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

Abstract

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) T4 (Bi trimer centered on T4 site), (ii) H3 (Bi trimer centered on H3 site), and (iii) T4–H3 (which is formed by trimers with opposite orientations: one centered on a T4 site and the other on a H3). Our total energy calculations suggest that adsorption on the T4–H3 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 T4–H3. Charge density difference results indicate significant amount of the charge accumulation on the Bi/InAs interface.