Photoionization of the DX centers in Te-doped AlxGa1-xAs: Absence of two-step photoionization of DX centers.

Photoionization studies have been performed for Te-doped Al x Ga 1-x As to investigate the properties of the theoretically predicted intermediate neutral relaxed state of the DX center, i.e., DX 0 . The expected effect of the DX 0 state on the photoionization process in the neutral charge region, where the recapture of an electron by DX 0 is possible, was calculated from the rate equations for a two-electron system. The photoionization measurements were made in both the depletion region and the neutral charge region. It is found that the photoionization rates of DX centers in the two charge regions are identical, indicating no significant effect of the DX 0 state on the photoionization of DX(Te) centers