Abstract
This paper provides a first-principles study for the transport behavior of molecular devices exhibiting wide bias range of negative differential resistance (NDR). The devices are composed of a diphenyl-dimethyl connected to carbon chains from each side, which are then linked to gold electrodes through thiol-gold bond. The devices show an odd/even oscillating behavior: the NDR appears only for "odd" numbers of carbon atoms in the chain. We look at different device parameters in order to determine the sources of the NDR behavior. We attribute this behavior to a lack of electrons within the chain in case of "odd" number of carbon atoms. (C) 2013 AIP Publishing LLC.