  Polaron binding energy and effective mass are calculated for semiconductors
with wurtzite crystalline structure from the first order electron-phonon
corrections to the self-energy. A recently introduced Frohlich-like
electron-phonon interaction Hamiltonian which accounts for the LO and TO
polarizations mixing due to the anisotropy is used in the calculation. The
polaronic damping rates are evaluated for finite temperature. Numerical results
are reported for GaN. It is shown that the electron-phonon coupling is strong
enough to justify the necessity of the inclusion of second-order corrections.
