Optical dielectric function of semiconductors

The optical constants of a range of semiconductors, from wide bandgap mater ials (GaN and AlN) over mid-bandgap materials (GaAs and InP) to narrow band gap materials (InSb and HgTe) have been modeled over a wide spectral range. We compare several models in terms of accuracy, intricacy of model equatio ns and the number of adjustable parameters. It has been found that a modifi ed Adachi's model with adjustable broadening function obtains the best agre ement with the experimental data for all investigated materials. An adjusta ble broadening function enables greater flexibility of the model, since no broadening mechanism is specified a priori and inhomogeneous broadening can be taken into account. (C) 2000 Elsevier Science S.A. All rights reserved.