Surface reconstruction stability of Bi/GaSb surfaces

Abstract

The phase diagram of the Bi/GaSb surface reconstructions has been established using density functional theory and cluster expansion computational methods. The predominant reconstructions in the alloy system are the same as those found for pure GaSb. That is, the (4 × 3) family of reconstructions dominate the phase diagram. However, at low Sb and Bi chemical potentials, the calculations predict a (2 × 1) structure for both GaSb and Bi/GaSb. It is found that Bi does not stabilize any additional structures, and Bi does not readily incorporate into the surface in the presence of Sb.