Adatom-induced conductance modification of in nanowires: potential-well scattering and structural effects

First-principles calculations on the influence of adatoms (In, Pb, H, O) on the Landauer conductance of Si substrate-supported atomic-scale In nanowires are performed. Despite the increase of the total (and partially even local) density of states at the Fermi level due to the adsorption, all adatom species lower the nanowire conductance. Apart from hydrogen, which barely changes the transport properties, the conductance drop is pronounced, ranging from 17% for Pb to 38% for In. It is related to potential-well scattering and/or structural deformations of the nanowires.