Optical constants of InP and GaP

Calculation of the optical constants of InP and GaP is presented. The employed model is a modification of Adachi´s model of the optical constants of semiconductors, which employs adjustable broadening instead of the conventional Lorentzian one. In this work we do not take into account excitonic effects at E/sub 1/ and E/sub 1/+/spl Delta//sub 1/ critical points. In such a manner, fewer adjustable model parameters are required and the term with dubious physical interpretation describing excitons at E/sub 1/ and E/sub 1/+/spl Delta//sub 1/ is left out. We obtain excellent agreement with experimental data over the entire 1-6 eV range, with relative rms error for the refractive index equal 1.0% for InP and 1.2% for GaP.