Theoretical model of structure-dependent conductance crossover in disordered carbon
Nano-Scale Transport Physics Laboratory and School of Physics, University of the Witwatersrand Private Bag 3, WITS 2050, Johannesburg, South Africa
Received: 11 May 2012
Accepted: 10 July 2012
We analyze the effects of sp2/sp3 bond aspect ratio on the transport properties of amorphous carbon quasi-1D structures where structural disorder varies in a very non-linear manner with the effective band gap. Using a tight-binding approach the calculated electron transmission showed a high probability over a wide region around the Fermi level for sp2-rich carbon and also distinct peaks close to the band edges for sp3-rich carbon structures. This model shows a sharp rise of the structure resistance with the increase of sp3-C % followed by saturation in the wide band gap regime for carbon superlattice-like structures and suggests the tuneable characteristic time of carbon-based devices.
PACS: 73.21.-b – Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems / 72.80.Rj – Fullerenes and related materials / 72.80.Vp – Electronic transport in graphene
© EPLA, 2012