Silicon Dangling Bond Chains

Abstract

We present the characterization of close-spaced linear dangling bond structures, or dangling bond chains, two to seven dangling bonds long, on a hydrogen terminated silicon (100)-2x1 surface using a scan- ning tunnelling microscope. Constant height differential conductance maps reveal their local density of states. We demonstrate maximal charging configurations for odd numbered chains, rendering dan- gling bonds of the chain alternately negatively and non-negatively charged. Perturbing a chain electrostatically with negatively charged single dangling bonds, we find that we significantly change the elec- tronic structure of the chain, shifting its electronic state density away from the perturbing charge. Turning the single dangling bond into a bare dimer, the chain takes on its unperturbed character, proving that bare dimers do not support localized charge. Using the differential conductance mapping technique, we measure the energetic position of an unexplained bright feature often seen between two dangling bonds.