Effect of nitrogen on the GaAs0.9-xNxSb0.1 dielectric function from the near-infrared to the ultraviolet

Abstract

We study the effect of nitrogen on the GaAs0.9-x Nx Sb0.1 (x=0.00, 0.65%, 1.06%, 1.45%, and 1.90%) alloy dielectric function by spectroscopic ellipsometry in the energy range from 0.73 to 4.75 eV. The compositional dependences of the critical points energies for the GaAs0.9-x Nx Sb0.1 are obtained. In addition to the GaAs intrinsic transitions E1, E1 + Δ1, and E0′, the nitrogen-induced -point optical transitions E0 and E+, together with a third transition E#, are identified. We find that with increasing the N content, the E0 transition shifts to lower energies while the E+ and E# transitions shift to higher energies. We suggest that the origin of the E0, E+, and E# transitions may be explained by the double band anticrossing (BAC) model, consisting of a conduction BAC model and a valence BAC model. © 2010 American Institute of Physics.