Air‐stable Cl‐terminated Ge(111)

It is shown that an air‐stable Ge(111) surface can be made by wet chemical HCl treatment in ambient atmosphere. X‐ray photoelectron spectroscopy (XPS) and photon electrical field polarization‐dependent Cl K‐edge x‐ray absorption spectroscopy (XANES) were used to study the chemical structure and the physical orientation of chemisorbed Cl. It is found that Cl forms a monovalent bond with the Ge(111) dangling bond (DB) along 〈111〉 surface normal. The stability of HCl‐treated Ge(111) is attributed to the surface DBs being terminated by monochloride. Thermodynamics are found to be the governing force in the Ge–HCl reaction processes.