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.
|Titolo:||GaAs(001): Surface structure and optical properties|
ONIDA, GIOVANNI (Ultimo)
|Settore Scientifico Disciplinare:||Settore FIS/03 - Fisica della Materia|
|Data di pubblicazione:||2001|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1002/1521-396X(200112)188:4<1401::AID-PSSA1401>3.0.CO;2-1|
|Appare nelle tipologie:||01 - Articolo su periodico|