Total energy, binding energy, recombination rate (of the electron–hole pair) for an exciton
(X) bound in a parabolic two-dimensional quantum dot by a donor impurity located on the z-
axis at a distance d from the dot plane, are calculated by using the Hartree formalism with a
recently developed numerical method (PMM) for the solution of the Schrödinger equation.
As our analysis indicates there is a critical dot radius Rc such that for R< Rc the complex is
unstable and with an increase of the impurity distance this critical radius increases …