ISSN - 10980121, Physical Review B - Condensed Matter and Materials Physics, 2003, vol. 69, p. 333051-333054
Bulklike behavior of the optical anisotropy of cation-rich (001) surfaces of Ga1-xInxAs alloys
Using reflectance anisotropy spectroscopy, we have studied cation-rich (001) surfaces of Ga1-xInxAs. All the spectra contain a dominant negative line, for which the energy shifts between 1.8 eV for InAs and 2.3 eV for GaAs. The dependence of this energy on In concentration is nonlinear and is perfectly interpreted using a bowing parameter characteristic of bulk transitions. Using the present results, the amplitude of the energy shift, and the fact that the transition lies far away from bulk critical points, we propose that the final state of the optical transition penetrates deeply into the bulk, whereas the initial state of the transition keeps a more pronounced surface character.