Polaron Effective Mass and Binding Energy in Semiconducting InxGa1?xN

Abstract

Polaron binding energy and effective mass are calculated for bulk hexagonal InxGa1—xN with the use of a dielectric continuum Fröhlich-like electron–phonon Hamiltonian. The calculation includes the evaluation of polaronic corrections up to second order in the coupling constants. The result obtained for the electron effective mass in hexagonal GaN is in very good agreement with recent experimental findings. The relevance of having reliable experimental values for the InN conduction band effective mass and optical dielectric constant in order to clarify the real contribution of second-order corrections to the binding energy and the anisotropy of the polaron mass in this material is discussed. The case of cubic alloys is briefly considered as well.