Altering regularities on resistances of doped Au-alkanedithiol-Au junctions

The electronic transport properties of alkanedithiol molecular junctions doped by boron (B) or phosphorus (P) on different sites are investigated by using the non-equilibrium Green's function method combined with the density functional theory. Results show that B or P doping can decrease the resistances of alkanedithiol molecular junctions obviously and the direct-current conductance becomes stronger gradually when doped sites vary from side to center. Namely, the B or P doped effects are not uniform which are sensitive to its doped sites. Interestingly, significant negative differential resistance behaviors are only found in B-doped molecular junctions and peak-to-valley ratios are also sensitive to the B doped sites. (C) 2013 Published by Elsevier B. V.