Adsorbate Effects on Charge Distribution of Carbon Nanotube Simulated by a Multi-scale Method

The apex structure of the SWCNT has been optimized to achieve higher FE efficiency. Obviously the apex-vacuum barrier (AVB) and thereby the FE characteristic will be strongly affected by the electron transfer between carbons and adsorbates and among the adsorbate atoms. The FE characteristics of open-ended SWCNTs with their open ends terminated by -O, -BH and -NH, respectively were compared. The simulations have shown that the -BH and -NH adsorbates have much larger binding energy than both oxygen saturated and hydrogen, two adsorbates should be superior for providing stable FE current. The -NH adsorbate is superior in FE characteristics than -O adsorbate, and -BH is the best among the three