Interface polarons in a realistic heterojunction potential
Department of Physics, State University of West Georgia, Carrollton, Georgia 30118,
Published online: 15 April 1999
The ground states of interface polarons in a realistic heterojunction potential are investigated by considering the bulk and the interface optical phonon influence. A self-consistent heterojunction potential is used and an LLP-like method is adopted to obtain the polaron effect. The numerical computation has been done for the ZnCdxSe/ZnSe system to obtain the polaron ground state energy, self energy and effective mass parallel to the interface. A simplified coherent potential approximation is developed to obtain the parameters of the ternary mixed crystal and the energy band offset of the heterojunction. It is found that at small Cd concentration the bulk longitudinal optical phonons give the main contribution for lower areal electron densities, whereas the interface phonon contribution is dominant for higher areal electron densities. The interface polaron effect is weaker than the effect obtained by the three dimensional bulk phonon and by the two dimensional interface phonon models.
PACS: 73.40.Lq – Other semiconductor-to-semiconductor contacts, junctions, and heterojunctions / 71.38.+i – Polarons and electron-phonon interactions / 63.20.kr – Phonon-electron and phonon-phonon interactions
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1999