Ultra-High Yield Growth of Vertical Single-Walled Carbon Nanotubes:   Hidden Roles of Hydrogen and Oxygen
  An oxygen assisted hydrocarbon chemical vapor deposition (CVD) method is developed to afford large-scale highly reproducible ultra high-yield growth of vertical single-walled carbon nanotubes (SWNT). It is revealed that reactive hydrogen (H)-species, inevitable in hydrocarbon-based growth, are damaging to the formation of sp2-like SWNTs. The addition of oxygen scavenges H-species and provides a powerful control over the C/H ratio to favor SWNT growth. The revelation of the roles played by hydrogen and oxygen leads to a unified and universal optimum growth condition for SWNTs. Further, a versatile method is developed to form vertical SWNT films on any substrate, lifting a major substrate-type limitation for aligned SWNTs. 
Guangyu Zhang, David Mann, Li Zhang, Ali Javey, Yiming Li, Erhan   Yenilmez, Qian Wang, James McVittie, Yoshio Nishi, James ...