Polaron binding energy and effective mass in nitride single semiconductor heterostructures

Polaronic corrections in the conduction band of III–V nitride-based single heterostructures (SHS) are calculated within second-order Rayleigh–Schrödinger perturbation theory, using the dielectric continuum model for the interface and half-space polar optical phonon modes. The particular case of the AlN/GaN system is considered for illustration. The formation of a polarization-induced sheet density charge at the interface between both materials allows to study the single-electron states with the use of an approximate analytical expression for the potential energy function. The band-bending profile is then described in a way that includes many-body effects through a one-dimensional Hartree potential. Comparison of the calculated polaron effective mass in this material with recent experimental results in nitride SHS shows that higher perturbative orders in the interaction should be included in order to obtain better agreement.