BINDING-ENERGY OF A POLARON IN ASYMMETRIC POLAR SEMICONDUCTOR HETEROSTRUCTURES

By using a modified Lee-Low-Pines variational method, we have investig ated the groundstate binding energy of a polaron confined in asymmetri c single and step quantum wells (QWs) due to interface phonons, confin ed bulk-like LO phonons, and half-space LO phonons. The relative impor tance of the different phonon modes is analysed in detail. Our results show that the asymmetry and the well width of the QWs have a signific ant influence on the polaron energy. The polaron binding energy has an intimate relation to the potential parameters of QWs. The subband non parabolicity has a little influence to the polaron binding energy. Com paring with the results calculated with perturbation theory, a good ag reement is found. (C) 1996 Academic Press Limited