1102.5645 (P. Poonam et al.)

Electronic transport in defective carbon nanotubes functionalized with
gold clusters on CO gas exposure    [PDF]

P. Poonam, N. Deo

We investigate the time-dependent electronic transport in single-walled carbon nanotubes (SWCNTs) functionalized with Au clusters during CO gas adsorption. Using a tight-binding Hamiltonian and the nonequilibrium Green's function (NEGF) formalism the time-dependent zeroth and first order contributions to the current are calculated. The zeroth order contribution is identified as the time-dependent Landauer formula in terms of the slow time variable, whereas the first order contribution is found to be small. The conductance is explicitly evaluated by considering a form for the hopping integral which accounts for the effect of dopants on the charge distribution and the carbon-carbon distance. The effect of dopants is also studied in terms of fluctuations by calculating the autocorrelation function for the experimental and theoretical data. These calculations allow direct comparison with the experiment and demonstrate how the presence of dopants modifies the experimentally measured conductance of the SWCNT and provide the only study of fluctuations in the sensor response in terms of the autocorrelation function.

View original: http://arxiv.org/abs/1102.5645