Electronic devices based on purified carbon nanotubes grown by high-pressure decomposition of carbon monoxide

The excellent properties of transistors, wires and sensors made from single-walled carbon nanotubes (SWNTs) make them promising candidates for use in advanced nanoelectronic systems1. Gas-phase growth procedures such as the high-pressure decomposition of carbon monoxide (HiPCO) method2,3 yield large quantities of small-diameter semiconducting SWNTs, which are ideal for use in nanoelectronic circuits. As-grown HiPCO material, however, commonly contains a large fraction of carbonaceous impurities that degrade the properties of SWNT devices4. Here we demonstrate a purification, deposition and fabrication process that yields devices consisting of metallic and semiconducting nanotubes with electronic characteristics vastly superior to those of circuits made from raw HiPCO. Source–drain current measurements on the circuits as a function of temperature and backgate voltage are used to quantify the energy gap of semiconducting nanotubes in a field-effect transistor geometry. This work demonstrates significant progress towards the goal of producing complex integrated circuits from bulk-grown SWNT material.