Method for synthesizing nanoscale structures in defined locations

Abstract

A method is disclosed for directly synthesizing nanoscale structures, particularly in defined locations. The method overcomes problems in nanoscale manufacturing by enabling the direct fabrication of composites useful for constructing electronic devices. In one aspect of the method, nanotubes and arrays of nanotubes are synthesized directly at defined locations useful for constructing electronic devices.

1 . A method for synthesizing a nanotube in a defined location, comprising:
 providing a substrate;   depositing a catalytic material in a defined location on the substrate; and   synthesizing a nanoscale structure using the catalytic material.   
     
     
         2 . The method according to  claim 1  where providing a substrate comprises forming metal pillars in defined locations on the substrate. 
     
     
         3 . The method according to  claim 2  where the metal is selected from the group consisting of W, Pt, Au, Al, Fe, Ni, Ti, Ta, Cu, and combinations thereof. 
     
     
         4 . The method according to  claim 2  where the metal is Pt 
     
     
         5 . The method according to  claim 1  where the catalytic material comprises Ag, Au, Cu, Co, Fe, Mo, Ni, Pt, Ti, Mg, Y, Zn alloys thereof, and combinations thereof. 
     
     
         6 . The method according to  claim 1  where the nanoscale structure comprises a nanotube. 
     
     
         7 . The method according to  claim 6  where the nanotube is a single-walled nanotube. 
     
     
         8 . The method according to  claim 7  where the nanotube has a diameter of from about 1 to about 10 nm. 
     
     
         9 . The method according to  claim 6  where the nanotube is a double-walled nanotube. 
     
     
         10 . The method according to  claim 9  where the nanotube has a diameter of from about 1.5 to about 20 nm. 
     
     
         11 . The method according to  claim 6  where the nanotube is a multi-walled nanotube. 
     
     
         12 . The method according to  claim 11  where the nanotube has a diameter of from about 8 nm to about 1 μm. 
     
     
         13 . The method according to  claim 1  where the catalytic material is patterned by focused ion beam. 
     
     
         14 . The method according to  claim 6  where synthesizing the nanotube comprises chemical vapor deposition. 
     
     
         15 . The method according to  claim 14  where chemical vapor deposition includes using a carbon source and hydrogen in about a 1 to 13 volume ratio. 
     
     
         16 . The method according to  claim 2  where the pillar has a width of from about 10 nm to about 5 μm. 
     
     
         17 . The method according to  claim 1  where the catalytic material comprises at least one of Ag, Au and Pt and where the nanoscale structure is a zinc oxide nanowire. 
     
     
         18 . The method according to  claim 1  where the catalytic material comprises at least one of Ag, Au and Pt and where the nanoscale structure is a silicon oxide nanowire. 
     
     
         19 . The method according to  claim 1  where the catalytic material comprises at least one of Ag, Au and Pt and where the nanoscale structure is a tungsten or tungsten oxide nanowire. 
     
     
         20 . A composite, comprising:
 a substrate;   a pillar formed on the substrate at a selected location comprising an insulating, semiconducting or conducting material; and   a nanoscale structure other than a carbon nanotube formed on the pillar.   
     
     
         21 . The composite of  claim 20  wherein the nanoscale structure is a nanowire, nanocoil, nanobelt, or combination thereof. 
     
     
         22 . The composite of  claim 21  wherein the nanoscale structure comprises zinc oxide, silicon dioxide, tungsten oxide, cadmium sulfide, carbon, silicon carbide, or combinations thereof. 
     
     
         23 . The composite of  claim 1  wherein the substrate comprises plastic, silicon nitride, quartz, or mica, or combinations thereof, the pillar comprises Pt, Au, Fe, Ni, Ti, or combinations thereof, and the nanoscale structure comprises zinc oxide, cadmium sulfide, silicon dioxide, or combinations thereof. 
     
     
         24 . A composite, comprising:
 a substrate;   a pillar formed on the substrate at a selected location comprising an insulating, semiconducting or conducting material, the pillar further comprising a catalyst; and   a single nanoscale structure formed on the pillar.