Electronic structure of Ag-adsorbed nanowire-like stripes onSi(110)−(16×2)surfaces. II. A one-dimensional tight-binding model with Green’s function approach

Abstract

$\mathrm{Si}(110)\text{\ensuremath{-}}(16\ifmmode\times\else\texttimes\fi{}2)$ surface has nanowire-like stripes, where the separation between stripes is $\ensuremath{\sim}5\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$. We initially ignore the interaction between these stripes and treat a stripe as a one-dimensional (1D) system. We have carried out a 1D tight-binding model calculation by considering various modified chains. In theoretical analysis of the model, real space renormalization technique and Green's function approach are adopted. The results obtained from the 1D model are consistent with the observed features in the local density of states. Scanning tunneling spectroscopy results obtained on the stripes of the $\mathrm{Si}(110)\text{\ensuremath{-}}(16\ifmmode\times\else\texttimes\fi{}2)$ structures following a low-coverage Ag deposition show the following features: (i) band gap broadening, (ii) band gap variation, (iii) band offset, and (iv) appearance of new electronic states within the band gap. Our model qualitatively explains these features.