Self-consistent analysis of persistent photoconductivity data in Si delta-doped AlxGa1-xAs (x = 0.32) superlattices

Hall measurements were performed on a series of Si delta-doped AlxGa1-xAs ( x = 0.32) superlattices, The DX center has been detected in these structure s through the observation of persistent photoconductivity at low temperatur e. Electrical properties of this defect are investigated as a function of t he delta-doping content. The results have been analyzed using the large lat tice relaxation model. We have calculated the minibands for the delta-dopin g AlxGa1-xAs:Si superlattices studied as well. Evidence that the Si DX cent er is present in these structures and has a negative-U character will be gi ven in this study, (C) 1998 American Institute of Physics. [S0021-8979(98)0 9820-X].