Optical ionization of DX center in AlGaAs : Se by inner-shell excitation

Abstract

DX state is strongly localized. This nature could be investigated by observing relaxation process of localized electrons to emptied inner shells. We have found two different optical ionization processes of the DX center in AlxGa1−xAs:Se (x=0.33, NSe=5×1017(cm−3)) by using synchrotron radiation (SR). They are tentatively assigned to be a direct lift of an inner-shell electron to the conduction band (CB) followed by a capture of an electron at the DX center to the emptied inner shell (DX−+hν(L, K-edge)→DX0+eCB) and the Auger ionization of one electron of the DX center to the CB followed by a capture of another electron to the emptied inner shell (DX−+hν(L, K-edge)→DX++eCB+evacuum).