Atomic structure and electronic properties of the In/Si(111)2 × 2 surface

The Si(111)2×2-In reconstruction can be considered as a precursor phase for the formation of the metallic 7×3 phases of In overlayers on a Si(111) surface. Using the ab initio random structure searching method, comparison of simulated and experimental scanning tunneling microscopy images, and resemblance of the calculated band structure to the experimental angle-resolved photoelectron spectra, we examined various 2×2 structure models with 0.5, 0.75, 1.0, and 1.25 monolayer In coverage. The only model which fits well all the requirements is the one-monolayer model, where three In atoms in the T4 sites form a trimer centered in the H3 site and the fourth In atom occupies the on-top (T1) site. © 2014 American Physical Society.