Polaron effects due to interface optical-phonons in wurtzite GaN/AlN quantum wells

摘要

Considering the effects of the built-in electric field (BEF) induced by the spontaneous and piezoelectric polarizations of wurtzite GaN/AlN quantum wells (QW's), the polaron energy shift and the effective mass due to the electron interactions with the interface optical-phonons are investigated theoretically by means of Lee-Low-Pines variational approach. We find that the BEF has a remarkable influence on the polaron effects especially for a QW with well width d > 6 nm. The polaron energy shift increases slowly and its effective mass approaches to a constant if d is further increased. On the contrary, both the polaron energy shift and the effective mass decrease slowly with the increasing of d if the BEF is ignored. (c) 2005 WILEY-VCH Verlag GmbH C Co.