Nanostructures with electrodeposited nanoparticles

Abstract

A nanoelectronic device includes a nanostructure, such as a nanotube or network of nanotube, disposed on a substrate. Nanoparticles are disposed on or adjacent to the nanostructure so as to operatively effect the electrical properties of the nanostructure. The nanoparticles may be composed of metals, metal oxides or salts and nanoparticles composed of different materials may be present. The amount of nanoparticles may be controlled to preserve semiconductive properties of the nanostructure, and the substrate immediately adjacent to the nanostructure may remain substantially free of nanoparticles. A method for fabricating the device includes electrodeposition of the nanoparticles using one of more solutions of dissolved ions while providing an electric current to the nanostructures but not to the surrounding substrate.

1 . An electronic device comprising:
 a substrate;   at least one nanostructure disposed on the substrate;   at least one first nanoparticle operatively associated with the at least one nanostructure, the nanoparticle having a first composition;   at least one second nanoparticle operatively associated with the at least one nanostructure, the at least one second nanoparticle having a second composition differing substantially from the first composition.   
     
     
         2 . The device of  claim 1 , wherein the at least one nanostructure compromises a nanotube. 
     
     
         3 . The device of  claim 1 , wherein at least one of the first composition and the second composition comprises a metal. 
     
     
         4 . The device of  claim 3 , wherein the metal compromises a transition metal. 
     
     
         5 . The device of  claim 3 , wherein the metal is selected from the group consisting Pd, Pt, Au, Cu, Rh, Ir, Os, Ni, Ru, and Ag. 
     
     
         6 . The device of  claim 1 , wherein at least one of the first composition and the second composition comprises a salt. 
     
     
         7 . The device of  claim 1 , wherein at least one of the first composition and the second composition comprises a metal core surrounded by a metal oxide surface layer. 
     
     
         8 . The device of  claim 1 , further comprising a contact in electrical communication with the at least one nanostructure. 
     
     
         9 . The device of  claim 1 , wherein the at least one nanostructure comprises a nanowire. 
     
     
         10 . The device of  claim 1 , wherein the substrate comprises silicon. 
     
     
         11 . The device of  claim 1 , wherein the substrate is selected from the group consisting of silicon dioxide, silicon nitride, and aluminum oxide. 
     
     
         12 . The device of  claim 1 , wherein the substrate comprises a polymer. 
     
     
         13 . The device of  claim 1 , wherein at least one of the first nanoparticle and the second nanoparticle are disposed on the at least one nanostructure. 
     
     
         14 . The device of claim l, wherein the at least one second nanoparticle is disposed on the at least one first nanoparticle. 
     
     
         15 . An electronic device, comprising:
 a substrate;   at least one nanostructure disposed on the substrate;   at least one nanoparticle operatively associated with the at least one nanostructure, the nanoparticle comprising at least two layers having substantially different compositions from one another.   
     
     
         16 . An electronic device, comprising:
 a substrate;   a film disposed over the substrate, the film comprising at least two nanostructures and divided into at least two distinct regions by at least one electrode;   at least one first nanoparticle operatively associated with the film in a first region of the at least two distinct regions;   at least one second nanoparticle operatively associated with the film in a second region of the at least two distinct regions.   
     
     
         17 . A method of forming an electronic device, comprising:
 disposing at least one nanostructure on a substrate;   establishing electrical communication with the nanostructure;   exposing the nanostructure to a first solution comprising dissolved ions;   flowing an electric current to the nanostructure during the exposing step to cause electrodeposition from the first solution of at least one nanoparticle adjacent to the nanostructure; and   ending at least one of the exposing step and the flowing step after the at least one nanoparticle has been electrodeposited.   
     
     
         18 . The method of  claim 17 , wherein the ending step is performed before an amount of material sufficient to conduct electricity across the entire nanostructure has been electrodeposited. 
     
     
         19 . The method of  claim 17 , wherein the ending step comprises removing the first solution after a period of time. 
     
     
         20 . The method of  claim 17 , further comprising:
 exposing the nanostructure to a second solution comprising dissolved ions, the second solution having a composition substantially different from the first solution;   flowing an electric current to the nanostructure during the second exposing step to cause electrodeposition from the second solution of at least one second nanoparticle adjacent to the nanostructure; and   ending at least one of the second exposing step and the second flowing step after the at least one second nanoparticle has been electrodeposited.