Electronic transport properties of carbon chains between Au and Ag electrodes: A first-principles study

We report first-principles calculations of the current-voltage characteristic and the conductance of carbon-based molecular wires with different length capped with sulfur ends between two metallic electrodes made of different metals. The optimized molecular structure of carbon chain in the junction is presented on the structure of polyyne. The conductance of the polyyne wires shows oscillatory behavior depending on the number of carbon atoms (triple bonds). Current rectification is found and rectification direction presents inversion with the odd and even number of carbon atoms.

► Au and Ag as two asymmetric electrodes.
► Relaxed carbon chain structure is in the form of polyyne.
► Oscillatory conductance behavior with the number of carbon atoms.
► Current rectification of carbon chains in the asymmetric electrodes.
► Rectification inversion with the number of carbon atoms.