Theoretical investigation of charge accumulation layer on the Bi-induced InAs(111)-(2 × 2) surface

Based on pseudopotential method and density functional theory, we have investigated the stability, atomic geometry, and detailed electronic structures for Bi adsorbates on the InAs(111)-(2 × 2) surface with three different sites: (i)  T 4  (Bi trimer centered on  T 4  site), (ii)  H 3  (Bi trimer centered on  H 3  site), and (iii)  T 4 – H 3  (which is formed by trimers with opposite orientations: one centered on a  T 4  site and the other on a  H 3 ). Our total energy calculations suggest that adsorption on the  T 4 – H 3  site is the energetically most stable structure among the proposed structures. The electronic band structure calculations reveal the existence of an accumulation layer between InAs(111) surface and Bi adatoms for  T 4 – H 3 . Charge density difference results indicate significant amount of the charge accumulation on the Bi/InAs interface.