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

► Model to study impurities in realistic EuS/PbS/EuS finite confining height QW. ► Strong contrast of available material parameters at the heterointerfaces are taken into account. ► Q2D Coulomb form factor study is carried out and deviations from the infinite wall model are derived. ► An explicit expression for impurity binding energy in the limit of thin QW is derived for the first time. ► A monotonic strong increase of binding energy with decreasing QW width is seen.