Intermediate-coupling polaron properties in wurtzite nitride semiconductors

Intermediate-coupling polarons in bulk III–V nitride semiconductors with wurtzite crystal structure are studied within the macroscopic dielectric continuum model and the uniaxial model. The polaronic self-trapping energy and effective mass are analytically derived by taking the mixing properties of the LO and TO polarizations due to the anisotropic effect into account. The numerical computation has been performed for wurtzite nitrides GaN, AlN, and InN. The results show that the polaronic self-trapping energies in the wurtzite nitrides are bigger than that in zinc-blende structures for the materials calculated. It is also found that the structure anisotropy increases the electron–phonon interaction in wurtzite nitride semiconductors. It indicates that the LO-like phonon influences on the polaronic effective mass and self-trapping energy are dominant, and the anisotropic effect is obvious. [Copyright &y& Elsevier]