Eur. Phys. J. B 43, 339-345 (2005)
https://doi.org/10.1140/epjb/e2005-00061-3

Polaron properties in ternary group-III nitride mixed crystals

¹ CCAST (World Laboratory), P.O. BOX 8730, Beijing 100080, P.R. China and College of Science, Inner Mongolia Agricultural University, Hohhot 010018, P.R. China
² Department of Physics, Inner Mongolia University, Hohhot 010021, P.R. China

Corresponding author: ^a zwyan@imau.edu.cn

Received: 22 October 2004
Revised: 10 December 2004
Published online: 15 March 2005

Abstract

Polaron properties are studied in bulk wurtzite nitride ternary mixed crystals A_xBN (A, B = Al, Ga, In) with the use of a dielectric continuum Fröhlich-like electron-phonon interaction Hamiltonian. 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 anisotropy effect into account in the mono-phonon approximation. The numerical computation has been performed for the wurtzite ternary mixed crystal materials In_xGaN, Al_xGaN, and Al_xInN as functions of the composition x. The results show that the polaronic self-trapping energies in the wurtzite structures 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 wurtizte nitride semiconductors. The results indicate that the LO-like phonon influence on the polaronic self-trapping energy and effective mass is dominant, and the anisotropy effect is obvious.