Investigation of hydrogenic-donor states confined by spherical quantum dots with B-splines

The energy spectra of an off-centre hydrogenic donor confined in finite spherical quantum dots have been calculated as a function of the donor position for different radii based on the effective-mass approximation using the linear variational method. B-splines have been used as basis functions, which can easily construct the trial wavefunction with appropriate boundary and cusp conditions. Comparison with other results given in the literature is made and good agreement is achieved. The changing feature of energy levels in accord with the nuclear position is analysed.