IMPURITIES IN A QUANTUM-DOT - A COMPARATIVE-STUDY

The donor binding energies and density of impurity states of a hydroge nic impurity in a quantum dot are presented within the effective-mass approximation following a variational procedure. The emphasis is place d on the dependence of the binding energy on the volume of the dot and on the impurity position. We show that the results for the donor bind ing energy in the quantum dot go to the exact limits of a square-cross -sectional quantum-well wire and a quantum well when appropriate limit s are considered. Comparing the donor binding energies for cubic and s pherical quantum dots, we found that the values are very close provide d the dots have similar volumes.