Shallow impurity properties of EuS/PbS/EuS finite confining potential quantum well

A model for investigation of impurity states in realistic EuS/PbS/EuS finite confining potential quantum well (QW) is theoretically developed. A strong contrast of available material parameters across the QW interfaces and the characteristic band-nonparabolicity effect of lead salt semiconductor are taken into account while using a variational approach. In the presence of medium polarization a quasi two-dimensional (Q2D) Coulomb form factor analysis is carried out. Initial deviations from the infinite confining model results are established. An impurity binding energy problem has been investigated and for the first time an explicit analytical expression in the limit of very thin QW is derived. With decreasing finite confining potential QW width a monotonic increase of the binding energy is seen for quite small values of width. For realistic nanostructures a comparison of strongly enhanced donor and acceptor binding energies is presented.