Method of forming a heterojunction of a carbon nanotube and a different material, method of working a filament of a nanotube

Abstract

A carbon nanotube is contacted with a reactive substance which is a metal or a semiconductor. The reactive substance is heated to diffuse atoms of the reactive substance into the carbon nanotube so that the carbon nanotube is partially transformed or converted into carbide as a reaction product. Thus, a heterojunction of the reaction product and the carbon nanotube is formed. For example, the carbon nanotube ( 2 ) is contacted with a silicon substrate ( 1 ). The silicon substrate ( 1 ) is heated to cause solid-solid diffusion of Si. As a result, SiC ( 3 ) is formed as the heterojunction. At least a part of a filament material of a carbon nanotube is irradiated with electromagnetic wave to deform the filament material.

What is claimed is:  
     
         1 . A method of forming a heterojunction of a carbon nanotube and a different material, comprising the step of contacting said carbon nanotube with a reactive substance to cause reaction between a part of said carbon nanotube and said reactive substance so that a bond of a reaction product and said carbon nanotube is formed as said heterojunction.  
     
     
         2 . A method as claimed in    claim 1   , wherein the reaction between said carbon nanotube and said reactive substance is performed by solid-solid diffusion using said reactive substance as a diffusion source.  
     
     
         3 . A method as claimed in    claim 1   , wherein said reactive substance is a metal or a semiconductor.  
     
     
         4 . A method as claimed in    claim 1   , wherein the reaction between said carbon nanotube and said reactive substance is performed in a vacuum or in an inactive gas.  
     
     
         5 . A method as claimed in    claim 1   , wherein the reaction between said carbon nanotube and said reactive substance is performed in a heated condition such that at least the reactive substance is heated.  
     
     
         6 . A method as claimed in    claim 5   , wherein said heated condition is caused by feeding an electric current to said reactive substance or between said carbon nanotube and said reactive substance.  
     
     
         7 . A filament comprising a filament material which is deformed by irradiation of electromagnetic wave to at least a part thereof.  
     
     
         8 . A filament as claimed in    claim 7   , wherein said filament material is a nanotube.  
     
     
         9 . A filament as claimed in    claim 8   , wherein said nanotube is a single-wall nanotube.  
     
     
         10 . A filament as claimed in    claim 8   , wherein said nanotube has a bundled structure.  
     
     
         11 . A filament as claimed in    claim 8   , wherein said nanotube is a carbon nanotube.  
     
     
         12 . A method of inducing an electric current in a filament, comprising the step of irradiating at least a part of a filament material with electromagnetic wave to selectively induce the electric current in said filament material.  
     
     
         13 . A method of working a filament, comprising the step of irradiating at least a part of a filament material with electromagnetic wave to deform said filament material.  
     
     
         14 . A method as claimed in    claim 13   , wherein said electromagnetic wave is visible light.