Energy distributions of field emitted electrons from a multi-wall carbon nanotube.

Field emission energy distributions of electrons from one of the six pentagons located at the end of a multi-wall carbon nanotube have been measured by means of a high-resolution cylindrical energy analyzer. In a clean pentagon, the sub-peak was obtained at about 500 meV below the main peak, exhibiting a shift with increasing applied voltage. For electrons emitted from an adsorbate onto the pentagon, no fine structure was observed in the spectra. The broadening of the leading edge was also observed for both clean and adsorbed pentagon, indicating the field penetration into the nanotube due to its semimetallic nature. The full-width at half-maximum was 280 meV at the applied voltage of 660 V and increased linearly with applied voltage.