Abstract
We have performed experiments on single-wall carbon nanotube (SWNT) networks and compared with density-functional theory (DFT) calculations to identify the microscopic origin of the observed sensitivity of the network conductivity to physisorbed and . Previous DFT calculations of the transmission function for isolated pristine SWNTs have found physisorbed molecules have little influence on their conductivity. However, by calculating the four-terminal transmission function of crossed SWNT junctions, we show that physisorbed and do affect the junction’s conductance. This may be understood as an increase in tunneling probability due to hopping via molecular orbitals. We find the effect is substantially larger for than for , and for semiconducting rather than metallic SWNTs junctions, in agreement with experiment.
- Received 11 February 2009
DOI:https://doi.org/10.1103/PhysRevB.79.195431
©2009 American Physical Society