Reflectance anisotropy spectroscopy (RAS) has been applied to study the oxidation of decapped InAs(0 0 1) surfaces at room temperature. (2 × 4) and (4 × 2) surfaces were prepared in ultra high vacuum by annealing, and then exposed to increasing amounts of molecular oxygen. During exposure to gas, RAS spectral structures at 2.4 eV in (2 × 4) and at 1.7 eV in (4 × 2) are progressively reduced. After about 1 × 104 L, a broad residual anisotropy spectrum is still measured for (2 × 4), while relic anisotropy is nearly null for (4 × 2). Residual features are visible at bulk critical points (E1, E1 + Δ1 and E′0). The different behavior versus gas contamination evidences the origin of RAS spectral structures, allowing interpretation in terms of surface-state or bulk transitions (the latter modified by the surface). By using Kramers-Kronig relations, the anisotropy of the imaginary part of the surface dielectric function (Δε″s) between [1̄ 1 0] and [1 1 0] directions of the substrate has been obtained from RAS data. We conclude that the main RAS structures (at 2.4 eV in (2 × 4), at 1.7 eV in (4 × 2)) are related to the surface reconstruction, although only the latter is a transition involving true surface states. We observe bulk contributions in coincidence with critical points (E1, E1 + Δ1 and E′0). © 2002 Elsevier Science B.V. All rights reserved.

Arciprete, F., Goletti, C., Almaviva, S., Chiaradia, P. (2002). Optical anisotropy of oxidized InAs(0 0 1) surfaces. SURFACE SCIENCE, 515(2009/03/02 00:00:00.000), 281-286 [10.1016/S0039-6028(02)01774-0].

Optical anisotropy of oxidized InAs(0 0 1) surfaces

ARCIPRETE, FABRIZIO;GOLETTI, CLAUDIO;CHIARADIA, PIETRO
2002-01-01

Abstract

Reflectance anisotropy spectroscopy (RAS) has been applied to study the oxidation of decapped InAs(0 0 1) surfaces at room temperature. (2 × 4) and (4 × 2) surfaces were prepared in ultra high vacuum by annealing, and then exposed to increasing amounts of molecular oxygen. During exposure to gas, RAS spectral structures at 2.4 eV in (2 × 4) and at 1.7 eV in (4 × 2) are progressively reduced. After about 1 × 104 L, a broad residual anisotropy spectrum is still measured for (2 × 4), while relic anisotropy is nearly null for (4 × 2). Residual features are visible at bulk critical points (E1, E1 + Δ1 and E′0). The different behavior versus gas contamination evidences the origin of RAS spectral structures, allowing interpretation in terms of surface-state or bulk transitions (the latter modified by the surface). By using Kramers-Kronig relations, the anisotropy of the imaginary part of the surface dielectric function (Δε″s) between [1̄ 1 0] and [1 1 0] directions of the substrate has been obtained from RAS data. We conclude that the main RAS structures (at 2.4 eV in (2 × 4), at 1.7 eV in (4 × 2)) are related to the surface reconstruction, although only the latter is a transition involving true surface states. We observe bulk contributions in coincidence with critical points (E1, E1 + Δ1 and E′0). © 2002 Elsevier Science B.V. All rights reserved.
2002
Pubblicato
Rilevanza internazionale
Articolo
Sì, ma tipo non specificato
Settore FIS/03 - FISICA DELLA MATERIA
English
Con Impact Factor ISI
Chemisorption; Indium arsenide; Oxidation; Surface relaxation and reconstruction
Arciprete, F., Goletti, C., Almaviva, S., Chiaradia, P. (2002). Optical anisotropy of oxidized InAs(0 0 1) surfaces. SURFACE SCIENCE, 515(2009/03/02 00:00:00.000), 281-286 [10.1016/S0039-6028(02)01774-0].
Arciprete, F; Goletti, C; Almaviva, S; Chiaradia, P
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2108/52165
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