Symmetric Versus Nonsymmetric Structure of the Phosphorus Vacancy on InP(110)

摘要

The atomic and electronic structure of positively charged P vacancies onInP(110) surfaces is determined by combining scanning tunneling microscopy,photoelectron spectroscopy, and density-functional theory calculations. Thevacancy exhibits a nonsymmetric rebonded atomic configuration with a chargetransfer level 0.75+-0.1 eV above the valence band maximum. The scanningtunneling microscopy (STM) images show only a time average of two degenerategeometries, due to a thermal flip motion between the mirror configurations.This leads to an apparently symmetric STM image, although the ground stateatomic structure is nonsymmetric.