FORMATION OF SEMIMAGNETIC SEMICONDUCTOR SUPERLATTICES BY IONIZED CLUSTER-BEAM TECHNIQUE AND THEIR QUANTUM-SIZE EFFECTS

The formation of semimagnetic semiconductor Cd1-xMnxTe superlattices o n GaAs (100) and sapphire (0001) substrates by the ionized cluster-bea m (ICB) deposition technique and their quantum-size effects on the opt ical and magneto-optical properties are reported. The observation of h igh-order satellite x-ray diffraction and the Raman scattering from fo lded longitudinal acoustic (LA) phonons suggests that the Cd1-xMnxTe s uperlattices have a satisfactory periodic structure. Transitions to th e 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-Penne y band model. The change in MCD peak height with the well. width can b e explained in terms of the Zeeman splitting of the subband levels and the oscillator strengths of transitions to those levels.