Interlevel absorption of electromagnetic waves by nanocrystal with   divalent impurity
  The energy spectrum of central divalent impurity is calculated using the effective mass approximation in a spherical quantum dot (QD). The dipole moment and oscillator strength of interlevel transition is defined. The dependence of linear absorption coefficient on the QD size and electromagnetic frequency is analyzed. The obtained results are compared with the results of univalent impurity. 
V.I Boichuk, R.Ya. Leshko
cond-mat.mes-hall