Spectroscopy of Be Acceptor Ground State in GaAs/AlGaAs Heterostructure
J. Łusakowskia, R. Buczkob, M. Sakowicza, K.J. Friedlandc, R. Heyc, K. Ploogc
c Institute of Experimental Physics, Warsaw University, Hoża 69, 00-681 Warsaw, Poland
b Institute of Physics, Polish Academy of Sciences, al. Lotnikłw 32/46, 02-668 Warsaw, Poland
c Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin, Germany
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Received: 9 06 2007;
Photoluminescence measurements were carried out on Be δ-doped GaAs/Al 0.33 Ga 0.67 As heterostructure at 1.6 K in magnetic fields (B) up to 4 T. Luminescence originating from recombination of a two-dimensional electron gas and photoexcited holes localized on Be acceptors was analyzed. The degree of circular polarization ( γ C ) of the luminescence from fully occupied Landau levels was determined as a function of B and the two-dimensional electron gas concentration, n s . At B constant, γ C decreased with the increase in n s . The intensity of the optical transition considered was calculated with taking into account s- and d-like parts of the acceptor envelope function. It is shown that the presence of the d-like part explains the observed γ C (n s ) dependence quantitatively. This shows that polarization spectroscopy on acceptor δ-doped heterostructures enables one to test experimentally the contribution of the L > 0 component of the envelope in a shallow acceptor description.
DOI: 10.12693/APhysPolA.112.209
PACS numbers: 71.70.Ej, 78.67.De