First-principles study of (2×1) and (2×2) phosphorus-rich InP(001) surfaces

The dependence of the InP(001) surface reconstruction on the chemical potentials of its constituents is explored. Based on first-principles pseudopotential plane-wave calculations the surface phase diagram is constructed. 17 structural models are studied for the phosphorus-rich InP(001) surfaces, with (2×1), p(2×2) and c(2×2) translational symmetry. P-top dimer reconstructions are favoured. Under less P-rich preparation conditions a tendency for disorder is predicted. STM images are also calculated in order to contribute to a solution of the structural puzzle.