The dispersion of the refractive index of III-V semiconductors

Abstract

The refractive index dispersions of semiconductors at wavelengths longer than the fundamental absorption edge have been analyzed with a theoretical prediction which is based on a modification of the simplified models of the interband transitions by taking into account the contribution of the free-carrier absorptions to the index of refraction. This approach has been applied to III-V semiconductor compounds, and the results exhibit excellent agreement with the previously published experimental data over the entire range of wavelengths concerned, thus not only confirming the validity of the presented model, but also demonstrating the non-negligible role played by the free-carrier absorption on the dispersion of the refractive index of semiconductors at wavelengths longer than the intrinsic absorption edge.