Hydrogenic impurity in two-dimensional semiconductors with anisotropic energy spectrum of carriers

The binding energy and wave function of a ground state of a shallow hydrogenic impurity in two-dimensional semi-conductors with isotropic and anisotropic effective mass of carriers m* = {m(perpendicular to), m(perpendicular to), m(parallel to)} are derived. The calculations are performed by the variational method based on a two-parametric trial wave function. The dependence of binding energy and deformation of an impurity on 2D layer thickness and effective mass anisotropy parameter m(perpendicular to)/m(parallel to) is investigated. The obtained results are in a good agreement with experiment data and in the limiting cases coincide with the theoretical calculations of shallow impurity binding energy for bulk semiconductors [1] and two-dimensional semiconductors with isotropic effective mass of electrons [2].