Reflectance anisotropy was calculated, from first principles, for the (001)-(2 x 4) surface. The features of the calculated spectra were related to specific surface bonding configurations. It was found that there was a marked negative anisotropy, around 1.7eV, which was linked to transitions between σ-like In-In bonding states and empty dangling bonds which were localized at the surface cations. The strength of the anisotropy was directly related to the number of In-In bonds at the surface. Positive anisotropies at higher energies arose from transitions between P-P dimer-related states and surface resonances. The results indicated that the (2 x 4) reconstructed (001) surface featured In-In bonds along [110] and P-P dimers parallel to [1¯10], respectively. The relative numbers of these bonds varied with the growth conditions.

Structural fingerprints in the reflectance anisotropy spectra of InP(001)-(2 x 4) surfaces W.G.Schmidt, E.L.Briggs, J.Bernholc, F.Bechstedt: Physical Review B, 1999, 59[3], 2234-9