Scanning electron microscopy of field-emitting individual single-walled carbon nanotubes

Carbon nanotubes are promising electron emitters because of their sharp geometries that lead to significant external field enhancement, as well as their mechanical strength. However, distinguishing the emission due to an individual single-walled carbon nanotube $(SWCNT)$ from that due to surrounding structures is a challenge. Here, we demonstrate how a scanning electron microscope $(SEM)$ can be used to view the emission from individual $SWCNTs$ by applying an external field close to the onset of field-emission and then scanning the tube with the electron beam of the $SEM$⁠. The stimulated emission is revealed in the $SEM$ image as localized bright spots.