Semiconductor effective charges from tight-binding theory

We calculate the transverse effective charges of zinc-blende compound semiconductors using Harrison's tight-binding model to describe the electronic structure. Our results, which are essentially exact within the model, are found to be in much better agreement with experiment than previous perturbation-theory estimates. Efforts to improve the results by using more sophisticated variants of the tight-binding model were actually less successful. The results underline the importance of including quantities that are sensitive to the electronic wave functions, such as the effective charges, in the fitting of tight-binding models.