Formation of atomic gold chain on hydrogen terminated Si(001):3×1 surface: A density functional study

Abstract

Electronic structure calculations are carried out for investigating the formation of a stable atomic gold wire on the hydrogen terminated Si(001):3×1 [H–Si(001):3×1] surface. The H–Si(001):3×1 surface is patterned in various ways by removing desired hydrogen atoms from the surface. Gold atoms are adsorbed on the patterned H–Si(001):3×1 surface at various submonolayer coverage. However, zigzag continuous Au chains are found to be favorable on patterned H–Si(001):3×1 surfaces at a 4/9 monolayer (ML) coverage. The stabilities of continuous atomic gold chains on the patterned H–Si(001):3×1 surfaces are compared. In addition, the Au chains on the patterned H–Si(001):3×1 surfaces are compared with the existing results of the favorable Au chain structures on patterned H–Si(001):1×1 surfaces [Konar et al., Phys. Rev. B 77, 245411 (2008)], and it is found that a continuous Au chain on the H–Si(001):3×1 surface is energetically more favorable. Our calculations also reveal that beyond the 4/9 ML coverage, the additional Au atoms take part in the formation of Au clusters on the surface. However, beyond the 4/9 ML coverage, the gold structures on the surface are found to be less favorable compared to the chain structures at the 4/9 ML coverage. The continuous atomic gold chains supported by a substrate may be used as atomic scale devices, and therefore, experiments may be designed in this direction to produce a continuous atomic Au chain on the patterned H–Si(001):3×1 surface.