Surface reconstructions on GaAs(001)

This paper reviews the recent experimental findings on the atomic structures on the (001) surface of GaAs. We systematically studied the structure and composition of the GaAs(001) surfaces using reflection high-energy electron diffraction, reflectance difference spectroscopy, scanning tunneling microscopy, and X-ray photoelectron spectroscopy. We found that the As-rich c ( 4 × 4 ) β , c ( 4 × 4 ) α , and (2×4), and Ga-rich (6×6), c ( 8 × 2 ) , and (4×6) reconstructions are formed on the GaAs(001) surface critically depending on the preparation conditions. Atomic structures on these reconstructions will be discussed on the basis of the recent findings of experiments and first-principles calculations.