Temperature dependence and origin of InP(100) reflectance anisotropy down to 20 K - art. no. 245303

InP(100) surfaces were investigated by reflectance anisotropy spectroscopy (RAS) in the temperature range between 20 and 840 K. Surfaces were prepared via metal-organic chemical vapor deposition (MOCVD) resulting in P-termina ted (2x1)-like and In-terminated (2x4) reconstructions. Additionally, inter mediate states of different phosphorus coverage were prepared. RA spectra w ere recorded bath inside the MOCVD reactor and in an ultrahigh vacuum chamb er. At low temperatures, features in the RA spectra sharpened significantly due to the reduced lattice vibrations and electron-phonon interactions. Th e temperature-dependent energy shift of specific RAS features was determine d between 20 and 840 K, and fitted with a model containing the Bose-Einstei n occupation factor for phonons. The respective fitting parameters were com pared to those of the InP bulk critical-point transitions nearby. Careful d ata analysis provided evidence for surface transitions and surface modified bulk transitions in the RA spectra.