Modeling AlxGa1−xAs 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.