Modelling the optical constants of GaAs: excitonic effects at E_1, E_1 + Δ_1 critical points

摘要

Calculation of the optical constants of GaAs is presented. In this work we do not take into account excitonic effects at El and El + Al critical points. In such a manner, fewer adjustable model parameters are required and the term with dubious physical interpretation describing excitons at E_1 and E_1 + Δ_l is left out. Reasons for exclusion of this term are discussed in detail. In spite of the fewer terms describing the contributions of different transitions to the dielectric function, we obtain excellent agreement with experimental data over the entire 0.125-6 eV range, with relative rms error for the refractive index equal to 2.6%.