Dynamical low-energy electron-diffraction analysis of bismuth and antimony epitaxy on GaAs(110)

Optical Properties of Ordered As Layers on InP(110) Surfaces

“…Arsenic adsorbates on GaAs(100) surfaces have been studied in the past by optical methods because of their role in the epitaxial growth process [5]. However, studies of As on InP(110) surfaces have been restricted to low-energy electron diffraction (LEED) and photoemission investigations by Tulke and Lüth [6] and Chassé, Neuhold, and Horn [7], and theoretical calculations of their atomic structure are not available.The question to be addressed here is whether As remains on the substrate surface forming well-defined surface monolayers, as in the case of antimony and bismuth terminated III-V surfaces [8][9][10][11], or whether a significant chemical reaction with the substrate top layers occurs, such as observed for the (100) InP surface [12]. For this purpose we present an investigation of arsenic monolayers on InP(110) surfaces (hereafter InP:As) combining a spectroscopic study of the surface optical properties with microscopic calculations of the atomic structure and optical spectra.…”

“…The question to be addressed here is whether As remains on the substrate surface forming well-defined surface monolayers, as in the case of antimony and bismuth terminated III-V surfaces [8][9][10][11], or whether a significant chemical reaction with the substrate top layers occurs, such as observed for the (100) InP surface [12]. For this purpose we present an investigation of arsenic monolayers on InP(110) surfaces (hereafter InP:As) combining a spectroscopic study of the surface optical properties with microscopic calculations of the atomic structure and optical spectra.…”

Optical anisotropy of ordered Sb layers on III-V (110) surfaces

“…In the energy regime between 2 eV and 2.7 eV, the reflectance anisotropy and SDR spectra show a strong structure. These results can be well explained by a calculation of the optical properties within a tight binding approximation (Goletti et al 1992, Chiaradia et al 1993, Esser et al 1994. The calculations show that the feature at 2.2eV is associated with Sb-lone-pair to Sb-back-antibonds transitions near the centre of the Brillouin zone, stronger for light perpendicular to the chains, while many transitions of different symmetries coalesce around 2.5 eV.…”

“…The light was polarized along the symmetry axes of the surface, namely along the directions parallel to the chains of atoms along [liO] and perpendicular to them, along [OOl]. Two broad transitions with onsets at about 1.5eV and maxima at 2.2 eV are observed, which can be ascribed to the Sb overlayer (Chiaradia et al 1980, Selci et al 1987, Goletti, Chiaradia, Wang Jian and Chiarotti 1992. These transitions are very intense (R/R,= 3%) and belong to different polarizations, but are only partially anisotropic (Chiaradia, Shkrebtii, Goletti, Wang Jian and Del Sole 1993).…”

“…From this point of view, the ordered Sb monolayer formed on 111-V (1 10) substrates represent an ideal testing system. The geometrical structure and the electronic band structure of Sb monolayers on GaAs(ll0) and InP(l10) have been thoroughly investigated for several years by a variety of experimental (Esser et al 1992, Ford, Guo, Lessor and Duke, 1990, Ford, Guo, Wan and Duke 1992, Mirtensson and Feenstra 1989 and theoretical methods (Mailhiot, Duke and Chadi 1985, Shrivastava 1992, Di Felice, Shkrebtii, Finocchi and Bertoni 1993. More recently, Sb was also discovered to form well ordered multilayers (MLs) on GaAs (1 10) and InP (1 10) under appropriate preparation (Resch, Esser andRichter 1991, Patrin, Li, Chander andWeaver 1992a, b).…”