Polaron effect on the binding energy of hydrogenic impurities in a cylindrical quantum dot

Abstract

AbstractThe binding energy of a shallow hydrogenic impurity in a cylindrical quantum dot (QD) is investigated by using a variational method, where a two‐parameter trial wave function is introduced to consider the anisotropic nature of the QD system. We have taken into consideration the influence of the confined longitudinal optical (LO) phonons as well as the side‐surface (SSO) and top‐surface (TSO) optical phonons. Our calculations are performed within the effective‐mass approximation for an infinitely deep confinement potential system model. Numerical calculation shows that the binding energy of an impurity is greatly modified by the electron–phonon interactions and the phonon contribution to the impurity binding energy is dependent on the QD sizes (radius and height). It is noted that we obtain about a 4% higher impurity binding energy than that based on a one‐parameter trial wave function. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)