Modeling Al<i>x</i>Ga1−<i>x</i>As optical constants as functions of composition

Abstract

Three models for the dielectric function εx(hν) of AlxGa1−xAs are reviewed. All are based on measured optical constants at discrete compositions. The validity of each model near critical point energies, and otherwise, is evaluated. Only the energy-shift model is appropriate over the entire available spectrum (1.5–6.0 eV), including the band-gap (E0) region.