OPTICAL-PROPERTIES OF SB-TERMINATED GAAS AND INP(110) SURFACES

The dielectric function and the Raman scattering cross section for sur face vibrations on InP and GaAs (110) surfaces terminated with an anti mony monolayer were calculated using the empirical tight-binding metho d. The calculations reproduce well the surface dielectric function and its anisotropy. The Raman cross section for surface vibrations was de termined for deformation-potential-induced scattering by calculating t he changes in the dielectric function caused by the surface phonon eig enmodes. In agreement with the experimental results, the different sur face phonon modes exhibit different resonance profiles since the coupl ing to the surface electronic states strongly depends on the respectiv e atomic displacements. The results demonstrate that, as for the bulk case, resonant Raman scattering can be used to probe the surface elect ronic properties.