Hydrogenic impurity states in semiconducting nanostructures with anisotropic effective mass

A hydrogenic impurity located in a semiconducting nanostructure with anisotropic effective mass of carriers m*={m⊥,m⊥,m∥} is investigated with variation of the impurity position taken into account. A binding energy and deformation of the impurity are analyzed as a function of the layer thickness and impurity position in 2D structures with different effective mass of carriers. The results obtained for the shallow impurity binding energy are in a good agreement with the theoretical calculations both for bulk semiconductors [W. Kohn, J.H. Luttinger, Phys. Rev. 98 (1955) 915] and 2D semiconductors with isotropic effective mass of electrons [G. Bastard, Phys. Rev. B 24 (1981) 4714].