Electronic structure of superlattices incorporating diluted magnetic semiconductors

The electronic properties of superlattices (SL's) containing a diluted magnetic semiconductor (DMS) as one of the constituents are studied with use of the envelope-function formalism. The effects of Mn d electrons are explicitly included in an effective K{·}p Hamiltonian. It is shown that the application of the mean-field model to include spin polarization in the DMS layers before calculating SL states is equivalent to the present approach, provided that the energy difference between the valence-band edge and the Mn d bands is large compared with the energy range of the subbands of interest. The results are applied to two SL systems, the experimentally studied CdTe/Cd0.76{Mn}0.24$Te SL and a lattice-matched ${Zn}_{1{{-}}y}CdySe/Zn_1-x{Mn}ₓ$Se SL having an energy gap in the blue-green range of the spectrum. The value of the valence-band offset in the former SL is reanalyzed with inclusion of excitonic effects.