Selective removal of metallic single-walled carbon nanotubes in full length by organic film-assisted electrical breakdown
An organic film-assisted electrical breakdown technique is proposed to selectively remove metallic (m-) single-walled carbon nanotubes (SWNTs) in full length towards creation of pure semiconducting SWNT arrays which are available for the large-scale fabrication of field effect transistors (FETs). The electrical breakdown of horizontally aligned SWNT arrays embedded in organic films resulted in a maximum removal length of 16.4 μm. The removal of SWNTs was confirmed using scanning electron microscopy and Raman mapping measurements. The on/off ratios of FETs were improved up to ca. 10 000, similar to that achieved for in-air breakdown. The experimental results suggest that exothermic oxidation of organic films induces propagation of oxidation reaction, hence the long-length removal of m-SWNTs.