EVIDENCE FOR 2 DX-LIKE CENTERS IN SN-DOPED ALXGA1-XAS

The photocapacitance method was used to investigate the two donor states with optical ionization energies of 0.73 and 1.30 eV in Sn-doped AlxGa1-xAs. Evidence is presented that both large-lattice-relaxation states are independent charge states and originate from different deep centers. The observation of phonons at about 10 meV accompanying the multiphonon processes in the photocapacitance transient implies that the atomic structures of the two deep centers are substitutional-interstitial in character.