Formation of semimagnetic semiconductor superlattices by ionized cluster-beam technique and their quantum-size effects

The formation of semimagnetic semiconductor Cd1-xMnxTe superlattices on GaAs (100) and sapphire (0001) substrates by the ionized cluster-beam (ICB) deposition technique and their quantum-size effects on the optical and magneto-optical properties are reported. The observation of high-order satellite x-ray diffraction and the Raman scattering from folded longitudinal acoustic (LA) phonons suggests that the Cd1-xMnxTe superlattices have a satisfactory periodic structure. Transitions to the subband levels formed in the wells of superlattices are observed in the optical absorption spectra and the magneto-circular dichroism (MCD) spectra. The transition energies shift widely toward higher energies as the well width is decreased. The experimental results for subband energies agree well with the results calculated using the Kronig-Penney band model. The change in MCD peak height with the well. width can be explained in terms of the Zeeman splitting of the subband levels and the oscillator strengths of transitions to those levels.