Optical Γ6 → Γ8 Free-to-Bound Transitions in Acceptor δ-Doped Single Heterostructure - Theoretical Analysis

R. Buczko a, J. Łusakowski b, K.-J. Friedland c, R. Hey c and K. Ploog c a Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warsaw, Poland b Institute of Experimental Physics, University of Warsaw, Hoża 69, 00-681 Warsaw, Poland c Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin, Germany

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Received: 7 06 2008;

A theoretical analysis was carried out of an optical transition observed in high-quality GaAs/AlGaAs heterostructures δ-doped with shallow acceptors. The transition involves a 2D electron and a 3D acceptor-localized hole. The wave functions of a bulk Be acceptor were calculated within the spherical model with both the s-like and d-like parts of the envelope taken into account. The electron envelope wave functions resulted from self-consistent calculations of the electrostatic potential and were dependent on the 2D electron concentration, ns. We show that: (i) including the d-like part of the acceptor envelope relaxes the selection rules of free-to-bound transitions at k=0; (ii) in the magnetic field, the selection rules depend on the number of the electron Landau level; (iii) the ratio of the intensity of the strongest transitions in both circular polarizations is essentially different from 3:1, and strongly depends on ns. These results show that a description that neglects the d-like part of the acceptor envelope is both qualitatively and quantitatively unjustified.

DOI: 10.12693/APhysPolA.114.1079 PACS numbers: 71.70.Ej, 78.67.De