The optical anisotropy of differently reconstructed GaAs(001) surfaces has been analysed both theoretically and experimentally. The atomic structures and RAS spectra are calculated from first principles for the As-rich c(4 x 4) and beta2(2 x 4) as well as for the stoichiometric alpha2(2x4) and the Ga-rich zeta(4 x 2) surface phases. These results are compared with spectra recorded at low temperature (40 K). We find good agreement between the calculated and measured data, in particular for the As-rich surface phases. In marked contrast to earlier calculations we find the peak near the E-1 critical point energy, characteristic of the beta2(2 x 4) surface, to originate from electronic transitions in bulk layers. The experimental data for the Ga-rich (4 x 2) surface phase are less well reproduced, possibly due to surface defects or structural deviations from the zeta(4 x 2) model for the surface geometry.

GaAs(001): Surface structure and optical properties / W. Schmidt, F. Bechstedt, K. Fleischer, C. Cobet, N. Esser, W. Richter, J. Bernholc, G. Onida. - In: PHYSICA STATUS SOLIDI. A, APPLIED RESEARCH. - ISSN 0031-8965. - 188:4(2001), pp. 1401-1409.

GaAs(001): Surface structure and optical properties

G. Onida
Ultimo
2001

Abstract

The optical anisotropy of differently reconstructed GaAs(001) surfaces has been analysed both theoretically and experimentally. The atomic structures and RAS spectra are calculated from first principles for the As-rich c(4 x 4) and beta2(2 x 4) as well as for the stoichiometric alpha2(2x4) and the Ga-rich zeta(4 x 2) surface phases. These results are compared with spectra recorded at low temperature (40 K). We find good agreement between the calculated and measured data, in particular for the As-rich surface phases. In marked contrast to earlier calculations we find the peak near the E-1 critical point energy, characteristic of the beta2(2 x 4) surface, to originate from electronic transitions in bulk layers. The experimental data for the Ga-rich (4 x 2) surface phase are less well reproduced, possibly due to surface defects or structural deviations from the zeta(4 x 2) model for the surface geometry.
Settore FIS/03 - Fisica della Materia
Article (author)
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

Caricamento pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2434/186616
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 57
  • ???jsp.display-item.citation.isi??? 53
social impact