Carbon nanotube array, material, electronic device, process for producing carbon nanotube array, and process for producing field effect transistor

Abstract

In order to obtain a carbon nanotube array including no m-CNTs through simple steps using a mechanism that is different from thermocapillary flow, there are provided a process for producing a carbon nanotube array including (A) a step of preparing a carbon nanotube array in which m-CNTs and s-CNTs are horizontally aligned; (B) a step of forming an organic layer on the carbon nanotube array; (C) a step of applying voltage to the carbon nanotube array in a long axis direction of the carbon nanotubes constituting the carbon nanotube array in the air; and (D) a step of removing the organic layer, and a carbon nanotube array obtained by the process.

1 . A carbon nanotube array including no metallic carbon nanotubes,
 wherein semiconducting carbon nanotubes are horizontally aligned at a density of 1 line/μm or more.   
     
     
         2 . The carbon nanotube array according to  claim 1 ,
 wherein a density of the semiconducting carbon nanotubes is 1,000 lines/μm or less.   
     
     
         3 . The carbon nanotube array according to  claim 1 ,
 wherein a length of each semiconducting carbon nanotube of the carbon nanotube array is 10 μm or more.   
     
     
         4 . The carbon nanotube array according to  claim 1 ,
 wherein in a case of forming a field effect transistor (FET) with the carbon nanotube array, an ON/OFF ratio of the FET is 10,000 or more.   
     
     
         5 . A material including the carbon nanotube array according to  claim 1 . 
     
     
         6 . An electronic device including the carbon nanotube array according to  claim 1 . 
     
     
         7 . A process for producing a carbon nanotube array comprising:
 (A) a step of preparing a carbon nanotube array in which metallic carbon nanotubes and semiconducting carbon nanotubes are horizontally aligned;   (B) a step of forming an organic layer on the carbon nanotube array;   (C) a step of applying voltage to the horizontally aligned carbon nanotube array in a long axis direction of the carbon nanotubes constituting the carbon nanotube array in the air; and   (D) a step of removing the organic layer.   
     
     
         8 . The process for producing a carbon nanotube array according to  claim 7 ,
 wherein the organic substance in the (B) step has a thermal diffusion coefficient of 2×10 −7  m 2 /s or less.   
     
     
         9 . The process for producing a carbon nanotube array according to  claim 7 ,
 wherein the organic layer in the (B) step is a layer made of only α,α,α′-tris(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene or a layer made of only poly(methyl methacrylate).   
     
     
         10 . The process for producing a carbon nanotube array according to  claim 7 ,
 wherein the semiconducting carbon nanotubes are horizontally aligned at a density of 1 line/μm or more.   
     
     
         11 . The process for producing a carbon nanotube array according to  claim 7 ,
 wherein a length of the semiconducting carbon nanotube is 10 μm or more.   
     
     
         12 . A process for producing a field effect transistor (FET) using a carbon nanotube array that is produced using the process for producing a carbon nanotube array according to  claim 7 ,
 wherein an ON/OFF ratio is 10,000 or more.