Potential-shape effect on photoionization cross section of a donor in quantum dots

A donor impurity confined to a semiconductor quantum dot with the power-exponential potentials is considered as we study potential-shape effect. The power-exponential potential proposed is flexible enough to be applicable to both the self-assembled and electrostatic quantum dots. The commonly used model confinement potentials, i.e. the parabolic and rectangular potential wells, can be obtained as the limit forms of the power-exponential potential. The photoionization cross section associated with intersubband transitions in a spherical symmetry quantum dot with the power-exponential potentials have been calculated by using the numerical matrix diagonalization method and optimized basis sets in an effective-mass Hamiltonian approach.