SELF-TRAPPING ENERGY AND EFFECTIVE MASS OF POLARON IN WURTZITE NITRIDE SEMICONDUCTORS

Abstract

A variational approach is used to study the intermediate-coupling polaron in bulk III-V nitride semiconductors with wurtzite crystal structure within the macroscopic dielectric continuum model and the uniaxial model. The polaronic self-trapping energy and effective mass are theoretically derived for the LO and TO polarizations mixing due to the anisotropy effect. The numerical computation has been performed for the polaronic self-trapping energy and effective mass for wurtzite nitrides GaN , AlN and InN . The results show that the self-trapping energies of the wurtzite nitrides are bigger than the zinc-blende structures above calculated materials. It is also found that the structure anisotropy increases the electron–phonon interaction in wurtizte nitride semiconductors. It indicates that the LO-like phonon influence on the polaronic effective mass and self-trapping energy are dominant and anisotropy effect is obvious.