Odd-even effects of electronic transport in carbon-chain-based molecular devices

Electronic transport properties of two Au electrodes are examined on the basis of carbon chains with different numbers of carbon atoms, capped with two end groups NO ₂ and NH ₂, connected to their surfaces. The first-principles analysis of the microscopic nature reveals that their I-V characteristics and rectifying behaviors show obvious odd-even effects, namely, different bond patterns for even- and odd-numbered carbon atoms can obviously affect the rectifying ratio and directions, charge transfer, electronic transmission possibility, and evolutions of molecular orbitals. © 2012 American Chemical Society.