Increasing the semiconducting fraction in ensembles of single-walled carbon nanotubes

The carbon source and growth conditions for single-walled carbon nanotube (SWCNT) growth in hot-wall chemical vapor deposition affect the chirality of the SWCNT ensemble produced. Raman spectroscopy elucidates the trends of the SWCNT semiconducting percentage grown under different conditions. Field-effect transistors using few SWCNTs per transistor were fabricated to allow for a semiconducting SWCNT enumeration and to confirm these trends. The semiconducting SWCNT percent in isopropanol-based devices peaked at 800°C with 85% semiconducting. 2-Butanol-based and methane-based devices were 70% and 32% semiconducting, respectively.