The effect of the electron-phonon interaction on an electron bound to an impurity in a spherical quantum dot embedded in a nonpolar matrix is studied theoretically. The adiabatic variational method is used to calculate the polaron energy shift. General analytical results are obtained for small and large dots for different impurity positions. Numerical calculations were performed for ZnSe quantum dots of different radii. It is shown that (1) the interaction with interface phonons is absent when the impurity is in the center of the dot, reaches its maximum when the impurity is close to the boundary, and decreases in value if the impurity is on the interface; (2) unlike the interaction with bulk-type LO phonons, the interaction with interface phonons is negligible in small dots but gives a considerable contribution to the energy in the large dots provided the impurity is located near the dot’s boundary.

• Received 31 August 2000

DOI:https://doi.org/10.1103/PhysRevB.63.165302