of metallic and semiconducting carbon nanotubes based on differences in solubility resulting from preferentially reacting the metallic carbon nanotubes with an acid functional aryldiazonium salt to form a substantially fully functionalized metallic nanotubes which can be easily separated from the unfunctionalized semiconducting carbon nanotubes.

Abstract: A photosensitive monolayer is self-assembled on an oxide surface. The chemical compound of the photosensitive monolayer has three components. A first end group provides covalent bonds with the oxide surface for self assembly on the oxide surface. A photosensitive group that dissociates upon exposure to ultraviolet radiation is linked to the first end group. A second end group linked to the photosensitive group provides hydrophobicity. Upon exposure to the ultraviolet radiation, the dissociated photosensitive group is cleaved and forms a hydrophilic derivative in the exposed region, rendering the exposed region hydrophilic. Carbon nanotubes or nanocrystals applied in an aqueous dispersion are selectively attracted to the hydrophilic exposed region to from electrostatic bonding with the hydrophilic surface of the cleaved photosensitive group.

Abstract: The present invention provides a method for selectively placing carbon nanotubes on a substrate surface by using functionalized carbon nanotubes having an organic compound that is covalently bonded to such carbon nanotubes. The organic compound comprises at least two functional groups, the first of which is capable of forming covalent bonds with carbon nanotubes, and the second of which is capable of selectively bonding metal oxides. Such functionalized carbon nanotubes are contacted with a substrate surface that has at least one portion containing a metal oxide. The second functional group of the organic compound selectively bonds to the metal oxide, so as to selectively place the functionalized carbon nanotubes on the at least one portion of the substrate surface that comprises the metal oxide.