Contribution of bulk and surface phonons to the properties of polaron in a Zn1−XCdXSe∕ZnSe heterojunction confined in a triangular potential

Abstract

The contributions of bulk and surface phonons to the properties of a polaron in a Zn1 −XCdXSe∕ZnSe heterojunction confined in a triangular potential have been studied using the Lee-Low-Pines variational method and the Tokuda linear-combination operator method. We obtain expressions for the wave function of the system, the ground state energy, effective mass, the average number of phonons, the mobility and the lifetime of the polaron. Our numerical results show that the two Interface-optical (IO)-phonon modes and the longitudinal-optical (LO)-phonon mode contribute to the ground state energy, the average number of phonons, the mobility, the effective mass and the lifetime of the polaron. It is seen that both the ground state energy and the average number of phonons increase with an increase in the Cd composition X while the effective mass, mobility and lifetime of polaron decrease as the Cd composition X increases. We observe that there are more phonons in the bulk than at the surface. It is also noticed that the polaron disintegrates when the temperature is increased to certain values. Thus, at high temperatures, the electron-phonon interaction is destroyed. It is seen that even though the contribution of the LO phonon is more important; the contribution of the IO phonon to the polaron's properties is also quite significant.