Deep levels in Si-doped AlxGa1 − xAs layers

Deep-level transient spectroscopy (DLTS), multi-exponential DLTS and optical DLTS measurements were performed to investigate the deep levels in Si-doped AlxGa1 − xAs layers grown by molecular beam epitaxy. The results of the DLTS and the multi exponential DLTS measurements showed two DX centers and those of the optical DLTS measurements showed two OX centers. The DX centers originate from the emission of the carriers toward the conduction band and the OX centers are related to the capture of the carriers from the conduction band by the DX centers. These results are in good agreement with the theory in which the levels of the DX centers in Si-doped AlxGa1 − xAs layers have a capture and emission barrier due to the Si-doping.