Abstract:
A semiconductor nanowire is coated with a chemical coating layer that slectively attaches to the semiconductor material and which forms a dye in a chemical reaction. The dye layer comprises a material that absorbs electromagnetic radiation. A portion of the absorbed energy induces electronic excitation in the chemical coating layer from which additional free charge carriers are temporarily donated into the semiconductor nanowire. Thus, the conductivity of the semiconductor nanowire increases upon illumination on the dye layer. The semiconductor nanowire, and the resulting dye layer collective operate as a detector for electromagnetic radiation.
Abstract:
Separation of carbon nanotubes or fullerenes according to diameter through non- covalent pi-pi interaction with molecular clips is provided. Molecular clips are prepared by Diels- Alder reaction of polyacenes with a variety of dienophiles. The pi-pi complexes of carbon nanotrubes with molecular clips are also used for selective placement of carbon nanotubes and fullerenes on substrates.
Abstract:
The invention is directed to a method of forming carbon nanomaterials or semiconductor nanomaterials. The method comprises providing a substrate and attaching a molecular precursor to the substrate. The molecular precursor includes a surface binding group for attachment to the substrate and a binding group for attachment of metal-containing species. The metal-containing species is selected from a metal cation, metal compound, or metal or metal-oxide nanoparticle to form a metallized molecular precursor. The metallized molecular precursor is then subjected to a heat treatment to provide a catalytic site from which the carbon nanomaterials or semiconductor nanomaterials form. The heating of the metallized molecular precursor is conducted under conditions suitable for chemical vapor deposition of the carbon nanomaterials or semiconductor nanomaterials.
Abstract:
The present invention provides a method for the selective placement of carbon nanotubes on a particular surface. In particular, the present invention provides a method in which self-assembled monolayers formed on an unpatterned or patterned metal oxide surface are used to attract or repel carbon nanotubes from a dispersion containing the same. In accordance with the present invention, the carbon nanotubes can be attracted to the self-assembled monolayers so as to be attached to the metal oxide surface, or they can be repelled by the self-assembled monolayers bonding to a predetermined surface other than the metal oxide surface containing the self-assembled monolayers.
Abstract:
Biological and chemical sensors based on surface charge changes in a pore or channel, such as a nanopore or nanochannel, are employed to detect targeted analytes in an electrolyte solution having a low ion concentration. Receptors within the pore or channel capture a targeted analyte, causing a change in surface charge that affects ionic conductance. The change in ionic conductance is detected, evidencing the presence of the targeted analyte. A secondary tag may be introduced to the pore or channel for binding with a captured analyte in certain circumstances for causing a change in the surface charge.
Abstract:
Techniques for increasing conductivity of graphene films by chemical doping are provided. In one aspect, a method for increasing conductivity of a graphene film includes the following steps. The graphene film is formed from one or more graphene sheets. The graphene sheets are exposed to a solution having a one-electron oxidant configured to dope the graphene sheets to increase a conductivity thereof, thereby increasing the overall conductivity of the film. The graphene film can be formed prior to the graphene sheets being exposed to the one-electron oxidant solution. Alternatively, the graphene sheets can be exposed to the one-electron oxidant solution prior to the graphene film being formed. A method of fabricating a transparent electrode on a photovoltaic device from a graphene film is also provided.
Abstract:
Techniques for increasing conductivity of carbon nanotube films are provided. In one aspect, a method for increasing conductivity of a carbon nanotube film includes the following steps. The carbon nanotube film is formed from a mixture of metallic and semiconducting carbon nanotubes. The carbon nanotubes are exposed to a solution comprising a one-electron oxidant configured to dope thesemiconducting carbon nanotubes to increase a conductivity thereof, thereby increasing the overall conductivity of the film. The step of forming the carbon nanotube film can be performed prior to the step of exposing the carbon nanotubes to the one-electron oxidant solution. Alternatively, the step of exposing the carbon nanotubes to the one-electron oxidant solution can be performed prior to the step of forming the carbon nanotube film. A method of fabricating a transparent electrode on a photovoltaic device from a carbon nanotube film is also provided.
Abstract:
Separation of carbon nanotubes or fullerenes according to diameter through non- covalent pi-pi interaction with molecular clips is provided. Molecular clips are prepared by Diels- Alder reaction of polyacenes with a variety of dienophiles. The pi-pi complexes of carbon nanotrubes with molecular clips are also used for selective placement of carbon nanotubes and fullerenes on substrates.
Abstract:
The present invention provides a method for the selective placement of carbon nanotubes on a particular surface. In particular, the present invention provides a method in which self-assembled monolayers formed on an unpatterned or patterned metal oxide surface are used to attract or repel carbon nanotubes from a dispersion containing the same. In accordance with the present invention, the carbon nanotubes can be attracted to the self-assembled monolayers so as to be attached to the metal oxide surface, or they can be repelled by the self-assembled monolayers bonding to a predetermined surface other than the metal oxide surface containing the self-assembled monolayers.
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.