Structural analysis of an InP(111)A surface using reflection high-energy electron diffraction rocking curves

The surface structure of InP(111) A has been investigated using reflection high-energy electron diffraction (RHEED) rocking curves and first-principles calculations. We used Ar ion sputtering and low-temperature annealing at about 200 degrees C as a cleaning method, which yields a (1 x 1) surface structure. RHEED rocking curves reveal that the interatomic distance of the top surface bilayer is compressive. First-principles calculations were performed based on a (2 x 2) unit mesh to obtain a stable structure. The calculated results suggest that a surface compressive bilayer is necessary when In atoms are removed from the surface. We conclude that the InP(111)A-(1 x 1) surface structure comprises about 20%-40% In defects, which exist randomly on the surface, and the compressed surface bilayer has an interval of 0.1 angstrom. (C) 2019 The Japan Society of Applied Physics