Disorder-Induced Effects in III--V Semiconductors with Mn

J. Masek and F. Maca Institute of Physics, AS CR, Na Slovance 2, 182 21 Prague 8, Czech Republic

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The substitution of Mn in the III--V diluted magnetic semiconductors leads to a strong electron scattering on impurities. Besides the features induced in the valence band by the hybridization with the Mn d-states, also the conduction band is affected by the absence of the Mn s-states at its edge. Also the high concentration of compensating donors modifies the band structure. This is shown on the absorption coefficient ϵ2(ω) of GaP doped with Mn and Se. The absorption evaluated by ab initio density functional calculations starts with a smooth tail and does not show the structure typical of III--V materials. We analyze these features and the role of the donors on model systems using the tight-binding coherent potential approach.

DOI: 10.12693/APhysPolA.102.667 PACS numbers: 71.15.Ap, 71.20.Nr, 71.55.Eq, 75.50.Pp