A surface reconstruction model was presented for GaAs(111)A and B surfaces. The surface reconstruction mechanism was investigated using ab initio Hartree–Fock molecular-orbital calculations. Two model clusters, H3Ga3As3H6 and H6Ga3As3H3, were used to reveal different lateral interactions in the vicinity of the first bi-atomic surface layer for GaAs(111)A and B surfaces. Lateral interactions originating from the site specific atomic character (Ga/As) were shown to determine the Ga-As-Ga and As-Ga-As bond angles, which differ significantly from those for bulk GaAs. This causes each of the three surface nearest-neighbour Ga (As) atomic rings to become considerably larger (smaller) than the three nearest-neighbour As (Ga) atomic rings lying beneath them. The propagation of such lateral interactions across the surface explains a fundamental inability of Ga (As) -terminated surfaces to match to respective underlying As (Ga) atomic layers, providing the driving force for Ga (As) atom removal from Ga (As) -terminated (111) surfaces. Changes in surface reconstruction were thus attributed to this lateral interaction. It was shown how the 2 x 2 {2 x 2, √3 x √3, 3 x 3 and √19 x √19} reconstructed phases of Ga {As}-terminated surfaces depend on this lateral interaction. The models for GaAs(111)A and B surface reconstruction were shown to be applicable to the polar surfaces of other III-V compound semiconductors.

Influence of Chemical Character on GaAs(111) Surface Reconstruction. J.G.Ping, H.E.Ruda: Journal of Applied Physics, 1994, 75[10], 5332